The Red Clay Watershed The Red Clay Watershed encompasses 50-square miles in southern Chester County, Pennsylvania and northern New Castle County, Delaware and is home to over 50,000 people. The Red Clay Valley Association The Red Clay Valley Association, a non-profit conservation organization founded in 1952, is committed to promoting and protecting the natural resources of the Red Clay Valley through technical assistance and research projects, as well as through environmental education programs and demonstration projects for all ages. Water: A Finite Resource in Our Valley Most of us take water for granted. We want to believe that our supply is boundless. But that is not reality. The truth is that in the Red Clay Watershed the water supply is under constant pressure from the rapid growth that is taking place now and will continue into the future. About half of the people who live in the Red Clay Watershed depend on ground water for their drinking water supply. Many of the new developments will depend on ground water as well. As more water is taken from this finite source, will the supply be adequate for the future? Since 1987, the Red Clay Valley Association has been working to better understand the limits of our ground water resources. That work has lead to the development of a computer based model which can predict the effect of proposed development on ground water systems and the streams which they support.

What Can The Model Do? Simulation The model is designed to simulate the effect of additional ground water use. If a proposed development will remove water from the ground, it will indicate what the future ground water levels will be. Demonstration The model can take into account the loss of recharge from impervious surfaces (e.g. roofs, roads, driveways, and parking lots), and, as part of the modeling process, will show the overall effect of development, including both water withdrawal and reduced recharge. Identification It also is useful in identifying ground water sources that supply larger production wells. This information is invaluable to municipalities and water suppliers interested in protecting the wellhead area from uses that would reduce recharge or cause contamination. Prediction/Evaluation The model can predict how much ground water will change with future use. In addition, it can also show the effect on streams in the area which may have reduced flow as a result of lowered ground water levels. Both of these conditions should be considered in evaluating proposed land use changes. Reducing ground water levels and streamflows below acceptable limits could require changes in proposed land use or other means of water supply so that ground water is not as seriously affected.

Ground Water Model Uses Predict ground water level changes for proposed developments and large-scale production wells Define wellhead protection areas for municipalities and water utilities Design effective stormwater infiltration systems Show the effect from different types of land application systems Predict the effect on streamflow of land use changes Help to create better development design for ground water protection Who Could Benefit From The Model? Municipal governments (e.g. supervisors, planning commissions, and environmental advisory counsels Local, county, and professional land use planners Developers Water and wastewater utilities Conservation organizations School districts as part of their environmental education programs How To Access The Model The model, owned by Red Clay Valley Association, is available for general use. To find out if the model will apply to specific situations, please contact the Red Clay Valley Association. Certain information will be required to run the model, such as well locations, pumping rate, infiltration, and impervious coverage. It can be run quickly and inexpensively and provides an output which can be easily understood by a non-technical audience. The model is suitable for any size land use from a single acre lot to a large subdivision in the Red Clay Valley.   Benefits of the Model Can predict ground water and streamflow changes in advance of land use changes Is quick and economical to run Is easy to understand Can help to improve land use designs, especially at the sketch plan stage Will help to provide long-term protection for ground water supplies   You are a Red Clay Watershed resident if you live in the following areas: Pennsylvania: East Marlborough Township Kennett Borough Kennett Township New Garden Township Delaware: Ashland Hockessin Stanton Yorklyn