Development and Application of Unsteady Flood Models Using 
Geographic Information Systems 
 
by 
 
Daniel Baldwin Snead 
 
 
Departmental Report 
 
 
Presented to the Faculty of the Civil Engineering Department 
of the University of Texas at Austin 
in Partial Fulfillment 
of the Requirements 
for the Degree of 
 
 
Master of Science in Engineering 
 
 
The University of Texas at Austin 
December 2000
 ii 
Acknowledgements 
  I am very grateful to all who have helped me throughout my research.  I am 
indebted to Dr. David Maidment, my graduate advisor, who has always been very 
supportive of my work with the Corps of Engineers. 
  A special thanks also goes to Jesper Kjelds from the Danish Hydraulic 
Institute for providing the DHI developed software.  His expertise and support 
throughout my research made this project possible.  Another special thanks goes to 
the Louisville District of the U.S. Army Corps of Engineers, especially to Glen 
Beckham and Lynn Funke for providing the study area data and financial support 
throughout the duration of this project. 
  I am also grateful to the professors, students, and staff at the Center for 
Research in Water Resources, especially Dr. Francisco Olivera, Pete Andrysiak, Dave 
Anderson, Kwabena Asante, Esteban Azagra, and Ty Lehman.  Without their 
assistance during some trying times, the results of my work would have been less 
than desirable.  To the rest of the CRWR team, especially the members of the ?Blue 
Collar Room?, thanks for the camaraderie and best wishes to you all.  
  Finally, I would sincerely like to thank my wife Melinda and my daughter 
Charlotte.  They know all too well how difficult life can be as military dependents.  
Their continued love and support has made this project?s success possible. 
 
December, 2000 
 iii 
Abstract 
Development and Application of Unsteady Flood Models using 
Geographic Information Systems 
 
by 
 
Daniel Snead, M.S.E. 
The University of Texas at Austin, 2000 
 
Supervisors: David Maidment and Francisco Olivera 
 
 This document presents the application of two unsteady flow hydraulic models 
used for flood routing and visualization: the MIKE 11 model from the Danish 
Hydraulic Institute (DHI) and the HEC River Analysis System model, better known as 
HEC RAS, from U.S. Army Corps of Engineer?s Hydrologic Engineering Center.  In 
this study, both hydraulic models use rainfall-runoff data in time series format from 
an existing HEC Hydrologic Modeling System (HEC HMS) model.  The approach for 
both models leads to the spatial integration of unsteady flow simulations into a 
geographic information system (GIS) for flood visualization and animation.  The 
study area applied to both models is the Mill Creek Watershed located in Cincinnati, 
Ohio.  The Mill Creek watershed area is approximately 165 square miles consisting of 
28 main stream miles.  The study area used for the hydraulic models, referred to as 
the Primary Damage Center, is approximately 5.3 square miles in area consisting of 
3.97 stream miles.  The results found from this project support an on-going flood 
analysis study conducted by the Louisville District, U.S. Army Corps of Engineers.  
The primary source for the data used in the project was the Louisville District. 
 The study?s focus was on 1) the development of an accurate and workable 
digital terrain model of the study area; 2) the development of a MIKE 11 model based 
on surveyed, stream cross-section data; 3) the development of a HEC RAS model 
based on stream cross-section data extracted from the terrain model; and 4) the 
creation of flood animations from the two hydraulic model simulations.  The results 
 iv 
of this study provide information on the two unsteady flow hydraulic model methods 
as well as what advantages they have over steady flow hydraulic models. 
 The MIKE 11 model?s stream geometry was based on surveyed data, which did 
not extent over the full width of the inundated flood plain.  The HEC RAS model?s 
stream geometry was extracted from the digital terrain model, which ensured that the 
flood plain?s extent was fully accounted for.  The results were faster flood wave 
attenuation, higher maximum water surface elevation, and shorter flood duration for 
the MIKE 11 model simulation as compared to the HEC RAS simulation.  The results 
of the HEC RAS unsteady flow model were also compared to the HEC RAS steady 
flow model based on steady flow peak runoff discharge values.  The unsteady flow 
hydraulic model?s maximum water surface elevation was less than the steady flow 
hydraulic model?s water surface elevation because the steady flow hydraulic model 
assumes peak runoff occurs simultaneously in the individual drainage basins within 
the watershed, while the unsteady flow model more closely mimics the movement of 
the flood wave through the drainage area. 
 
 v 
Table of Contents 
List of Tables.................................................................................................................x 
List of Figures ..............................................................................................................xi 
Chapter 1: Introduction ................................................................................................. 1 
1.1 Objectives................................................................................................................ 2 
1.2 Study Area............................................................................................................... 3 
1.3 Structure of Report.................................................................................................. 6 
Chapter 2: Literature Review ........................................................................................ 8 
2.1 Flood Modeling....................................................................................................... 8 
2.2 Dynamic Models ................................................................................................... 11 
Chapter 3: Data Discussion......................................................................................... 16 
3.1 Data Requirements ................................................................................................ 16 
3.1.1 Hydraulic Data ............................................................................................... 16 
3.1.2 Hydrologic Data ............................................................................................. 20 
3.1.3 Spatial Data .................................................................................................... 22 
3.2 Data Sources and Processing................................................................................. 23 
3.2.1 Coordinate System ......................................................................................... 24 
3.2.2 Terrain Data.................................................................................................... 24 
3.2.3 Geometric Data .............................................................................................. 26 
 vi 
3.2.4 Flow Data ....................................................................................................... 31 
Chapter 4: Modeling Methods..................................................................................... 33 
4.1 The MIKE 11 Model............................................................................................. 33 
4.1.1 The MIKE 11 Hydrodynamic Model............................................................. 33 
4.1.2 MIKE View.................................................................................................... 41 
4.1.3 The MIKE 11 GIS Extension......................................................................... 41 
4.2 The HEC RAS Model ........................................................................................... 42 
4.2.1 The HEC RAS Unsteady Flow Model ........................................................... 42 
4.2.2 The HEC GeoRAS Extension ........................................................................ 48 
4.3 The HEC HMS Model........................................................................................... 49 
4.3.1 Loss Determinations....................................................................................... 50 
4.3.2 Runoff Transformations ................................................................................. 50 
4.3.3 Routing........................................................................................................... 50 
4.3.4 Parameter Optimization.................................................................................. 52 
Chapter 5: Terrain Model Development ..................................................................... 53 
5.1 Methodology of Terrain Model Development ...................................................... 54 
5.1.1 Initial Terrain Model Development................................................................ 54 
5.1.2 Limitations of Digital Terrain Data used for Hydraulic Modeling ................ 56 
5.1.3 Integration of Streambed Geometry and Terrain Data................................... 59 
5.2 Application of the Terrain Model to the MIKE 11 GIS Interface......................... 68 
Chapter 6: Application of the MIKE 11 Model .......................................................... 71 
 
 vii 
6.1 Geometric Processing............................................................................................ 71 
6.1.1 Stream Network Development....................................................................... 71 
6.1.2 Cross-section Data Development................................................................... 72 
6.2 Bed Resistance Factors.......................................................................................... 74 
6.3 Boundary Conditions............................................................................................. 75 
6.3.1 Simulating Base Flow Conditions.................................................................. 76 
6.3.2 Incorporating Hydrologic Data as Boundary Conditions............................... 76 
6.4 Post Processing in MIKE 11 GIS.......................................................................... 80 
6.4.1 Geo-referencing the Stream Network to the Terrain Model .......................... 80 
6.4.2 Importing Q and h Data into MIKE 11 GIS................................................... 81 
6.4.3 Generating Flood Maps and Animations from the Unsteady Flow Model.... 83 
Chapter 7: Application of the HEC RAS Model......................................................... 86 
7.1 Extracting Stream Geometry from the Terrain Model.......................................... 86 
7.1.1 Developing the Stream Centerline and Main Channel Banks........................ 87 
7.1.2 Developing Cross-section Cut Lines and Flow Paths .................................... 88 
7.1.3 Generating the RAS GIS Import File from Terrain Data............................... 90 
7.2 Geometric Processing............................................................................................ 91 
7.2.1 Import GIS Stream Geometry Data................................................................ 92 
7.2.2 Bed Resistance Factors................................................................................... 93 
7.3 Development of Unsteady Flow Initial Conditions and Boundary Conditions .... 94 
7.3.1 Establishing Initial Conditions as Base Flow................................................. 94 
7.3.2 Boundary Conditions Derived from the Hydrologic Data ............................. 94 
 
 viii 
7.4 Unsteady Flow Simulations in HEC RAS............................................................. 97 
7.5 Post Processing in HEC GeoRAS ......................................................................... 99 
7.5.1 Read RAS GIS Export File ............................................................................ 99 
7.5.2 Water Surface TIN Generation .................................................................... 100 
7.5.3 Delineating Flood Plains from Unsteady Flow Model Results.................... 101 
Chapter 8: Results and Conclusions.......................................................................... 105 
8.1 Model Results...................................................................................................... 105 
8.1.1 MIKE 11 Model Results .............................................................................. 105 
8.1.2 HEC RAS Model Results............................................................................. 108 
8.1.3 Comparison of the Unsteady Flow Model Results....................................... 112 
8.1.4 Comparison to Steady Flow Modeling ........................................................ 114 
8.2 Conclusions ......................................................................................................... 117 
8.2.1 Unsteady Flow Model Advantages and Limitations.................................... 120 
8.2.2 Future Work ................................................................................................. 122 
Appendix A: MIKE 11 Chainage - HEC-2 River Station Conversions.................... 123 
Appendix B: Visual Fortran Program used for Cross-section Data Conversion....... 126 
Appendix C: MIKE 11 Cross-section File ................................................................ 131 
Appendix D: HEC RAS Cross-section Data............................................................. 151 
Appendix E: HEC HMS Input for MIKE 11............................................................. 168 
Appendix F: Data Dictionary.................................................................................... 186 
 ix 
Bibliography.............................................................................................................. 192 
Vita............................................................................................................................ 195 
 
 x 
List of Tables 
Table 3-1. Base flows for the flow model stream network. ........................................ 31 
Table 5-1. Stream definition points for the study area................................................ 65 
Table 7-1. River ID data for each reach in the PDC stream network. ........................ 87 
Table 7-2. Hydrograph sources for the HEC RAS model........................................... 96 
Table 8-1. Time of peaks for the PDC study area boundary conditions. .................. 116 
Table A-1. HEC-2 River Station conversion to MIKE 11 Chainages ...................... 123 
Table E-1. Mill Creek PDC model?s upstream and downstream boundary data. ..... 168 
Table E-2. Mill Creek PDC model?s lateral boundary data extracted from the HEC 
HMS model. ...................................................................................................... 182 
 
 
 xi 
List of Figures 
Figure 1-1. Location of the Mill Creek Watershed in Cincinnati, OH.......................... 4 
Figure 1-2. Mill Creek location with respect to the Ohio River. .................................. 4 
Figure 1-3. Location of the Primary Damage Center in the Mill Creek Watershed. .... 6 
Figure 2-1. Channel geometry incorporated into a digital terrain model (Tate 1999).. 9 
Figure 2-2. Flood visualization using AVRas and a TIN (Azagra-Camino 1999). .... 10 
Figure 2-3.  Finite element of a stream channel with force terms............................... 12 
Figure 2-4. FLOOD WATCH applied to a region in India (Kjelds 1997).................. 15 
Figure 3-1. 3-D depiction of a stream with cross-sections in HEC RAS.................... 17 
Figure 3-2. Comparison of Chainage and River Station network referencing............ 18 
Figure 3-3. Differentiation of streambed and flood plain resistance in MIKE 11. ..... 19 
Figure 3-4. HEC RAS cross-section with Manning?s n values................................... 19 
Figure 3-5. Schematic view of the HEC HMS model developed by Andrysiak......... 22 
Figure 3-6. A triangular mesh and TIN theme in Arcview GIS.................................. 23 
Figure 3-7. Portion of the 2-ft contour theme depicting the PDC............................... 25 
Figure 3-8. Stream network digitized in Arcview GIS using a point theme............... 28 
Figure 3-9. Example of cross-section data in a HEC-RAS .G01 text file................... 29 
Figure 3-10. Cross-section text file readable by the MIKE 11 software..................... 30 
Figure 3-11. Runoff hydrograph for the Mill Creek Watershed?s Basin 109. ............ 32 
Figure 4-1. Input tab in a MIKE 11 Simulation File................................................... 34 
Figure 4-2. Simulation file with a ?Hotstart? Initial Conditions Type........................ 35 
 xii 
Figure 4-3. River network file defined by XY coordinate data points........................ 36 
Figure 4-4. Tabular view of a river network depicting XY coordinate data points. ... 37 
Figure 4-5. Raw data view of a cross-section in MIKE 11......................................... 38 
Figure 4-6. MIKE 11 boundary file. ........................................................................... 39 
Figure 4-7. Bed resistance from chainage to chainage in the hydrodynamic file. ...... 41 
Figure 4-8. Main menu of HEC RAS version 3.0, with the unsteady flow option. .... 43 
Figure 4-9. HEC RAS version 3.0 geometric data file editor. .................................... 44 
Figure 4-10. HEC RAS version 3.0 unsteady flow data file editor............................. 46 
Figure 4-11. HEC RAS version 3.0 unsteady flow analysis file editor. ..................... 47 
Figure 4-12. Bounding polygon derived from cross-sections using GeoRAS............ 49 
Figure 4-13. Discontinuities between watersheds in a hydrologic model and the 
boundaries of the hydraulic model...................................................................... 51 
Figure 5-1. Example of a TIN-based terrain model. ................................................... 55 
Figure 5-2. Points, contours, and bounding polygon used for the PDC terrain model.
............................................................................................................................. 56 
Figure 5-3. A surveyed cross-section of Mill Creek compared to terrain model data.57 
Figure 5-4. Comparison of the Mill Creek streambed?s longitudinal profile developed 
from the terrain model and the HEC-2 surveyed data......................................... 58 
Figure 5-5. Terraced streambed of Mill Creek created from the TIN data. ................ 59 
Figure 5-6. Tate?s Method of incorporating flood plains into a terrain model. .......... 60 
Figure 5-7. Comparison of the stream and a 3-D stream centerline and bank lines 
created by the Arcview GIS Floodmap utility. ................................................... 61 
 xiii 
Figure 5-8. A revised depiction of cross-sections and bank lines as compared to the 
stream centerline. ................................................................................................ 62 
Figure 5-9. Cross-sections interpolated between existing cross-sections in HEC RAS.
............................................................................................................................. 63 
Figure 5-10. Sharon Rd. used as an intermediate point for geo-referencing. ............. 64 
Figure 5-11. PolylineZ themes of the stream channel and cross-sections................... 66 
Figure 5-12. Section of Mill Creek with mass points data and stream geometry. ...... 67 
Figure 5-13. TIN-based terrain model modified with surveyed stream geometry...... 68 
Figure 5-14. The PDC Grid-based terrain model shown with hill shading effect. ..... 69 
Figure 5-15. Rough edge created when delineating the water surface from the terrain 
using the MIKE 11 GIS grid-based delineation method..................................... 70 
Figure 6-1. MIKE 11 Stream network created with the Define Branch tool, from point 
to point................................................................................................................. 72 
Figure 6-2. Cross-section #19166 in MIKE 11........................................................... 73 
Figure 6-3. The MIKE 11 Cross-section interpolation tool. ....................................... 74 
Figure 6-4.  The overall resistance factors in the MIKE 11 model............................. 75 
Figure 6-5. A MIKE 11 time-series file extracted from the HEC HMS hydrologic 
model................................................................................................................... 77 
Figure 6-6. The Mill Creek HEC HMS schematic imported as a background image 
into the MIKE 11 river network file.................................................................... 78 
Figure 6-7. A MIKE 11 boundary file......................................................................... 79 
Figure 6-8. A profile of Mill Creek in the PDC study area......................................... 80 
 xiv 
Figure 6-9. The MIKE 11 flow model inputs for MIKE 11 GIS: the river network file 
and the simulation data........................................................................................ 81 
Figure 6-10. Q-points and h-points imported into MIKE 11 GIS............................... 82 
Figure 6-11. MIKE 11 flow model results were imported into the Hpoints.txt attribute 
table. .................................................................................................................... 83 
Figure 6-12. Flood map of the Mill Creek PDC developed from MIKE 11 model data.
............................................................................................................................. 84 
Figure 6-13. Snapshot from a MIKE 11 ?Flyby? animation....................................... 85 
Figure 6-14. 3-D animation of the Mill Creek PDC with buildings. .......................... 85 
Figure 7-1. Stream centerline and main channel banks defined for East Fork on the 
TIN-based terrain model. .................................................................................... 88 
Figure 7-2. The HEC-2 cross-sections and the GeoRAS cross-section cut lines shown 
along the stream network in the terrain model.................................................... 89 
Figure 7-3. Flow paths, channel banks, and cross-section cut lines defined with 
respect to the PDC terrain model. ....................................................................... 90 
Figure 7-4. Theme setup menu for GeoRAS pre-processing. ..................................... 91 
Figure 7-5. The right bank location shown was shifted up and to the right to depicting 
the most natural transition from flood plain to streambed. ................................. 92 
Figure 7-6. The HEC RAS geometry data schematic of the GIS imported data......... 93 
Figure 7-7. Initial flow conditions used for the HEC RAS model, in m
3
/s................. 94 
Figure 7-8. The DSS Path window in HEC RAS........................................................ 97 
 xv 
Figure 7-9. The HEC RAS Unsteady Flow Analysis plan shown for the Mill Creek 
PDC model. ......................................................................................................... 98 
Figure 7-10. The X-Y-Z Perspective Plot in HEC RAS. ............................................. 99 
Figure 7-11. For HEC GeoRAS post-processing, the inputs for Arcview GIS were 
defined............................................................................................................... 100 
Figure 7-12. The water surface TIN created from HEC RAS input overlapping the 
terrain model of the PDC study area. ................................................................ 101 
Figure 7-13. Maximum water surface for the April 1998 flood delineated from the 
terrain model. .................................................................................................... 102 
Figure 7-14. Three-dimensional representation of the TIN-based terrain model and 
water surface using 3D Analyst......................................................................... 103 
Figure 7-15. The view shows the distinction between water and terrain using TIN-
based surfaces in HEC GeoRAS. ...................................................................... 104 
Figure 8-1. The horizontal, red dotted line above the cross-section at Chainage 19.998 
is the maximum water surface at that location for the MIKE 11 model. .......... 106 
Figure 8-2. An example of a reversed cross-section shown in an XYZ plot in HEC 
RAS. .................................................................................................................. 110 
Figure 8-3. The Arcview GIS view shows the polygon themes in the legend imported 
from the HEC RAS flow model for different time steps................................... 112 
Figure 8-4. A visual comparison is shown of the maximum stage heights for the 
MIKE 11 model and the HEC RAS model. ...................................................... 113 
 xvi 
Figure 8-5. The MIKE 11 and HEC RAS cross-sections shown are approximately 12 
meters from each other along the stream network. The flood plain conveyance is 
accounted for in the HEC RAS model, significantly slowing down flow as 
compared to the MIKE 11 model results. ......................................................... 114 
Figure 8-6. Schematic of the watersheds contributing runoff to the Primary Damage 
Center. ............................................................................................................... 115 
Figure 8-7. Comparison of maximum water surfaces for the HEC RAS unsteady flow 
model and the steady model for the 25-yr storm event..................................... 117 
Figure 8-8. Schematics of the initial hydraulic models developed in MIKE 11 and 
HEC RAS. ......................................................................................................... 118 
 
 
 
 
 
1 
 
Chapter 1: Introduction 
 Flood analysis assists decision makers with the prevention and prediction of 
flood events.  Computer modeling techniques have assisted engineers with 
determining more accurately where and when flooding may occur.  Computer models 
for the determination of flood effects require four parts:  1) the hydrologic model 
which develops rainfall-runoff from a design storm or historic storm event, and 2) the 
hydraulic model which routes the runoff through stream channels to determine water 
surface profiles at specific locations along the stream network, 3) a tool for floodplain 
mapping and visualization, and 4) the extraction of geospatial data for use in the 
model(s).  Most of the previous hydraulic modeling techniques use one-dimensional 
(1-D) steady-state flows measured at a specified point in time.  Since flows in 
streambeds are naturally random and unsteady, steady-state methods do not always 
accurately depict water surface profiles.  The steady-state modeling technique is also 
limited by how the modeler spatially synchronizes the rainfall-runoff routing for 
multiple drainage basins at a specified point in time.  Such methods are subject to 
human error and can be very time consuming. 
 Developments in fully dynamic, unsteady models have provided engineers with 
highly accurate hydraulic modeling methods that result in graphical two- and three-
dimensional visualizations for the purpose of analysis.  The key to graphical 
visualizations in dynamic modeling is the inclusion of time-series data within a 
spatial interface, like a Geographic Information System (GIS).  The Danish Hydraulic 
Institute (DHI) is one of the world-leading software developers for incorporating 
water resources related time-series data into modeling.  DHI?s MIKE 11 
hydrodynamic model uses 1-D implicit, dynamic wave routing based on the St. 
Venant equations for unsteady flow.  Additionally, DHI?s MIKE 11 GIS extension to 
ESRI?s Arcview GIS interface allows the user to import MIKE 11 model simulations 
2 
 
in a time-series format into the Arcview GIS spatial environment. 
 The Army Corps of Engineers? Hydrologic Engineering Center has recently 
revamped their widely used 1-D, steady-state HEC RAS modeling software.  The 
HEC RAS 3.0 version can also run 1-D unsteady flow simulations.  The unsteady 
flow is processed in HEC RAS using the UNET algorithm developed by Dr. Robert 
L. Barkau (UNET, 1997).  Like DHI?s MIKE 11 model, UNET is a 1-D unsteady 
flow model that can simulate flow in a complex network of open channels.  Unlike 
MIKE 11, the UNET algorithm can include off-channel storage and flood plain 
storage areas in the model. 
 This study involved the development and application of the two unsteady flow 
models mentioned previously.  The models were applied to a critical location within 
the study area.  Discharge hydrographs from the HEC HMS hydrologic model were 
extracted and imported into both models.  The time-series results from both unsteady 
flow models were imported into Arcview GIS using corresponding Arcview 
extensions to develop floodplain determination and visualization in a spatial 
environment. 
1.1 Objectives 
 The primary research objective was to develop flood visualization tools from 
the two modeling techniques of the Mill Creek Watershed for the Louisville District.  
To attain this objective, completion of the following steps was required:  
1. Develop a MIKE 11 unsteady flow model for a section of the stream network 
within the Mill Creek Watershed using data obtained from the Louisville 
District?s Engineering Division.   
2. Develop a HEC RAS unsteady flow model for the same section of stream network 
3 
 
as the MIKE 11 model. 
 
3. Incorporate existing results of the Mill Creek Watershed?s HEC HMS model into 
both the MIKE 11 and HEC RAS models for the 25-yr flood event of April 1998. 
4. Develop digital terrain models for the same portion of the Mill Creek Watershed 
in which the MIKE 11 and HEC RAS modeled stream network exists.  
Incorporate stream characteristics into both terrain models. 
5. Create two- and three-dimensional flood animations of the April 1998 storm from 
both models for future analysis and public presentations. 
6. Determine benefits and limitations of using the two modeling methods. 
 To complete these tasks, an extensive amount of data stored in different formats 
was required.  Current data processing and management practices were used in most 
cases.  Otherwise, dissimilar data sources and modeling software required additional 
data processing solutions and conversions. 
1.2 Study Area 
 The Mill Creek Watershed is located in Butler and Hamilton Counties in 
southwestern Ohio.  It flows from the southeastern part of the rural Butler County in a 
southerly direction across the highly urbanized Hamilton County and through the city 
of Cincinnati to its confluence with the Ohio River.  The total fall in elevation from 
the headwaters of Mill Creek to the Ohio River is about 250 feet over an approximate 
distance of 28 stream miles, with an average gradient of 8.9 feet per mile (0.16%).  
The watershed is in the northeastern finger of the Hydrologic Unit Code (HUC) 
#05090203.  In 1997, the environmental interest group, American Rivers, designated 
Mill Creek as ?the most threatened urban stream in North America? (Project Study 
4 
 
Plan, 1997).  
 
 
Figure 1-1. Location of the Mill Creek Watershed in Cincinnati, OH. 
 Flooding has been a significant problem for the Mill Creek Watershed for some 
time. The most damaging flood occurred in January 1959.  Since then, there have 
been numerous floods of lesser magnitude.  Over bank flooding occurred in some 
areas as late as the spring of 1998. 
 
Figure 1-2. Mill Creek location with respect to the Ohio River. 
 Based on a Local Cooperation Agreement in 1975, construction by the Corps of 
Engineers to reduce flooding in the watershed was initiated in 1981 and eventually 
suspended in 1992, with approximately 50% of the construction complete.  The 
5 
 
construction was suspended for a number of reasons.  The Assistant Secretary of the 
Army for Civil Works suspended the project because: 1) there were problems in 
acquiring real estate and relocations for the remaining sections of the creek requiring 
construction, 2) project costs had soared over 126% of the authorized amount, 3) 
there was likely contamination of the water from non-point source pollutants from old 
landfills along some of the uncompleted portions of the reach, and 4) there were 
problems maintaining and operating the sections where construction was completed 
(Project Study Plan, 1997).  
 In 1997, a reevaluation study was performed.  The effort showed that even with 
the partially completed plan in place that significant damage would occur from a 
flood with a 50% chance of occurrence.  Total residual damage is estimated over 
$486 million for the 1% chance flood and over $910 million for the 0.2% chance 
flood. Total expected annual damage for the flood area is estimated over $32 million, 
almost 96% of the damage being commercial or industrial (Project Study Plan, 1997). 
 Although completion of the previous plan is economically feasible, the 
Louisville District believes that a more cost effective and environmentally acceptable 
plan can be formulated.  There is currently strong local support in Cincinnati to 
address the environmental needs of Mill Creek.  
 This study models unsteady flow for a 25-yr storm event for a 3-mile section of 
Mill Creek referred to as the Primary Damage Center (PDC).  After numerous flood 
events in recent years, approximately 90% of the overall damage from flooding in the 
watershed occurs within the PDC.  The PDC is located in the northern part of the Mill 
Creek watershed and is a highly industrialized area.  The average gradient of Mill 
Creek in the PDC is 0.017%.  Since the PDC can almost be considered as level 
ground, the area acts almost like a reservoir after intense storms.  Most of the 
facilities have tried to accommodate for the flood problems by building levees around 
6 
 
their property?s boundaries.  
 For the unsteady flow model, the stream network in the PDC study area will 
have two streams and one tributary.  In the northern portion of the PDC, East Fork 
flows southward from the northeast portion of the study area into Mill Creek.  The 
stream flow from additional tributaries along Mill Creek in the PDC is accounted for 
as lateral inflow data from the hydrologic model. 
 
Figure 1-3. Location of the Primary Damage Center in the Mill Creek 
Watershed. 
 
1.3 Structure of Report 
 This report documents the data development and implementation of a MIKE 11 
and HEC RAS unsteady flow model for flood visualization.  The report is divided 
into eight chapters.  Chapter 2 includes a review of previously used methods in 
7 
 
literature related to this research.  Chapter 3 is a discussion of the data used for both 
models.  The technical capabilities of the computer programs used during the research 
are outlined in Chapter 4.  Chapter 5 discusses the development of the study area?s 
digital terrain models, which use different formats for the two models.  Application of 
the data and program interface of the MIKE 11 model is documented in Chapter 6.  
Chapter 7 is the documentation of the HEC RAS model application, and Chapter 8 
presents the results and conclusions of the project. 
 Information supplemental to the results of this report are included as 
appendices.  Appendix A includes the conversion of HEC-2 River Station 
identification numbers to MIKE 11 Chainages for the purposes of geo-referencing.  
Appendix B provides the Visual Fortran program used to convert HEC RAS cross-
sections, in text format, into a MIKE 11 cross-section file.  Appendix C provides the 
MIKE 11 cross-section file created by the Visual Fortran program previously 
discussed.  Appendix D is the initial HEC RAS geometry file created from the HEC-2 
data files.  Appendix E shows the time-series data transferred from the HEC HMS 
hydrologic model into the MIKE 11 and HEC RAS flow model.  Finally, Appendix F 
is a data dictionary describing the data used in the project. 
8 
 
Chapter 2: Literature Review 
2.1 Flood Modeling 
 Incorporating hydraulic model results into a GIS environment has improved 
flood analysis in recent years.  Numerous modeling techniques have been 
interconnected in an attempt to find an optimum combination of various methods.  In 
an attempt to connect hydraulic results to a spatial interface, Djokic (1994) developed 
an interface between the Hydrologic Engineer Center?s HEC-2 1-D, steady-state 
hydraulic model and the Arc/info spatial GIS.  The interface, known as ARC/HEC2, 
exports the terrain data from Arc/info into HEC-2.  The ARC/HEC2 interface 
converts HEC-2 water surface elevations into GIS coverages in Arc/info. 
 Evans (1998) developed a data exchange format to transfer physical element 
descriptions between hydrologic and hydraulic software packages and GIS software.  
The package studied was HEC RAS, with the ability to import cross-section locations 
as XYZ coordinates from terrain models to develop channel and reach geometry.  
Upon completion of the hydraulic calculations, HEC RAS exports the data back to a 
GIS for comparison with the terrain model.  In 1998, ESRI translated and improved 
Evans? code and added some utilities to facilitate its use.  The result was an Arcview 
GIS extension called AVRas. 
 Tate (1999) further investigated how to improve upon the HEC RAS model?s 
accuracy by incorporating field surveyed, stream geometry and control structures into 
a GIS-based terrain model.  His research led to the development of Avenue scripts for 
Arcview GIS that integrate such data.  The terrain model Tate used for his study was 
based on very accurate digital orthography.  Andrysiak (2000) applied Tate?s Avenue 
scripts to a larger study area using a digital elevation model (DEM) with 30-meter 
accuracy as the terrain model.  When studying both cases, one can deduce that terrain 
9 
 
model refinement is limited to the accuracy of the data.  In addition, accuracy of the 
geo-referencing of the surveyed cross-sections and control structures is imperative in 
the development of an optimum terrain model.   
 
Figure 2-1. Channel geometry incorporated into a digital terrain model (Tate 
1999). 
 Azagra-Camino (1999) focused on a smaller study area using more precise 
terrain data from the development of a Triangulated Irregular Network (TIN) in 
Arcview GIS.  The TIN was created from aerial photography, which resulted in a 
highly accurate terrain depiction of the study area.  Using the AVRas extension, 
Azagra-Camino extracted topographic information from the TIN and imported it as 
channel and stream geometry for use in the HEC RAS model.  The flood visualization 
results provided highly accurate 2-D and 3-D flood maps.  Azagra-Camino?s method 
was limited to one output in time for each run from the steady state HEC RAS model, 
making the process of developing flood animations tedious.  The animations he 
created required multiple runs of the HEC RAS model and importing the data into the 
TIN.  Additionally, Azagra-Camino extracted the cross-section data directly from the 
10 
 
terrain model.  Since the terrain data was based on aerial photography, the cross-
section data did not account for existing water surfaces in the stream channel when 
the photographs were taken.  Thus, results from his HEC RAS model may not have 
been accurate. 
 
Figure 2-2. Flood visualization using AVRas and a TIN (Azagra-Camino 
1999). 
 The previously mentioned 1-D flood modeling methods used steady state 
hydraulic modeling to determine stream water surface elevations and flows.  The 
steady-state models do not take into account all of the hydrodynamic effects that 
more accurately depict actual flood events.  The development of 2-D and 3-D 
animations from steady state models also requires numerous runs at different flow 
inputs.  This makes flood animation development tedious and very time consuming.   
 
