Why are Best Management Practices (BMPs) a requirement of Regional Permit 1 (Residential, Commercial and Institutional Developments) & Regional Permit 2 (Recreation Projects)?
A31. It has been found that development impacts on wetlands are two-fold: water quality impacts and hydrologic impacts. While properly designed wet or wetland detention basins can often address the water quality impacts of development, they may not be adequate to fully mitigate the hydrologic impacts. Even with detention, storm water is discharged to wetlands over a relatively short period of time (1 to 3 days) compared to the undeveloped landscape. Further, because urban surfaces cause much of the runoff to be diverted from sub-surface runoff to surface runoff, much less groundwater flow reaches the wetland. As a result, the wetland often experiences much greater hydrologic variability after development. Because groundwater flow is much cooler than surface runoff, there can be temperature effects as well. With proper site planning, these impacts can be significantly reduced, minimizing degradation of water quality, destruction of aquatic habitat, and shifts in wetland plant communitie
A30. It has been found that development impacts on wetlands are two-fold: water quality impacts and hydrologic impacts. While properly designed wet or wetland detention basins can often address the water quality impacts of development, they may not be adequate to fully mitigate the hydrologic impacts. Even with detention, storm water is discharged to wetlands over a relatively short period of time (1 to 3 days) compared to the undeveloped landscape. Further, because urban surfaces cause much of the runoff to be diverted from sub-surface runoff to surface runoff, much less groundwater flow reaches the wetland. As a result, the wetland often experiences much greater hydrologic variability after development. Because groundwater flow is much cooler than surface runoff, there can be temperature effects as well. With proper site planning, these impacts can be significantly reduced, minimizing degradation of water quality, destruction of aquatic habitat, and shifts in wetland plant communitie
