PPT Slide

This stream has a surrounding area of approximately 30% impervious cover. The large amount of impervious cover has increased the size of the stream by a factor of five to ten. The manhole in the middle of the diagram was originally in the floodplain and is an indicator of the degree to which channel erosion has occurred.

Copyright 2000, Center for Watershed Protection

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At 30% impervious cover, the stream structure becomes effectively blown out. The large amount of impervious cover has increased the size of the stream five- to ten-fold. The manhole in the middle of the diagram was originally in the floodplain and is an indicator of the degree to which channel erosion has occurred.