11 
 
2.2 Dynamic Models 
 More complex methods of 1-D hydraulic modeling have become more accepted 
during recent years, as windows-based computer technology has emerged as the 
optimum graphical analysis tool.  Dynamic wave routing was first used in the early 
1950s, but was not widely accepted as a flood analysis method.  Computer limitations 
and the complexity of solving methods initially made dynamic wave routing 
unpopular for practical applications. 
 In 1871, Adhemar Jean Claude Barre de Saint-Venant derived the continuity 
and momentum equations for 1-D unsteady flow in an open channel, known as the St. 
Venant equations.  The equations he derived assume uniform cross-sections and bed 
slope for a segment of open channel with no flow above the banks.  Danny L. Fread 
(1976) further investigated the St. Venant equations and developed an implicit 
method of solving the dynamic wave for the modeling of meandering streams.  He 
distinguished left and right flood plains from the flow channel in a stream?s cross-
section.  The method was used to solve for the unknowns h (water surface elevation) 
and Q (stream flow) for specified points along the stream over a series of time steps.  
Fread first approached the problem by dividing stream channels into two conceptual 
channels ? the stream channel and floodplain.  He made four additional assumptions 
to simplify the 1-D flow problem: 1) the water surface at each cross-section is 
horizontal (normal to the direction of flow), 2) the momentum exchange between the 
stream channel and floodplain is negligible, 3) the flow is distributed to the stream 
channel and floodplain according to conveyance, and 4) the bed channel slope is 
small (denoting subcritical flow).  These assumptions led Fread to an implicit method 
to solve the St. Venant equations using a finite difference solution. 
12 
 
 
Figure 2-3.  Finite element of a stream channel with force terms. 
 To better understand unsteady flow equation terms, consider a finite segment of 
the stream as shown in Figure 2-3.  There are five acceleration and pressure terms that 
act on the control volume: convective acceleration, local acceleration, hydrostatic 
pressure, bed resistance, and gravity.  The convective acceleration, local acceleration, 
and hydrostatic pressure terms are important to dynamic wave motion because they 
account for pressure and inertial forces which characterize the movement of a large 
flood wave in the stream (Chow et al 1988).  The equations simplify to the following: 
 Continuity equation 
?Q + ?A = q    (1) 
?x     ?t 
 Momentum equation 
 ?Q + ?(?Q
2
/A) + gA?h + gQIQI = 0    (2) 
  ?t          ?x               ?x    C
2
AR 
where  
 Q: discharge 
 A: flow area 
 q: lateral inflow 
 h: stage above datum 
 C: Chezy resistance coefficient 
13 
 
 R: hydraulic radius 
 g: gravity constant 
 ?: momentum coefficient 
For Fread?s methodology, the above equations were separated between stream 
channel and flood plains.  The momentum coefficient, also known as the Boussinesq 
coefficient, accounts for uniform distribution of velocity at a cross-section.  Its value 
ranges from 1.01 for straight prismatic channels to 1.33 for river valleys with flood 
plains (Chow et al 1988). 
 Fread?s methodology led to the development of the U.S. National Weather 
Service?s (NWS) DWOPER (Dynamic Wave Operational Model) and DAMBRK 
models.  The DWOPER and DAMBRK models use the implicit method for solving 
the St. Venant equations for unsteady flow.  The DAMBRK model was used by the 
NWS to analyze floods resulting from dam breaks.  The NWS models eventually led 
to the development of the FLDWAV model by Fread (1985).  FLDWAV is a dynamic 
wave model for 1-D unsteady flows for a single stream or a stream network.  Like the 
DWOPER and DAMBRK models, it is based on an implicit finite-difference solution 
of the St. Venant equations. 
 Expanding on Fread?s work, Robert L. Barkau (1982) defined a new set of 
equations that were more convenient to solve by computation methods.  He combined 
the convective terms for both the floodplain and channel using a velocity distribution 
factor.  Barkau also replaced the friction slope (bed resistance term) with equivalent 
force terms.  His work is the basis of the Hydrologic Engineering Center?s 1-D, 
unsteady flow model called UNET.  HEC recently improved upon HEC RAS by 
including unsteady flow using the UNET program as an extension to the software.  
The unsteady flow option currently exists for HEC RAS version 3.0.  Time-series 
water surface elevations results developed from a HEC RAS model can now be 
14 
 
imported into Arcview GIS using the HEC GeoRAS extension, a new version of 
AVRas. 
 In Europe, the Danish Hydraulic Institute (DHI) developed the MIKE 11 
hydraulic model in 1987 and it became a widely applied 1-D dynamic modeling tool 
for rivers and channels.  Its ability to simulate unsteady stream flows for specified 
time durations and time steps currently make it a powerful graphical tool.  When 
using the MIKE 11 GIS extension for Arcview GIS, time-series results from a MIKE 
11 simulation can be imported into a GIS-based digital terrain model for flood 
visualization. 
 Carr (1989) and Kjelds (1997) have previously incorporated a DHI-developed 
hydrologic model, MIKE SHE, with the MIKE 11 and MIKE 11 GIS interfaces for 
the presentation and analysis of flood impacts.  Because of the commonality of the 
hydrologic and hydraulic models, DHI-based models have been successfully updated 
into a real-time flood-forecasting tool, known as FLOOD WATCH.   
 
15 
 
 
Figure 2-4. FLOOD WATCH applied to a region in India (Kjelds 1997). 
 Flood visualization using the HEC RAS and MIKE 11 models are limited to the 
accuracy of the topographic data from the terrain model and the continuous 
availability from numerous gage stations.  Further discussion of the multiple data 
sources used in this project are addressed in Chapter 3.  If stream geometry and 
topographic data are obtained from different sources and are not included in the 
terrain model, then flood visualization results from the hydraulic model can be 
affected.  Flood visualization can still provide some validity, especially when 
analyzing a complete watershed system where multiple rainfall-runoff inputs are 
sequenced in time. 
16 
 
Chapter 3: Data Discussion 
This chapter analyzes the data used in this project.  The first section discusses 
the data requirements for the two unsteady flow models applied in this project, and 
the last section discusses the source of the data used and the processing of that data.  
The inclusion of the data in the models is described in Chapters 5 through 7. 
3.1 Data Requirements 
 The data used in this project is classified into three sections: hydraulic, 
hydrologic, and spatial data.  Each section is examined below.  Discussion of all data 
is applied to both the MIKE 11 and HEC RAS models, unless otherwise specified. 
3.1.1 Hydraulic Data 
 Unsteady 1-D flow models require, at a minimum, three forms of hydraulic 
data: 1) stream geometry, 2) streambed resistance factors, and 3) time-series flow 
and/or stage height boundary conditions.  For both models, streambed cross-sections 
at locations along the network make up a significant portion of the overall geometry 
data.  Cross-sections act as upstream and downstream boundaries for each finite 
element in the model.  Cross-sections provide the cross-sectional area data required 
for unsteady flow computations. 
17 
 
 
Figure 3-1. 3-D depiction of a stream with cross-sections in HEC RAS. 
 The network, or stream centerline, of a 1-D flow model can theoretically be 
modeled as a straight line since natural dispersive effects of flow are not considered.  
For this project, the stream network contains x- and y-coordinate data in a 2-D plane 
so as to spatially connect the unsteady flow models to the corresponding terrain 
models.  To accurately depict historic flows in an unsteady flow model, cross-sections 
must b accurately referenced along the network.  For the MIKE 11 model this 
reference system is referred to as Chainages, and starts from the most upstream 
location of a stream and heads downstream to its confluence.  Chainage values are 
derived the same way for any additional branches within the hydraulic model.  
Chainage values are measured in meters. 
 When using the HEC RAS model, the network referencing of the cross-sections 
is known as River Stations, and runs opposite of Chainages (starts at a stream?s 
confluence and goes upstream).  Unlike Chainages, River Stations can use any 
sequential method to identify cross-sections, as long as downstream reach lengths 
from each cross-section to the next are known. 
18 
 
 
Figure 3-2. Comparison of Chainage and River Station network referencing. 
 Bed resistance factors are also necessary when defining hydrodynamic 
parameters for unsteady flow models.  The resistance factors are used in the bed 
resistance term in the St. Venant momentum equation.  In MIKE 11, the bed 
resistance factors are differentiated between the streambed and flood plains.  Thus, 
the location where the streambed ends and the left and right flood plains begin must 
be defined in each cross-section.  Resistance factors can be defined in the MIKE 11 
model from one chainage value to another for a segment of the reach, as well as 
locally per individual cross-section.  Resistance factors can be inputted as Manning?s 
n, Manning?s M, or Chezy?s C values (MIKE 11 automatically converts resistance 
factors to Chezy?s C values).   
19 
 
 
Figure 3-3. Differentiation of streambed and flood plain resistance in MIKE 
11. 
 In the HEC RAS model, bed resistance is defined at each cross-section as 
Manning?s n values.  Unlike the MIKE 11 model, defining the bed resistance for each 
cross-section is not limited to only the streambed and flood plains.  Differences in 
resistance can be defined for additional portions of each cross-section as well. 
 
Figure 3-4. HEC RAS cross-section with Manning?s n values shown above 
the graph. 
20 
 
 The final hydraulic data requirement for unsteady flow models is the boundary 
conditions.  Unlike steady-state conditions, a boundary condition for unsteady flow 
may be in time-series format defined by a user-specified time range and time step.  
Time-series boundary types are discharge (Q) and stage heights (h).  Another 
commonly used boundary type not in time-series format is a stage-discharge 
relationship known as a rating curve.  For the MIKE 11 model, the boundary 
conditions are limited to Q hydrographs for upstream boundaries and h hydrograph 
for downstream boundaries.  When h hydrographs do not exist, the data can be 
interpolated using the downstream cross-sections rating curve and the existing flow 
conditions.  In HEC RAS, upstream boundaries are defined as Stage, Flow or Stage 
and Flow hydrographs; downstream boundaries are defined as Stage, Flow, Stage and 
Flow, Rating Curve, or Normal Depth. 
 Boundary conditions usually depict a flood event for a specified design storm 
and are obtained from upstream and/or downstream gage station data.  The boundary 
conditions can also be determined from hydrologic models as well.  When hydrologic 
model data is incorporated, lateral runoff hydrographs at watershed outlets along the 
network provide a more accurate depiction of runoff for that specified storm event. 
 Initial conditions depict base flow conditions prior to a storm event, and are 
used in MIKE 11 to optimize the model?s performance.  When modeling a storm 
event, the MIKE 11 model can first be used to establish base flow conditions from the 
gage or hydrologic model data.  The simulation is known as a hotstart and is 
explained in more detail in Chapter 5. 
3.1.2 Hydrologic Data 
 As previously discussed, hydrologic data is the output response of a 
precipitation (storm) hyetograph input to a watershed system.  The output response is 
a flow (runoff) hydrograph for each individual watershed in the system.  There are 
21 
 
numerous methods used to model hydrology for a specified watershed.   
 In MIKE 11, a hydrologic model can be developed directly from the MIKE 11 
software interface using the Rainfall Runoff file.  The NAM (lumped, conceptual 
model), UHM (unit hydrograph method), or SMAP (soil moisture accounting model) 
modeling methods can be used.  Limitations to the Rainfall Runoff file are hydrologic 
attributes, like a drainage basin?s area and Curve Number for example, must be 
inputted into the file by hand. 
 For the HEC RAS model, hydrologic data can be imported into the model?s 
flow data from the HEC Hydrologic Modeling System (HMS).  Results from the HEC 
HMS model are imported by using the HEC Data Storage System (DSS) utility.  
Further discussion and implementation of the DSS utility can be found in Chapter 7.  
The HEC HMS model has a wide range of hydrologic modeling methods.  Loss rates 
can be determined using either the SCS Curve Number or the Green and Ampt 
method.  Transformation of the rainfall into a runoff hydrograph can be accomplished 
using the UHM, Clark, Modified Clark, or Snyder hydrographs (HEC-HMS, 1998). 
 When incorporating hydrologic model results into an unsteady flow model, the 
key is to accurately geo-reference each watershed outlet to the stream network.  Most 
hydraulic models have means to import or geo-reference a hydrologic model?s results, 
as long as the flow model and hydrologic model were developed and packaged as 
supporting software tools.  This is the case for both the MIKE 11 and HEC RAS 
models.   
 Since this project?s focus is on unsteady flow modeling, the hydrologic results 
for both hydraulic models were derived from the same hydrologic model, previously 
developed by Andrysiak (2000).  Andrysiak?s HEC HMS model results were 
imported directly into the HEC RAS model using the DSS utility.  To integrate the 
hydrologic results into the MIKE 11 model, the resulting flow hydrograph at each 
22 
 
watershed outlet was geo-referenced by using the same x- and y- coordinate plane for 
both the MIKE 11 stream network and HEC HMS watershed schematic. 
 
Figure 3-5. Schematic view of the HEC HMS model developed by Andrysiak 
(2000). 
3.1.3 Spatial Data 
 Visualization of floods in Arcview GIS requires a detailed representation of the 
terrain to accurately depict flood inundation.  As the study area?s size increases, 
computer memory requirements increase and software-processing speeds decrease 
substantially.  The modeler must find a medium that best fits modeling requirements 
and computer capacity. 
 The critical spatial data necessary for flood visualization are used to develop a 
terrain representation of the study area.  The data is usually available for the 
23 
 
continental United States as grid- or vector-based GIS themes.  At a minimum, a 
Digital Elevation Model (DEM) can be used to develop the terrain model, but is not 
the optimum data source.  Availability of more accurate terrain depictions, like digital 
orthographic photo images, vector-based contour themes, or Triangulated Irregular 
Networks (TINs) usually provide more accurate terrain representations.  TINs are 3-D 
GIS themes created by a random mesh of triangles that best fit the depiction of the 
terrain.  An example of a TIN is shown in Figure 3-6.  Additional themes in GIS like 
roads, buildings, levees, and railroads, can also be integrated into the spatial model to 
improve upon the accuracy of the terrain model. 
 
Figure 3-6. A triangular mesh and TIN theme in Arcview GIS. 
3.2 Data Sources and Processing 
 The first step in data processing for spatial modeling is to determine a common 
coordinate system for data sources.  Once that is established, identification of data 
sources and initial processing can begin.  The sources and processing of the data for 
24 
 
use in this project are categorized into three sections ? terrain data, geometric data, 
and flow data.  For 1-D flow models, the processed data is organized and understood 
using stream network referencing.  Network referencing is the key step to integrating 
unsteady flow model results with the terrain model in Arcview GIS.  This section 
discusses this project?s data development. 
3.2.1 Coordinate System 
The project required a common projection to spatially correspond the unsteady 
flow model results to the GIS environment.  Since both of the unsteady flow models 
use an XYZ coordinate system, a Cartesian coordinate system is required.  The Ohio 
State Plane (OSP) Coordinate System for southern Ohio was used throughout the 
project.  All the GIS themes were projected into OSP system using Arc/info, with the 
following formatted text file as the output projection properties: 
output 
projection LAMBERT 
/* datum NAD83 
zunits METERS 
spheroid GRS1980 
xshift 0.0 
yshift 0.0 
parameters 
38.733333 
40.033333 
-82.5 
38.0 
600000 
end 
3.2.2 Terrain Data 
 The Louisville District provided the terrain data used in this study.  The data 
included three vector-based Arcview GIS themes, depicting 1-ft contour lines for the 
25 
 
Primary Damage Center (the model area).  The three themes were merged into one 
single theme in Arcview.  The terrain model created from the 1-ft contour lines 
consisted of 6,028,127 triangles within the TIN mesh (240 MB of computer memory).  
Because of limitations with computer memory capacity, a new terrain model was 
required.  Deleting every other contour line in the study area?s 1-ft contour theme 
revised the terrain data to a 2-ft contour theme.  The new TIN-based terrain model 
was developed from the 2-ft contour theme.  The development of the 2-ft contour 
theme and the TIN-based terrain model is explained in Chapter 5.  The terrain model 
now consisted of 134,470 triangles in the TIN mesh, using 4.39 MB of computer 
memory.  The result was an accurate terrain data depiction that could be effectively 
used within the processing constraints of the computer.  A practical limit to the 
number of triangles to use in the TIN mesh is 500,000 triangles.  Obviously this 
number can be adjusted based on computer speed, computer capacity, and modeler 
requirements. 
 
Figure 3-7. Portion of the 2-ft contour theme depicting the Primary Damage 
Center (study area). 
 Additional Arcview GIS themes can be used to further improve the terrain data.  
The building and street themes of the study area were also provided by the Louisville 
26 
 
District.  Existing buildings that lie within a flood plain can create a physical barrier 
to high stage flows.  By incorporating buildings into the terrain model, the stream 
cross-sectional geometry used in the unsteady flow model can change accordingly.  
Buildings can divert water flow that may have an impact on the flow model?s results.  
Building themes can also provide a visual reference when delineating floods with the 
terrain model. 
 The street theme also has a purpose for use in flood visualization, mainly as a 
reference tool.  When the network referencing of cross-sections, control structures, 
and watershed outlets are not obvious to the modeler, a street theme can assist with 
referencing where the street theme intersects with the stream network.  When 
visualizing the results of the flow model in Arcview GIS, streets can assist an 
observer unfamiliar with the study area by providing a spatial reference for the terrain 
model.  The street theme was unnecessary in the development of the terrain model, 
since the contour data already contains the topography of the roads. 
3.2.3 Geometric Data 
 The geometric data used for the unsteady flow models consists of three basic 
data sets: 1) the stream network, 2) cross-sections of the stream network, and 3) 
channel and flood plain resistance factors. 
3.2.3.1 The Stream Network 
 The stream network for 1-D unsteady flow models can be created directly in the 
model or imported from another source.  Since the model is 1-D, the model does not 
differentiate whether the stream is a straight line or has an x- and y-coordinate system 
related to the terrain model.  As long as downstream reach lengths for the channel and 
flood plain flow paths from cross-section to cross-section are known, and all other 
geometric data is accurately referenced along the network, the flow model will 
27 
 
provide the same results.  For this study, the x- and y-coordinates for the network are 
necessary to integrate the flow model?s simulation results into the GIS spatial 
environment. 
 One method of developing the stream network is to digitize a polyline in 
Arcview GIS using orthographic photo images or U.S. Geological Survey (USGS) 
quadrangle maps in Arcview GIS.  Another method is to clip a section of an existing 
river network theme that corresponds to the terrain model.  Existing network themes 
can be downloaded from the Internet for use in Arcview GIS.  One network theme, 
called an RF3 river reach file, is downloadable from the Environment Protection 
Agency?s (EPA) Office of Water web site (http://www.epa.gov/ow/soft.html) and 
contains all the river networks existing in maps of the continental United States at a 
1:100,000 scale.  An even more accurate network file can be found from the National 
Hydrography Dataset (NHD), which can be obtained from the USGS web site, 
http://nhd.usgs.gov/.  When working with smaller study areas with more detailed 
data, RF3 and NHD data may require some editing to better fit the stream network to 
the terrain model?s stream channel. 
 To create a stream network that fits the same coordinate system as the terrain 
data, the stream network was digitized from the terrain model in this study.  An RF3 
river reach file was initially used, but it did not correspond with the terrain model?s 
stream channel.  A point theme was created from the RF3 river reach file and adjusted 
to fit the stream channel?s centerline.  The stream network was digitized from point to 
point along the stream channel.  The same stream network was used for both the 
MIKE 11 and HEC RAS unsteady flow models. 
 
28 
 
 
Figure 3-8. Stream network digitized in Arcview GIS using a point theme. 
3.2.3.2 Cross-section Data 
 The Louisville District provided two HEC-2 text files that contained cross-
sectional data for the stream network.  The HEC-2 files were imported into the HEC 
RAS model to develop geometry files.  The geometry files contain x- and z-
coordinate profiles of cross-sections at specified locations along the stream network.  
The resistance factors were also included in the files.  The geometry files were saved 
as .G01 files in the HEC RAS model. 
 
29 
 
 
Figure 3-9. Example of cross-section data in a HEC-RAS .G01 text file. 
 The HEC-2 files also contained downstream reach lengths and a River Station 
designation for each cross-section for network referencing.  This was important in the 
conversion process to MIKE 11, to ensure the cross-sections were properly referenced 
as Chainages along the MIKE 11 stream network.  The conversion of the River 
Station designations to Chainages in MIKE 11 is shown in Appendix A. 
 Using a Visual Fortran program developed by Mr. Stefan Szylkarski from DHI, 
the .G01 files were converted into text files that the MIKE 11 software could read.  
The Visual Fortran developed is shown in Appendix B.  The resistance factors were 
was not imported into the file, and are discussed in the next section. 
30 
 
 
Figure 3-10. Cross-section text file readable by the MIKE 11 software. 
 The HEC-2 cross-sectional data was not used for the HEC RAS model.  Flood 
visualization using the HEC GeoRAS extension requires the geometry data to be 
extracted from the terrain model in Arcview GIS.  Using the stream network 
previously developed, cross-section locations along the stream were manually 
digitized.  River Station referencing and downstream reach lengths were 
automatically calculated by the HEC GeoRAS extension.  This process is discussed in 
Chapters 4 and 7.   
 
31 
 
3.2.3.3 Channel and Flood Plain Resistance Factors 
 Channel and flood plain resistance factors for this study were also provided in 
the HEC-2 files as Manning?s n values.  For this project, the resistance data was 
inputted into the MIKE 11 and HEC RAS models manually. 
 HEC GeoRAS provides an option to extract the Manning?s n values from 
Arcview GIS.  If an accurate Land Use theme is available, the HEC GeoRAS 
extension will automatically calculate Manning?s n values for each cross-section and 
export those values with the extracted geometry data into the HEC RAS flow model. 
3.2.4 Flow Data 
 Flow data for both of the flow models consisted of the stream network?s average 
base flows and runoff hydrographs derived from the hydrologic model.  The average 
base flows for the stream network was provided by the Louisville District and was 
assumed constant for both flow models.  The base flows were necessary to establish 
normal flow conditions.  The base flow data was provided in cubic feet per second 
and was converted to cubic meters per second for use in both models. 
Table 3-1. Base flows for the flow model stream network. 
Stream ft
3
/s m
3
/s 
Mill Creek 200 5.663 
East Fork 40 1.133 
 The Hydrologic flow data was extracted from Andrysiak?s HEC HMS model 
using precipitation data from a 25-yr storm event that occurred in April 1998.  Since 
the HEC HMS model results were in a DSS format, the data could not easily be 
imported into the MIKE 11 interface.  To make the data MIKE 11 readable, the 
runoff data derived from each drainage basin in the hydrologic model was converted 
32 
 
into an Adobe Acrobat file (.pdf file) using Adobe Distiller.  The runoff data was 
copied and pasted into a MIKE 11 time-series file and identified by each drainage 
basin identification number. 
 
Figure 3-11. Runoff hydrograph for the Mill Creek Watershed?s Basin 109. 
 Each watershed outlet was referenced to a location along the stream network.  
Thus, each runoff hydrograph was incorporated as lateral inflow into the stream 
network for both flow models.  Accumulation of all the runoff data over a specified 
time range simulated the flood event for the model. 
 For drainage basins not directly connected to the river network, runoff 
hydrographs were accumulated for corresponding drainage basins for connectivity 
purposes.  The accumulated runoff data existed in the HEC HMS model as flow at 
junctions.  The runoff hydrographs computed from the HEC HMS model are 
provided in Appendix E. 
33 
 
Chapter 4: Modeling Methods 
 This chapter describes the modeling methodologies and capabilities of the 
computer software used in this study.  The description discusses the hydraulic 
models, MIKE 11 and HEC RAS, and the hydrologic model, HEC HMS.  The GIS-
based applications, MIKE 11 GIS and HEC GeoRAS, which correspond to the MIKE 
11 and HEC RAS models, respectively, are also discussed.  Chapters 5 through 7 
document the application of the computer models presented in this chapter using the 
data described in Chapter 3. 
4.1 The MIKE 11 Model 
 The MIKE 11 hydrodynamic model was created by DHI in 1987.  It is one of 
the most widely applied 1-D dynamic modeling tools for rivers and channels (DHI, 
1999).  Along with the MIKE 11 GIS extension to MIKE 11 GIS, time-series results 
from the MIKE 11 model can be imported into a GIS spatial environment for 2-D and 
3-D flood visualization.   
4.1.1 The MIKE 11 Hydrodynamic Model 
 The MIKE 11 model runs from a windows-based interface called MIKE Zero.  
To develop a MIKE 11 hydrodynamic model, five files are necessary: a River 
Network file, a Cross-section file, a Boundary file, a Hydrodynamic Parameter file, 
and a Simulation file.  Implementation of the MIKE 11 model used in this study is 
discussed in Chapter 6.   
 In additional to the previously mentioned files, the hydrodynamic model can be 
expanded to model Water Quality (advection and dispersion modeling), Sediment 
Transport, and Eutrophication.  MIKE 11 can also incorporate a Flood Forecasting 
file designed to perform calculations required to predict the variation in water levels 
34 
 
and discharges in streams as a result of the Rainfall-Runoff hydrologic model 
implemented through the hydraulic model?s boundaries.  The Water Quality, 
Sediment Transport, Eutrophication, and Flood Forecasting options were not used in 
this study.  Hydrologic modeling results were incorporated into the hydrodynamic 
model as lateral inflows in the Boundary file. 
4.1.1.1 The Simulation file 
The Simulation file acts as a ?simulation manager? for the other files and does 
not require any external data.  It defines the model type under the Model tab.  By 
defining all the input files of the model under the Input tab, it acts as the link between 
the Network file and the other MIKE 11 files.  
 
Figure 4-1. Input tab in a MIKE 11 Simulation File. 
 The Simulation tab contains the simulation and computation control parameters.  
The modeler defines simulation start and end times and time step under this tab.  
Under the Initial Conditions on the Simulation tab, the user establishes the initial 
35 
 
conditions for the simulation.  Options are Steady State, Parameter file, Hotstart, or 
Steady and Parameter.  In the case of this study, the initial conditions were 
established using a hotstart file, as shown in Figure 4-2.  A hotstart is a file that 
establishes base flow conditions for unsteady flow.  The hotstart simulation is the 
steady-state solution for an unsteady flow model, which eliminates instability in the 
simulation created by initial conditions.  
 
Figure 4-2. Simulation file with a ?Hotstart? Initial Conditions Type. 
 The Simulation file also allows the modeler to determine the name of the results 
file.  Once all information is inputted into the file, the Simulation file identifies any 
errors with the established conditions before running a simulation, as well as running 
an unsteady flow simulation. 
4.1.1.2 The River Network File 
 The MIKE 11 model?s River Network file is the common link to the various 
36 
 
MIKE 11 files.  It also has an XY coordinate system, allowing the model to import 
and export data to and from a GIS environment using the MIKE 11 GIS extension.  
The River Network file allows the modeler to 1) define the river network and 
reference cross-sections and control structures to the network; and 2) graphically 
obtains an overview of model information in the current simulation.   
 
Figure 4-3. River network file defined by XY coordinate data points. 
 The River Network file can be digitized graphically, or inputted as XY 
coordinate data points, which are then manually connected.  Chainage values along 
the network are automatically determined once the user defines the most upstream 
Chainage value(s).  Control structures like dams, culverts, and weirs are added to the 
model in the River Network file, where the Chainage value referencing already exists. 
37 
 
 
Figure 4-4. Tabular view of a river network depicting XY coordinate data 
points. 
4.1.1.3 The Cross-section File 
 The Cross-section file contains streambed cross-sections as specified locations 
along the river network.  The geometry of cross-sections usually is obtained from one 
of two sources - field-surveyed data or extracted from user-defined locations in a 
terrain model.  
38 
 
 
Figure 4-5. Raw data view of a cross-section in MIKE 11. 
 There are two types of cross-section data in MIKE 11:  the raw data, and the 
processed data.  The raw data is the geometric data of each cross-section derived 
from the above-mentioned sources.  It also includes the local variation in bed 
resistance specific to that cross-section.  The processed data is derived from the raw 
data and contains the cross-section?s computational information used by the computer 
model.  Cross-section raw data can be imported as a readable text file and can be 
edited directly from the Cross-section file editor. 
4.1.1.4 The Boundary File 
 The Boundary file consists of boundary conditions in time-series format for the 
river network?s boundaries.  The file consists of four boundary condition options:  
Hydrodynamic, Advection Dispersion, Sediment Transport, and Rainfall Runoff.  The 
Hydrodynamic option is the only boundary condition option used in this study.   
 Boundary types include Water level (h), Discharge (Q), Q/h Relation, Wind 
39 
 
Field, Dambreak, and Resistance Factor.  The Water level boundary must be applied 
to either the upstream or downstream boundary condition in the model.  The 
Discharge boundary can be applied to either the upstream or downstream boundary 
condition, and can also be applied to side tributary flow (lateral inflow).  The lateral 
inflow is used to depict runoff for this study.  The Q/h Relation boundary can only be 
applied to the downstream boundary. 
 The Wind Field boundary accounts for wind effects and can be applied globally 
or at specific branches in the river network.  The Dambreak boundary simulates a 
dam?s failure on the river network.  The Resistance Factor boundary accounts for a 
time varying bed resistance along the river network.  Only hydrodynamic boundary 
conditions were applied to this research. 
 
Figure 4-6. MIKE 11 boundary file. 
 Boundary types are linked to a time-series data file in the Boundary file.  As 
40 
 
shown in Figure 4-6, the boundary at Chainage value 15407.15 is defined as a 
Discharge boundary and is linked to a Time Series File under the Discharge 
Specifications. 
4.1.1.5 The Hydrodynamic Parameter File 
 The Hydrodynamic Parameter file requires bed and flood plain resistance data 
for the river network.  Differentiation between the streambed and flood plain along 
the river network is accomplished at each cross-section in the Cross-section file.  Bed 
and flood plain resistance can be inputted as Chezy?s C, Manning?s M, or Manning?s 
n values.  The resistance factors are inputted from one location to another along the 
river network (chainage to chainage), as resistance changes.  Resistance for 
streambeds and flood plains is inputted separately.  Any local differences in 
resistance may be incorporated into the Cross-section file at a specified cross-section.  
The overall resistance is then the product of the resistance factor from the Cross-
section file and the Hydrodynamic Parameter file at that specified location. 
 
 
41 
 
Figure 4-7. Bed resistance from chainage to chainage in the hydrodynamic 
file. 
4.1.2 MIKE View 
 Results of MIKE 11 simulations can be observed using the MIKE View 
software.  MIKE View displays longitudinal profile animations of both stage height 
and discharge resulting for a MIKE 11 model.  It also can display stage height at any 
given cross-section, as well as provide rating curves at a specified location along the 
network. 
 MIKE View can also provide time-series results of stage heights at cross-section 
locations and time-series results of discharge at midpoints between two cross-section 
locations.  This tool has been beneficial for this research by providing a facility for 
creating new boundary conditions for the model, as the study area was refined from 
the entire extent of the Mill Creek reach to a smaller area defined as the Primary 
Damage Center.  To incorporate the contour data into the model, limitations to 
computer capacity had to be accounted for by refining the model area.  The 
refinement focused on the most critical location of flood damage in the Mill Creek 
Watershed.  Thus, the study area was refined to the Primary Damage Center. 
4.1.3 The MIKE 11 GIS Extension 
 The MIKE 11 GIS extension integrates the MIKE 11 model with Arcview GIS.  
Like the MIKE 11 model, MIKE 11 GIS was developed by DHI.  It acts as a bi-
directional exchange between MIKE 11 and Arcview GIS.  MIKE 11 GIS provides 
the following options to the modeler: 
? Terrain model development in Arcview GIS using a grid-based mesh 
? Extraction of geometric data from the terrain model for use in the MIKE 11 
model 
? Import MIKE 11 model time-series results into Arcview GIS for flood 
42 
 
visualization 
? Develop 2-D and 3-D views and animations with the MIKE 11 model results 
and the corresponding terrain model (DHI, 1998) 
 If the river network in the MIKE 11 model already has a corresponding XY 
coordinate system to the terrain model, extraction of geometry data using MIKE 11 
GIS is not required to import MIKE 11 results into Arcview GIS.  If this is the case, 
the modeler needs to be aware of the differing data sources and ensure the existing 
geometry data is accurately geo-referenced with the river network. 
4.2 The HEC RAS Model 
 HEC RAS is a hydraulic model created by the Hydrologic Engineering Center.  
The first version of HEC RAS was developed in 1990 and evolved from a steady flow 
model called HEC-2, first developed in 1966 (HEC-RAS, 1998).  As computer 
capabilities improved, the HEC-2 software was converted to the windows-based HEC 
RAS software to better assist hydraulic modeling with a graphical user interface.  In 
April 2000, the Hydrologic Engineering Center also developed the HEC GeoRAS 
extension of Arcview GIS, a pre- and post-processing tool for the HEC RAS model.  
HEC GeoRAS is an upgrade to the previously used AvRAS extension. 
4.2.1 The HEC RAS Unsteady Flow Model 
 The HEC RAS model was initially used for calculating water surface profiles 
for 1-D steady-state flow.  The results from the model have been applied to flood 
management and flood insurance studies throughout the United States.  Recently, 
HEC RAS has incorporated an unsteady flow model in its beta version 3.0 (the final 
3.0 version should be available by the end of calendar year 2000).  The HEC RAS 3.0 
version provides the modeler with an option to use either the steady flow or unsteady 
flow option.  The unsteady flow option runs the UNET algorithm from the software.  
Results from the UNET algorithm are then imported back into HEC RAS for viewing 
43 
 
of simulations. 
 
