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dc.contributor.advisorPaterson, Robert G.en
dc.creatorVermillion, Elizabeth Lauren, 1982-en
dc.date.accessioned2010-11-24T21:53:09Zen
dc.date.accessioned2010-11-24T21:53:18Zen
dc.date.available2010-11-24T21:53:09Zen
dc.date.available2010-11-24T21:53:18Zen
dc.date.issued2010-05en
dc.date.submittedMay 2010en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2010-05-1296en
dc.descriptiontexten
dc.description.abstractDrainage area is a measure of the number of acres feeding into a creek. Drainage area threshold is the amount of acreage required for the creek to be included on a map. Watersheds mapped according to higher drainage area thresholds will show creek systems that are shorter and concentrated at the bottom of the watershed. Watersheds mapped according to lower drainage area thresholds show creek systems that are longer and extend further up the watershed. Since all watersheds are subject to different land uses, soil types, geology, etc., they should be mapped according to different drainage area thresholds. Headwaters are where creeks begin. There is empirical evidence that properly functioning headwaters significantly reduce erosion, improve water quality, slow stormwater flows, and provide habitat. If municipalities use lower drainage area thresholds to define their creeks, they can include more headwaters in their creek setback requirements. This professional report identifies the Harris Branch watershed as being under relatively more pressure to develop and exhibiting more environmental risk than other watersheds in Austin, Texas’ Desired Development Zone. Creeks in the watershed are redrawn according to reduced drainage area thresholds using a simple ArcGIS analysis. The analysis reveals a critical mass where creek setbacks appear to be too extensive. If creeks with a drainage area of 5 acres are protected by development code, the setbacks created have excessive branching that could be too restrictive for development. A critical mass ratio should be considered when determining which drainage area threshold is most appropriate for a watershed. The critical mass ratio is equal to the number of branches allowed per a specified distance of creek centerline. The process of identifying this critical mass ratio can help growing cities find a balance between the need to encourage development in designated areas and the need to protect natural creek systems everywhere. I recommend that municipalities review the effects of reducing drainage area threshold for each watershed, and then identify the drainage area threshold that, when protected by setback requirements, allows for extended and connected greenways as well as an increase in density.en
dc.format.mimetypeapplication/pdfen
dc.language.isoengen
dc.subjectDrainage area thresholden
dc.subjectCreek setbacksen
dc.subjectWatershed managementen
dc.subjectWater qualityen
dc.subjectStorm water managementen
dc.subjectAustin, Texasen
dc.titleEastern watershed analysis of alternate approaches to delineation in Austin, TXen
dc.date.updated2010-11-24T21:53:19Zen
dc.contributor.committeeMemberSchuster, Stefanen
dc.description.departmentCommunity and Regional Planningen
dc.type.genrethesisen
thesis.degree.departmentCommunity and Regional Planningen
thesis.degree.disciplineCommunity and Regional Planningen
thesis.degree.grantorUniversity of Texas at Austinen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Science in Community and Regional Planningen


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