Why do we need to manage stormwater?
Urbanization causes significant changes in stormwater runoff characteristics, including increased volume and rate of runoff entering streams and the storm sewer infrastructure and reduced amounts of water filtering into the soil. Such changes cause increased erosion and formation of gullies in upland areas, increased in-stream scour and erosion, increased sediment deposition in lower areas, degradation of water quality, peak storm flows that are higher and faster, more frequent flooding, and negative effects on stream ecological communities. These impacts on both man-made structures and natural systems require continuous management, maintenance, repair and replacement of the Town’s stormwater management system, and careful planning to mitigate existing and future problems.
Urbanization causes significant changes in stormwater runoff characteristics. As the natural landscape is cleared, graded, and covered with buildings and parking lots, rainwater can no longer filter into the soil to become groundwater. As a result, more rainwater enters our lakes and streams, and it enters more quickly. As it flows across parking lots, streets, and hard surfaces, it picks up pollutants and debris and carries them to the lakes and stream along with the water. This increased volume and rate of run-off increases erosion and formation of gullies in upland areas, increases scour and erosion in streams, increases sediment deposition in lower areas, degrades water quality, causes more frequent flooding, and negatively effects stream ecology. These impacts on both man-made and natural systems require continuous management, maintenance, repair and replacement and careful planning to mitigate existing and future problems. Federal law requires that Redmond participate in activiti