Figure 4-8. Main menu of HEC RAS version 3.0, with the unsteady flow 
option. 
 Along with the unsteady and steady flow options, the HEC RAS model also 
provides the following capabilities: 
? Modeling of open channel networks and single rivers (both unsteady and 
steady flow options) 
? Analysis of bridges, weirs, and culverts (unsteady and steady flow options) 
? Modeling storage areas, navigation dams, tunnels, pumping stations, and levee 
failures (unsteady flow option only) 
? Handling of subcritical, supercritical, and mixed-flow regimes (steady flow 
option only) (HEC-RAS, 1998) 
The unsteady flow option was used for this project.  To develop an unsteady flow 
model, three files are required:  the Geometric Data file, the Unsteady Flow Data file, 
and the Unsteady Flow Analysis file. 
4.2.1.1 The Geometric Data File 
 The Geometric Data File contains all the pertinent geometry necessary for 
hydraulic modeling.  It establishes the connectivity of the river network (using River 
44 
 
Stations for network referencing), cross-section data (to include Manning?s n 
resistance factors), stream junctions, and hydraulic structures.  The file editor allows 
the importing of geometric data from previous HEC RAS versions, UNET models, 
and from Arcview GIS.  Editing any of the geometric features can also be 
accomplished from this file. 
 
Figure 4-9. HEC RAS version 3.0 geometric data file editor. 
 HEC RAS version 3.0 also includes a Storage Area editor, a Hydraulic 
Connectivity editor, and HTAB Parameters editor.  The Storage Area editor provides 
the modeler the capability to add and edit storage areas within the river network 
45 
 
system.  The Hydraulic Connectivity editor connects the river network and cross-
sections with existing hydraulic structures and storage areas.  The HTAB Parameters 
editor establishes the initial conditions for the unsteady flow option (initial water 
surface elevation at each cross-section in the network) and the incremental unit value 
(for the change in water surface elevations) used in the UNET algorithm.  The 
incremental unit value is the incremental change of water surface elevation used by 
the UNET algorithm, and is set to a default of 0.1 meters. 
4.2.1.2 The Unsteady Flow Data File 
 The Unsteady Flow Data file consists of the boundary conditions and initial 
conditions for the model.  The initial conditions contain the initial flow distribution 
for each reach within the river network.  The time-series boundary conditions contain 
the upstream and downstream boundary conditions (at a minimum) defined as a 
Stage, Flow, or Stage and Flow hydrograph.  Internal river network boundary 
condition options include Lateral Inflow, Uniform Lateral Inflow, and Groundwater 
Interflow hydrographs.  The Lateral Inflow hydrograph option depicts tributary, point 
source, or watershed outlet (runoff) inflows.  The uniform lateral inflow depicts 
overland inflow evenly distributed from one River Station location to another along 
the river network.  Lastly, the Groundwater interflow hydrograph models inflow into 
the river network from groundwater recharge. 
46 
 
 
Figure 4-10. HEC RAS version 3.0 unsteady flow data file editor. 
 Once the boundary and initial conditions are defined in the Unsteady Flow Data 
File editor, each boundary condition is linked to a user inputted time-series data 
editor.  The time-series data can be linked to a HEC HMS or HEC RAS model results 
using the DSS interchange or inputted manually into the time-series data chart.  The 
modeler also defines the time-series data?s time interval and reference starting time 
from this editor. 
4.2.1.3 The Unsteady Flow Analysis File 
 The Unsteady Flow Analysis file establishes the user specified conditions for 
the unsteady flow simulation.  The modeler sets the starting and ending time for the 
simulation, and establishes the computational settings for running the UNET 
47 
 
algorithm.  The computational settings include the computational interval, 
hydrograph output interval, and instantaneous profile interval.  The instantaneous 
profile interval must be equal to or greater than the computational interval to run the 
simulation. 
 
Figure 4-11. HEC RAS version 3.0 unsteady flow analysis file editor. 
 Once the unsteady flow model is simulated, errors in logic for the geometric, 
HTAB, and unsteady flow data are identified by the software.  Once all errors have 
been resolved, the HEC RAS software runs an HTAB algorithm to establish the initial 
conditions for the entire river network, in preparation for running the UNET 
algorithm.  Once that is accomplished, the computer executes the UNET algorithm 
for the simulation.  Results include water surface profiles for each cross-section at 
48 
 
each time step within the starting and ending time ranges for the entire river network. 
4.2.2 The HEC GeoRAS Extension 
 The HEC GeoRAS extension integrates results from the HEC RAS model into 
Arcview GIS.  It acts as a geometric data pre-processor and HEC RAS results data 
post-processor in Arcview GIS.  HEC GeoRAS provides the following options to the 
modeler: 
? Extraction of geometric data from a TIN-based terrain model for use in the HEC 
RAS model (pre-processing) 
? Import of the HEC RAS model time-series results into Arcview GIS for flood 
visualization (post-processing)  
Unlike the MIKE 11 model, geometric data must be extracted from the terrain 
model into the HEC RAS model to develop flood visualization in Arcview GIS.  This 
pre-processing step geo-references the unsteady flow model results to the terrain 
model.  The GeoRAS extension also develops a bounding polygon in Arcview GIS, 
which establishes the limits of flooding in the terrain model.  If the modeler is 
unaware of floodplain extents prior to developing the model, the bounding polygon 
may be too wide or too narrow when observing the HEC RAS results in Arcview GIS 
using the post-processor.  By iteration, the optimum size of the bounding polygon can 
be determined. 
 
49 
 
 
Figure 4-12. Bounding polygon derived from cross-sections using GeoRAS.  
The terrain model is of Waller Creek flowing through the University of 
Texas Main Campus. 
4.3 The HEC HMS Model 
 HEC HMS is a hydrologic model developed by the Hydrologic Engineering 
Center of the U.S. Army Corps of Engineers.  In 1968, HEC released the HEC-1 
computer model to aid engineers in hydrologic analysis.  The windows-based HEC 
HMS software was released in 1998.  The program simulates a rainfall runoff 
response of a watershed system to a precipitation input by representing the entire 
watershed as an interconnected system of hydrologic and hydraulic components, 
which include watersheds, streams, and reservoirs.  The results from a HEC HMS 
model can be used as input data for hydraulic modeling. 
 The HEC HMS software provides the following computational options to 
deriving runoff responses to simulate precipitation-runoff processes: 
? Several alternatives for loss determination 
? Lumped or linearly distributed runoff transformation methods 
? Routing options 
50 
 
? An optimization system for calibration (HEC-HMS 1998) 
4.3.1 Loss Determinations 
 The term ?losses? refers to the amount of the rainfall from a storm event that is 
diverted from runoff, usually infiltrating to soil or flowing to other means of storage 
in the watershed system.  The HEC HMS model supports the most common methods 
for calculating losses, like the initial/constant rates, Soil Conservation Services (SCS) 
Curve Number method, and the Green and Ampt method.  These methods can be 
lumped or linearly distributed throughout the model.  In a lumped analysis, losses are 
spatially averaged over a watershed within the watershed system.  For a linearly 
distributed method, the rainfall is spatially defined for the entire watershed system, 
and losses are averaged for each watershed in the system. 
4.3.2 Runoff Transformations 
 Runoff transformations convert the precipitation from a storm event, minus the 
losses, to direct runoff for each watershed in the system.  The runoff is computed as a 
hydrograph response at each watershed?s outlet.  Like the loss determination, the 
HEC HMS software allows the modeler to use lumped or linearly distributed 
approaches to runoff transformation.  In a lumped analysis, the amount of runoff is 
determined either using unit hydrographs like the Clark, Snyder, or SCS hydrographs, 
or the kinematic wave method.  In a linearly distributed method, like the Modified 
Clark hydrograph, the watersheds in the watershed system are spatially interpreted as 
numerous grid cells within a user-defined grid mesh, and the time (known as lag 
time) for excess rainfall to move from that grid cell to the watershed?s outlet is 
determined.  The hydrograph for the Modified Clark method is created from the sum 
of the all the grid cell?s lag times for each watershed in the system. 
4.3.3 Routing 
51 
 
 Routing is the movement of the runoff from the different watershed outlets 
throughout the system along the streambed, and ultimately to the outlet or sink of the 
entire watershed system.  The HEC HMS model routing options include the 
Muskingum, Modified Puls, Kinematic Wave, and Muskingum-Cunge methods.   
 
Figure 4-13. Discontinuities between watersheds in a hydrologic model and 
the boundaries of the hydraulic model (shown in bold). 
 Hydraulic models do not always model the entire stream network used in a 
corresponding hydrologic model, as shown in Figure 4-13.  Some modelers may 
further refine the study area to a smaller range.  In such cases, the routing methods 
provided in HEC HMS software can provide flow hydrographs at locations known as 
junctions along the stream network as well.  This provision can compensate for 
discontinuities between the two models by providing upstream and downstream 
boundary conditions for the further refined hydraulic model. 
 
52 
 
4.3.4 Parameter Optimization 
 To use the HEC HMS model as an engineering modeling tool, it requires 
calibration to the historic flow conditions of the actual watershed system.  The 
process can be simple or complex and requires the adjustment of numerous 
parameters to optimize model results.  The HEC HMS software provides an option 
for model optimization. 
 The HEC HMS model used for this study was not calibrated, because of a 
number of complications existing in the actual watershed system.  Combined sewer 
overflows, the unknown capacity for storage, and the diurnal effects of wastewaters 
all contribute to the on-going hydrologic problems with the Mill Creek Watershed.  
More information on the hydrologic model and its calibration is discussed in further 
detail in Andrysiak?s report. 
53 
 
Chapter 5: Terrain Model Development 
 When delineating floods in a spatial environment, the accuracy of the terrain 
model is very critical.  The most accurate terrain data currently used is obtained from 
photogrammetry.  Photogrammetry is the science or art of obtaining reliable 
measurements by means of photographs (Tate, 1998).  One of the most common uses 
of photogrammetry is the analysis of aerial photography to extract ground elevations 
to produce topographic maps. 
 Digital terrain data is obtained from a plane traveling over a study area taking 
photographs.  Photographs are taken from two passes of the study area, so that every 
point on the ground appears in at least two successive photographs.  Digital terrain 
data, like a DEM or contour data, is obtained from the photographs using either an 
analog instrument called a stereoplotter, or by using digital image processing software 
(Tate, 1998).  Photogrammetry data is limited to the many arbitrary surfaces that 
make up the terrain.  So, if water exists in a streambed when the photographs are 
taken, the water surface elevation data (not the streambed?s geometry data) is 
included as part of the terrain data. 
 In such cases, hydraulic modelers find themselves in a quandary ? how can one 
integrate accurate terrain data with existing streambed geometry (i.e. surveyed data of 
the streambed) to delineate flood events?  As previously discussed, Tate created a 
terrain model from surveyed flood plain data and a DEM.  Azagra-Camino developed 
a terrain model from accurate photogrammetry data, but did not compensate for water 
in the streambeds, making the streambed geometry inaccurate.  For this study, both 
methods were examined to optimize the terrain model.  Since the contour data was 
accurate to 2-ft for this study, using Tate?s method to integrate the entire flood plain 
of the study area?s hydraulic model into the terrain model was not the solution.  
Highly accurate contour data existed near the stream, like bridge embankments and 
54 
 
levees.  Using Tate?s method may compromise the contour data.  After numerous 
iterations and trials, the best option used for this study was to integrate only the 
streambed geometry, without the flood plain geometry, with the terrain model. 
5.1 Methodology of Terrain Model Development 
 Using the contour data provided by the Louisville District, the three 1-ft contour 
themes were merged in Arcview GIS to account for the entire PDC study area.  As 
previously discussed, the 1-ft merged contour theme was modified to a 2-ft contour 
theme by deleting every other contour line in the file.  The new contour theme was 
created and saved as pdc2ftcontrs.shp.   
 No data was available for a small section on the west side of the study area 
(which was outside the extent of the flood plain).  To compensate for this lack of data, 
point elevations were extracted from a 30-meter DEM.  The section?s missing data 
was clipped from the point elevations and saved as a point shape theme called 
pdctmpts.shp. 
5.1.1 Initial Terrain Model Development 
 Using an algorithm known as Delaunay Triangulation, Arcview GIS optimizes 
a 3-D representation of the terrain by creating triangles that are as close to equilateral 
as possible.  The result is a TIN-based terrain model.  It is a terrain representation 
using points in three-dimensional space, with topological faces in two dimensions 
(ESRI, 1999). 
55 
 
 
Figure 5-1. Example of a TIN-based terrain model.  The TIN represents a 
portion of Lake Austin in Austin, TX, developed by Kevin Donnelly at the 
Center for Research in Water Resources. 
 Using the 3D Analyst extension in Arcview GIS, the terrain elevation data was 
extracted from the pdctmpts.shp and pdc2ftcontrs.shp file to develop a TIN of the 
study area.  A bounding polygon, called theme1.shp, was used to define the study 
area?s boundaries, as shown in Figure 5-1.  The point elevations were defined as mass 
points and the contour lines were defined as soft breaklines during the setup.  Like 
mass points data, soft breaklines act as elevation input to the terrain model, but 
maintain continuous slope for the terrain?s surface.  The TIN was created using the 
Create TIN from Features command in Arcview GIS.  The initial TIN-based terrain 
model was saved as Crtin1.   
56 
 
 
Figure 5-2. Points, contours, and bounding polygon used for the PDC terrain 
model. 
5.1.2 Limitations of Digital Terrain Data used for Hydraulic Modeling 
 The digital terrain data did not contain an accurate geometric representation of 
the streambed for use in the unsteady flow models.  To verify this, the geometric data 
of the streambed was extracted from the terrain model and imported into HEC RAS 
(this extraction was accomplished using HEC GeoRAS, and is explained further in 
Chapter 7).  There were two problems with the digital terrain data that affected the 
overall hydraulics of the system.  First, the digital terrain data streambed elevations 
are on average 2.25 meters higher along the length of Mill Creek when compared to 
the surveyed cross-section data, as shown for River Station 43982 in Figure 5-3.  
Thus, the photogrammetry data is accounting for water in the stream.  The range of 
the elevation difference ranged from approximately 2.1 to 2.4 meters higher for the 
57 
 
extracted terrain data than the surveyed data along Mill Creek?s longitudinal profile.  
Figure 5-4 illustrates the difference in the two profiles.  This is a difference of 
approximately 259,000 m
3
 in water volume that the initial terrain model did not 
account for. 
River Station 43982
171
172
173
174
175
176
177
178
179
180
0 20406080
x (m)
z (m)
Surveyed Data
Terrain Model Data
 
Figure 5-3. A surveyed cross-section of Mill Creek compared to terrain 
model data. 
 
58 
 
Mill Creek Longitudinal Profile Comparison
168
169
170
171
172
173
174
175
176
0 2000 4000 6000
x (m)
z (m)
Terrain Model
Surveyed Data
 
Figure 5-4. Comparison of the Mill Creek streambed?s longitudinal profile 
developed from the terrain model and the HEC-2 surveyed data. 
 Secondly, the longitudinal axis of Mill Creek, as viewed in HEC RAS, depicted 
a terraced streambed, as shown in Figures 5-4 and 5-5.  The axis did not accurately 
represent the streambed of Mill Creek.  The natural effects from erosion and 
deposition create a much smoother transition from upstream to downstream.  The 
terraced effect also created supercritical and subcritical flow regimes along the 
stream, which was difficult to represent in an unsteady flow model based on the 
initial assumption of subcritical flow.  The terraced streambed was created from the 
interpolated TIN data.  Using contour line data as the input, the interpolation was not 
linear, but instead developed plateaus at each contour line.  This may have been the 
result from defining the contour lines as soft breaklines instead of hard breaklines.  
59 
 
 
Figure 5-5. Terraced streambed of Mill Creek created from the TIN data. 
5.1.3 Integration of Streambed Geometry and Terrain Data 
 To integrate the geometric attributes of the streambed with the digitial terrain 
data, a Floodmap utility developed by Tate (1999) was used.  Tate created the utility 
for the purpose of incorporating HEC RAS geometry data into a terrain model for 
floodplain delineation.  The utility produces a modified TIN-based terrain model by: 
1) Importing stream cross-sectional data from HEC RAS into Arcview GIS 
2) Geo-referencing the cross-sections to the corresponding location along the 
stream in the terrain model 
3) Converting the stream geometry to 3-D themes in Arcview GIS 
4) Adding the 3-D stream geometry to the existing digital terrain data 
The floodmap utility first removes the spatial bounds defined by the digital terrain 
data before adding the 3-D stream geometry.  Then the entire floodplain is 
incorporated into the terrain model.  For this study, surveyed data of the streambed 
only was incorporated into the terrain model by modifying Tate?s methodology. 
60 
 
 
Figure 5-6. Tate?s Method of incorporating flood plains into a terrain model 
(Tate, 1999). 
5.1.3.1 Importing Cross-sectional Surveyed Data into Arcview GIS 
  The floodmap utility was limited to defining the 3-D stream centerline and 
bank lines from the imported cross-section locations, as a straight line from cross-
section to cross-section, as shown in Figure 5-7.  If the number of cross-sections is 
limited and the cross-sections do not account for every bend in the stream, then the 
stream centerline location with respect to the terrain model will be inaccurate.  By 
increasing the number of cross-sections along the stream centerline, the straight line 
segments derived by the floodmap utility would get smaller and smaller, creating a 
more accurate depiction of curves in the stream for the model.  More cross-sections 
were required, especially along curved sections of the stream centerline.  To 
compensate for this, cross-sections between surveyed cross-section data were 
interpolated in the HEC RAS model before being imported into Arcview GIS.   
61 
 
 
Figure 5-7. Comparison of the stream (blue arrows) and a 3-D stream 
centerline and bank lines created by the Arcview GIS Floodmap utility. 
 The development of interpolated cross-sections between the surveyed cross-
sections in HEC RAS when defining the stream centerline and bank lines was an 
iterative process.  Imported data were compared to the actual stream centerline in 
Arcview GIS for accuracy.  If they did not match, then additional cross-sections were 
interpolated until the derived stream centerline overlapped the actual stream 
centerline.  Spacing between interpolated cross-sections was typically around 25 
meters in stream centerline length. 
62 
 
 
Figure 5-8. A revised depiction of cross-sections and bank lines as compared 
to the stream centerline (shown with blue arrows).  A significant 
improvement is apparent when compared to the non-interpolated cross-
sections shown in Figure 5-7. 
 Figure 5-8 shows the addition of the interpolated cross-sections to the surveyed 
cross-section data.  This method decreased straight line distances between cross-
sections using the floodmap utility, thus improving the depiction of curvature for the 
stream centerline.  A significant improvement is noticed when comparing the stream 
bed depiction to the stream centerline shown in Figure 5-8 to the previous depiction 
in Figure 5-7. 
63 
 
 
Figure 5-9. Cross-sections interpolated between existing cross-sections in 
HEC RAS. 
 Once the interpolated cross-sections were finally developed, the data was 
exported into Arcview GIS by using the Generate Report command in HEC RAS.  
Tate?s Floodmap utility creates a text file in dBASE format from the HEC RAS 
report.  The text file includes River Station identification numbers, water elevation 
(for steady-state profiles in HEC RAS), lateral and elevation coordinates of all cross-
section points (stored in a global variable, not in the table), the width of the left and 
right flood plains with respect to the stream centerline, the elevation of the left and 
right banks and stream centerline, and downstream reach lengths between cross-
sections.  Once the data was imported into Arcview GIS, the stream centerline was 
geo-referenced to the digital terrain data prior to incorporating the stream geometry 
into the terrain model. 
 
64 
 
5.1.3.2 Cross-section Geo-referencing 
 Locations along the stream network require accurate geo-referencing with the 
terrain data.  It is possible that the digital stream centerline may have minor 
differences in length compared to the HEC RAS stream centerline.  To compensate 
for these inconsistencies, the floodmap utility assigns upstream boundaries, 
downstream boundaries, and intermediate stream definition points along the stream.  
This is accomplished by assigning definition points at a cross-section located near a 
well-defined reference point in the terrain data, such as a bridge or culvert location.  
For this study, the corresponding road network, called rd3dclp.shp, was used to 
identify bridge locations along the stream network. 
 
Figure 5-10. Sharon Rd. used as an intermediate point for geo-referencing. 
 For this study there are four intermediate points identified at the intersection of 
the roads and the stream centerline.  The upstream boundary is defined as the 
Hamilton/Butler County line and the downstream boundary is defined as Glendale 
Road. 
 
65 
 
Table 5-1. Stream definition points for the study area. 
Type of Point Location RS Number 
Mill Creek 
Upstream Boundary County Line 200055 
Intermediate Point Highway I-275 195540 
Intermediate Point Kemper Road 194227 
Intermediate Point Sharon Road 188635 
Downstream Boundary Glendale Road 182205 
East Fork 
Upstream Boundary County Line 388 
Downstream Boundary  Confluence with Mill 
Creek 
0.0 
 
5.1.3.3 Converting Stream Geometry Data into 3-D Themes 
 The River Stations (RS) for the surveyed cross-sections that correspond with the 
stream definition points (as shown in Table 5-1) were labeled in the imported dBASE 
table.  The geo-referencing process, as well as the subsequent 3-D theme 
development, is accomplished separately for Mill Creek and East Fork.  The 
Floodmap utility creates a 3-D cross-section theme and a 3-D stream theme for the 
two streams in the study area using the Mapping HEC RAS Cross-sections command.  
The HEC RAS cross-section locations are geo-referenced to the terrain, defines the 
stream centerline and bank lines.  The 3-D cross-section themes were saved as 
3dxsectmc.shp and 3dxsectef.shp.  The 3-D stream themes, consisting of a stream 
centerline and channel banks, were saved as Stream3dmc1.shp and Stream3def1.shp. 
 The 3-D themes created in this process are polylineZ files.  PolylineZ files 
contain an elevation attribute to form a three-dimensional line, or arc.  A 3-D 
66 
 
depiction of the Mill Creek polylineZ files is shown in Figure 5-11.  The next step in 
the process was to integrate the polylineZ themes into the terrain model. 
 
Figure 5-11. PolylineZ themes of the stream channel and cross-sections. 
 
5.1.3.4 Incorporating Stream Geometry into the Terrain Model 
 Prior to integrating the stream geometry into the terrain model from the existing 
polylineZ themes, the terrain model was converted to a mass points theme, with each 
point representing a point elevation.  The purpose of the conversion was to create a 
depiction of the existing terrain model that can be edited in Arcview GIS.  This was 
first accomplished by converting the existing terrain model, Crtin1, to a Grid-based 
model.  By using the 3D Analysis extension, the TIN-based model was converted to a 
Grid-based model using the Convert to Grid command.  The grid mesh was defined 
by 5-meter by 5-meter grids.  The Grid-based terrain model was saved as Pdcgrid1.  
The Grid-based terrain model was converted to mass points using the Convert Grid to 
Points command in the Floodmap utility.  The mass points were saved as Gridpts.shp. 
67 
 
 In Tate?s method, a bounding polygon is developed from the 3-D cross-section 
themes, defining the extent of the flood plain.  For this study, this step was modified.  
Instead of highlighting the 3-D cross section themes to define the bounding polygon, 
the 3-D stream themes were highlighted.  This established the stream banks as the 
extent of the bounding polygon.  The 3-D cross-sectional data was also limited to the 
stream channel as well, by clipping the Mill Creek and East Fork cross-section 
themes, saving them as Mcclip.shp and Efclip.shp.  This process alleviated any 
overlap in the data, as shown in Figure 5-12, and then was used to develop a modified 
terrain model. 
 
Figure 5-12. Section of Mill Creek with mass points data and stream 
geometry. 
 Defining Gridpts.shp as mass points and channel geometry as hard breaklines, a 
modified terrain model was developed, using the Create TIN from Features command 
from the 3D Analyst extension.  The developed TIN-based terrain model was saved as 
Nwtin1.  Figure 5-13 shows the depiction of the modified terrain model, with the 
surveyed stream geometry. 
68 
 
 
Figure 5-13. TIN-based terrain model modified with surveyed stream 
geometry. 
 The modified TIN-based terrain model was used with the HEC GeoRAS 
interface.  Unlike the MIKE 11 model, stream geometry data were extracted from the 
terrain model for use in the HEC RAS unsteady flow model, as discussed in Chapter 
7. 
5.2 Application of the Terrain Model to the MIKE 11 GIS Interface 
 The MIKE 11 GIS extension uses a Grid-based terrain model instead of a TIN-
based terrain model.  The MIKE 11 GIS interface in Arcview GIS has the capability 
to edit the terrain model, but the modifications accomplished previously for this study 
remove the need for editing.  The Grid-based terrain model was developed from 
Arcview GIS by converting the TIN theme to a Grid-based theme.  The Grid mesh 
was defined as 5-meter by 5-meter cells.  The Grid-based terrain model was called 
69 
 
Pdcdem. 
 
Figure 5-14. The PDC Grid-based terrain model shown with hill shading 
effect. 
 A disadvantage of the Grid-based terrain model is poor resolution as compared 
to the TIN-based terrain model.  As shown in Figure 5-15, the water surface 
delineation with the terrain creates a rough edge since a grid mesh accomplished the 
delineation.  The Grid-based terrain model requires less computer memory as 
compared to a TIN-based terrain model.  The Pdcdem was 450 kilobytes in computer 
memory size, whereas the TIN-based Nwtin1 was 4.4 megabytes.   
70 
 
 
Figure 5-15. Rough edge created when delineating the water surface from the 
terrain using the MIKE 11 GIS grid-based delineation method. 
71 
 
Chapter 6: Application of the MIKE 11 Model 
 This chapter discusses the development of the MIKE 11 model as applied to the 
Mill Creek study area.  The three steps to developing the model were processing of 
the geometric data, inclusion of bed resistance factors, and the integration of flow 
data from the hydrologic model.  Upon completion of model development, simulation 
results were post-processed in MIKE 11 GIS.  The results provided 2-D and 3-D 
flood animations for the Mill Creek Watershed?s 25-year flood event. 
6.1 Geometric Processing 
 As discussed in Chapter 3, the MIKE 11 model consists of two geometric files ? 
the network file and the cross-section file.  This section explains how the processed 
data was incorporated into the MIKE 11 flow model. 
6.1.1 Stream Network Development 
 The stream network used for the MIKE 11 model was the network digitized and 
saved as stream1.shp in Arcview GIS.  The X- and Y-coordinates were added to the 
databases of the Millpdcreachpts.shp and Eastpdcreachpts.shp point themes (stream 
points defining stream1.shp).  The XY-coordinates in the databases were copied into 
the tabular view of the MIKE 11 network file editor.  Using the Define Branch tool in 
MIKE 11, the data points were connected to create the network file.  The network file 
was saved as pdc1model.nwk11. 
72 
 
 
Figure 6-1. MIKE 11 Stream network created with the Define Branch tool, 
from point to point.  The figure shows the location where East Fork flows 
into Mill Creek. 
6.1.2 Cross-section Data Development 
 Upon conversion of the HEC-2 geometry files into readable text files for the 
MIKE 11 interface, the surveyed cross-section data was imported into the MIKE 11 
cross-section file editor.  The cross-section file required manual editing of the 
Chainage values for each cross-section (which was defined as River Stations in HEC-
2), and streambed and stream bank locations for each cross-section.  The Chainage 
values were inputted for each cross-section using the conversion table in Appendix A.  
The stream bank and the streambed locations, as identified in the HEC-2 files, were 
defined in the cross-section editor using the MIKE 11 Mark tool.  The Mark tool 
defined a number 1, 2, or 3 along the cross-section in the MIKE 11 cross-section 
editor.  Mark 1 defined the left stream bank, Mark 2 defined the streambed (or 
centerline), and Mark 3 defined the right bank.  Figure 6-2 shows an example of the 
MIKE 11 cross-section file?s streambed and stream bank locations. 
73 
 
 
Figure 6-2. Cross-section #19166 in MIKE 11.  The Marks 1, 2, and 3 are 
identified on the cross-section?s graphical view as red ?X?s. 
 Interpolation of cross-sections at the Primary Damage Center model?s upstream 
and downstream boundaries was required.  The new bounding cross-sections were 
interpolated from corresponding upstream and downstream surveyed cross-sections 
from the HEC-2 files.  The interpolated cross-sections were located at Chainage 
#15407.15 (Mill Creek?s upstream boundary), #11427.12 (East Fork?s upstream 
boundary), and #20732.45 (Mill Creek?s downstream boundary).  Once all editing 
was completed, the MIKE cross-section file was saved as pdcXSec1.xns11. 
74 
 
 
Figure 6-3. The MIKE 11 Cross-section interpolation tool. The cross-section 
interpolation at the model?s boundaries was accomplished using cross-
sections outside the PDC terrain model?s boundaries from previous MIKE 11 
models. 
6.2 Bed Resistance Factors 
 Bed resistance is defined in two different files in the MIKE 11 model.  Bed 
resistance values are defined for a segment of the stream network, from an upstream 
cross-section location to a downstream cross-section location, using the MIKE 11 
hydrodynamic file editor.  Bed resistance factors are also defined in the MIKE 11 
cross-section file editor.  The overall resistance for the model is the product of the 
resistance factors in the cross-section file and the hydrodynamic file.  An example of 
the resistance factors defined in the two MIKE 11 files are shown in Figure 6-4.  The 
resistance factor in the MIKE 11 cross-section file for each cross-section was set to a 
default of 1.  The Manning?s n values were extracted from the HEC-2 geometry data 
and manually inputted as bed resistance and flood plain resistance values in the 
hydrodynamic file.  The Marks tool in the MIKE 11 cross-section file editor 
75 
 
delineates the stream channel from the flood plains, defining where the bed resistance 
values change along the cross-section.  Once the bed resistance factors were manually 
inputted into the MIKE 11 hydrodynamic file, the file was saved as HDPar1.hd11. 
 
Figure 6-4.  The overall resistance factors in the MIKE 11 model are the 
product of a) the Cross-section File resistance factors, and b) the 
Hydrodynamic File resistance factors. 
6.3 Boundary Conditions 
 The PDC MIKE 11 model contained two separate boundary condition sets.  The 
first boundary condition set established base flow conditions for the model.  The 
76 
 
second boundary condition set modeled the 25-yr storm event for the Mill Creek 
Watershed.  In essence, the first set was a steady-state solution of the unsteady 
algorithm, establishing mathematically stable initial conditions for the second 
boundary condition set.   
6.3.1 Simulating Base Flow Conditions 
 The first boundary file created a hotstart file (as explained in Chapter 4) for 
the flow model, establishing base flow conditions.  The first MIKE 11 boundary file 
was Bnd1.bnd11.  The time-series boundary conditions for Bnd1.bnd11 consisted of 
the upstream base flow conditions for Mill Creek and East Fork, and the downstream 
stage height conditions for Mill Creek.  The Mill Creek stage height was set to 169.3 
meters. 
 The base flow conditions were run for a 10-day period using a 10-minute time 
step.  The simulation was saved as pdc1hotstart.sim11, and was used as the initial 
conditions for the second set of boundary conditions. 
6.3.2 Incorporating Hydrologic Data as Boundary Conditions 
 The second set of boundary conditions simulated the runoff effects on the PDC 
study area for the 25-year storm event.  The upstream, downstream, and lateral 
boundary conditions were obtained from the HEC HMS hydrologic model of the Mill 
Creek Watershed.  The hydrologic data used is shown in Appendix E.  The time-
series data could not be exported directly from the HEC HMS model for use in the 
MIKE 11 model.  The upstream and lateral boundaries defined as runoff and flow 
hydrographs from the hydrologic model were converted to an Adobe Acrobat file as 
explained in Chapter 3.  From the Acrobat file, the data was copied into the MIKE 11 
time-series file editor.  The time step used in the HEC HMS model was 15-minutes, 
and the same time step was used for the runoff hydrograph inflows in the MIKE 11 
77 
 
model. 
 
