2001 Phase 1 Watersheds Report Volume 2

EXECUTIVE SUMMARY: The mission of the Watershed Protection Department (WPD) is to reduce the impact of flooding, erosion and water pollution on our community in order to protect lives, property and the environment. To accomplish this mission, WPD completed Phase I of a Watershed Protection Master Plan to better prioritize service needs and refine program direction. The Master Plan inventories existing watershed problems and gauges the impact of future urbanization in seventeen (17) watersheds - including all of the urban watersheds and five surrounding non-urban watersheds: Blunn (BLU); Boggy (BOG); Buttermilk (BMK); East Bouldin (EBO); Fort Branch (FOR); Harper's Branch (HRP); Johnson (JOH); Little Walnut (L W A); Shoal (SHL); Tannehill (TAN); Waller (WLR); West Bouldin (WBO); Barton (BAR); Bull (BUL); Country Club (CNT); Walnut (WLN); Williamson (WMS) Phase I studies helped to locate and prioritize problem areas where watershed protection goals and objectives are not currently being met or are not expected to be met in the future. These studies are categorized by mission as creek flooding, localized flooding, streambank erosion and water quality degradation. Integrated problem areas were determined by overlaying the results of the individual mission studies to identify areas of concurrent flooding, erosion and water quality problems. Integrated problem areas demonstrate an increased need for multi-purpose solutions. These studies determined that watershed problems are widespread and will worsen if corrective action is not taken. Creek flooding poses a recurring citywide risk to public safety and property. For example, a relatively small 2-year storm creates structure flooding in 14 of the 17 Phase I watersheds. Localized flooding also threatens property across the City due to undersized, deteriorated, clogged or inadequate storm drain systems. Over 4000 localized flooding complaints have been logged over the last ten years. New erosion data identifies numerous existing threats to property with nearly 500 sites currently threatened. Increased stormflows from urban development have accelerated streambank erosion, leading to enlarged and unstable creek channels. Water quality studies document the fact that urbanization has led to the degradation of our urban creeks and receiving waters. Future development is predicted to continue the trend of degrading habitat and creek biology and increasing pollutant levels in local surface waters. The Master Plan identifies opportunities for optimizing existing resources through improved prioritization, mission integration and a renewed commitment to the use of environmentally responsible, cost-effective and sustainable solutions. Problem priorities were established based on the severity of the identified problem at each location and the number and type of affected community resources (such as homes, roadways and receiving waters).