OtherBuildings 100yr

The Nature Conservancy and Texas A&M AgriLife Extension completed the Green Stormwater Infrastructure for Urban Resilience: Opportunity Analysis for Dallas, Texas in collaboration with the City of Dallas and The Trust for Public Land, to identify areas in Dallas where green stormwater infrastructure can most effectively enhance urban flood management – considering capacity, cost, and future impacts of climate change. The focus was on evaluating opportunities where the existing drainage network may be limited, and likely to lead to areal flooding. The priority subwatersheds and GSI opportunity layers included here are outputs from modeling and spatial analysis, which have inherent limitations and uncertainties [1]. We share these layers to facilitate community, policy, and investment considerations, and recommend they be considered together with additional data, such as: City data on channel flooding, customer service calls and upcoming streets and parks projects; FEMA floodplain maps and Community Rating System scores; and data on water quality, equity and land use types available within The Trust for Public Land’s Smart Growth for Dallas tool [2]. Data from this analysis has been integrated into TPL’s Smart Growth for Dallas Decision Support Tool. Priority Subwatersheds. These subwatersheds represent priority areas where GSI could improve stormwater drainage. These areas drain to stormwater network inlets that overflowed in study models* under a variety of rainfall events and indicate where the drainage network is undersized and likely to contribute to aerial flooding. These areas do not represent areal flood risk. (*modeled using EPA SWMM v 5.1.; see analysis sections 2.1-2.3 and 3.2). Green Stormwater Infrastructure (GSI) Opportunity Areas, for the 100-year current conditions storm. The GSI opportunity areas identified are high level and focus on the three types of GSI systems included in the study: bioretention areas, rain gardens, and rainwater harvesting cisterns falling within priority subwatersheds for current conditions storms. Opportunities exist outside of these areas and for other types of GSI. Furthermore, additional detailed feasibility studies would be required for any potential site.