Figure 6-5. A MIKE 11 time-series file extracted from the HEC HMS 
hydrologic model. The time step used is 15-minutes. 
 The Chainage location for each lateral inflow hydrograph was determined by 
importing the HEC HMS model schematic into the MIKE 11 river network file.  By 
overlapping the network file on top of the watershed schematic, the Chainage location 
of each watershed outlet was determined and established as a lateral boundary 
condition in the MIKE 11 boundary file. 
78 
 
 
Figure 6-6. The Mill Creek HEC HMS schematic imported as a background 
image into the MIKE 11 river network file.  The schematic was used to 
identify Chainage values at watershed outlets. 
 The downstream boundary condition, a time-series stage hydrograph, was not 
available.  Successive runs of the model at different steady-state flows were used to 
determine the downstream hydrograph.  The stage height values were interpolated for 
intermediate time steps.  Further modifications of the stage hydrograph were required 
to fit the stage height corresponding to the inflow, by viewing the longitudinal profile 
results in MIKE View. 
 Since the PDC study area was a smaller section of the initial study area, 
upstream and downstream boundary conditions were extracted from the results of 
previous models.  Previous model simulation results used a 4-minute time step, thus 
the time-series data was set to a 4-minute time step as well.  The difference in time 
steps for the upstream and downstream boundaries as compared to the lateral 
boundaries did not affect the MIKE 11 model results. 
79 
 
 
Figure 6-7. A MIKE 11 boundary file. The boundary file connects the 
upstream, downstream, and lateral inflow hydrographs to Chainage values 
along the network. 
 Setting the hotstart file as the initial condition and the time-series runoff and 
flow hydrographs from the HEC HMS model as boundary conditions, the MIKE 11 
model was run using a 4-minute time step over a 31-hour time range.  Results of the 
model were observed in MIKE View for any necessary editing.  Using the longitudinal 
profile in MIKE View for stage height and discharge, time-series changes transitioned 
smoothly between time steps.  Some random fluctuation in stream flow was observed 
at the East Fork tributary.  Additional cross-sections were interpolated there to 
provide less severe jumps in streambed elevations.  This alleviated some of the stage 
height fluctuation at that location. 
 
80 
 
 
Figure 6-8. A profile of Mill Creek in the PDC study area. The red dotted 
line denotes maximum stage height; the green dotted line denotes base flow. 
Initially, stage fluctuation occurred at the East Fork tributary (Chainage 
#16401). 
6.4 Post Processing in MIKE 11 GIS 
 Once the MIKE 11 model of the Mill Creek PDC was run simulating the 25-yr 
storm event (April 1998 storm), the data was imported into Arcview GIS for flood 
visualization purposes.  The MIKE 11 model accomplished this by linking the 
unsteady flow results with the terrain model through the Branch Route System, which 
is the MIKE 11 river network file.  The MIKE 11 river network file linked the MIKE 
11 simulation data (saved as pdc1.msd) to corresponding XY-coordinate locations on 
the terrain model. 
6.4.1 Geo-referencing the Stream Network to the Terrain Model 
 Since the MIKE 11 river network file was initially created from the terrain 
model, the network was already geo-referenced, making the link between the 
unsteady flow simulation and Arcview GIS effortless.  When opening the MIKE 11 
GIS Flood Management Tool, the interface automatically asked the user for the 
MIKE 11 river network file and the MIKE 11 simulation data results. 
81 
 
 
Figure 6-9. The MIKE 11 flow model inputs for MIKE 11 GIS: the river 
network file and the simulation data. 
6.4.2 Importing Q and h Data into MIKE 11 GIS 
 The Q- and h-points were imported into the Arcview GIS interface from the 
MIKE 11 network file data.  The Q-points are average flows at the midpoint of each 
finite segment within the model (half the distance between successive cross-sections).  
The h-points are stage heights at upstream and downstream finite segment boundaries 
(cross-section locations).  The simulation data (pdc1.msd) was spatially imported to 
each corresponding Q- or h-point along the stream network, using the Chainage 
values for geo-referencing.  The result was the creation of two point themes in 
Arcview GIS, Qpoints.txt and Hpoints.txt. 
82 
 
 
Figure 6-10. Q-points and h-points imported into MIKE 11 GIS. Q-points are 
located between two corresponding cross-sections; h-points are located at 
each cross-section. 
 The Hpoints.txt theme is the required MIKE 11 flow model data for flood 
delineation.  MIKE 11 GIS linked the pdc1.msd data to the corresponding record in 
the Hpoints.txt theme?s attribute table.  As shown in Figure 6-11, water surface 
elevations for cross-section at each time step from the MIKE 11 flow model were 
imported into the Hpoints.txt attribute table. 
83 
 
 
Figure 6-11. MIKE 11 flow model results were imported into the Hpoints.txt 
attribute table. Water surface elevations at each cross-section are represented 
for each time step. 
6.4.3 Generating Flood Maps and Animations from the Unsteady Flow Model 
 Using the Hpoints.txt data, flood maps were developed in MIKE 11 GIS for 
user-specified time steps.  A water level surface grid was interpolated using inverse 
distance-weighted interpolation of the nearest h-points.  The difference between the 
water level surface grid and the terrain model grid created flood maps.  Figure 6-12 
shows the water surface elevation at 10:00 am on April 16, 1998. 
84 
 
 
Figure 6-12. Flood map of the Mill Creek PDC developed from MIKE 11 
model data. 
 3-D animations and ?fly-bys? were also developed in MIKE 11 GIS.  Buildings 
were added to the animations for reference purposes.  An advantage to using MIKE 
11 GIS for flood visualization is the simplicity of low memory, grid-based models for 
processing.  The major disadvantage is that the 2-D and 3-D grid-based images depict 
a rough edge where the water surface is delineated from the terrain model. 
 
85 
 
 
Figure 6-13. Snapshot from a MIKE 11 ?Flyby? animation. Notice the rough 
edge where the water surface is delineated from the terrain. 
 
 
Figure 6-14. 3-D animation of the Mill Creek PDC with buildings. The 
image shows the peak stage height for the 25-yr storm event. 
86 
 
Chapter 7: Application of the HEC RAS Model 
 The four steps to flood visualization using the HEC RAS flow model and the 
HEC GeoRAS extension were 1) extraction of the stream geometry data from the 
modified terrain model for use in the HEC RAS unsteady flow model, 2) processing 
the geometry data in HEC RAS, 3) integration of hydrologic data as initial conditions 
and boundary conditions in the HEC RAS unsteady flow data file, and 4) post-
processing (i.e. flood visualization) of HEC RAS model results in Arcview GIS.  
Unlike the MIKE 11 model, the stream geometry was extracted from the terrain 
model and incorporated into the unsteady flow model, maintaining spatial referencing 
between the model and the Arcview GIS environment.  Flood delineation with the 
terrain model was limited by the bounding polygon created by HEC GeoRAS pre-
processing, which required several iterations of the stream geometry extraction to 
attain an optimum solution. 
7.1 Extracting Stream Geometry from the Terrain Model 
 Geometry data extracted from the modified terrain model is similar to having a 
?virtual? surveying team on the surface of the terrain model.  The modeler identifies 
what stream data is needed, and the HEC GeoRAS extension extracts the data from 
user-defined locations on the terrain model.  The data locations required are the 
stream?s centerline, stream banks, stream cross-sections, stream channel flow path, 
and flood plain flow paths. 
 To assist in the process, digital orthographic photo images or USGS quadrangle 
sheets can assist the modeler when defining the stream geometry with respect to the 
terrain model.  For this study, the TIN-based terrain model was used to differentiate 
stream banks from the rest of the terrain.  The stream centerline was already defined, 
using the stream1.shp theme.  An iterative process was used to define flood plain 
87 
 
flow paths and the extent of cross-sections.  Importing the geometry data into HEC 
RAS, running a simulation, and then viewing the results in Arcview GIS using the 
postRAS menu accomplished this process.  If the cross-sections limited the extent of 
the flooding, then the cross-sections were extended and the process was repeated.  
After six iterations, the optimum results were developed. 
7.1.1 Developing the Stream Centerline and Main Channel Banks 
 The stream centerline theme was copied from the previously developed 
stream1.shp theme.  The stream centerline theme was saved as Pdcstream.shp.  Using 
the River ID tool, each section of the stream centerline was defined with a Stream_ID 
and Reach_ID.  Based on the terrain data, lengths of each section in the stream 
centerline were calculated.  Results from using the River_ID tool are shown in Table 
7-1.  The Nodes shown in the table are defined accordingly: Node #1 ? upstream 
boundary of East Fork, Node #2 ? East Fork tributary connection with Mill Creek, 
Node #3 ? upstream boundary of Mill Creek, and Node #4 ? downstream boundary of 
Mill Creek. 
Table 7-1. River ID data for each reach in the PDC stream network. 
Stream_ID Reach_ID From Node To Node Length 
(ft) 
From RS# To RS# 
Eastfk Eastfk 1 2 1217.381 1217.381 0.0 
Millcrk MillcrkUS 3 2 1029.274 5190.737 4161.464 
Millcrk MillcrkDS 2 4 4161.464 4161.464 0.0 
 
 The main channel banks were digitized based on the terrain model.  Differences 
in slope found in the TIN mesh were identified and used to distinguish the extent of 
the stream banks.  Once the digitizing was complete for both the Mill Creek and East 
88 
 
Fork stream banks, the theme was saved as Pdcbanks.shp.  Any significant 
irregularities with defining the main channel banks were adjusted in HEC RAS by 
redefining the boundary between the flood plains and the stream channel. 
 
Figure 7-1. Stream centerline and main channel banks defined for East Fork 
on the TIN-based terrain model. Changes in the TIN mesh?s slope assisted 
with digitizing the main channel banks. 
7.1.2 Developing Cross-section Cut Lines and Flow Paths 
 The cross-section cut line locations in HEC GeoRAS were initially established 
as the cross-section locations defined in the HEC-2 files.  Through an iterative 
process, it was determined that the HEC- 2 cross-section locations limited the extent 
of the flood plain and required to be extended well beyond the initial surveyed cross-
section extents.  To also minimize overlapping of cross-sections, the cross-section cut 
lines were shifted to different locations along the stream network.  The cross-section 
cut lines theme was called Xscutlines.shp. 
89 
 
 
Figure 7-2. The HEC-2 cross-sections (blue) and the GeoRAS cross-section 
cut lines (green, with arrows) shown along the stream network in the terrain 
model. The cross-section cut lines were extended beyond the extent of the 
flood plain and shifted to prevent cross-section overlap. 
 Flow paths were defined for the stream centerline, and the left and right flood 
plains.  Flow paths were used in HEC RAS to determine downstream reach lengths.  
Using the Label flowpaths tool, the flow path for the stream centerline was identified 
as Channel, the left flood plain as Left, and the right flood plain as Right.  The flow 
path theme was called Pdcflowpath.shp. 
90 
 
 
Figure 7-3. Flow paths (shown in blue), channel banks, and cross-section cut 
lines defined with respect to the PDC terrain model. 
7.1.3 Generating the RAS GIS Import File from Terrain Data 
 HEC GeoRAS extracts 3-D features from the terrain model corresponding to the 
stream centerline, main channel banks, cross-section cut lines, and flow path themes.  
The digitized themes were selected for input into the HEC GeoRAS pre-processing.  
Each digitized theme was identified in the Theme setup menu.  As shown in Figure 7-
4, there was no Land use theme identified for this study.  The land use theme is an 
optional step in the GeoRAS pre-processing which allows the modeler to extract 
Manning?s n values based on a spatial land use corresponding to the terrain model.  
For this study, the Manning?s resistance factors were inputted into the HEC RAS 
geometry file manually. 
91 
 
 
Figure 7-4. Theme setup menu for GeoRAS pre-processing. 
 The intermediate data shown in Figure 7-4, the Stream Centerline (3D) and the 
XS Surface Line (3D), was created during the HEC GeoRAS pre-processing.  The 3-D 
themes created from the pre-processing were called Pdcstream3D1.shp and 
Xscutlines3D1.shp, respectively.  Once the pre-processing was completed, the RAS 
GIS Import file (defined as pdcinput.geo) was processed and imported into HEC 
RAS.  The import file developed was a text file containing the pertinent geometry 
data for use in the HEC RAS unsteady flow model. 
7.2 Geometric Processing 
 Once the geometry data from HEC GeoRAS was imported into the HEC RAS 
geometry data editor, two additional edits were required to further refine the 
geometry data.  Each cross-section?s bank station locations required verification and 
92 
 
bed resistance factors required input into the model. 
 Bank stations may have not been placed correctly in each cross-section from the 
digitized main channel banks using HEC GeoRAS.  In such cases, the bank stations 
were adjusted to best define the stream channel for each cross-section.  As shown in 
Figure 7-5, the right bank station was shifted up and to the right to the best location 
defining the natural stream channel in the cross-section. 
 
Figure 7-5. The right bank location shown was shifted up and to the right to 
depicting the most natural transition from flood plain to streambed. 
7.2.1 Import GIS Stream Geometry Data 
 The data extracted from the HEC GeoRAS pre-processing was imported into the 
HEC RAS geometry data editor.  Under the Import Geometry data command in the 
HEC RAS geometry data editor, the GIS Format option was chosen and the 
pdcinput1.geo file was highlighted.  The schematic of the imported geometry data is 
93 
 
shown in Figure 7-6.  Since the geometry data was extracted in unit of meters, the 
River Stationing was also in meters.  HEC GeoRAS automatically determined the 
River Stationing, thus there was no correlation with the previous HEC-2 River 
Stations. 
 
Figure 7-6. The HEC RAS geometry data schematic of the GIS imported 
data.  The numbers are the River Stations for each cross-section. 
7.2.2 Bed Resistance Factors 
 Bed resistance factors in HEC RAS are inputted for each cross-section in the 
geometry data editor.  Since the Manning resistance factors were not imported from 
the RAS GIS import file, the Manning?s n values were manually inputted for each 
cross-section, using the data included in the HEC-2 files.  The Manning?s n values 
stayed constant for the streambed and flood plains for each reach in the stream 
94 
 
network, thus no interpolation of resistance factors at any cross-section was required. 
7.3 Development of Unsteady Flow Initial Conditions and Boundary Conditions 
 Initial conditions and boundary conditions for the HEC RAS model were 
extracted from flow, stage, and/or hydrologic time-series data corresponding to the 
specific model area.  For the unsteady flow model, the time-series data is inputted 
into the Unsteady Flow Data editor.  The data inputted into the editor are Initial 
Conditions and Boundary Conditions. 
7.3.1 Establishing Initial Conditions as Base Flow 
 The initial flow conditions were inputted into the Unsteady Flow Data editor 
using the base flow conditions for Mill Creek and East Fork.  For continuity purposes, 
the initial flow for the Mill Creek reach downstream of the East Fork tributary was 
2.43 m
3
/s, the sum of the two upstream base flows (as shown in Figure 7-7). 
 
Figure 7-7. Initial flow conditions used for the HEC RAS model, in m
3
/s. 
7.3.2 Boundary Conditions Derived from the Hydrologic Data 
95 
 
 The boundary conditions were obtained from the HEC HMS model of the Mill 
Creek Watershed.  The HEC RAS model linked with the HEC HMS model results 
saved in a DSS file.  The HEC RAS model interface extracted pertinent time-series 
data from the specified DSS file. 
 The HEC HMS model interface automatically saved the results as a DSS file 
called MllCreek_CSO.dss.  Unlike the MIKE 11 model, where lateral inflows (at 
watershed outlets) can be entered at any location along the stream network, lateral 
inflows in the HEC RAS model can only be entered at a cross-section location.  Thus, 
the runoff hydrographs at the watershed outlets were connected to the nearest 
downstream cross-section along the stream network. 
7.3.2.1 Corresponding Stream Flow and Runoff Hydrographs 
 Since the MIKE 11 model size was decreased from previously developed flow 
models, the upstream and downstream flow and stage hydrographs were copied from 
the previous models into the current HEC RAS model.  All watershed hydrographs 
were extracted from the HEC HMS model via the DSS utility.  One watershed outlet 
along the HEC RAS model included the inflow from five watersheds, so the 
hydrologic data was imported from the DSS file as an Outflow hydrograph at Junction 
#23 in the HEC HMS model.  Table 7-2 shows the source of the hydrograph data 
used for the HEC RAS model, along with the watershed outlet referencing that 
corresponded with the MIKE 11 model. 
 
 
96 
 
Table 7-2. Hydrograph sources for the HEC RAS model 
Description River Station 
(m) 
Corresponding 
MIKE 11 Chainage 
(m) 
Data Source 
Mill Creek  
Upstream Boundary 5179.47 15407.15 MIKE 11 model 
Basin 109 runoff 4822.088 15829.00 DSS file 
Basin 115 runoff 525.691 20000.00 DSS file 
Basin 110 runoff 4043.303 16443.00 DSS file 
Basin 111 runoff 4577.873 15850.00 DSS file 
Basins 112 thru 117 runoff 
(Junction #23 outflow) 
336.56 20248.00 DSS file 
Downstream Boundary 18.83 20732.45 MIKE 11 model 
East Fork 
Upstream Boundary 1173.84 11427.12 MIKE 11 model 
 
7.3.2.2 Extracting Hydrographs using the DSS Utility 
 When defining a boundary condition hydrograph, the time-series data can either 
be entered directly into the editor, or read from a DSS file.  The DSS file data was 
imported into the HEC RAS model by defining the boundary condition as Lateral 
Inflow in the Unsteady Flow Data editor.  Highlighting the Read from DSS file 
option, the HEC HMS Mllcreek_CSO.dss file was opened.  From the DSS file, the 
hydrograph pertaining to the watershed outlet in the HEC RAS stream network was 
highlighted, making the connection between the HEC RAS model and the HEC HMS 
hydrograph data.  An example of the DSS connection is shown in Figure 7-8.  The 
figure depicts the connection with the Flow hydrograph for Basin #109, with a 15-
minute time step, for Run #16 of the HEC HMS model.  The DSS utility imported the 
97 
 
hydrograph into the HEC RAS model for River Station #4722.088.  From the DSS 
Path window, the hydrograph was graphically plotted to ensure the correct data was 
extracted from the HEC HMS model. 
 
Figure 7-8. The DSS Path window in HEC RAS. The window imports 
hydrograph data from a HEC HMS DSS file into the HEC RAS Unsteady 
Flow Data file. 
7.4 Unsteady Flow Simulations in HEC RAS 
 The simulation plan for the HEC RAS model was the same as for the MIKE 
11 model.  The plan is shown in Figure 7-9.  Using a 4-minute time step, the range of 
the simulation ran from 12:00 pm on April 15, 1998 to 7:00 pm on April 16, 1998 (31 
hour time duration).  The hydrograph output interval was set to 30-minutes to 
decrease the overall processing time. 
98 
 
 
Figure 7-9. The HEC RAS Unsteady Flow Analysis plan shown for the Mill 
Creek PDC model. 
 The simulation results were graphically displayed a number of ways in the HEC 
RAS user interface.  Simulations were displayed as longitudinal profiles, X-Y-Z 
perspective plots, and as cross-section profiles.  As previously discussed, the 
geometry extraction process was repeated numerous times until the optimum 
simulation results were obtained.  If the extent of the cross-sections limited the extent 
of flooding in the HEC RAS model, the process was repeated.  Fortunately, additional 
editing of the flow data was not required. 
99 
 
 
Figure 7-10. The X-Y-Z Perspective Plot in HEC RAS.  The water level 
shown is the maximum water surface elevation for the PDC area from the 25-
year storm event. 
7.5 Post Processing in HEC GeoRAS 
 Once the optimum simulation was obtained, the data from the simulation was 
ready for exporting into Arcview GIS for flood visualization.  This was accomplished 
through the HEC GeoRAS post-RAS menu.  Water surface elevation data created 
from the HEC RAS model was connected to each corresponding cross-section 
location for each time step.  Since the cross-section and stream channel was created 
from the HEC GeoRAS pre-processor, the unsteady flow data was already geo-
referenced to the modified terrain model. 
7.5.1 Read RAS GIS Export File 
100 
 
 Once the simulation was complete, the unsteady flow data was exported into 
Arcview GIS.  Time steps from the simulation data were selected for exporting.  The 
HEC GeoRAS Theme Setup command in the postRAS menu defined the GIS export 
file created from the HEC RAS model, the modified terrain model, the output 
directory, and the rasterization cell size used for post-processing.  As shown in Figure 
7-11, the cell size of 5 was selected, thus the grid-based water surface output had 5-m 
by 5-m grid cell sizes.  Once the RAS GIS export file was inputted into GeoRAS, 
delineation of the water surfaces with the terrain model was the next step. 
 
Figure 7-11. For HEC GeoRAS post-processing, the inputs for Arcview GIS 
were defined. 
7.5.2 Water Surface TIN Generation 
 To accomplish water surface delineation, the shape themes depicting each water 
surface required conversion to a TIN-based surface.  A TIN-based surface was 
created by interpolating elevations between cross-sections, based on the imported 
water surface elevations along each cross-section?s length.  The result was a 3-D, 
TIN-based surface depicting the water surface at the time step defined in HEC RAS. 
101 
 
 
Figure 7-12. The water surface TIN created from HEC RAS input 
overlapping the terrain model of the PDC study area. 
 The TIN-based water surface still required three-dimensional delineation with 
the terrain model surface to create flood visualization.  The view shown in Figure 7-
12 shows the overlapping of the two TIN-based surfaces.  Notice how the cross-
sections act as boundaries for the water surface.  The subsequent step develops the 
flood plain. 
7.5.3 Delineating Flood Plains from Unsteady Flow Model Results 
 Once the water surface was created, the flood plain was delineated from the 
terrain model in the next step.  In the two-dimensional plane, the delineation resulted 
in grid-based themes and shape themes depicting the water surface.  The grid-based 
theme showed the spatial difference in water depth with respect to the terrain model, 
as shown in Figure 7-13 of the maximum water surface. 
102 
 
 
Figure 7-13. Maximum water surface for the April 1998 flood delineated 
from the terrain model. 
 Using the delineated shape theme, editing can be accomplished in Arcview GIS 
to remove water pits or ponds, which can be seen in Figure 7-13.  Obviously such 
editing would not change the overall model, to do so would require either 
modifications to the cross-sections using the GeoRAS pre-processor, or the 
establishment of ineffective flow areas for specific cross-sections in the HEC RAS 
geometry data. 
 Delineation of the TIN-based water surface from the terrain model was also 
observed using the 3D Scene from the Arcview GIS 3D Analyst extension.  The 3D 
Scene showed the three-dimensional attributes of the Arcview GIS themes in a three 
dimensional plane.  Figure 7-14 displays the delineation of the water surface profile 
from the terrain model.  The entire water surface TIN actually exists in the 3-D view, 
where the water surface elevations less than the terrain elevation fall underneath the 
terrain surface and cannot be observed from a perspective above the terrain. 
 
103 
 
 
Figure 7-14. Three-dimensional representation of the TIN-based terrain 
model and water surface using 3D Analyst. 
 A significant difference when viewing the results of the HEC GeoRAS interface 
versus MIKE 11 GIS is along the lines of water surface delineation, which is clearly 
better defined in HEC GeoRAS.  As shown in Figure 7-15, there is a clearer 
distinction of where the water intersects the terrain, creating better graphical 
representations of flood delineation. 
104 
 
 
Figure 7-15. The view shows the distinction between water and terrain using 
TIN-based surfaces in HEC GeoRAS.  The maximum water surface elevation 
developed from the HEC RAS model of the PDC study area is shown. 
105 
 
Chapter 8: Results and Conclusions 
 This chapter discusses the overall results of the research and the conclusions 
leading from the application of the two unsteady flow models.  The analysis focuses 
on the applicability of the unsteady models and their connectivity with the spatial GIS 
environment. 
8.1 Model Results 
 The limited number of gage stations in the Mill Creek watershed (one existing 
station for the entire watershed) led to both flow models not being properly 
calibrated.  The accuracy of each model could not be validated.  Without the model 
validation, this study?s results can be analyzed qualitatively to assess the efficiency of 
flood modeling technologies. 
 The significance of flood visualization is the ability to portray a model?s results 
to community members, planners, and officials in a way that is understandable to 
everyone.  Unlike the steady flow models, the unsteady flow models can portray the 
effects of flood duration, which also have an important role in flood prevention 
planning.  The model results section of this chapter summarizes the results of the 
models used in the study, and compare the results to steady flow modeling. 
8.1.1 MIKE 11 Model Results 
 Importing water surface elevations derived from the MIKE 11 model into 
Arcview GIS was accomplished effortlessly since the stream network was accurately 
geo-referenced to the terrain model.  The flood delineation process was faster using 
MIKE 11 GIS than using the HEC GeoRAS extension.  The MIKE 11 GIS 
delineation process finds the difference between the water surface elevation and the 
ground elevation for each grid cell in the model.  The delineation is accomplished 
106 
 
using inverse distance-weighted interpolation from known water surface points 
(known as h-points) located at the center of each cross-section along the stream 
network, whereas the TIN-based delineation (used for the HEC RAS model) 
interpolates using 3-D water surface lines along the extent of each cross-section.  One 
would presume that the HEC GeoRAS interpolation method would achieve more 
accurate results, because the flood plain was delineated using two surfaces (the terrain 
model and water surface TIN coverages) instead of by interpolation based on one h-
point elevation value at each cross-section, as in the case for MIKE 11 GIS. 
 Surveyed data is the most accurate stream geometry data source.  Using 
surveyed cross-section data in the flow model removes the iterative stream geometry 
extraction process required for the HEC RAS model.  Unfortunately, the HEC-2 
surveyed data did not cover the entire flood plain.  An example is shown in Figure 8-
1.  The maximum water stage heights for the 25-yr storm event were well above the 
stream banks, and in some cases extended beyond the flood plains as well. 
 
Figure 8-1. The horizontal, red dotted line above the cross-section at 
Chainage 19.998 is the maximum water surface at that location for the MIKE 
11 model.  In this case, the model does not account for the total conveyance 
in the flood plains. 
107 
 
 Since the extent of the surveyed cross-sections was limited, the MIKE 11 
model?s flow characteristics did not account for the entire flood plain resistance or 
flood conveyance that actually occurs.  This resulted in higher maximum water 
surface elevations and shorter flood durations than for the HEC RAS model.  To 
improve the MIKE 11 model, the stream geometry data could be extracted from the 
terrain model, as was accomplished with the HEC RAS model.  Another option is to 
re-survey the cross-sections to expand the left and right flood plains for each cross-
section.  Obviously the second option would be a more costly alternative. 
 An issue with the MIKE 11 model is the use of grid-based coverages (terrain 
model and water surface) in MIKE 11 GIS.  An advantage to the grid-based method is 
it minimizes the use of computer memory and processing.  The limitation to grid-
based models, especially for smaller study areas, is the intersection of the terrain 
model and water surface coverages does not accurately represent flood delineation as 
well as using TIN-based coverages (this is discussed in Chapters 6 and 7).  Based on 
this study, the MIKE 11 GIS post-processing tool (known as the Flood Management 
tool) is not the optimum choice for a study area with the size of the Primary Damage 
Center, which has an area of approximately 13.5 km
2
 (5 km in length by 2.7 km in 
width).  The MIKE 11 GIS post-processing tool would provide better images of flood 
delineation for study areas larger than the Primary Damage Center, where resolution 
becomes less important as area increases. 
 An advantage of the MIKE 11 model is its graphical user interface.  Editing data 
is simple and easy to accomplish.  The interface provides graphical representations 
for the geometric data and the time-series boundary conditions.  Instead of creating a 
separate GIS export file for the MIKE 11 GIS post-processor, the interface 
automatically connects the GIS spatial data to the hydraulic model results.  This is 
accomplished by the interconnectivity of the river network file to the flow model and 
the terrain model.  As long as the XY-coordinates of the MIKE 11 river network file 
108 
 
correspond to the terrain model coordinates, the flow data is easily imported and 
delineated.   
 Once the flow model results are imported into MIKE 11 GIS, the user 
effortlessly develops 2-D and 3-D flood map animations directly from Arcview GIS.  
The process eliminates the need to obtain screen captured images and subsequently 
copy them into an external animation software tool to accomplish the task as required 
by HEC GeoRAS. 
8.1.2 HEC RAS Model Results 
 The HEC RAS model?s stream geometry data is extracted from the terrain using 
the HEC GeoRAS extension.  This difference in the two modeling methods is 
significant to flood visualization results.  Unlike the MIKE 11 model, the stream 
cross-sections were extended beyond the extent of overbank flows, ensuring the flood 
plain?s bed resistance covered the entire flow in the model.  Unlike the HEC RAS 
model, the overall flood plain conveyance is not accounted for in the MIKE 11 model 
results.  The HEC RAS model?s overall flooding extent was less than what was found 
in the MIKE 11 model.  Lower maximum water surface elevations and longer flood 
durations as compared to the MIKE 11 model were also observed. 
 A significant difference in flood visualization for the two models was also 
noticed.  The TIN-based delineation method creates a more realistic delineation of 
flood levels from the terrain model.  The TIN-based delineation works well for 
smaller study areas because of its high resolution, but can become cumbersome as the 
study area increases.  The initial TIN-based terrain model of the Primary Damage 
Center (Crtin1) developed from the 1-ft contour data was cumbersome to use, 
because its TIN mesh consisted of 6,028,127 triangles (240 MB of computer memory 
capacity).  Loading the Crtin1 file into an Arcview GIS view takes 3-5 minutes to 
accomplish.  Using 2-ft contours to develop the terrain model (Nwtin1) resulted in the 
109 
 
new model loading quicker (less than 10 seconds) than the initial terrain model 
because the TIN mesh consists of 134,470 triangles (4.39 MB of computer memory 
capacity) ? a significant decrease in computer memory and processing requirements.  
The water surface TIN developed in HEC GeoRAS was not an issue regarding 
computer memory and processing, since the TIN mesh contained around 500 triangles 
for each water surface developed.  Obviously the processing is dependent on the data 
sources used to develop the terrain model, computer speed and capacity, and what 
accuracy the modeler expects for his or her results. 
 A limitation to the HEC GeoRAS model is the requirement to pre-process, or 
extract, stream geometry data from the terrain model to develop flood visualization 
images.  There is no certainty that independent stream cross-sections can perfectly fit 
a terrain model accurately.  If some or all of the cross-sections can be accurately geo-
referenced to the terrain model, then the option to extract or not extract cross-sections 
from the terrain should be provided to the modeler.  For flood visualization, an 
accurate depiction of the stream channel is of greater importance for the hydraulic 
model than for the terrain model.  Most flood event models focus on the flow above 
the stream channel, so if the hydraulic model contains the best geometric data of the 
stream and flood plains, and the terrain model contains the best ground surface 
elevation beyond the stream channel, then the visualization tool should be valid.  But 
when using HEC GeoRAS, pre-processing is necessary because the stream geometry 
data used in HEC RAS can only be extracted from the terrain model for ultimately 
developing flood maps in the HEC GeoRAS post-processor.  The HEC GeoRAS 
interface should provide the pre-processing step as an option, not a requirement, to its 
users. 
 Some difficulties lie in importing GIS data from the terrain model into the HEC 
RAS geometry data editor.  When data is unavailable, the HEC GeoRAS iterative 
process can derive cross-sections for a stream network from a terrain model in an area 
110 
 
that has no cross-section data available.  Sometimes the data exported into HEC RAS 
does not always import accurately.  This occurs near junction locations (where 
tributaries connect with the main stream in the stream network).  For this study, cross-
section directions were occasionally reversed near junctions when imported from 
HEC GeoRAS preprocessor into the HEC RAS geometry data editor, not allowing the 
HEC RAS unsteady flow option to run properly.  An example is shown in Figure 8-2.  
When this problem arises, the direction of the cross-section cut lines in the HEC 
GeoRAS pre-processor can first be verified and flipped as necessary, using the Flip 
Polyline command.  If that is not the problem, then the cross-section?s direction can 
be reversed in the geometry data editor in the HEC RAS interface, using the Move 
Object command. 
 
Figure 8-2. An example of a reversed cross-section shown in an XYZ plot in 
HEC RAS. Importing GIS data from HEC GeoRAS will occasionally reverse 
cross-section orders near junctions. 
 
