As more land is covered by impervious surfaces, less rainfall infiltrates into the ground and instead becomes runoff. Too much runoff is problematic. Flooding increases, streambanks erode, and water quality is reduced. An increase of impervious area of as little 10 percent has been shown to negatively impact streams. The purpose of this publication is to explain low impact development strategies and how they can be used to improve stormwater management by reducing impacts on streams.