Reducing Impacts of Development on Water Quality: Policy Directions for Guiding Urban Growth

Paving and developing open land have many obvious impacts on water. First, impervious cover essentially eliminates the groundwater recharge service that land can perform. Land is both conduit and filter for water returning to the aquifer for further use. Secondly, paving or otherwise constructing on open land results in excess surface water (in most climates), some diffused over the surface, some collected in pools or streams causing flooding or other damage. Thirdly, excess water from impervious areas often carries pollutants and sediment into drains, streams, lakes and other collection points, pollutants that come from whatever activity is underway on the covered surface. Finally, paving open land deprives consumers of the many services available from that open land. Included are food and fiber production with the related economic benefits, and a set of open land amenities that people value. Certainly development creates its own rewards, but open land has services to be weighed against those rewards; open land is more than the absence of development.

By Lawrence Libby

Publication type: 
Policy brief
Date published: 
Wednesday, January 1, 2003