111 
 
 An advantage to using the HEC GeoRAS post-processing for flood delineation 
is the development of high resolution images for small areas (like the PDC study 
area).  The TIN-based delineation method creates clearer flood map images as 
compared to the MIKE 11 grid-based delineation method.  A disadvantage to the 
TIN-based method is the increase in computer processing time and computer memory 
requirements. 
 Flood delineation in the HEC GeoRAS post-processor is simple, but animation 
processing is tedious.  When reading a GIS export file created from the HEC RAS 
model results, the HEC GeoRAS post-processor truncates the name of the data file for 
each time step.  When this occurs, the water surfaces created for the different time 
steps cannot be differentiated by the computer, as shown in Figure 8-3.  To resolve 
this problem, water surface profiles for individual time steps were imported as 
separate GIS export files into HEC GeoRAS.  This procedure required numerous GIS 
export file development iterations from the HEC RAS interface.  Once accomplished, 
each time step was copied with a screen captured image and pasted into an animation 
software tool to develop an animated GIF of the flood event. 
112 
 
 
Figure 8-3. The Arcview GIS view shows the polygon themes (called 
?Bpw16apr199.shp?) in the legend imported from the HEC RAS flow model 
for different time steps.  Each polygon theme was imported with the same 
name, thus Arcview GIS could not differentiate between the different time 
steps. 
8.1.3 Comparison of the Unsteady Flow Model Results 
 As previously discussed, a significant difference occurred with maximum flood 
stage, time of peak stage, and flood duration for the two flow models.  The time of the 
peak stage differed by 3 hours, occurring at 08:32 am for the MIKE 11 model and 
11:00 am for the HEC RAS model.  The HEC RAS model?s flow attenuated more 
rapidly, with a lower maximum stage height and a longer flood duration.  The MIKE 
11 model did not attenuate as quickly, resulting in a higher maximum stage height 
and shorter flood duration. 
113 
 
 
 (a)  (b) 
Figure 8-4. A visual comparison is shown of the maximum stage heights for 
(a) the MIKE 11 model and (b) the HEC RAS model. 
 Extracting the stream geometry data from the terrain model for the HEC RAS 
model initially did not seem important, since overbank flow is usually the focus for 
flood analysis.  But the survey cross-section data did not accommodate the extent of 
inundation in the flood plains.  An example of the difference in the HEC RAS and 
MIKE 11 model cross-sections are shown in Figure 8-4.  Adding the flood plain 
extents to the HEC RAS model affected the model results in three ways: 1) maximum 
stage was reduced, 2) flood duration increased, and 3) the time of peak stage was 
delayed.  The factor causing the changes to the two models is the inclusion of the 
flood plain conveyance to the overall flow.  Since the flood plains are limited in the 
MIKE 11 model, the results are a higher maximum stage, a more rapid time of peak, 
114 
 
and a shorter flood duration. 
Comparison of HEC RAS and MIKE 11 Cross-sections
170
172
174
176
178
180
182
0 500 1000 1500
x (m)
z (m)
RS 3443.06
Chainage 17276
MIKE 11 WSE
HEC RAS WSE
 
Figure 8-5. The MIKE 11 (in dark blue) and HEC RAS (in red) cross-
sections shown are approximately 12 meters from each other along the 
stream network. The total flood plain conveyance is accounted for in the 
HEC RAS model, significantly slowing down flow as compared to the MIKE 
11 model results. The figure also depicts the maximum water surface 
elevations for the MIKE 11 (dashed line) and HEC RAS (dotted line) 
models, which are affected by the flood plain conveyance included or not 
included in the model(s). 
8.1.4 Comparison to Steady Flow Modeling 
 An additional analysis of the study area was conducted using the HEC RAS 
steady-state model to compare steady flow modeling to unsteady flow modeling.  
When using a steady flow model, most modelers consider the peak runoff flows at the 
boundary conditions for a specified storm event, resulting in water stage height being 
significantly higher than one for the unsteady flow model.  This occurs because the 
steady flow model does not account for the timing differences in the runoff 
hydrograph rainfall responses into the system, the differences being depicted in Table 
8-1.  Figure 8-6 is provided to understand the relation of the contributing runoff from 
115 
 
the watersheds.  Using the peak runoff flows for storm events in a steady flow model 
will result in over design. 
 
 
Figure 8-6. Schematic of the watersheds contributing runoff to the Primary 
Damage Center.  The extent of the hydraulically modeled stream system is 
bolded in blue.  Any upstream watersheds contributing flow into this portion 
of the streams is accounted for in the upstream boundaries. 
 
 
 
116 
 
Table 8-1. Time of peaks for the PDC study area boundary conditions. 
Boundary Condition Peak Value Time of Peak 
Mill Creek  
Upstream flow boundary 97.069 m
3
/s 08:56 am 
Basin 109 runoff 32.505 m
3
/s 08:00 am
Basin 110 runoff 6.236 m
3
/s 07:45 am 
Basin 111 runoff 26.565 m
3
/s 07:45 am
Basin 115 runoff 43.274 m
3
/s 08:15 am 
Basins 112-117 runoff 34.615 m
3
/s 06:45 am
Downstream stage boundary 174.24 m 08:32 am 
East Fork  
Upstream flow boundary 53.347 m
3
/s 07:45 am 
HEC RAS Unsteady Flow Model 11:00 am 
MIKE 11 Unsteady Flow Model 08:32 am 
  
 A comparison of the maximum stage height of the steady and unsteady HEC 
RAS flow models is shown in Figure 8-7.  Based on this comparison, the unsteady 
flow model provides two significant points to consider for future design and 
modeling.  For most cases, the unsteady flow model will provide a maximum water 
stage height less than the stage height found from the steady flow model since most 
steady flow models consider the peak discharges as occurring simultaneously 
everywhere, which may not peak at the same time.  Secondly, the unsteady flow 
model also considers flood duration as a factor in flood analysis.  Real property can 
significantly be affected by the difference in time of inundation. 
117 
 
 
Figure 8-7. Comparison of maximum water surfaces for the HEC RAS 
unsteady flow model (on the left) and the steady model (on the right) for the 
25-yr storm event.  Because of timing differences in peak flows, the steady 
flow results show a greater portion of inundation for the PDC study area. 
8.2 Conclusions 
 Using unsteady flow models to develop flood visualizations is complicated and 
lengthy, depending on the size of the study area.  Many factors can affect the results, 
especially if the data sources are inaccurate or incomplete.  The amount of stream 
geometry data can become very substantial as the size of the stream network 
increases.  It is best to choose a modeling method that best accommodates the 
processing of the geometry data. 
 Many factors become problematic in the model developing process for unsteady 
flow models that are not an issue for steady flow models.  The best approach is to 
initially gain an understanding of how the unsteady flow algorithm(s) work, and 
obtain some experience working with existing unsteady flow models.  For this study, 
development of the MIKE 11 model was the initial focus.  After approximately six 
months of HEC-2 and HEC HMS data conversions, understanding the nuances of 
unsteady flow, and resolving errors with the flow simulation, a MIKE 11 hydraulic 
model was developed for approximately 17.3 kilometers of Mill Creek, with two 
118 
 
branching streams.  The HEC RAS model was easier to develop, since the unsteady 
flow learning curve was minimized during the MIKE 11 model development, and the 
HEC-2 and HEC HMS data was easier to incorporate into the HEC RAS model.  A 
model similar to the MIKE 11 model using the HEC RAS interface was developed 
within two weeks.  Once the terrain model was created, the process of developing 
flood maps with the MIKE 11 GIS and HEC GeoRAS extensions was simple. 
 
  (a) (b) 
Figure 8-8. Schematics of the initial hydraulic models developed in (a) 
MIKE 11 and (b) HEC RAS.  The initial models covered over 17.3 
kilometers of Mill Creek as well as two additional branching streams. 
 
 The unsteady flow algorithms are not as mathematically stable as steady flow 
models.  When a water stage height is calculated at a value less than the streambed 
elevation, the flow simulation crashes.  This calculation may be mathematically 
accurate.  Natural systems do not always follow the rules of mathematics.  In such 
119 
 
cases, additional cross-sections may be added to the model, which decreases the 
incremental step in the stage difference from element to element in the system.  
Another option is to decrease the model?s simulation time step, as was the case for 
this study.  10 and 30-minute time steps were initially used for both the MIKE 11 and 
HEC RAS models, leading to both models crashing.  A 4-minute time step was the 
optimum time increment used for both models. 
 The unsteady flow model has the powerful capability to model the 
characteristics of watershed runoff responses from a storm event over time.  This 
makes flood animations more accurate than for those created from steady flow 
models.  To minimize data processing, it is recommended to use an unsteady flow 
model that can import results from a linked hydrologic model.  The process of 
importing the runoff hydrographs from the HEC HMS model into the HEC RAS 
model was simple because of the DSS utility.  Exporting the HEC HMS model results 
into the MIKE 11 interface was not easy to accomplish.  The Danish Hydraulic 
Institute has created a hydrologic model, called NAM, which the MIKE 11 model can 
be linked to. 
 The final point to consider in unsteady flow model applications in Arcview GIS 
is the depiction of the flood delineated from the terrain model.  A lot of research has 
been conducted on how to integrate separate data sources into one modified terrain 
model to show accurate flood maps and visualizations.  Since flood visualization 
looks at flow over the stream bank, the concern should not be for the stream channel, 
but for what occurs in the flood plains.  If the terrain data is accurate (as was the case 
for this study), then inclusion of surveyed stream geometry into the terrain model may 
not be necessary.  As found within this study, the surveyed stream geometry data 
could not accommodate the flow derived from the 25-yr storm event, thus the terrain 
model was necessary for developing the stream geometry data, as in the case of the 
HEC RAS model.   
120 
 
8.2.1 Unsteady Flow Model Advantages and Limitations 
 When applying the two methodologies of unsteady flow to the same study area, 
it was difficult to determine which model was more advantageous to use.  Both 
methods use unsteady flow algorithms that are valid and widely accepted techniques 
used in the United States and abroad.  This section summarizes the quality-based 
findings when using both modeling methodologies; most points being previously 
addressed in this report.  The purpose of compiling the key points from this research 
is to provide future unsteady flow modeling a better approach to save on time and 
resources. 
The MIKE 11 Model 
Advantages  
? The interface is easy to use.  Editing is simple and easy to accomplish. 
? The conversion of flood map to 2-D and 3-D animations in Arcview GIS 
requires no additional animation software.   
Limitations 
? The software package is expensive, currently running approximately 6,000 
U.S. dollars. 
? The software is currently limited to using metric units.  Chainage values can 
only be inputted in units of meters. 
? The Grid-based surfaces used by MIKE 11 GIS depict a jagged flood plain 
boundary where the water stage is delineated from the terrain.  Graphical 
images of smaller study areas, that require a higher resolution image, are 
affected more than larger study areas. 
? The stream network referencing method for the MIKE 11 model starts from 
the most upstream location and increases as you move downstream 
(Chainage values).  Not all upstream stream sources can easily be defined to 
begin at a specific location. 
121 
 
? Since the MIKE 11 model is not yet widely used in the United States, 
current U.S. hydraulic model data are not easily imported into the interface. 
The HEC RAS Model 
Advantages  
? The HEC RAS software is available to anyone over the internet. 
? The River Station stream network referencing method accommodates both 
U.S. customary units and metric units.  The referencing method starts from 
the most downstream location of the stream and increases as you move 
upstream, unlike the MIKE 11 model.  This method is easier to define since 
the most downstream location of a stream is easy to spatially define. 
? The HEC RAS model accommodates either U.S. customary units or metric 
units for all values defined in the model. 
? Existing HEC-2, HEC RAS, and UNET flow model data are easily imported 
into the HEC RAS interface. 
? The TIN-based surfaces used in the HEC GeoRAS post-processor depict 
more accurate looking flood delineations, regardless of study area size. 
Limitations 
? The development of flood animations from HEC GeoRAS requires 
additional animation software.  The process of obtaining screen captures and 
including the images into an animation software interface is tedious and 
time consuming. 
? Modelers are forced to use the stream geometry data extraction pre-
processing in HEC GeoRAS to ultimately use the post-processing 
visualization tools.  Even when surveyed data is accurate and geo-referenced 
by the stream network, the geometry extraction from the terrain model is 
still required. 
 
 
 
122 
 
8.2.2 Future Work 
 As for most flow visualization techniques, additional modifications to the 
existing model can still be improved upon for future studies.  Adding the man-made 
structures within the study area into the terrain model would affect the overall results 
of the unsteady flow models.  Azagra (1999) developed a method to include the 
buildings into a TIN-based terrain model.  If using the HEC GeoRAS pre-processor, 
buildings and structures can be incorporated into the flow model?s geometric data. 
 Another improvement to the current model is the inclusion of bridges and other 
hydraulic structures into the flow model.  The PDC study area has eight bridges 
(roadway and railway bridges) that have not been added to the flow model.  The 
integration of the bridges into the model would be simpler for HEC RAS since the 
bridge data can be obtained from HEC-2 files.  Based on the modeled characteristics 
of the study area?s flood plains, adding bridges into the model would amplify flood 
inundation through backwater effects from piers and abutments.  The bridges would 
require extensive analysis to determine an optimum modeling method for high (flow 
over the bridge?s roadway) or low (flow under the bridge?s roadway) bridge flows 
(Bonner, 2000).   
123 
 
Appendix A: MIKE 11 Chainage - HEC-2 River Station Conversions 
 The cross-section data for this study was initially available as a HEC-2 
geometry file.  The file was imported into HEC RAS, and converted into a text file 
readable by the MIKE 11 software.  Unfortunately, the river network referencing for 
HEC RAS and MIKE 11 required two conversions: 
1) Movement of the initial point of reference from the most downstream location 
(HEC RAS) to the most upstream location (MIKE 11) 
2) The conversion of units of feet (HEC-2 files) to units of meters (MIKE 11) 
This was accomplished by developing a spreadsheet for the conversion of the initial 
HEC-2 River Stations to MIKE 11 Chainages.  The Chainage values in the MIKE 11 
model were inputted manually from the spreadsheet results.  MIKE 11 Chainages 
values were initially based on a stream network for the entire extent of Mill Creek. 
Table A-1. HEC-2 River Station conversion to MIKE 11 Chainages 
HEC-2 River 
Stations 
(ft) 
Downstream 
Length 
(ft) 
Downstream 
Length 
(m) 
MIKE 11 
Chainages 
(m) 
Mill Creek 
200332 292 89.00 15779 
200040 1220 371.86 15496 
198820 1130 344.42 15868 
197690 960 292.61 16213 
Interpolated Cross-section at the confluence of East Fork into Mill Creek 16401.453 
196730 730.00 222.50 16505 
196000 170.00 51.82 16728 
195830 60.00 18.29 16780 
124 
 
HEC-2 River 
Stations 
(ft) 
Downstream 
Length 
(ft) 
Downstream 
Length 
(m) 
MIKE 11 
Chainages 
(m) 
195770 150.00 45.72 16798 
195620 10.00 3.05 16844 
195610 210.00 64.01 16847 
195400 170.00 51.82 16911 
195230 365.00 111.25 16962 
194865 550.00 167.64 17074 
194315 275.00 83.82 17241 
194040 620.00 188.98 17325 
193420 2320.00 707.14 17514 
191100 200.00 60.96 18221 
190900 1285.00 391.67 18282 
189615 865.00 263.65 18674 
188750 340.00 103.63 18938 
188410 410.00 124.97 19041 
188000 500.00 152.40 19166 
187500 350.00 106.68 19319 
187150 1290.00 393.19 19425 
185860 590.00 179.83 19818 
185270 230.00 70.10 19998 
185040 500.00 152.40 20068 
184540 610.00 185.93 20221 
183930 220.00 67.06 20407 
183710 15.00 4.57 20474 
125 
 
HEC-2 River 
Stations 
(ft) 
Downstream 
Length 
(ft) 
Downstream 
Length 
(m) 
MIKE 11 
Chainages 
(m) 
183695 95.00 28.96 20478 
183600 20.00 6.10 20507 
183580 320.00 97.54 20513 
183260 925.00 281.94 20611 
182335 0.00 0.00 20732.45 
East Fork 
1246.63 169.16 51.56 11296 
1077.47 190.50 58.06 11465 
886.97 185.93 56.67 11656 
701.04 390.14 118.91 11842 
310.90 310.90 94.76 12232 
0.00 25.00 7.62 12543 
-25.00 0.00 0.00 12550 
 
126 
 
Appendix B: Visual Fortran Program used for Cross-section Data 
Conversion 
Prepared by 
Stefan Szylkarski 
Danish Hydraulic Institute 
11 October 1999 
Content-Type: application/octet-stream; 
 name="HEC2M11.for" 
Content-Transfer-Encoding: 7bit 
Content-Disposition: attachment; 
 filename="HEC2M11.for" 
 
 PROGRAM hec2m11 
 
C ********************************************** 
C Program reads HEC-RASv2.1 GO1 files and extracts cross 
C  section information and write to MIKE11 inport text file. 
C  IMPORTANT:-  Please check all cross sections converted. 
C Errors may occur as the program has not 
C been fully tested. 
C  
C Stefan Szylkarski - Danish Hydraulic Institute 
C       - sps@dhi.dk  
127 
 
C         - 11 October 1999 
C       ********************************************** 
 
 CHARACTER*8  chain 
 CHARACTER*50 fin,fut 
 CHARACTER*80 line 
 
 REAL*4       xz(20,10) 
 INTEGER*2    npts 
 
c** Open Files 
 
 WRITE(*,'('' HECRAS G01 File name? : ''\)') 
 READ(*,'(A)') fin 
 
 WRITE(*,'('' M11 Output file name? : ''\)') 
 READ(*,'(A)') fut 
 WRITE(*,'(/)') 
 
 OPEN (UNIT=10, FILE=fin) 
 OPEN (UNIT=20, FILE=fut) 
 
c********Search for Chainage Lines 
128 
 
 
10 CONTINUE 
 
 READ (10,'(A80)',END=9000) line 
 
 IF ( line(1:7) .EQ. 'Type RM' ) THEN 
11 chain = line(28:35) 
12 READ (10,'(A80)',END=9000) line 
 
c********Search for Station Elevation lists associated with chainage        
 
 IF (line(1:9) .EQ. '#Sta/Elev' ) THEN 
 READ(line(12:14),'(I3)') npts   
 ELSEIF( line(1:7) .EQ. 'Type RM' ) THEN 
 GOTO 11 
 ELSE 
 GOTO 12     
 ENDIF 
 ELSE 
 GOTO 10 
 ENDIF 
 
c********Read up the cross section X,Z pairs 
129 
 
 
 nrows = ANINT((REAL(npts) / 5.0 ) + 0.5) 
 
 DO I = 1, nrows 
 IF ( I.EQ.nrows) THEN 
 nvals = (npts - (nrows-1)*5)*2 
 
 ELSE 
 nvals = 10 
 
 ENDIF 
 READ(10,*) (xz(i,j),j=1,nvals) 
 ENDDO 
 
c** WRITE out Cross Section in Mike11 format 
 
 WRITE(20,'(''HECRAS'')') 
 WRITE(20,'(''RIVER1'')') 
 WRITE(20,'(14X,A8)') chain 
 WRITE(20,'(''COORDINATES'')') 
 WRITE(20,'(4X,''0'')') 
 WRITE(20,'(''FLOW DIRECTION'')') 
 WRITE(20,'(4X,''0'')') 
130 
 
 WRITE(20,'(''DATUM'')') 
 WRITE(20,'(6X,''0.000'')') 
 WRITE(20,'(''RADIUS TYPE'')') 
 WRITE(20,'(4X,''0'')') 
 WRITE(20,'(''DIVIDE X-Section'')') 
 WRITE(20,'(''0'')') 
 WRITE(20,'(''PROFILE'',9X,i3)') npts 
 n = 0 
 DO K = 1,nrows 
 DO L = 1,5 
 n = n+1 
 IF (n .LE. npts ) THEN 
 WRITE(20,30) xz(k, (l*2)-1 ),xz(k,l*2) 
30 FORMAT(3X,F7.2,4X,F6.2,6X,'1.00') 
 ENDIF 
 ENDDO 
 ENDDO 
 WRITE(20,*)'******************************' 
 
 GOTO 10 
9000 CONTINUE 
 STOP 
 END 
131 
 
Appendix C: MIKE 11 Cross-section File 
 The MIKE 11 cross-section file data is read as input in column form.  Each 
cross-section is identified with a TOPO identification number, branch identification, 
and Chainage number.  The TOPO identification differentiates different cross-section 
to be processed during the simulation.  A default TOPO identification number of 100 
was used for the entire river network.  Interpolated cross-sections are identified with a 
?1? value.  In the profile data, the first two columns are the X and Z coordinates for 
the cross-section.  The third column is the local resistance factor for each cross-
section, and is multiplied by the global resistance factors in the hydrodynamic file 
(the default being 1).  The fourth column identifies the differentiates the stream 
channel from the flood plains.  The number 1 identifies the left bank, 2 identifies the 
stream bed, and 3 identifies the right bank.   
 
100 
East Fork 
           11427.124 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    1 
ANGLE 
    0.00 
PROFILE        37 
      4.51    182.06      1.00     <#0>      
      7.44    181.57      1.00     <#0>      
      8.69    181.09      1.00     <#0>     
     10.43    180.61      1.00     <#0>     
     16.55    179.64      1.00     <#0>     
132 
 
     19.72    179.15      1.00     <#0>      
     23.31    178.66      1.00     <#0>      
     29.05    178.16      1.00     <#0>      
     35.13    177.95      1.00     <#0>      
     44.72    177.61      1.00     <#0>      
     57.69    177.53      1.00     <#0>      
     58.50    177.51      1.00     <#1>      
     58.50    177.48      1.00     <#0>      
     59.49    176.86      1.00     <#0>      
     62.01    175.00      1.00     <#2>      
     66.68    175.00      1.00     <#0>      
     67.23    175.11      1.00     <#0>      
     67.34    175.13      1.00     <#0>      
     69.46    176.23      1.00     <#0>      
     69.97    176.43      1.00     <#0>      
     71.67    176.99      1.00     <#0>      
     73.14    177.55      1.00     <#3>      
     73.42    178.27      1.00     <#0>      
     76.31    178.68      1.00     <#0>      
     80.64    178.21      1.00     <#0>      
     86.90    177.74      1.00     <#0>      
    119.09    177.89      1.00     <#0>      
    124.11    177.30      1.00     <#0>      
    151.12    177.16      1.00     <#0>                
    163.65    177.35      1.00     <#0>                
    163.92    177.49      1.00     <#0>                
    165.04    178.11      1.00     <#0>                
    185.61    177.84      1.00     <#0>                
    199.02    177.97      1.00     <#0>                
    202.54    178.07      1.00     <#0>                
    223.68    178.54      1.00     <#0>                
    240.79    178.54      1.00     <#0>                
******************************* 
100 
East Fork 
           11465.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
133 
 
PROFILE        24 
      0.00    182.88      1.00     <#0>                
      3.14    182.27      1.00     <#0>                
      4.48    181.66      1.00     <#0>                
      6.34    181.05      1.00     <#0>                
     12.89    179.83      1.00     <#0>                
     16.28    179.22      1.00     <#0>                
     20.12    178.61      1.00     <#0>                
     26.27    178.00      1.00     <#0>                
     43.04    177.39      1.00     <#0>                
     57.79    177.39      1.00     <#1>                
     57.79    177.36      1.00     <#0>                
     58.64    176.78      1.00     <#0>                
     60.81    174.96      1.00     <#2>                
     65.87    174.96      1.00     <#0>                
     68.37    176.17      1.00     <#0>                
     69.98    176.78      1.00     <#0>                
     71.38    177.42      1.00     <#3>                
     74.46    178.00      1.00     <#0>                
     78.67    177.39      1.00     <#0>                
     84.76    176.78      1.00     <#0>                
    180.78    177.39      1.00     <#0>                
    197.24    178.00      1.00     <#0>                
    217.81    178.61      1.00     <#0>                
    234.45    178.61      1.00     <#0>                
******************************* 
100 
East Fork 
           11656.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        22 
      0.00    179.83      1.00     <#0>                
      0.18    179.22      1.00     <#0>                
     24.87    178.61      1.00     <#0>                
     27.95    178.00      1.00     <#0>                
     29.08    177.39      1.00     <#1>                
     30.45    176.78      1.00     <#0>                
134 
 
     31.30    176.17      1.00     <#0>                
     32.77    175.57      1.00     <#0>                
     37.92    174.44      1.00     <#2>                
     39.53    175.57      1.00     <#0>                
     41.15    176.17      1.00     <#0>                
     42.00    176.78      1.00     <#0>                
     44.32    178.00      1.00     <#3>                
     44.50    178.03      1.00     <#0>                
     47.27    178.61      1.00     <#0>                
     51.66    178.61      1.00     <#0>                
     55.02    177.39      1.00     <#0>                
     65.01    176.78      1.00     <#0>                
    132.47    176.78      1.00     <#0>                
    218.05    176.78      1.00     <#0>                
    249.75    178.00      1.00     <#0>                
    263.29    178.00      1.00     <#0>                
******************************* 
100 
East Fork 
           11842.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        16 
      0.00    179.83      1.00     <#0>                
      0.12    178.61      1.00     <#0>                
      0.49    178.00      1.00     <#0>                
     12.13    177.39      1.00     <#0>                
     25.48    176.69      1.00     <#1>                
     26.55    176.17      1.00     <#0>                
     27.77    175.57      1.00     <#0>                
     29.84    174.96      1.00     <#0>                
     33.74    174.35      1.00     <#2>                
     35.69    174.96      1.00     <#0>                
     37.31    175.57      1.00     <#0>                
     38.04    176.17      1.00     <#3>                
     41.45    176.88      1.00     <#0>                
     42.37    177.39      1.00     <#0>                
     51.18    177.39      1.00     <#0>                
135 
 
     53.43    176.78      1.00     <#0>                
******************************* 
100 
East Fork 
           12232.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        10 
      0.00    177.55      1.00     <#0>                
     54.86    177.55      1.00     <#0>                
     59.44    178.77      1.00     <#0>                
     61.57    178.77      1.00     <#0>                
     70.10    175.12      1.00     <#1>                
     71.63    173.90      1.00     <#2>                
     73.15    173.90      1.00     <#0>                
     77.72    175.12      1.00     <#3>                
     91.44    176.64      1.00     <#0>                
    182.88    176.64      1.00     <#0>                
******************************* 
100 
East Fork 
           12534.439 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
136 
 
PROFILE        8 
      0.00    176.11      1.00     <#0>                
     30.48    175.81      1.00     <#1>                
     33.53    173.98      1.00     <#0>                
     41.15    173.16      1.00     <#2>                
     51.82    174.59      1.00     <#0>                
     56.39    175.20      1.00     <#3>                
     70.10    175.81      1.00     <#0>                
     79.25    176.11      1.00     <#0>                
******************************* 
100 
Mill Creek 
           15407.150 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    1 
ANGLE 
    0.00 
PROFILE        62 
     17.27    180.80      1.00     <#0>                
     17.60    178.49      1.00     <#0>                
     18.33    178.38      1.00     <#0>                
     20.16    178.16      1.00     <#0>                
     29.89    178.11      1.00     <#0>                
     53.80    178.08      1.00     <#0>                
     81.66    177.99      1.00     <#0>                
     99.53    177.96      1.00     <#0>                
    154.19    177.85      1.00     <#0>                
    180.73    177.83      1.00     <#0>                
    196.85    177.85      1.00     <#0>                
    211.21    177.82      1.00     <#0>                
    221.38    177.72      1.00     <#0>                
    221.99    177.69      1.00     <#0>                
    223.30    177.56      1.00     <#0>                
    225.41    177.55      1.00     <#0>                
    228.03    177.46      1.00     <#0>                
    229.61    177.26      1.00     <#1>                
    229.79    177.22      1.00     <#0>                
    231.39    176.47      1.00     <#0>                
    232.65    175.91      1.00     <#0>                
    232.88    175.83      1.00     <#0>                
137 
 
    234.02    174.54      1.00     <#0>                
    234.16    174.50      1.00     <#0>                
    234.82    174.38      1.00     <#0>                
    236.19    174.02      1.00     <#0>                
    236.21    174.01      1.00     <#0>                
    236.55    173.96      1.00     <#0>                
    236.64    173.96      1.00     <#0>                
    238.72    173.88      1.00     <#2>                
    240.65    174.31      1.00     <#0>                
    240.82    174.36      1.00     <#0>                
    241.27    174.75      1.00     <#0>                
    242.96    174.89      1.00     <#0>                
    244.47    174.99      1.00     <#0>                
    244.89    175.08      1.00     <#0>                
    246.04    175.37      1.00     <#0>                
    246.71    175.60      1.00     <#0>                
    246.82    175.61      1.00     <#0>                
    247.20    175.71      1.00     <#0>                
    247.27    175.72      1.00     <#0>                
    247.30    175.73      1.00     <#0>                
    249.51    176.34      1.00     <#0>                
    251.82    176.60      1.00     <#0>                
    251.89    176.61      1.00     <#0>                
    253.75    176.95      1.00     <#0>                
    255.57    177.36      1.00     <#0>                
    255.68    177.37      1.00     <#3>                
    258.55    177.55      1.00     <#0>                
    260.57    177.46      1.00     <#0>                
    261.43    177.52      1.00     <#0>                
    263.16    177.62      1.00     <#0>                
    264.88    177.63      1.00     <#0>                
    266.03    177.57      1.00     <#0>                
    269.48    177.64      1.00     <#0>                
    278.98    177.78      1.00     <#0>                
    319.25    178.00      1.00     <#0>                
    346.00    178.03      1.00     <#0>                
    374.19    178.11      1.00     <#0>                
    417.06    178.33      1.00     <#0>                
    458.74    178.49      1.00     <#0>                
    459.05    180.77      1.00     <#0>                
******************************* 
100 
Mill Creek 
           15496.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
138 
 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        27 
      0.00    181.36      1.00     <#0>                
      0.30    178.16      1.00     <#0>                
    167.55    178.00      1.00     <#0>                
    190.44    177.85      1.00     <#0>                
    198.12    177.36      1.00     <#1>                
    198.36    177.36      1.00     <#0>                
    200.50    176.78      1.00     <#0>                
    202.48    176.30      1.00     <#0>                
    204.00    174.65      1.00     <#0>                
    205.07    174.47      1.00     <#0>                
    206.90    174.01      1.00     <#0>                
    206.93    174.01      1.00     <#0>                
    207.39    173.95      1.00     <#0>                
    207.51    173.95      1.00     <#0>                
    210.28    173.92      1.00     <#2>                
    212.57    174.53      1.00     <#0>                
    213.06    175.05      1.00     <#0>                
    216.53    175.20      1.00     <#0>                
    218.97    175.78      1.00     <#0>                
    219.09    175.78      1.00     <#0>                
    219.58    175.84      1.00     <#0>                
    219.61    175.84      1.00     <#0>                
    224.61    176.66      1.00     <#0>                
    228.60    177.55      1.00     <#0>                
    228.72    177.55      1.00     <#3>                
    426.72    178.13      1.00     <#0>                
    427.02    181.36      1.00     <#0>                
******************************* 
100 
Mill Creek 
           15868.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
139 
 
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        12 
      0.00    178.00      1.00     <#0>                
      3.05    176.78      1.00     <#0>                
     30.48    176.48      1.00     <#0>                
    109.73    176.78      1.00     <#0>                
    194.46    176.78      1.00     <#0>                
    196.60    176.17      1.00     <#1>                
    198.12    174.96      1.00     <#0>                
    201.17    173.74      1.00     <#0>                
    202.69    173.74      1.00     <#2>                
    210.31    176.78      1.00     <#3>                
    323.09    176.78      1.00     <#0>                
    329.18    178.00      1.00     <#0>                
******************************* 
100 
Mill Creek 
           16213.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        12 
    295.66    176.17      1.00     <#0>                
    335.28    176.17      1.00     <#0>                
    396.24    176.48      1.00     <#0>                
    457.20    176.48      1.00     <#0>                
    490.73    176.17      1.00     <#1>                
    492.25    174.35      1.00     <#0>                
    496.82    173.43      1.00     <#2>                
    498.35    173.43      1.00     <#0>                
    502.92    174.35      1.00     <#0>                
    506.88    176.78      1.00     <#3>                
    513.89    177.39      1.00     <#0>                
    515.11    178.00      1.00     <#0>                
******************************* 
100 
140 
 
Mill Creek 
           16728.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        9 
      0.00    175.87      1.00     <#0>                
     30.48    175.57      1.00     <#1>                
     33.53    173.74      1.00     <#0>                
     41.15    172.82      1.00     <#2>                
     49.99    173.74      1.00     <#0>                
     51.82    174.35      1.00     <#0>                
     56.39    174.96      1.00     <#3>                
     70.10    175.57      1.00     <#0>                
     79.25    175.87      1.00     <#0>                
******************************* 
100 
Mill Creek 
           17074.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        8 
      0.00    176.78      1.00     <#0>                
     73.15    176.78      1.00     <#1>                
     82.30    173.74      1.00     <#0>                
141 
 
