Watershed Management Studies and Plans provide a holistic and systematic watershed perspective to land use planning and development review activities. They provide tools necessary to facilitate daily land use and infrastructure decisions to protect watershed resources. They provide an informed basis for prioritizing watershed restoration and preservation initiatives and total maximum daily load (TMDL) implementation plans. They characterize watershed baseline conditions and resources while identifying existing and potential concerns along with short and long-term opportunities for improvement of water quality issues. Watershed management studies and plans enhance government’s ability to integrate and link existing watershed management business processes with watershed models to provide interactive information on how changes in land use, development regulations, best management practices, and other watershed conditions affect water quality and waterway habitat. Watershed modeling involves analysis of environmental impacts of land use changes through simulation of storm water run-off water quality; soil erosion from the land surface; flooding and changes in flow regime; groundwater and surface water interactions and stream habitat quality. Watershed modeling allows simulation of point and non-point source pollutant loads; and the fate and transport of pollutants on land and in the water body; both temporally and spatially. Watershed modeling results can be used to examine “future conditions” of the watershed in categories such as pollutant loading; flooding of road crossings; stream erosion potential; and hydrology of streams and groundwater. Utilizing historical environmental data, the baseline assessment of watershed conditions, and watershed modeling results, subwatersheds and stream reaches most in need of restoration or preservation can be determined. Results such as these are crucial for prioritizing where to focus restoration and preservation investment as well as selection of the most appropriate alternative solutions or best management practices. Information of this nature allows reassessment of current land use plans related to where future growth is being directed, its zoning potential, and policy decisions regarding subdivision regulations which designate the character of site planning and its implementation. The reassessment of these existing policies can be modeled to seek and predict future watershed water quality conditions more favorable to meeting defined water quality standards and established TMDL’s. |
