GIS Tools to Help Manage Dynamic Urban Watersheds

The City of Greensboro, North Carolina, USA is developing and implementing a Municipal Stormwater and Watershed Management Program that includes unique Geographic Information System (GIS) database and application tools for a higher level of GIS automation for urban stormwater management than has previously been attempted. For example, the GIS technology allows the City to prioritize stormwater infrastructure maintenance, assist with implementation of the municipal NPDES stormwater discharge permit, track water quality data and improvements, enhance the local floodplain management program, and facilitate multi-objective, watershedbased modeling and stormwater management master planning. Advanced technology coupled with dedicated staff and stakeholder involvement, clearly defined goals, and a watershed-based focus are allowing the City to develop optimal plans for urban stormwater management, watershed protection, and watershed restoration.This paper provides an overview of the City's Stormwater Management Program with a focus on an integration of interactive hydrologic, hydraulic, and water quality models with a robust GIS database to create a tool that provides a sound technical basis for informed watershed-based management and restoration decisions by local officials. A foundational aspect of the City's program includes ongoing stakeholder and community input as staff attempt to balance science and engineering with local values related to natural resources and urban watershed management. Once legal requirements are satisfied for designated water resources, community values provide an ultimate measure of success for local watershed management programs.The current work is referred to as the “Dynamic Watershed Management” (DWM) project and represents initial steps at the local level towards development of a holistic and sustainable urban watershed management program. Due to the flexibility of the GIS tools and databases, the DWM program could be expanded in the future to include water supply system optimization, sanitary sewer system inventory and modeling, and advanced water quality modeling to support Total Maximum Daily Load (TMDL) programs, pollutant load allocations and discharge limits for local watersheds. The GIS-based modeling tools are therefore helping the City of Greensboro effectively meet today's stormwater management requirements while also preparing for the comprehensive watershed-based management challenges and opportunities of the 21st century.