     91.44    172.36      1.00     <#2>                
     96.01    173.74      1.00     <#0>                
    115.21    174.35      1.00     <#0>                
    117.35    176.48      1.00     <#3>                
    138.68    176.78      1.00     <#0>                
******************************* 
100 
Mill Creek 
           17276.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        18 
      0.09    177.52      1.00     <#0>                
     15.97    177.64      1.00     <#0>                
     16.00    175.02      1.00     <#1>                
     21.64    172.79      1.00     <#0>                
     26.34    172.64      1.00     <#0>                
     26.36    172.64      1.00     <#0>                
     26.64    172.64      1.00     <#0>                
     26.70    172.64      1.00     <#2>                
     29.87    173.13      1.00     <#0>                
     43.37    173.43      1.00     <#0>                
     43.43    173.43      1.00     <#0>                
     43.62    173.43      1.00     <#0>                
     43.68    173.43      1.00     <#0>                
     45.87    173.74      1.00     <#0>                
     51.57    175.47      1.00     <#0>                
     54.44    175.53      1.00     <#3>                
     54.47    177.61      1.00     <#0>                
     70.17    177.46      1.00     <#0>                
******************************* 
100 
Mill Creek 
           17514.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
142 
 
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        13 
    140.21    174.96      1.00     <#0>                
    166.12    174.96      1.00     <#0>                
    173.74    176.78      1.00     <#1>                
    182.88    173.74      1.00     <#0>                
    190.50    173.13      1.00     <#0>                
    196.60    173.13      1.00     <#0>                
    198.12    172.52      1.00     <#0>                
    204.22    172.21      1.00     <#2>                
    210.92    172.52      1.00     <#0>                
    213.36    173.74      1.00     <#0>                
    222.50    175.57      1.00     <#3>                
    233.17    176.17      1.00     <#0>                
    265.18    176.17      1.00     <#0>                
******************************* 
100 
Mill Creek 
           17971.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        12 
    365.76    176.78      1.00     <#1>                
    370.33    174.96      1.00     <#0>                
    376.43    174.35      1.00     <#0>                
    377.95    173.74      1.00     <#0>                
    382.52    173.13      1.00     <#0>                
143 
 
    388.62    172.52      1.00     <#0>                
    391.06    172.36      1.00     <#0>                
    404.47    171.72      1.00     <#2>                
    405.38    172.52      1.00     <#0>                
    411.48    173.74      1.00     <#0>                
    432.82    176.78      1.00     <#3>                
    509.02    176.78      1.00     <#0>                
******************************* 
100 
Mill Creek 
           18247.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        24 
     15.24    178.31      1.00     <#0>                
     18.29    176.08      1.00     <#0>                
     30.51    176.08      1.00     <#0>                
     47.06    174.44      1.00     <#0>                
     47.09    174.32      1.00     <#1>                
     48.98    174.19      1.00     <#0>                
     51.24    172.09      1.00     <#0>                
     52.70    171.42      1.00     <#2>                
     56.08    171.51      1.00     <#0>                
     59.01    172.30      1.00     <#0>                
     59.07    172.24      1.00     <#0>                
     60.35    172.30      1.00     <#0>                
     60.50    172.30      1.00     <#0>                
     64.89    171.66      1.00     <#0>                
     67.06    174.04      1.00     <#0>                
     69.95    174.16      1.00     <#0>                
     70.81    174.22      1.00     <#0>                
     71.29    174.22      1.00     <#0>                
     74.25    174.22      1.00     <#0>                
     74.26    174.26      1.00     <#3>                
     74.28    174.29      1.00     <#0>                
     74.31    174.35      1.00     <#0>                
     91.44    176.78      1.00     <#0>                
     94.49    178.31      1.00     <#0>                
144 
 
******************************* 
100 
Mill Creek 
           18674.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        11 
    124.97    176.78      1.00     <#0>                
    143.26    174.96      1.00     <#0>                
    149.96    173.74      1.00     <#1>                
    160.02    171.91      1.00     <#0>                
    164.90    171.24      1.00     <#2>                
    176.78    171.91      1.00     <#0>                
    182.88    173.74      1.00     <#0>                
    186.23    174.80      1.00     <#3>                
    189.89    174.83      1.00     <#0>                
    198.12    175.57      1.00     <#0>                
    225.55    176.17      1.00     <#0>                
******************************* 
100 
Mill Creek 
           18983.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
145 
 
PROFILE        22 
      0.00    175.50      1.00     <#0>                
     31.21    175.84      1.00     <#0>                
     31.27    174.32      1.00     <#1>                
     40.63    173.19      1.00     <#0>                
     43.56    172.00      1.00     <#0>                
     43.59    172.00      1.00     <#0>                
     43.80    171.88      1.00     <#0>                
     43.89    171.94      1.00     <#0>                
     45.81    171.63      1.00     <#0>                
     50.48    171.30      1.00     <#0>                
     53.46    171.18      1.00     <#2>                
     59.38    171.76      1.00     <#0>                
     59.47    171.69      1.00     <#0>                
     59.68    171.69      1.00     <#0>                
     59.71    171.69      1.00     <#0>                
     61.57    171.60      1.00     <#0>                
     66.05    173.43      1.00     <#0>                
     71.78    174.44      1.00     <#3>                
     71.81    175.96      1.00     <#0>                
     87.63    175.99      1.00     <#0>                
    137.16    174.96      1.00     <#0>                
    198.12    174.96      1.00     <#0>                
******************************* 
100 
Mill Creek 
           19166.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        12 
     77.72    176.78      1.00     <#0>                
     85.34    174.35      1.00     <#0>                
     98.15    173.74      1.00     <#0>                
    106.07    173.13      1.00     <#1>                
    111.56    171.30      1.00     <#0>                
    115.82    170.87      1.00     <#2>                
    119.79    171.30      1.00     <#0>                
    123.44    173.13      1.00     <#3>                
146 
 
    124.36    173.74      1.00     <#0>                
    144.78    174.35      1.00     <#0>                
    213.36    174.35      1.00     <#0>                
    219.46    176.78      1.00     <#0>                
******************************* 
100 
Mill Creek 
           19998.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        20 
    128.02    173.04      1.00     <#0>                
    128.32    172.79      1.00     <#0>                
    128.63    172.49      1.00     <#0>                
    148.38    172.36      1.00     <#0>                
    155.48    172.24      1.00     <#0>                
    162.12    171.88      1.00     <#1>                
    162.31    171.88      1.00     <#0>                
    169.62    169.87      1.00     <#0>                
    171.85    169.65      1.00     <#0>                
    173.74    169.56      1.00     <#0>                
    175.35    169.44      1.00     <#0>                
    176.11    169.01      1.00     <#0>                
    176.39    169.01      1.00     <#2>                
    178.92    169.71      1.00     <#0>                
    178.95    170.90      1.00     <#0>                
    178.95    171.39      1.00     <#3>                
    193.97    173.92      1.00     <#0>                
    195.35    174.32      1.00     <#0>                
    199.92    174.32      1.00     <#0>                
    204.06    173.10      1.00     <#0>                
******************************* 
100 
Mill Creek 
           20221.000 
COORDINATES 
    0 
FLOW DIRECTION 
147 
 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        18 
     24.38    173.13      1.00     <#0>                
     54.86    173.13      1.00     <#0>                
     59.44    174.35      1.00     <#0>                
     70.10    174.35      1.00     <#0>                
     76.20    173.74      1.00     <#0>                
     79.25    173.13      1.00     <#1>                
     82.30    172.52      1.00     <#0>                
     83.21    171.91      1.00     <#0>                
     85.34    170.69      1.00     <#0>                
     85.95    170.38      1.00     <#0>                
     87.17    169.62      1.00     <#0>                
     91.44    169.38      1.00     <#2>                
     96.01    169.62      1.00     <#0>                
     99.06    170.69      1.00     <#0>                
    103.63    171.45      1.00     <#0>                
    107.90    172.21      1.00     <#0>                
    109.73    172.52      1.00     <#3>                
    152.40    172.82      1.00     <#0>                
******************************* 
100 
Mill Creek 
           20446.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
148 
 
PROFILE        18 
     23.96    175.02      1.00     <#0>                
     43.46    172.91      1.00     <#1>                
     43.49    172.91      1.00     <#0>                
     53.95    171.48      1.00     <#0>                
     54.10    171.48      1.00     <#0>                
     55.35    171.48      1.00     <#0>                
     55.44    171.42      1.00     <#0>                
     58.61    171.39      1.00     <#0>                
     60.99    169.68      1.00     <#0>                
     66.39    169.04      1.00     <#2>                
     66.54    169.10      1.00     <#0>                
     67.91    169.16      1.00     <#0>                
     68.00    169.16      1.00     <#0>                
     70.29    169.71      1.00     <#0>                
     73.06    172.43      1.00     <#0>                
     76.90    173.52      1.00     <#0>                
     76.93    173.52      1.00     <#3>                
     95.71    175.44      1.00     <#0>                
******************************* 
100 
Mill Creek 
           20526.000 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    0 
ANGLE 
    0.00 
PROFILE        21 
      0.00    175.17      1.00     <#0>                
     11.25    175.17      1.00     <#0>                
     22.07    173.46      1.00     <#0>                
     30.30    172.88      1.00     <#1>                
     30.72    172.85      1.00     <#0>                
     38.37    172.49      1.00     <#0>                
     40.20    170.78      1.00     <#0>                
     42.03    171.05      1.00     <#0>                
     44.62    169.53      1.00     <#0>                
     45.54    168.80      1.00     <#0>                
     47.21    168.71      1.00     <#2>                
     50.26    169.01      1.00     <#0>                
149 
 
     52.09    169.56      1.00     <#0>                
     55.14    170.63      1.00     <#0>                
     56.81    171.60      1.00     <#0>                
     59.41    172.18      1.00     <#0>                
     65.50    172.70      1.00     <#0>                
     65.62    172.43      1.00     <#3>                
     76.17    172.85      1.00     <#0>                
     81.96    175.17      1.00     <#0>                
     97.35    175.20      1.00     <#0>                
******************************* 
100 
Mill Creek 
           20732.448 
COORDINATES 
    0 
FLOW DIRECTION 
    0       
DATUM 
      0.00 
RADIUS TYPE 
    0 
DIVIDE X-Section 
0 
SECTION ID 
      
INTERPOLATED 
    1 
ANGLE 
    0.00 
PROFILE        36 
     98.90    174.11      1.00     <#0>                
    108.95    173.91      1.00     <#0>                
    118.61    173.27      1.00     <#0>                
    121.19    173.16      1.00     <#0>                
    122.14    172.92      1.00     <#0>                
    122.78    172.68      1.00     <#0>                
    123.42    172.22      1.00     <#0>                
    124.37    171.97      1.00     <#0>                
    125.01    171.73      1.00     <#0>                
    125.96    171.26      1.00     <#1>                
    126.39    171.10      1.00     <#0>                
    126.58    171.03      1.00     <#0>                
    127.49    170.79      1.00     <#0>                
    128.41    170.56      1.00     <#0>                
    129.02    170.44      1.00     <#0>                
    133.99    170.07      1.00     <#0>                
    135.80    169.51      1.00     <#0>                
    137.62    169.47      1.00     <#0>                
    138.19    169.35      1.00     <#0>                
    140.20    168.98      1.00     <#0>                
    141.10    168.76      1.00     <#0>                
    142.77    168.68      1.00     <#2>                
150 
 
    144.35    168.81      1.00     <#0>                
    145.30    168.98      1.00     <#0>                
    146.88    169.31      1.00     <#0>                
    147.32    169.45      1.00     <#0>                
    147.75    169.69      1.00     <#0>                
    149.10    170.17      1.00     <#0>                
    149.59    170.31      1.00     <#0>                
    152.26    171.20      1.00     <#0>                
    152.32    171.14      1.00     <#3>                
    154.43    171.84      1.00     <#0>                
    155.03    172.97      1.00     <#0>                
    163.24    173.05      1.00     <#0>                
    169.23    173.66      1.00     <#0>                
    185.15    173.67      1.00     <#0>                
******************************* 
 
151 
 
Appendix D: HEC RAS Cross-section Data 
 The HEC RAS cross-section data was imported from various HEC-2 text files 
and combined into one .G01 geometry file.  The geometry file was the initial file used 
for the HEC RAS 3.0 flow model.  For accurate depiction of the stream channel in the 
terrain model (as explained in the terrain model refinement process in Chapter 5), 
interpolated cross-sections were included to successive geometry files until an 
optimum number of cross-sections were attained.  XY-coordinates were digitized 
from the modified terrain model and included in this file. 
 To better understand the data, the geometry file first provides the geometry file 
title and extent of the XY-coordinates used for the file.  The second section describes 
the junctions and reaches within the geometry file.  The rest of the geometry is broken 
down by reach, first defining the XY-coordinate points for each reach, then each 
cross-section within the reach. 
 Each cross-section in the file is defined by a River Station identification number 
and downstream reach lengths (for left overbank, stream centerline, and right 
overbank).  The next section of data is the X- and Z- coordinates in space-delimited 
format (sequenced horizontally) defining the cross-section (unlike the columnar 
format for MIKE 11 cross-section files).  The number of times Manning?s n changes 
across the cross-section, and at what location follows the XZ-coordinate data.  Lastly, 
left and right river bank coordinates, initial and incremental HTAB data (for unsteady 
flow calculations), whether the cross-section has been identified to provide a rating 
curve after processing (0 for no, 1 for yes), and expansion/contraction coefficients are 
shown. 
 
152 
 
HEC RAS 3.0 Geometry File from HEC-2 Data 
Geom Title=pdc geometry from HEC02 cross-sections 
Version=Version 3.0 Beta April 15, 2000 
Viewing Rectangle= 432951.853815298, 433870.269332472 , 
146027.514925005, 140851.356231991  
 
Junct Name=one              
Junct Desc=, 0, 0, -1  
Junct X Y & Text X 
Y=433158.8981556,144927.5088831,433158.8981556,144927.5088831 
Up River,Reach=PDC             ,Mill Creek       
Up River,Reach=PDC             ,East Fork        
Dn River,Reach=PDC             ,Mill Creek DS    
Junc L&A=326,0 
Junc L&A=0,0 
 
River Reach=PDC             ,East Fork        
Reach XY= 44  
       433568.87       145914.24       433558.61       145864.87 
       433551.56       145828.97        433541.3       145794.35 
       433540.66       145750.76       433543.22       145702.68 
       433550.27       145661.01       433549.63       145622.54 
       433540.02        145564.2       433532.82        145530.7 
       433531.19       145485.41       433529.24       145475.31 
       433524.68       145465.21       433523.05       145445.34 
       433518.81       145411.78       433511.32       145378.22 
       433503.82       145347.59       433501.22       145326.09 
       433495.68       145306.54       433487.86       145297.41 
       433470.27       145288.94       433451.37       145281.12 
       433389.46       145268.09       433346.13       145257.34 
        433326.9       145248.54        433314.2       145236.49 
       433304.42       145221.82       433301.49       145205.53 
       433300.51       145184.68       433300.51       145151.45 
       433298.56       145107.14       433297.25       145067.39 
        433296.6       145049.79         433294.       145035.78 
       433295.95       145018.19       433292.69        144995.7 
       433284.55       144976.81        433275.1        144965.4 
       433260.44       144967.36        433244.8       144971.27 
       433223.94       144968.01       433198.86       144964.75 
       433180.28       144957.91  433158.8981556  144927.5088831 
Rch Text X Y=433466.3770389,145667.5572208 
Reverse River Text= 0  
 
Type RM Length L Ch R = 1 ,388     ,52.02,52.02,52.02 
BEGIN DESCRIPTION: 
5.1 
 The East Fork Mill Creek HEC-2 model was developed by  
 Water Resources & Coastal Engineering, Inc. under contract =  
END DESCRIPTION: 
Node Name= 
#Sta/Elev= 18  
153 
 
20.12  179.22   43.28  178.61   60.35     178   60.96  177.91   
66.17  175.14 
71.66  175.14    72.3  175.63   74.92  177.24   79.25     178   
79.55  181.05 
129.54  181.05  135.03  178.31  164.59  177.09  178.31   177.7  
178.61  178.31 
179.83  181.05  217.02  178.31  262.74  178.31 
#Mann= 4 ,-1 , 0  
20.12     .06       0   60.96     .03       0   79.25    .045      0 
79.55    .113       0 
Bank Sta=60.35,79.25 
XS Rating Curve= 0  
XS HTab Starting El and Incr=175.438,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,336     ,58,58,58 
BEGIN DESCRIPTION: 
199250 
East Fork Mill Creek at Mill Creek station 199250 
END DESCRIPTION: 
Node Name= 
#Sta/Elev= 24  
0  182.88    3.14  182.27    4.48  181.66    6.34  181.05   12.89  
179.83 
16.28  179.22   20.12  178.61   26.27     178   43.04  177.39   
57.79  177.39 
57.79  177.36   58.64  176.78   60.81  174.96   65.87  174.96   
68.37  176.17 
69.98  176.78   71.38  177.42   74.46     178   78.67  177.39   
84.77  176.78 
180.78  177.39  197.24     178  217.81  178.61  234.45  178.61 
#Mann= 3 , 0 , 0  
0     .15       0   57.79  .05625       0   71.38     .15       0 
Bank Sta=57.79,71.38 
XS Rating Curve= 0  
XS HTab Starting El and Incr=175.255,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,278     ,56.96,56.96,56.96 
BEGIN DESCRIPTION: 
198820 
East Fork Mill Creek at Mill Creek station 198820 
END DESCRIPTION: 
Node Name= 
#Sta/Elev= 22  
0  179.83     .18  179.22   24.87  178.61   27.95     178   29.08  
177.39 
30.45  176.78    31.3  176.17   32.77  175.57   37.92  174.44   
39.53  175.57 
41.15  176.17      42  176.78   44.32     178    44.5  178.03   
47.27  178.61 
51.66  178.61   55.02  177.39   65.01  176.78  132.47  176.78  
154 
 
218.05  176.78 
249.75     178  263.29     178 
#Mann= 3 , 0 , 0  
0     .15       0   29.08  .05625       0   44.32     .15       0 
Bank Sta=29.08,44.32 
XS Rating Curve= 0  
XS HTab Starting El and Incr=174.737,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,221     ,119,119,119 
BEGIN DESCRIPTION: 
197690 
East Fork Mill Creek at Mill Creek station 197690 
END DESCRIPTION: 
Node Name= 
#Sta/Elev= 16  
0  179.83     .12  178.61     .49     178   12.13  177.39   25.48  
176.69 
26.55  176.17   27.77  175.57   29.84  174.96   33.74  174.35   
35.69  174.96 
37.31  175.57   38.04  176.17   41.45  176.88   42.37  177.39   
51.17  177.39 
53.43  176.78 
#Mann= 3 , 0 , 0  
0     .15       0   25.48  .05625       0   38.04     .15       0 
Bank Sta=25.48,38.04 
XS Rating Curve= 0  
XS HTab Starting El and Incr=174.646,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,102     ,93.995,93.995,93.995 
BEGIN DESCRIPTION: 
196730 
(Total flow reduced - Flow crosses from Mill Creek to East Fork Mill 
= 
Mill Creek confluence with East Fork Mill Creek at Mill Creek 
station =  
END DESCRIPTION: 
Node Name= 
#Sta/Elev= 10  
0  176.78   54.86  176.78   59.44     178   61.57     178    70.1  
174.35 
71.63  173.13   73.15  173.13   77.72  174.35   91.44  175.87  
182.88  175.87 
#Mann= 3 , 0 , 0  
0     .15       0    70.1  .05625       0   77.72     .15       0 
Bank Sta=70.1,77.72 
XS Rating Curve= 0  
XS HTab Starting El and Incr=173.426,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,8       ,8,8,8 
155 
 
BEGIN DESCRIPTION: 
196000 
Mill Creek total flow from CofE HEC-1 Model 
Mill Creek (Main Stem)  
END DESCRIPTION: 
Node Name= 
#Sta/Elev= 8  
0  175.87   30.48  175.57   33.53  173.74   41.14 172.822   51.82  
174.35 
56.39  174.96    70.1  175.57   79.25  175.87 
#Mann= 3 , 0 , 0  
0     .15       0   30.48  .05625       0   56.39     .15       0 
Bank Sta=30.48,56.39 
XS Rating Curve= 0  
XS HTab Starting El and Incr=173.122,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,0       ,0,0,0 
BEGIN DESCRIPTION: 
196000 
Mill Creek total flow from CofE HEC-1 Model 
Mill Creek (Main Stem) 
END DESCRIPTION: 
Node Name= 
#Sta/Elev= 8  
0  175.87   30.48  175.57   33.53  173.74   41.15  172.82   51.82  
174.35 
56.39  174.96    70.1  175.57   79.25  175.87 
#Mann= 3 , 0 , 0  
0     .15       0   30.48  .05625       0   56.39     .15       0 
Bank Sta=30.48,56.39 
XS Rating Curve= 0  
XS HTab Starting El and Incr=173.122,.1 
Exp/Cntr=.5,.3 
 
River Reach=PDC             ,Mill Creek       
Reach XY= 26  
       433142.53        145849.3       433134.11       145797.91 
       433126.58       145728.37       433116.39       145689.39 
       433073.42       145615.41       433054.82       145576.43 
       433021.16       145533.02       433020.27       145507.77 
        433024.7        145487.4        433037.1       145463.92 
       433039.76       145451.96       433033.56       145409.44 
       433041.09       145373.56       433045.52       145301.35 
        433049.5       145284.52       433058.81       145270.79 
       433064.12       145225.16       433064.12       145194.15 
       433054.82       145173.78       433062.35       145152.96 
       433065.01       145124.17       433067.67       145080.31 
       433078.74       145044.88       433088.93       145003.24 
       433126.14       144966.03  433158.8981556  144927.5088831 
Rch Text X Y=433146.6220389,145618.8522208 
Reverse River Text= 0  
156 
 
 
Type RM Length L Ch R = 1 ,45485   ,89.01,89.01,89.01 
Node Name= 
#Sta/Elev= 46  
145.09   178.9  145.53  178.63  146.31  178.24  147.34  178.05   
149.6  177.61 
150.44   177.6  160.61  177.59  172.44  177.51  180.03  177.48  
203.26  177.39 
214.54  177.39  227.49  177.46  232.07  177.39  232.63   177.3  
233.52  177.39 
234.64  177.42  235.31  177.27     237  175.68  237.84  175.06  
238.54  174.67 
240.39  173.96   241.4  173.96  242.49   174.1  243.79  174.36  
244.88  174.54 
245.53  174.69  246.18  174.95  247.48  175.46  247.89  175.49  
248.78  175.82 
249.87  176.28  250.95  176.84  252.11  177.06  252.92  176.96  
253.27  177.03 
253.97  177.16  254.66  177.17  255.13  177.11  256.52   177.2  
260.35   177.4 
275.55  177.81  276.58  177.82  287.37  177.78  298.73  177.81  
316.01  177.97 
332.94  178.05 
#Mann= 3 , 0 , 0  
145.09     .15       0  235.31    .052       0  250.95     .15       
0 
Bank Sta=235.31,250.95 
XS Rating Curve= 0  
XS HTab Starting El and Incr=174.258,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,45396   ,371,371,371 
Node Name= 
#Sta/Elev= 27  
0  181.36     .31  178.16  167.55     178  190.44  177.85  198.12  
177.36 
198.36  177.36   200.5  176.78  202.48   176.3     204  174.65  
205.07  174.47 
206.9  174.01  206.93  174.01  207.39  173.95  207.51  173.95  
210.28  173.92 
212.57  174.53  213.06  175.05  216.53   175.2  218.97  175.78  
219.09  175.78 
219.58  175.84  219.61  175.84  224.61  176.66   228.6  177.55  
228.72  177.55 
426.72  178.13  427.03  181.36 
#Mann= 3 , 0 , 0  
0     .15       0  198.12  .05625       0   228.6     .15       0 
Bank Sta=198.12,228.6 
XS Rating Curve= 0  
XS HTab Starting El and Incr=174.2189,.1 
Exp/Cntr=.5,.3 
 
157 
 
Type RM Length L Ch R = 1 ,45025   ,341.38,344.42,344.42 
Node Name= 
#Sta/Elev= 12  
0     178    3.05  176.78   30.48  176.48  109.73  176.78  194.46  
176.78 
196.6  176.17  198.12  174.96  201.17  173.74  202.69  173.74  
210.31  176.78 
323.09  176.78  329.18     178 
#Mann= 3 , 0 , 0  
0     .15       0   196.6  .05625       0  210.31     .15       0 
Bank Sta=196.6,210.31 
XS Rating Curve= 0  
XS HTab Starting El and Incr=174.036,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,44680   ,189,189,189 
Node Name= 
#Sta/Elev= 12  
295.66  176.17  335.28  176.17  396.24  176.48   457.2  176.48  
490.73  176.17 
492.25  174.35  496.82  173.43  498.35  173.43  502.92  174.35  
506.88  176.78 
513.89  177.39  515.11     178 
#Mann= 3 , 0 , 0  
295.66     .15       0  490.73  .05625       0  506.88     .15     0 
Bank Sta=490.73,506.88 
XS Rating Curve= 0  
XS HTab Starting El and Incr=173.7309,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,44491   ,326,326,326 
Node Name= 
#Sta/Elev= 16  
187.47  176.06  214.85  176.04     257   176.2  299.13  176.16  
322.31  175.95 
324.25  174.21  324.53   174.1  330.08  173.21  331.89   173.3  
337.01  174.09 
337.33  174.17  338.45  174.72  342.03  176.12  350.18  176.61  
353.61   176.8 
355.62  177.22 
#Mann= 3 , 0 , 0  
187.47     .15       0  322.31  .05625       0  342.03     .15       
0 
Bank Sta=322.31,342.03 
XS Rating Curve= 0  
XS HTab Starting El and Incr=173.508,.1 
Exp/Cntr=.3,.1 
 
River Reach=PDC             ,Mill Creek DS    
Reach XY= 71  
  433158.8981556  144927.5088831       433158.92       144927.49 
       433177.52       144896.93       433175.31       144872.56 
158 
 
       433220.05       144763.15       433234.22        144725.5 
       433250.17       144647.98       433259.91        144552.3 
       433263.01       144452.19       433276.75       144363.15 
       433269.21       144257.73       433278.07       144197.93 
       433266.11        144121.3       433254.15        144092.5 
       433255.48       144037.13        433254.6       143960.94 
       433239.09       143886.08       433244.85       143816.09 
       433239.98       143718.64       433235.55       143520.64 
       433220.49       143465.71       433228.46       143429.39 
       433247.07       143392.18       433252.38       143345.22 
       433252.38       143295.17       433252.38       143260.62 
       433262.57       143231.82       433267.89       143163.61 
       433264.34       143135.26       433269.21       143082.54 
       433276.75       143041.35       433285.16       142976.23 
       433282.06       142905.36       433274.97       142848.22 
       433278.07        142783.1       433283.83       142694.95 
       433278.52        142660.4       433275.86       142585.54 
        433279.4        142543.9       433267.44       142409.24 
       433245.74       142333.93       433235.55       142283.44 
       433237.76       142244.01       433235.99       142152.76 
       433244.41       142060.18       433243.52       141985.76 
       433260.36       141949.44       433280.29       141889.64 
       433312.18       141828.07       433339.65       141776.24 
       433418.05       141684.99       433445.51       141664.62 
       433508.86        141605.7       433523.03       141587.98 
       433558.91       141566.28       433614.28       141509.58 
       433643.52       141496.73       433668.33       141489.65 
       433697.12       141466.17        433726.8       141448.89 
       433760.46       141430.73       433813.62       141385.11 
       433830.01       141358.97        433837.1       141290.31 
       433833.11         141250.       433814.95       141194.63 
       433807.86       141116.67       433802.99       141041.37 
       433798.56       140958.09       433788.81       140928.85 
        433786.6        140903.6 
Rch Text X Y=433315.8236167,143921.5316623 
Reverse River Text= 0  
 
Type RM Length L Ch R = 1 ,44165   ,52,52,52 
Node Name= 
#Sta/Elev= 9  
0  175.87   30.48  175.57   33.53  173.74   41.15  172.82   49.99  
173.74 
51.82  174.35   56.39  174.96    70.1  175.57   79.25  175.87 
#Mann= 3 , 0 , 0  
0     .15       0   30.48  .05625       0   56.39     .15       0 
Bank Sta=30.48,56.39 
XS Rating Curve= 0  
XS HTab Starting El and Incr=173.1219,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,44113   ,15.24,17.68,21.34 
Node Name= 
159 
 
#Sta/Elev= 20  
33.22  178.31    44.2  176.78   49.99  175.26   51.82  174.65   
54.56  174.35 
56.69  173.43    57.3  173.37   58.83  172.82   60.96  172.82    
63.4  172.82 
64.31  173.37   64.92  173.74   66.45  174.35   71.63  174.65   
72.54  175.26 
78.64  175.87   81.69  175.87   87.78  175.57  112.17  176.17  
148.74  179.83 
#Mann= 3 , 0 , 0  
33.22     .15       0   49.99  .05625       0   72.54     .15      0 
Bank Sta=49.99,72.54 
XS Rating Curve= 0  
XS HTab Starting El and Incr=173.1219,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,44095   ,46,46,46 
Node Name= 
#Sta/Elev= 21  
28.96  178.31   37.19  176.78   46.03  175.26   47.85  174.65   
50.29  174.35 
54.86  174.35   55.78  174.04   56.69  173.74   58.22  173.37   
58.83  172.82 
60.96  172.82   62.48  172.82    63.7  173.37   65.23  173.43   
66.14  173.73 
68.28  175.26   74.37  175.87   80.47  175.87  104.85  175.57  
129.24  176.17 
165.81  179.83 
#Mann= 3 , 0 , 0  
28.96     .15       0   46.03  .05625       0   68.28     .15      0 
Bank Sta=46.03,68.28 
XS Rating Curve= 0  
XS HTab Starting El and Incr=173.1219,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,44049   ,3,3,3 
Node Name= 
#Sta/Elev= 26  
15.03   184.4   22.16  184.53   22.19  181.78   27.13  180.23   
42.52  178.95 
44.07  177.79   46.85  176.78   48.86  174.86   49.99  174.74   
49.99   174.8 
50.63  174.53   50.63  174.59   53.52  172.82   61.05  172.58   
65.68  172.76 
67.61   174.5    71.6  174.59   71.63  174.59   72.15  174.71   
72.18  174.71 
76.26  175.99   79.68  177.49    95.8  180.96  100.04  182.15  
100.07  185.14 
107.23   185.2 
#Mann= 3 , 0 , 0  
15.03     .15       0   22.19  .05625       0  100.04     .15      0 
Bank Sta=22.19,100.04 
160 
 
XS Rating Curve= 0  
XS HTab Starting El and Incr=172.8781,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,44046   ,64,64,64 
Node Name= 
#Sta/Elev= 26  
15.03   184.4   22.16  184.53   22.19  181.78   27.13  180.23   
42.52  178.95 
44.07  177.79   46.85  176.78   48.86  174.86   49.99  174.74   
49.99   174.8 
50.63  174.53   50.63  174.59   53.52  172.82   61.05  172.58   
65.68  172.76 
67.61  174.51    71.6  174.59   71.63  174.59   72.15  174.71   
72.18  174.71 
76.26  175.99   79.68  177.49    95.8  180.96  100.04  182.15  
100.07  185.14 
107.23   185.2 
#Mann= 3 , 0 , 0  
15.03     .15       0   22.19  .05625       0  100.04     .15       
0 
Bank Sta=22.19,100.04 
XS Rating Curve= 0  
XS HTab Starting El and Incr=172.8781,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,43982   ,52,52,52 
Node Name= 
#Sta/Elev= 7  
313.94  176.78  320.04  176.78  331.01  173.74  343.21  172.33  
352.04  173.74 
359.66  176.17  371.86  176.48 
#Mann= 3 , 0 , 0  
313.94     .15       0  320.04  .05625       0  359.66     .15     0 
Bank Sta=320.04,359.66 
XS Rating Curve= 0  
XS HTab Starting El and Incr=172.6339,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,43930   ,108.81,110.64,112.47 
Node Name= 
#Sta/Elev= 7  
313.94  176.78  320.04  176.78  331.01  173.74  343.21  172.33  
352.04  173.74 
359.66  176.17  371.86  176.48 
#Mann= 3 , 0 , 0  
313.94     .15       0  320.04  .05625       0  359.66     .15     0 
Bank Sta=320.04,359.66 
XS Rating Curve= 0  
XS HTab Starting El and Incr=172.6339,.1 
Exp/Cntr=.3,.1 
 
161 
 
Type RM Length L Ch R = 1 ,43819   ,167.64,167.64,167.64 
Node Name= 
#Sta/Elev= 8  
0  176.78   73.15  176.78    82.3  173.74   91.44  172.36   96.01  
173.74 
115.21  174.35  117.35  176.48  138.68  176.78 
#Mann= 3 , 0 , 0  
0     .15       0   73.15  .05625       0  117.35     .15       0 
Bank Sta=73.15,117.35 
XS Rating Curve= 0  
XS HTab Starting El and Incr=172.6641,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,43652   ,84,84,84 
Node Name= 
#Sta/Elev= 10  
0  176.17   53.34  176.48   57.91  173.74   67.06  173.74   73.15  
172.33 
79.25  173.74   85.34  174.35   91.44  176.48  106.68  176.78  
121.92  176.78 
#Mann= 3 , 0 , 0  
0     .15       0   53.34  .05625       0   91.44     .15       0 
Bank Sta=53.34,91.44 
XS Rating Curve= 0  
XS HTab Starting El and Incr=172.6339,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,43568   ,189,189,189 
Node Name= 
#Sta/Elev= 10  
0  175.57   36.58  175.57    44.2  176.78   48.77  176.17   57.91  
173.74 
68.58  172.21   79.25  173.74      89  174.35   97.54  176.78  
115.82  176.78 
#Mann= 3 , 0 , 0  
0     .15       0   48.77  .05625       0   97.54     .15       0 
Bank Sta=48.77,97.54 
XS Rating Curve= 0  
XS HTab Starting El and Incr=172.512,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,43379   ,706.95,706.95,706.95 
Node Name= 
#Sta/Elev= 13  
140.21  174.96  166.12  174.96  173.74  176.78  182.88  173.74   
190.5  173.13 
196.6  173.13  198.12  172.52  204.22  172.21  210.92  172.52  
213.36  173.74 
222.5  175.57  233.17  176.17  265.18  176.17 
#Mann= 3 , 0 , 0  
140.21     .15       0  173.74   .0525       0   222.5     .15     0 
Bank Sta=173.74,222.5 
162 
 
XS Rating Curve= 0  
XS HTab Starting El and Incr=172.512,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,42672   ,452.97,452.97,452.97 
Node Name= 
#Sta/Elev= 12  
373.69  176.48  373.99  176.48  374.29  176.48   374.6  176.48   
374.9  176.48 
384.05  176.17  396.85  171.91  405.69  171.45  409.04   171.6  
411.48  173.74 
421.23  173.74  425.81  175.26 
#Mann= 3 , 0 , 0  
373.69     .15       0  384.05   .0525       0  411.48     .15     0 
Bank Sta=384.05,411.48 
XS Rating Curve= 0  
XS HTab Starting El and Incr=171.75,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,42219   ,265.18,263.96,262.13 
Node Name= 
#Sta/Elev= 11  
124.97  176.78  143.26  174.96  149.96  173.74  160.02  171.91   
164.9  171.24 
176.78  171.91  182.88  173.74  186.23   174.8  189.89  174.83  
198.12  175.57 
225.55  176.17 
#Mann= 3 , 0 , 0  
124.97     .15       0  149.96   .0525       0  186.23     .15     0 
Bank Sta=149.96,186.23 
XS Rating Curve= 0  
XS HTab Starting El and Incr=171.537,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,41955   ,103,103,103 
Node Name= 
#Sta/Elev= 17  
42.67  176.78   48.77  176.17   67.06  175.57   79.25  174.35   
81.99  173.74 
83.97  172.21   84.73  171.91   85.34   171.6   86.87   171.3   
91.44  171.15 
96.01   171.3   97.54   171.6   98.45  172.21  100.28  173.74  
106.68  174.35 
108.2  174.96  121.92  174.96 
#Mann= 3 , 0 , 0  
42.67     .15       0   81.99   .0525       0  100.28     .15      0 
Bank Sta=81.99,100.28 
XS Rating Curve= 0  
XS HTab Starting El and Incr=171.4449,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,41852   ,121.92,125.28,126.48 
163 
 
Node Name= 
#Sta/Elev= 15  
91.44  175.57   94.49  174.96   99.06  174.36  100.89  173.74  
102.72  172.21 
104.24  171.51  112.78  170.99  115.82  170.99  118.26  170.99  
122.23  171.51 
124.97  173.13   126.8  173.74  131.06  175.57   152.4  175.87  
167.64  175.87 
#Mann= 3 , 0 , 0  
91.44     .15       0   99.06  .05625       0  124.97     .15      0 
Bank Sta=99.06,124.97 
XS Rating Curve= 0  
XS HTab Starting El and Incr=171.2931,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,41727   ,152.4,152.4,152.4 
Node Name= 
#Sta/Elev= 12  
77.72  176.78   85.34  174.35   98.15  173.74  106.07  173.13  
111.56   171.3 
115.82  170.87  119.79   171.3  123.44  173.13  124.36  173.74  
144.78  174.35 
213.36  174.35  219.46  176.78 
#Mann= 3 , 0 , 0  
77.72     .15       0  106.07  .05625       0  123.44     .15      0 
Bank Sta=106.07,123.44 
XS Rating Curve= 0  
XS HTab Starting El and Incr=171.1709,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,41574   ,106,106,106 
Node Name= 
#Sta/Elev= 19  
60.96  176.17    76.2  174.96   80.16  173.74   82.91  172.52   
83.82  172.21 
85.04  171.91   86.87   171.3   87.78  171.08      89  170.69   
91.44   170.6 
93.88  170.69    95.1  171.08   95.71   171.6   97.23  172.21   
108.2  172.52 
126.5  173.13  129.54  173.74  134.11  174.96   146.3  175.57 
#Mann= 3 , 0 , 0  
60.96     .15       0   83.82  .05625       0   97.23     .15      0 
Bank Sta=83.82,97.23 
XS Rating Curve= 0  
XS HTab Starting El and Incr=170.8969,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,41468   ,393.21,393.21,393.21 
Node Name= 
#Sta/Elev= 19  
60.96  176.17    76.2  174.96   80.16  173.74   82.91  172.52   
83.82  172.21 
164 
 
85.04  171.91   86.87   171.3   87.78  171.08      89  170.69   
91.44   170.6 
93.88  170.69    95.1  171.08   95.71   171.6   97.23  172.21   
108.2  172.52 
126.49  173.13  129.54  173.74  134.11  174.96   146.3  175.57 
#Mann= 3 , 0 , 0  
60.96     .15       0   83.82  .05625       0   97.23     .15      0 
Bank Sta=83.82,97.23 
XS Rating Curve= 0  
XS HTab Starting El and Incr=170.8969,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,41074   ,179.83,179.83,179.83 
Node Name= 
#Sta/Elev= 18  
0  173.43     .03  173.43   45.72  173.43    82.3  173.13   84.13  
172.52 
85.65  172.21   87.78  170.69   88.39  170.57   89.31  170.08   
91.44  169.84 
93.27  170.08   94.49  170.57   96.93  170.69   99.06  171.91  
100.58  172.52 
155.45     173  182.88  173.13   228.6  173.13 
#Mann= 3 , 0 , 0  
0     .15       0   84.13  .05625       0   99.06     .15       0 
Bank Sta=84.13,99.06 
XS Rating Curve= 0  
XS HTab Starting El and Incr=170.1349,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,40895   ,223.41,223.41,223.41 
Node Name= 
#Sta/Elev= 20  
128.02  173.04  128.32  172.79  128.63  172.49  148.38  172.36  
155.48  172.24 
162.12  171.88  162.31  171.88  169.62  169.87  171.85  169.65  
173.74  169.45 
175.35  169.44  176.11  169.01  176.39  169.01  178.92  169.71  
178.95   170.9 
178.95  171.39  193.98  173.92  195.35  174.32  199.92  174.32  
204.06   173.1 
#Mann= 3 , 0 , 0  
128.02     .15       0  162.12  .05625       0  178.95     .15     0 
Bank Sta=162.12,178.95 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.3119,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,40672   ,187.44,186.54,185.94 
Node Name= 
#Sta/Elev= 18  
24.38  173.13   54.86  173.13   59.44  174.35    70.1  174.35    
76.2  173.74 
165 
 
79.25  173.13    82.3  172.52   83.21  171.91   85.34  170.69   
85.95  170.38 
87.17  169.62   91.44  169.38   96.01  169.62   99.06  170.69  
103.63  171.45 
107.9  172.21  109.73  172.52   152.4  172.82 
#Mann= 3 , 0 , 0  
24.38     .15       0   79.25  .05625       0  109.73     .15      0 
Bank Sta=79.25,109.73 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.677,.1 
Exp/Cntr=.3,.1 
 
Type RM Length L Ch R = 1 ,40486   ,67,67,67 
Node Name= 
#Sta/Elev= 20  
51.82  172.52   64.01  172.52    70.1  173.13   74.37  174.35   
77.72  174.35 
78.64  174.04   79.86  173.74   82.91  172.21   85.04  170.69   
85.65  170.08 
86.87  169.47   91.44  169.16   96.01  169.47   97.54  170.08   
98.45  170.69 
102.72  172.21  104.85  172.82  106.07  173.13  115.82  173.74  
137.16  173.74 
#Mann= 3 , 0 , 0  
51.82     .15       0   82.91  .05625       0  102.72     .15      0 
Bank Sta=82.91,102.72 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.464,.1 
Exp/Cntr=.7,.5 
 
Type RM Length L Ch R = 1 ,40419   ,3.35,3.35,3.35 
Node Name= 
#Sta/Elev= 21  
52.43  176.78   52.73  175.26   67.67  174.96   71.02  174.04   
71.93  173.74 
75.9  172.52   82.91   171.3   85.65  170.69   86.56  170.08   87.48  
169.16 
91.44  169.16   94.49  169.16   96.01  170.08   96.62  170.38   7.23  
170.69 
100.28  170.99  103.94   171.3   108.2   171.6  109.73  172.21  
112.78  173.74 
113.08  176.78 
#Mann= 3 , 0 , 0  
52.43     .15       0   82.91  .05625       0  100.28     .15       
0 
Bank Sta=82.91,100.28 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.464,.1 
Exp/Cntr=.7,.5 
 
Type RM Length L Ch R = 1 ,40415   ,29,29,29 
Node Name= 
166 
 
#Sta/Elev= 21  
52.43  176.78   52.73  175.26   67.67  174.96   71.02  174.04   
71.93  173.74 
75.9  172.52   82.91   171.3   85.65  170.69   86.56  170.08   87.48  
169.16 
91.44  169.16   94.49  169.16   96.01  170.08   96.62  170.38   
97.23  170.69 
100.28  170.99  103.94   171.3   108.2   171.6  109.73  172.21  
112.78  173.74 
113.08  176.78 
#Mann= 3 , 0 , 0  
52.43     .15       0   82.91  .05625       0  100.28     .15      0 
Bank Sta=82.91,100.28 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.464,.1 
Exp/Cntr=.7,.5 
 
Type RM Length L Ch R = 1 ,40386   ,6,6,6 
Node Name= 
#Sta/Elev= 25  
24.9  177.64   42.92  177.85   42.98  172.52   46.09  171.88   48.25  
171.48 
50.9  171.12   53.71  170.72    53.8  170.66   55.57  170.38   55.57  
170.32 
57.85  169.07   58.74  169.07   61.14  169.07   63.55  169.07   
65.23  169.07 
66.6   170.2   66.66  170.26   68.28   170.6   68.34  170.66   71.48  
171.05 
73.88   171.3   76.26  171.63   79.34  171.91   79.37   178.1    
95.1  178.28 
#Mann= 3 , 0 , 0  
24.9     .15       0   42.98  .05625       0   79.34     .15       0 
Bank Sta=42.98,79.34 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.3729,.1 
Exp/Cntr=.7,.5 
 
Type RM Length L Ch R = 1 ,40380   ,98,98,98 
Node Name= 
#Sta/Elev= 25  
24.9  177.64   42.92  177.85   42.98  172.52   46.09  171.88   48.25  
171.48 
50.9  171.12   53.71  170.72    53.8  170.66   55.57  170.38   55.57  
170.32 
57.85  168.86   58.74  168.92   61.14  168.95   63.55  168.92   
65.23  168.92 
66.6   170.2   66.66  170.26   68.28   170.6   68.34  170.66   71.48  
171.05 
73.88   171.3   76.26  171.63   79.34  171.91   79.37   178.1    
95.1  178.28 
#Mann= 3 , 0 , 0  
24.9     .15       0   42.98  .05625       0   79.34     .15       0 
167 
 
Bank Sta=42.98,79.34 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.1589,.1 
Exp/Cntr=.7,.5 
 
Type RM Length L Ch R = 1 ,40282   ,121.5,121.5,121.5 
Node Name= 
#Sta/Elev= 17  
70.1  172.52   82.91  171.91   84.73  171.91   85.95     171   86.87  
170.69 
87.78  169.71   90.83  169.16   92.96  169.16   96.01  169.16   
98.15  169.71 
100.58  170.69  102.41   171.3  106.68  172.21  117.04  172.52  
149.35  172.52 
155.45  173.74  161.54  174.96 
#Mann= 3 , 0 , 0  
70.1     .15       0   84.73  .05625       0  102.41     .15       0 
Bank Sta=84.73,102.41 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.464,.1 
Exp/Cntr=.5,.3 
 
Type RM Length L Ch R = 1 ,40160.5 ,105.92,102.49,100.58 
Node Name= 
#Sta/Elev= 31  
102.11  173.13   118.8  172.53  119.52  172.37  119.84  172.26  
119.99  172.21 
120.47  171.91  121.19  171.76  121.66   171.6  122.38   171.3  
122.79  171.06 
123.42  170.79  124.04  170.51  124.46  170.35  124.66  170.29  
126.38  170.04 
128.09  169.45  130.69  169.16  133.81  168.92  134.87  168.92   
136.4  168.92 
138.53  169.26  139.45  169.47  140.97  170.15   142.8  170.99  
145.76  171.86 
146.13  172.24  146.61  172.68  154.22  172.82  179.46  172.82  
184.22  173.43 
188.98  174.04 
#Mann= 3 , 0 , 0  
102.11     .15       0  122.38    .056       0   142.8     .15     0 
Bank Sta=122.38,142.8 
XS Rating Curve= 0  
XS HTab Starting El and Incr=169.22,.1 
Exp/Cntr=.5,.3 
 
 
 
168 
 
Appendix E: HEC HMS Input for MIKE 11 
 The hydrograph data used for both the HEC HMS and MIKE 11 models is the 
same.  The data is displayed in two sections.  The first section shown is the upstream 
(for East Fork and Mill Creek) and downstream (for Mill Creek) boundary data in 4-
minute time steps.  The upstream data is flow hydrographs and the downstream data 
is stage hydrographs.   The second section is flow data derived from the HEC HMS 
model.  It was inputted into both models at 15-minute time steps.  The flow data was 
extracted from the hydrologic model from the DSS utility for the HEC RAS model.  
For both sections, corresponding HEC RAS River Stations and MIKE 11 Chainages 
are provided for each boundary input. 
Table E-1. Mill Creek PDC model?s upstream and downstream boundary data. 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
1 4/15/1998 12:00 169.324 1.300 1.132 
2 4/15/1998 12:04 169.324 1.300 1.134 
3 4/15/1998 12:08 169.324 1.300 1.151 
4 4/15/1998 12:12 169.324 1.300 1.138 
5 4/15/1998 12:16 169.324 1.300 1.129 
6 4/15/1998 12:20 169.324 1.300 1.130 
7 4/15/1998 12:24 169.324 1.300 1.130 
8 4/15/1998 12:28 169.324 1.300 1.133 
9 4/15/1998 12:32 169.324 1.300 1.136 
10 4/15/1998 12:36 169.324 1.300 1.139 
11 4/15/1998 12:40 169.324 1.300 1.141 
12 4/15/1998 12:44 169.324 1.300 1.141 
13 4/15/1998 12:48 169.324 1.300 1.141 
14 4/15/1998 12:52 169.324 1.300 1.141 
15 4/15/1998 12:56 169.324 1.300 1.140 
16 4/15/1998 13:00 169.324 1.300 1.139 
17 4/15/1998 13:04 169.324 1.300 1.138 
      
169 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
18 4/15/1998 13:08 169.324 1.300 1.137 
19 4/15/1998 13:12 169.324 1.300 1.137 
20 4/15/1998 13:16 169.324 1.300 1.136 
21 4/15/1998 13:20 169.324 1.300 1.135 
22 4/15/1998 13:24 169.324 1.300 1.135 
23 4/15/1998 13:28 169.324 1.300 1.134 
24 4/15/1998 13:32 169.324 1.300 1.134 
25 4/15/1998 13:36 169.324 1.300 1.134 
26 4/15/1998 13:40 169.324 1.300 1.134 
27 4/15/1998 13:44 169.324 1.300 1.133 
28 4/15/1998 13:48 169.324 1.300 1.133 
29 4/15/1998 13:52 169.324 1.300 1.133 
30 4/15/1998 13:56 169.324 1.300 1.133 
31 4/15/1998 14:00 169.324 1.300 1.133 
32 4/15/1998 14:04 169.324 1.300 1.133 
33 4/15/1998 14:08 169.324 1.300 1.133 
34 4/15/1998 14:12 169.324 1.300 1.133 
35 4/15/1998 14:16 169.324 1.300 1.133 
36 4/15/1998 14:20 169.324 1.300 1.133 
37 4/15/1998 14:24 169.324 1.300 1.133 
38 4/15/1998 14:28 169.324 1.300 1.133 
39 4/15/1998 14:32 169.324 1.300 1.133 
40 4/15/1998 14:36 169.324 1.300 1.133 
41 4/15/1998 14:40 169.324 1.300 1.133 
42 4/15/1998 14:44 169.324 1.300 1.133 
43 4/15/1998 14:48 169.324 1.300 1.133 
44 4/15/1998 14:52 169.324 1.300 1.133 
45 4/15/1998 14:56 169.324 1.300 1.133 
46 4/15/1998 15:00 169.324 1.300 1.133 
47 4/15/1998 15:04 169.324 1.300 1.133 
48 4/15/1998 15:08 169.324 1.300 1.133 
49 4/15/1998 15:12 169.324 1.300 1.133 
50 4/15/1998 15:16 169.324 1.300 1.133 
51 4/15/1998 15:20 169.324 1.300 1.133 
52 4/15/1998 15:24 169.324 1.300 1.133 
53 4/15/1998 15:28 169.324 1.300 1.133 
170 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
54 4/15/1998 15:32 169.324 1.300 1.133 
55 4/15/1998 15:36 169.324 1.300 1.133 
56 4/15/1998 15:40 169.324 1.300 1.133 
57 4/15/1998 15:44 169.324 1.300 1.133 
58 4/15/1998 15:48 169.324 1.300 1.133 
59 4/15/1998 15:52 169.324 1.300 1.133 
60 4/15/1998 15:56 169.324 1.300 1.133 
61 4/15/1998 16:00 169.324 1.300 1.133 
62 4/15/1998 16:04 169.324 1.300 1.133 
63 4/15/1998 16:08 169.324 1.300 1.133 
64 4/15/1998 16:12 169.324 1.300 1.133 
65 4/15/1998 16:16 169.324 1.300 1.133 
66 4/15/1998 16:20 169.324 1.300 1.133 
67 4/15/1998 16:24 169.324 1.300 1.133 
68 4/15/1998 16:28 169.324 1.300 1.133 
69 4/15/1998 16:32 169.324 1.300 1.133 
70 4/15/1998 16:36 169.324 1.300 1.133 
71 4/15/1998 16:40 169.324 1.300 1.133 
72 4/15/1998 16:44 169.324 1.300 1.133 
73 4/15/1998 16:48 169.324 1.300 1.133 
74 4/15/1998 16:52 169.324 1.300 1.133 
75 4/15/1998 16:56 169.324 1.300 1.133 
76 4/15/1998 17:00 169.324 1.300 1.133 
77 4/15/1998 17:04 169.324 1.300 1.133 
78 4/15/1998 17:08 169.324 1.300 1.133 
79 4/15/1998 17:12 169.324 1.300 1.133 
80 4/15/1998 17:16 169.324 1.300 1.133 
81 4/15/1998 17:20 169.324 1.300 1.133 
82 4/15/1998 17:24 169.324 1.300 1.133 
83 4/15/1998 17:28 169.324 1.300 1.133 
84 4/15/1998 17:32 169.324 1.300 1.133 
85 4/15/1998 17:36 169.324 1.300 1.133 
86 4/15/1998 17:40 169.324 1.300 1.133 
87 4/15/1998 17:44 169.324 1.300 1.133 
88 4/15/1998 17:48 169.324 1.300 1.133 
89 4/15/1998 17:52 169.324 1.300 1.133 
171 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
90 4/15/1998 17:56 169.324 1.300 1.133 
91 4/15/1998 18:00 169.324 1.300 1.133 
92 4/15/1998 18:04 169.324 1.300 1.133 
93 4/15/1998 18:08 169.324 1.300 1.133 
94 4/15/1998 18:12 169.324 1.300 1.133 
95 4/15/1998 18:16 169.324 1.300 1.133 
96 4/15/1998 18:20 169.324 1.300 1.133 
97 4/15/1998 18:24 169.324 1.300 1.133 
98 4/15/1998 18:28 169.324 1.300 1.133 
99 4/15/1998 18:32 169.324 1.300 1.133 
100 4/15/1998 18:36 169.324 1.300 1.133 
101 4/15/1998 18:40 169.324 1.300 1.133 
102 4/15/1998 18:44 169.324 1.300 1.133 
103 4/15/1998 18:48 169.324 1.300 1.133 
104 4/15/1998 18:52 169.324 1.300 1.133 
105 4/15/1998 18:56 169.324 1.300 1.133 
106 4/15/1998 19:00 169.324 1.300 1.133 
107 4/15/1998 19:04 169.324 1.300 1.133 
108 4/15/1998 19:08 169.324 1.300 1.133 
109 4/15/1998 19:12 169.324 1.300 1.133 
110 4/15/1998 19:16 169.324 1.300 1.133 
111 4/15/1998 19:20 169.324 1.300 1.133 
112 4/15/1998 19:24 169.324 1.300 1.133 
113 4/15/1998 19:28 169.324 1.300 1.133 
114 4/15/1998 19:32 169.324 1.300 1.133 
115 4/15/1998 19:36 169.324 1.300 1.133 
116 4/15/1998 19:40 169.324 1.300 1.133 
117 4/15/1998 19:44 169.324 1.300 1.133 
118 4/15/1998 19:48 169.324 1.300 1.133 
119 4/15/1998 19:52 169.324 1.300 1.133 
120 4/15/1998 19:56 169.324 1.300 1.133 
121 4/15/1998 20:00 169.324 1.300 1.133 
122 4/15/1998 20:04 169.324 1.300 1.133 
123 4/15/1998 20:08 169.324 1.300 1.133 
124 4/15/1998 20:12 169.324 1.300 1.133 
125 4/15/1998 20:16 169.324 1.300 1.133 
172 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
126 4/15/1998 20:20 169.324 1.300 1.133 
127 4/15/1998 20:24 169.324 1.300 1.133 
128 4/15/1998 20:28 169.324 1.300 1.133 
129 4/15/1998 20:32 169.324 1.300 1.133 
130 4/15/1998 20:36 169.324 1.300 1.133 
131 4/15/1998 20:40 169.324 1.300 1.133 
132 4/15/1998 20:44 169.324 1.300 1.133 
133 4/15/1998 20:48 169.324 1.300 1.133 
134 4/15/1998 20:52 169.324 1.300 1.133 
135 4/15/1998 20:56 169.324 1.300 1.133 
136 4/15/1998 21:00 169.324 1.300 1.133 
137 4/15/1998 21:04 169.324 1.300 1.133 
138 4/15/1998 21:08 169.324 1.300 1.133 
139 4/15/1998 21:12 169.324 1.300 1.133 
140 4/15/1998 21:16 169.324 1.300 1.133 
141 4/15/1998 21:20 169.324 1.300 1.133 
142 4/15/1998 21:24 169.324 1.300 1.133 
143 4/15/1998 21:28 169.324 1.300 1.133 
144 4/15/1998 21:32 169.324 1.300 1.133 
145 4/15/1998 21:36 169.324 1.300 1.133 
146 4/15/1998 21:40 169.324 1.300 1.133 
147 4/15/1998 21:44 169.324 1.300 1.133 
148 4/15/1998 21:48 169.324 1.300 1.133 
149 4/15/1998 21:52 169.324 1.300 1.133 
150 4/15/1998 21:56 169.324 1.300 1.133 
151 4/15/1998 22:00 169.324 1.300 1.133 
152 4/15/1998 22:04 169.324 1.300 1.133 
153 4/15/1998 22:08 169.324 1.300 1.133 
154 4/15/1998 22:12 169.324 1.300 1.133 
155 4/15/1998 22:16 169.324 1.300 1.133 
156 4/15/1998 22:20 169.324 1.300 1.133 
157 4/15/1998 22:24 169.324 1.300 1.133 
158 4/15/1998 22:28 169.324 1.300 1.133 
159 4/15/1998 22:32 169.324 1.300 1.133 
160 4/15/1998 22:36 169.324 1.300 1.133 
161 4/15/1998 22:40 169.324 1.300 1.133 
173 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
162 4/15/1998 22:44 169.324 1.300 1.133 
163 4/15/1998 22:48 169.324 1.300 1.133 
164 4/15/1998 22:52 169.324 1.300 1.133 
165 4/15/1998 22:56 169.324 1.300 1.133 
166 4/15/1998 23:00 169.324 1.300 1.133 
167 4/15/1998 23:04 169.324 1.300 1.133 
168 4/15/1998 23:08 169.324 1.300 1.133 
169 4/15/1998 23:12 169.324 1.300 1.133 
170 4/15/1998 23:16 169.324 1.300 1.133 
171 4/15/1998 23:20 169.324 1.300 1.133 
172 4/15/1998 23:24 169.324 1.300 1.133 
173 4/15/1998 23:28 169.324 1.300 1.133 
174 4/15/1998 23:32 169.324 1.300 1.133 
175 4/15/1998 23:36 169.324 1.300 1.133 
176 4/15/1998 23:40 169.324 1.300 1.133 
177 4/15/1998 23:44 169.324 1.300 1.133 
178 4/15/1998 23:48 169.324 1.300 1.133 
179 4/15/1998 23:52 169.324 1.300 1.133 
180 4/15/1998 23:56 169.324 1.300 1.133 
181 4/15/1998 0:00 169.324 1.300 1.133 
182 4/16/1998 0:04 169.324 1.300 1.133 
183 4/16/1998 0:08 169.324 1.300 1.133 
184 4/16/1998 0:12 169.324 1.300 1.133 
185 4/16/1998 0:16 169.324 1.300 1.133 
186 4/16/1998 0:20 169.324 1.300 1.133 
187 4/16/1998 0:24 169.324 1.300 1.133 
188 4/16/1998 0:28 169.324 1.300 1.133 
189 4/16/1998 0:32 169.324 1.300 1.133 
190 4/16/1998 0:36 169.324 1.300 1.133 
191 4/16/1998 0:40 169.324 1.300 1.133 
192 4/16/1998 0:44 169.324 1.300 1.133 
193 4/16/1998 0:48 169.324 1.300 1.133 
194 4/16/1998 0:52 169.324 1.300 1.133 
195 4/16/1998 0:56 169.324 1.300 1.133 
196 4/16/1998 1:00 169.324 1.300 1.133 
197 4/16/1998 1:04 169.324 1.300 1.133 
174 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
198 4/16/1998 1:08 169.324 1.300 1.133 
199 4/16/1998 1:12 169.324 1.300 1.133 
200 4/16/1998 1:16 169.324 1.300 1.133 
201 4/16/1998 1:20 169.324 1.300 1.133 
202 4/16/1998 1:24 169.324 1.300 1.133 
203 4/16/1998 1:28 169.324 1.300 1.133 
204 4/16/1998 1:32 169.324 1.300 1.133 
205 4/16/1998 1:36 169.324 1.300 1.133 
206 4/16/1998 1:40 169.324 1.300 1.133 
207 4/16/1998 1:44 169.324 1.300 1.133 
208 4/16/1998 1:48 169.324 1.300 1.133 
209 4/16/1998 1:52 169.324 1.300 1.133 
210 4/16/1998 1:56 169.324 1.300 1.133 
211 4/16/1998 2:00 169.324 1.300 1.133 
212 4/16/1998 2:04 169.324 1.300 1.133 
213 4/16/1998 2:08 169.324 1.300 1.133 
214 4/16/1998 2:12 169.324 1.300 1.133 
215 4/16/1998 2:16 169.324 1.300 1.133 
216 4/16/1998 2:20 169.324 1.300 1.133 
217 4/16/1998 2:24 169.324 1.300 1.133 
218 4/16/1998 2:28 169.324 1.300 1.133 
219 4/16/1998 2:32 169.324 1.300 1.133 
220 4/16/1998 2:36 169.324 1.300 1.133 
221 4/16/1998 2:40 169.324 1.300 1.133 
222 4/16/1998 2:44 169.324 1.300 1.133 
223 4/16/1998 2:48 169.324 1.300 1.133 
224 4/16/1998 2:52 169.324 1.300 1.133 
225 4/16/1998 2:56 169.324 1.299 1.133 
226 4/16/1998 3:00 169.325 1.298 1.133 
227 4/16/1998 3:04 169.325 1.297 1.133 
228 4/16/1998 3:08 169.327 1.295 1.133 
229 4/16/1998 3:12 169.329 1.290 1.133 
230 4/16/1998 3:16 169.333 1.286 1.133 
231 4/16/1998 3:20 169.338 1.281 1.133 
232 4/16/1998 3:24 169.345 1.274 1.133 
233 4/16/1998 3:28 169.354 1.265 1.133 
175 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
234 4/16/1998 3:32 169.367 1.255 1.133 
235 4/16/1998 3:36 169.382 1.242 1.134 
236 4/16/1998 3:40 169.400 1.227 1.136 
237 4/16/1998 3:44 169.422 1.209 1.140 
238 4/16/1998 3:48 169.447 1.189 1.148 
239 4/16/1998 3:52 169.476 1.164 1.161 
240 4/16/1998 3:56 169.508 1.132 1.183 
241 4/16/1998 4:00 169.542 1.095 1.218 
242 4/16/1998 4:04 169.579 1.056 1.272 
243 4/16/1998 4:08 169.620 1.002 1.352 
244 4/16/1998 4:12 169.663 0.929 1.470 
245 4/16/1998 4:16 169.709 0.853 1.651 
246 4/16/1998 4:20 169.757 0.779 1.908 
247 4/16/1998 4:24 169.808 0.679 2.305 
248 4/16/1998 4:28 169.861 0.560 2.894 
249 4/16/1998 4:32 169.916 0.461 3.710 
250 4/16/1998 4:36 169.973 0.377 4.840 
251 4/16/1998 4:40 170.033 0.246 6.210 
252 4/16/1998 4:44 170.095 0.161 7.768 
253 4/16/1998 4:48 170.159 0.225 9.982 
254 4/16/1998 4:52 170.226 0.353 12.192 
255 4/16/1998 4:56 170.295 0.578 14.890 
256 4/16/1998 5:00 170.365 1.014 17.828 
257 4/16/1998 5:04 170.437 1.709 20.904 
258 4/16/1998 5:08 170.511 2.612 24.273 
259 4/16/1998 5:12 170.585 3.691 27.221 
260 4/16/1998 5:16 170.661 5.012 30.811 
261 4/16/1998 5:20 170.738 6.489 33.738 
262 4/16/1998 5:24 170.815 8.177 37.233 
263 4/16/1998 5:28 170.893 10.155 40.111 
264 4/16/1998 5:32 170.973 11.986 42.969 
265 4/16/1998 5:36 171.057 14.594 45.745 
266 4/16/1998 5:40 171.147 17.775 47.707 
267 4/16/1998 5:44 171.250 21.117 49.903 
268 4/16/1998 5:48 171.364 24.638 51.111 
269 4/16/1998 5:52 171.493 27.686 52.540 
176 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
270 4/16/1998 5:56 171.637 31.025 53.072 
271 4/16/1998 6:00 171.791 33.802 53.334 
272 4/16/1998 6:04 171.950 36.910 53.347 
273 4/16/1998 6:08 172.108 41.461 52.995 
274 4/16/1998 6:12 172.267 44.970 52.414 
275 4/16/1998 6:16 172.429 47.884 51.316 
276 4/16/1998 6:20 172.595 51.821 50.346 
277 4/16/1998 6:24 172.745 54.563 48.899 
278 4/16/1998 6:28 172.889 57.644 47.583 
279 4/16/1998 6:32 173.024 60.604 45.792 
280 4/16/1998 6:36 173.148 63.031 44.325 
281 4/16/1998 6:40 173.264 65.900 42.364 
282 4/16/1998 6:44 173.369 68.001 40.765 
283 4/16/1998 6:48 173.466 70.496 38.754 
284 4/16/1998 6:52 173.553 72.566 37.065 
285 4/16/1998 6:56 173.633 74.582 35.143 
286 4/16/1998 7:00 173.705 76.627 33.482 
287 4/16/1998 7:04 173.772 78.181 31.693 
288 4/16/1998 7:08 173.829 80.194 30.011 
289 4/16/1998 7:12 173.883 81.522 28.445 
290 4/16/1998 7:16 173.930 83.178 26.884 
291 4/16/1998 7:20 173.973 84.381 25.532 
292 4/16/1998 7:24 174.010 85.809 24.072 
293 4/16/1998 7:28 174.045 86.910 22.942 
294 4/16/1998 7:32 174.074 87.960 21.693 
295 4/16/1998 7:36 174.101 89.047 20.758 
296 4/16/1998 7:40 174.123 89.893 19.689 
297 4/16/1998 7:44 174.143 90.892 18.965 
298 4/16/1998 7:48 174.161 91.425 18.147 
299 4/16/1998 7:52 174.176 92.429 17.582 
300 4/16/1998 7:56 174.189 92.847 16.992 
301 4/16/1998 8:00 174.200 93.591 16.578 
302 4/16/1998 8:04 174.210 93.989 16.208 
303 4/16/1998 8:08 174.217 94.514 15.903 
304 4/16/1998 8:12 174.225 95.050 15.690 
305 4/16/1998 8:16 174.229 95.135 15.474 
177 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
306 4/16/1998 8:20 174.234 95.813 15.361 
307 4/16/1998 8:24 174.236 95.720 15.209 
308 4/16/1998 8:28 174.238 96.356 15.147 
309 4/16/1998 8:32 174.238 96.181 15.037 
310 4/16/1998 8:36 174.238 96.580 14.973 
311 4/16/1998 8:40 174.235 96.651 14.897 
312 4/16/1998 8:44 174.233 96.625 14.811 
313 4/16/1998 8:48 174.229 96.942 14.739 
314 4/16/1998 8:52 174.224 96.594 14.615 
315 4/16/1998 8:56 174.218 97.069 14.526 
316 4/16/1998 9:00 174.210 96.579 14.345 
317 4/16/1998 9:04 174.202 96.902 14.177 
318 4/16/1998 9:08 174.192 96.621 13.939 
319 4/16/1998 9:12 174.182 96.573 13.699 
320 4/16/1998 9:16 174.170 96.604 13.390 
321 4/16/1998 9:20 174.158 96.115 13.062 
322 4/16/1998 9:24 174.143 96.446 12.690 
323 4/16/1998 9:28 174.129 95.694 12.323 
324 4/16/1998 9:32 174.112 96.011 11.904 
325 4/16/1998 9:36 174.096 95.302 11.516 
326 4/16/1998 9:40 174.077 95.321 11.068 
327 4/16/1998 9:44 174.058 94.901 10.685 
328 4/16/1998 9:48 174.037 94.427 10.227 
329 4/16/1998 9:52 174.016 94.376 9.864 
330 4/16/1998 9:56 173.993 93.481 9.409 
331 4/16/1998 10:00 173.969 93.570 9.070 
332 4/16/1998 10:04 173.945 92.560 8.627 
333 4/16/1998 10:08 173.919 92.437 8.309 
334 4/16/1998 10:12 173.894 91.674 7.887 
335 4/16/1998 10:16 173.866 91.051 7.581 
336 4/16/1998 10:20 173.839 90.714 7.198 
337 4/16/1998 10:24 173.810 89.548 6.899 
338 4/16/1998 10:28 173.781 89.526 6.569 
339 4/16/1998 10:32 173.751 88.107 6.279 
340 4/16/1998 10:36 173.720 88.011 6.009 
341 4/16/1998 10:40 173.689 86.754 5.735 
178 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
342 4/16/1998 10:44 173.658 86.187 5.509 
343 4/16/1998 10:48 173.626 85.443 5.261 
344 4/16/1998 10:52 173.594 84.233 5.068 
345 4/16/1998 10:56 173.561 83.943 4.854 
346 4/16/1998 11:00 173.528 82.383 4.671 
347 4/16/1998 11:04 173.495 82.132 4.500 
348 4/16/1998 11:08 173.462 80.749 4.336 
349 4/16/1998 11:12 173.429 79.977 4.199 
350 4/16/1998 11:16 173.395 79.228 4.041 
351 4/16/1998 11:20 173.362 77.719 3.920 
352 4/16/1998 11:24 173.328 77.537 3.785 
353 4/16/1998 11:28 173.294 75.628 3.673 
354 4/16/1998 11:32 173.260 75.498 3.553 
355 4/16/1998 11:36 173.227 73.879 3.454 
356 4/16/1998 11:40 173.193 73.130 3.348 
357 4/16/1998 11:44 173.159 72.263 3.248 
358 4/16/1998 11:48 173.125 70.720 3.157 
359 4/16/1998 11:52 173.092 70.461 3.063 
360 4/16/1998 11:56 173.058 68.612 2.983 
361 4/16/1998 12:00 173.024 68.249 2.892 
362 4/16/1998 12:04 172.990 66.911 2.818 
363 4/16/1998 12:08 172.956 65.769 2.754 
364 4/16/1998 12:12 172.923 65.308 2.670 
365 4/16/1998 12:16 172.889 63.400 2.618 
366 4/16/1998 12:20 172.855 63.402 2.560 
367 4/16/1998 12:24 172.821 61.484 2.492 
368 4/16/1998 12:28 172.788 61.065 2.434 
369 4/16/1998 12:32 172.754 59.941 2.383 
370 4/16/1998 12:36 172.721 58.651 2.320 
371 4/16/1998 12:40 172.688 58.350 2.280 
372 4/16/1998 12:44 172.654 56.575 2.216 
373 4/16/1998 12:48 172.621 56.293 2.172 
374 4/16/1998 12:52 172.588 54.978 2.133 
375 4/16/1998 12:56 172.555 53.936 2.091 
376 4/16/1998 13:00 172.522 53.494 2.055 
377 4/16/1998 13:04 172.489 51.801 2.019 
179 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
378 4/16/1998 13:08 172.456 51.787 1.989 
379 4/16/1998 13:12 172.423 50.227 1.950 
380 4/16/1998 13:16 172.390 49.672 1.924 
381 4/16/1998 13:20 172.358 48.832 1.891 
382 4/16/1998 13:24 172.325 47.624 1.862 
383 4/16/1998 13:28 172.293 47.222 1.838 
384 4/16/1998 13:32 172.261 45.923 1.811 
385 4/16/1998 13:36 172.231 45.335 1.780 
386 4/16/1998 13:40 172.201 44.592 1.753 
387 4/16/1998 13:44 172.170 43.640 1.718 
388 4/16/1998 13:48 172.139 43.199 1.686 
389 4/16/1998 13:52 172.108 41.986 1.651 
390 4/16/1998 13:56 172.078 41.672 1.622 
391 4/16/1998 14:00 172.047 40.849 1.593 
392 4/16/1998 14:04 172.017 40.150 1.570 
393 4/16/1998 14:08 171.987 39.469 1.546 
394 4/16/1998 14:12 171.957 38.713 1.520 
395 4/16/1998 14:16 171.927 38.051 1.506 
396 4/16/1998 14:20 171.898 37.102 1.483 
397 4/16/1998 14:24 171.869 36.466 1.471 
398 4/16/1998 14:28 171.841 35.915 1.452 
399 4/16/1998 14:32 171.813 35.029 1.439 
400 4/16/1998 14:36 171.785 34.593 1.421 
401 4/16/1998 14:40 171.757 33.777 1.403 
402 4/16/1998 14:44 171.729 33.271 1.387 
403 4/16/1998 14:48 171.701 32.586 1.372 
404 4/16/1998 14:52 171.673 31.964 1.356 
405 4/16/1998 14:56 171.645 31.370 1.343 
406 4/16/1998 15:00 171.618 30.771 1.328 
407 4/16/1998 15:04 171.591 30.164 1.318 
408 4/16/1998 15:08 171.564 29.627 1.305 
409 4/16/1998 15:12 171.538 29.009 1.296 
410 4/16/1998 15:16 171.512 28.568 1.285 
411 4/16/1998 15:20 171.486 27.955 1.278 
412 4/16/1998 15:24 171.460 27.535 1.266 
413 4/16/1998 15:28 171.434 26.964 1.259 
180 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
414 4/16/1998 15:32 171.409 26.533 1.248 
415 4/16/1998 15:36 171.384 26.007 1.242 
416 4/16/1998 15:40 171.359 25.566 1.231 
417 4/16/1998 15:44 171.334 25.066 1.227 
418 4/16/1998 15:48 171.310 24.642 1.218 
419 4/16/1998 15:52 171.286 24.153 1.214 
420 4/16/1998 15:56 171.263 23.775 1.206 
421 4/16/1998 16:00 171.239 23.278 1.203 
422 4/16/1998 16:04 171.216 22.910 1.196 
423 4/16/1998 16:08 171.193 22.437 1.193 
424 4/16/1998 16:12 171.170 22.065 1.187 
425 4/16/1998 16:16 171.148 21.612 1.184 
426 4/16/1998 16:20 171.126 21.246 1.179 
427 4/16/1998 16:24 171.104 20.804 1.176 
428 4/16/1998 16:28 171.082 20.447 1.172 
429 4/16/1998 16:32 171.061 20.021 1.170 
430 4/16/1998 16:36 171.039 19.706 1.166 
431 4/16/1998 16:40 171.019 19.307 1.164 
432 4/16/1998 16:44 170.998 18.988 1.160 
433 4/16/1998 16:48 170.978 18.608 1.159 
434 4/16/1998 16:52 170.958 18.313 1.155 
435 4/16/1998 16:56 170.938 17.953 1.155 
436 4/16/1998 17:00 170.919 17.660 1.151 
437 4/16/1998 17:04 170.899 17.308 1.151 
438 4/16/1998 17:08 170.880 17.019 1.148 
439 4/16/1998 17:12 170.861 16.677 1.148 
440 4/16/1998 17:16 170.842 16.398 1.145 
441 4/16/1998 17:20 170.824 16.047 1.146 
442 4/16/1998 17:24 170.805 15.767 1.143 
443 4/16/1998 17:28 170.787 15.427 1.143 
444 4/16/1998 17:32 170.770 15.156 1.141 
445 4/16/1998 17:36 170.753 14.839 1.142 
446 4/16/1998 17:40 170.736 14.577 1.142 
447 4/16/1998 17:44 170.719 14.272 1.145 
448 4/16/1998 17:48 170.703 14.031 1.149 
449 4/16/1998 17:52 170.688 13.740 1.158 
181 
 
Time Step #: 
 
Date: 
 
Time: 
 
h (meters): 
 
U/S Mill Creek 
Q (m
3
/s) 
U/S East Fork 
Q (m
3
/s) 
Chainage: 20732.45 15407.15 11427.12 
 River Station: 18.83 5179.47 1173.84 
450 4/16/1998 17:56 170.672 13.498 1.171 
451 4/16/1998 18:00 170.657 13.214 1.193 
452 4/16/1998 18:04 170.643 12.986 1.225 
453 4/16/1998 18:08 170.628 12.714 1.270 
454 4/16/1998 18:12 170.614 12.487 1.332 
455 4/16/1998 18:16 170.601 12.226 1.414 
456 4/16/1998 18:20 170.587 12.011 1.522 
457 4/16/1998 18:24 170.575 11.763 1.654 
458 4/16/1998 18:28 170.563 11.563 1.810 
459 4/16/1998 18:32 170.551 11.333 1.987 
460 4/16/1998 18:36 170.539 11.151 2.186 
461 4/16/1998 18:40 170.528 10.941 2.394 
462 4/16/1998 18:44 170.517 10.780 2.596 
463 4/16/1998 18:48 170.506 10.596 2.789 
464 4/16/1998 18:52 170.496 10.459 2.962 
465 4/16/1998 18:56 170.485 10.298 3.122 
466 4/16/1998 19:00 170.475 10.180 3.245 
 
182 
 
Table E-2. Mill Creek PDC model?s lateral boundary data extracted from the 
HEC HMS model. 
Time 
Step #: 
 
 
Date: Time: 
Basin 
109 
Runoff 
(m
3
/s) 
Basin 
110 
Runoff 
(m
3
/s) 
Basin 
111 
Runoff 
(m
3
/s) 
Basin 
115 
Runoff 
(m
3
/s) 
Basins 
112 - 117 
Runoff 
(m
3
/s) 
Chainage: 
15829.00 16443.00 15850.00 20000.00 20248.00 
 River Station: 4822.09 4043.30 4577.87 525.69 336.56 
1 4/15/1998 12:00 0 0 0 0 0 
2 4/15/1998 12:15 0 0 0 0 0 
3 4/15/1998 12:30 0 0 0 0 0 
4 4/15/1998 12:45 0 0 0 0 0 
5 4/15/1998 13:00 0 0 0 0 0 
6 4/15/1998 13:15 0 0 0 0 0 
7 4/15/1998 13:30 0 0 0 0 0 
8 4/15/1998 13:45 0 0 0 0 0 
9 4/15/1998 14:00 0 0 0 0 0 
10 4/15/1998 14:15 0 0 0 0 0 
11 4/15/1998 14:30 0 0 0 0 0 
12 4/15/1998 14:45 0 0 0 0 0 
13 4/15/1998 15:00 0 0 0 0 0 
14 4/15/1998 15:15 0 0 0 0 0 
15 4/15/1998 15:30 0 0 0 0 0 
16 4/15/1998 15:45 0 0 0 0 0 
17 4/15/1998 16:00 0 0 0 0 0 
18 4/15/1998 16:15 0 0 0 0 0 
19 4/15/1998 16:30 0 0 0 0 0 
20 4/15/1998 16:45 0 0 0 0 0 
21 4/15/1998 17:00 0 0 0 0 0 
22 4/15/1998 17:15 0 0 0 0 0 
23 4/15/1998 17:30 0 0 0 0 0 
24 4/15/1998 17:45 0 0 0 0 0 
25 4/15/1998 18:00 0 0 0 0 0 
26 4/15/1998 18:15 0 0 0 0 0 
27 4/15/1998 18:30 0 0 0 0 0 
28 4/15/1998 18:45 0 0 0 0 0 
29 4/15/1998 19:00 0 0 0 0 0 
30 4/15/1998 19:15 0 0 0 0 0 
31 4/15/1998 19:30 0 0 0 0 0 
32 4/15/1998 19:45 0 0 0 0 0 
183 
 
Time 
Step #: 
 
 
Date: Time: 
Basin 
109 
Runoff 
(m
3
/s) 
Basin 
110 
Runoff 
(m
3
/s) 
Basin 
111 
Runoff 
(m
3
/s) 
Basin 
115 
Runoff 
(m
3
/s) 
Basins 
112 - 117 
Runoff 
(m
3
/s) 
Chainage: 
15829.00 16443.00 15850.00 20000.00 20248.00 
 River Station: 4822.09 4043.30 4577.87 525.69 336.56 
33 4/15/1998 20:00 0 0 0 0 0 
34 4/15/1998 20:15 0 0 0 0 0 
35 4/15/1998 20:30 0 0 0 0 0 
36 4/15/1998 20:45 0 0 0 0 0 
37 4/15/1998 21:00 0 0 0 0 0 
38 4/15/1998 21:15 0 0 0 0 0 
39 4/15/1998 21:30 0 0 0 0 0 
40 4/15/1998 21:45 0 0 0 0 0 
41 4/15/1998 22:00 0 0 0 0 0 
42 4/15/1998 22:15 0 0 0 0 0 
43 4/15/1998 22:30 0 0 0 0 0 
44 4/15/1998 22:45 0 0 0 0 0 
45 4/15/1998 23:00 0 0 0 0 0 
46 4/15/1998 23:15 0 0 0 0 0 
47 4/15/1998 23:30 0 0 0 0 0 
48 4/15/1998 23:45 0 0 0 0 0 
49 4/15/1998 0:00 0 0 0 0 0 
50 4/16/1998 0:15 0 0 0 0 0 
51 4/16/1998 0:30 0 0 0 0 0 
52 4/16/1998 0:45 0 0 0 0 0 
53 4/16/1998 1:00 0 0 0 0 0 
54 4/16/1998 1:15 0 0 0 0 0 
55 4/16/1998 1:30 0 0 0 0 0 
56 4/16/1998 1:45 0 0 0 0 0 
57 4/16/1998 2:00 0 0 0 0 0 
58 4/16/1998 2:15 0 0 0 0 0 
59 4/16/1998 2:30 0 0 0 0 0 
60 4/16/1998 2:45 0 0 0 0 0 
61 4/16/1998 3:00 0.03 0.006 0.032 0.043 0.034 
62 4/16/1998 3:15 0.151 0.0316 0.155 0.198 0.25 
63 4/16/1998 3:30 0.367 0.0783 0.382 0.465 0.832 
64 4/16/1998 3:45 0.694 0.1482 0.732 0.865 1.846 
65 4/16/1998 4:00 1.163 0.248 1.237 1.424 3.248 
66 4/16/1998 4:15 1.88 0.4042 2.004 2.26 5.032 
184 
 
Time 
Step #: 
 
 
Date: Time: 
Basin 
109 
Runoff 
(m
3
/s) 
Basin 
110 
Runoff 
(m
3
/s) 
Basin 
111 
Runoff 
(m
3
/s) 
Basin 
115 
Runoff 
(m
3
/s) 
Basins 
112 - 117 
Runoff 
(m
3
/s) 
Chainage: 
15829.00 16443.00 15850.00 20000.00 20248.00 
 River Station: 4822.09 4043.30 4577.87 525.69 336.56 
67 4/16/1998 4:30 2.9 0.6269 3.091 3.453 7.317 
68 4/16/1998 4:45 4.37 0.9416 4.589 5.163 10.239 
69 4/16/1998 5:00 6.248 1.3418 6.449 7.391 13.92 
70 4/16/1998 5:15 8.485 1.812 8.595 10.084 18.174 
71 4/16/1998 5:30 10.984 2.3372 10.976 13.142 22.548 
72 4/16/1998 5:45 13.776 2.909 13.54 16.558 26.537 
73 4/16/1998 6:00 16.746 3.5188 16.189 20.224 29.838 
74 4/16/1998 6:15 19.86 4.1353 18.784 24.149 32.293 
75 4/16/1998 6:30 22.88 4.7278 21.208 28.096 33.86 
76 4/16/1998 6:45 25.693 5.2432 23.245 31.896 34.615 
77 4/16/1998 7:00 28.098 5.6607 24.779 35.318 34.561 
78 4/16/1998 7:15 29.968 5.9592 25.834 38.187 33.764 
79 4/16/1998 7:30 31.318 6.1468 26.414 40.381 32.46 
80 4/16/1998 7:45 32.135 6.2362 26.565 41.911 30.866 
81 4/16/1998 8:00 32.505 6.2279 26.291 42.877 29.163 
82 4/16/1998 8:15 32.448 6.1302 25.691 43.274 27.557 
83 4/16/1998 8:30 31.977 5.9602 24.789 43.092 26.067 
84 4/16/1998 8:45 31.155 5.7344 23.759 42.467 24.64 
85 4/16/1998 9:00 30.085 5.4774 22.604 41.389 23.242 
86 4/16/1998 9:15 28.844 5.1956 21.33 39.998 21.839 
87 4/16/1998 9:30 27.45 4.8787 19.933 38.416 20.427 
88 4/16/1998 9:45 25.916 4.539 18.517 36.657 19.023 
89 4/16/1998 10:00 24.225 4.1923 17.124 34.633 17.675 
90 4/16/1998 10:15 22.478 3.861 15.797 32.447 16.399 
91 4/16/1998 10:30 20.728 3.5481 14.563 30.124 15.192 
92 4/16/1998 10:45 19.112 3.2603 13.392 27.839 14.065 
93 4/16/1998 11:00 17.599 2.9925 12.275 25.662 13.022 
94 4/16/1998 11:15 16.182 2.7401 11.225 23.646 12.05 
95 4/16/1998 11:30 14.855 2.504 10.246 21.762 11.16 
96 4/16/1998 11:45 13.629 2.2872 9.302 19.981 10.352 
97 4/16/1998 12:00 12.474 2.0807 8.387 18.331 9.611 
98 4/16/1998 12:15 11.405 1.8806 7.52 16.789 8.942 
99 4/16/1998 12:30 10.38 1.6903 6.708 15.345 8.335 
100 4/16/1998 12:45 9.386 1.5138 5.962 13.98 7.788 
185 
 
Time 
Step #: 
 
 
Date: Time: 
Basin 
109 
Runoff 
(m
3
/s) 
Basin 
110 
Runoff 
(m
3
/s) 
Basin 
111 
Runoff 
(m
3
/s) 
Basin 
115 
Runoff 
(m
3
/s) 
Basins 
112 - 117 
Runoff 
(m
3
/s) 
Chainage: 
15829.00 16443.00 15850.00 20000.00 20248.00 
 River Station: 4822.09 4043.30 4577.87 525.69 336.56 
101 4/16/1998 13:00 8.459 1.3503 5.287 12.668 7.297 
102 4/16/1998 13:15 7.602 1.2038 4.676 11.425 6.862 
103 4/16/1998 13:30 6.803 1.0705 4.129 10.276 6.48 
104 4/16/1998 13:45 6.09 0.949 3.657 9.214 6.141 
105 4/16/1998 14:00 5.444 0.8443 3.244 8.26 5.838 
106 4/16/1998 14:15 4.864 0.7531 2.878 7.413 5.567 
107 4/16/1998 14:30 4.36 0.6704 2.555 6.646 5.323 
108 4/16/1998 14:45 3.914 0.598 2.269 5.976 5.102 
109 4/16/1998 15:00 3.506 0.5333 2.018 5.382 4.9 
110 4/16/1998 15:15 3.145 0.4756 1.792 4.837 4.715 
111 4/16/1998 15:30 2.824 0.4247 1.591 4.351 4.545 
112 4/16/1998 15:45 2.532 0.3787 1.413 3.919 4.39 
113 4/16/1998 16:00 2.273 0.3379 1.253 3.524 4.245 
114 4/16/1998 16:15 2.042 0.3011 1.112 3.169 4.111 
115 4/16/1998 16:30 1.831 0.2681 0.988 2.853 3.984 
116 4/16/1998 16:45 1.642 0.2395 0.877 2.568 3.865 
117 4/16/1998 17:00 1.474 0.2136 0.779 2.308 3.752 
118 4/16/1998 17:15 1.322 0.1902 0.697 2.077 3.644 
119 4/16/1998 17:30 1.187 0.1699 0.627 1.883 3.543 
120 4/16/1998 17:45 1.082 0.1551 0.584 1.727 3.477 
121 4/16/1998 18:00 1.001 0.1449 0.561 1.608 3.476 
122 4/16/1998 18:15 0.943 0.1393 0.557 1.522 3.545 
123 4/16/1998 18:30 0.908 0.137 0.573 1.462 3.663 
124 4/16/1998 18:45 0.891 0.1388 0.616 1.431 3.784 
125 4/16/1998 19:00 0.891 0.1442 0.682 1.436 3.881 
 
186 
 
Appendix F: Data Dictionary 
Data Description Class Attribute Units 
3dxsectsef Shape file of East 
Fork cross-sections 
for use in terrain 
model modification 
PolylineZ XYZ 
coordinates 
Meters 
3dxsectsmc Shape file of Mill 
Creek cross-sections 
for use in terrain 
model modification 
PolylineZ XYZ 
coordinates 
Meters 
Bnd1 MIKE 11 boundary 
file depicting base 
flow conditions of 
study area 
.BND11 Time-series 
boundary 
conditions 
m
3
/s, Meters 
Bnd1PDC1 MIKE 11 boundary 
file depicting flow 
conditions of study 
area?s 25-yr storm 
event  
.BND11 Time-series 
boundary 
conditions 
m
3
/s, Meters 
Channelbds Shape file created 
from stream channel 
bounds for 
modifying terrain 
model  
Polygon XYZ 
coordinates 
Meters 
Crtin1 TIN of initial terrain 
model, without 
stream features 
TIN Elevation Meters 
Eastpdcreachpts Shape file of East 
Fork points 
extracted from 
Nwtin1, used to 
defined stream 
network 
Point XY coordinate Meters 
 
187 
 
Data Description Class Attribute Units 
Efclip Shape file of clipped 
East Fork cross-
sections of the 
stream channel 
PolylineZ XYZ 
coordinates 
Meters 
Floodmap GIS project file for -
terrain model 
modification 
.apr   
Gridpts Shape file of point 
elevations created 
from the Pdcgrid1 
file, for integrating 
stream features into 
terrain model 
Point Elevation Meters 
HDPar1 MIKE 11 
hydrodynamic 
parameter file of 
study area 
.HD11 Manning?s n 
values 
 
Hpoints.txt Shape file of MIKE 
11 simulation results 
Point Time-series 
stage height 
Meters 
Mcclip Shape file of clipped 
Mill Creek cross-
sections of the 
stream channel 
PolylineZ XYZ 
coordinates 
Meters 
Millpdcreachpts Shape file of Mill 
Creek points 
extracted from 
Nwtin1, used to 
defined stream 
network 
Point XY coordinate Meters 
MllCreek_CSO DSS file created 
from HEC HMS 
model 
.dss Runoff 
hydrographs 
m
3
/s 
Nwtin1 TIN of modified 
terrain model, with 
stream features 
TIN Elevation Meters 
188 
 
Data Description Class Attribute Units 
Pdc1 MIKE 11 simulation 
data created from 
flow model 
.MSD Time-series 
data 
m
3
/s, Meters 
Pdc1 MIKE 11 simulation 
file for study area?s 
25-yr storm event 
.SIM11   
pdc1hotstart MIKE 11 simulation 
file establishing the 
study area?s initial 
conditions 
.SIM11   
pdc1model MIKE 11 network 
file of study area 
.NWK11 XY 
coordinates, 
Chainage 
Meters 
pdc2ftcontrs Shape file with 2-ft 
contour lines for the 
PDC study area 
Polyline Elevation Meters 
pdc5 RAS geometry file 
of study area 
.g01   
pdc5 RAS GIS export file 
exported from RAS 
model into GIS 
.gis Time-series 
stage heights 
Meters 
pdc5 RAS plan file of 
study area 
.p01   
pdc5 RAS project file of 
study area 
.prj   
pdc5 RAS unsteady flow 
file of study area 
.u01   
Pdcbanks Shape file of 
GeoRAS stream 
banks 
Polyline XY 
coordinates 
Meters 
Pdcdem Grid of modified 
terrain model, with 
stream features 
5-m Grid Elevation  Meters 
189 
 
Data Description Class Attribute Units 
Pdcflowpath Shape file of 
GeoRAS stream and 
overbank flow paths 
Polyline XY 
coordinates, 
River 
Stationing 
Meters 
Pdcgrid1 Grid of initial terrain 
model, without 
stream features 
5-m Grid Elevation Meters 
pdcinput1 GIS import file 
created by GeoRAS 
for HEC RAS 
.geo XYZ 
coordinates 
Meters 
PDCstream1 Shape file of 
GeoRAS stream 
centerline 
Polyline XY 
coordinates 
Meters 
PDCstream3D1 Shape file of 
GeoRAS stream 
centerline 
PolylineZ XYZ 
coordinates 
Meters 
pdctmpts Shape file of point 
elevations created 
from 30-m DEM, 
for developing 
initial terrain model 
Point Elevation Meters 
pdcXSec1 MIKE 11 cross-
section file of study 
area using HEC-2 
data 
.XNS11 XZ 
coordinates 
Meters 
Qpoints.txt Shape file of MIKE 
11 simulation results 
Point Time-series 
flow 
m
3
/s 
rd3clip Shape file of study 
area road network 
Polyline XY 
coordinates 
Meters 
Stream1 Shape file of study 
area?s stream 
network, digitized 
from stream points 
Polyline XY 
coordinates 
Meters 
190 
 
Data Description Class Attribute Units 
Stream3def1 Shape file of East 
Fork stream and 
channel banks 
PolylineZ XYZ 
coordinates 
Meters 
Stream3dmc1 Shape file of Mill 
Creek stream and 
channel banks 
PolylineZ XYZ 
coordinates 
Meters 
theme1 Shape file used as 
boundary for study 
area 
Polygon XY 
coordinates 
Meters 
TS1EastUSQ MIKE 11 time-
series file of East 
Fork upstream base 
flow 
.dfs0 Time-series 
flow 
m
3
/s 
TS1MillDShlev
el 
MIKE 11 time-
series file of Mill 
Creek downstream 
base stage 
.dfs0 Time-series 
stage height 
Meters 
TS1MillUSQ MIKE 11 time-
series file of Mill 
Creek upstream base 
flow 
.dfs0 Time-series 
flow 
m
3
/s 
TS2Basin109Q MIKE 11 time-
series file of Basin 
109 runoff for 25-yr 
storm 
.dfs0 Time-series 
flow 
m
3
/s 
TS2Basin110Q MIKE 11 time-
series file of Basin 
110 runoff for 25-yr 
storm 
.dfs0 Time-series 
flow 
m
3
/s 
TS2Basin111Q MIKE 11 time-
series file of Basin 
111 runoff for 25-yr 
storm 
 
.dfs0 Time-series 
flow 
m
3
/s 
191 
 
Data Description Class Attribute Units 
TS2Basin112_1
17Q 
MIKE 11 time-
series file of Basins 
112 thru 117 (minus 
115) for 25-yr storm 
.dfs0 Time-series 
flow 
m
3
/s 
TS2Basin115Q MIKE 11 time-
series file of Basin 
115 runoff for 25-yr 
storm 
.dfs0 Time-series 
flow 
m
3
/s 
TS2EastUSQ MIKE 11 time-
series file of East 
Fork upstream flow 
for 25-yr storm 
.dfs0 Time-series 
flow 
m
3
/s 
TS2MillDShlev
el 
MIKE 11 time-
series file of Mill 
Creek downstream 
stage height for 25-
yr storm 
.dfs0 Time-series 
stage height 
Meters 
TS2MillUSQ MIKE 11 time-
series file of Mill 
Creek upstream flow 
for 25-yr storm 
.dfs0 Time-series 
flow 
m
3
/s 
Xscutlines Shape file of 
GeoRAS cross-
section cut lines 
Polyline XY 
coordinates 
Meters 
Xscutlines3D1 Shape file of 
GeoRAS cross-
section cut lines 
PolylineZ XYZ 
coordinates 
Meters 
192 
 
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 Annual Conference on Water 
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193 
 
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195 
 
Vita 
 Daniel Baldwin Snead was born in Melbourne, Florida on April 15, 1968 the 
fourth child of six parented by William Archer Snead and Joan Mullin Snead.  He 
received the Bachelor of Science degree in Mechanical Engineering from the Florida 
Institute of Technology, Melbourne, Florida in August 1990.  Upon graduation, 
Daniel was commissioned as an engineer officer in the United States Army through 
the Reserve Officer Training Corps.  Military schools that he has completed include 
the U.S. Army Airborne School, Engineer Officer Basic Course, U.S. Army Ranger 
School, Sapper Leaders Course, U. S. Army Jumpmaster School, Engineer Officer 
Advanced Course, and the Combined Arms Service and Staff School.  His duty 
assignments include Platoon Leader and Company Executive Officer, 307
th
 Engineer 
Battalion, Fort Bragg, North Carolina; Protocol Officer, Eighth U.S. Army and U.S. 
Forces Korea, Yongsan, Korea; Assistant Battalion Operations Officer, 19
th
 Engineer 
Battalion, Fort Knox, Kentucky; and Company Commander, B Company, 10
th
 
Engineer Battalion, Fort Stewart, Georgia.  As a Company Commander, his company 
participated in Operations Intrinsic Action 98-03 and Desert Fox in Kuwait.  In May 
1999, he entered the Environmental and Water Resources Department of the 
University of Texas at Austin as a full-time graduate student.  Daniel is married to the 
former Melinda Lee McCaslin, they have one daughter, Charlotte Katherine, and a 
basset hound named Chloe. 
 
Permanent Address:  477 Ironwood Drive 
    Melbourne, Florida 32935 
 
This report was typed by the author.