The Brandywine Valley Association
The Brandywine Valley Association (BVA), the first small watershed association in the country, was founded in 1945 and is committed to promoting and protecting the natural resources of the Brandywine 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 and want to believe that our supply is boundless. The truth, however, is that the Brandywine Watershed’s water supply is under constant pressure from the rapid growth that is taking place now and will continue into the future.

About half of thepeople who live in the Brandywine 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 1995, BVA 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.

• 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

Simulation
The model is designed to simulate the effects 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.

• 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 Brandywine Valley Association, is available for general use. To find out if the model will apply to specific situations, please contact the Brandywine 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 Brandywine 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

Townships:
Birmingham • East & West Bradford • East & West Brandywine • Caln • East & West Caln West Goshen • East Fallowfield • Highland Honeybrook • Londonderry • West Marlborough East & West Nantmeal • Newlin • Pennsbury Pocopson • Sadsbury • Thornbury • Upper Uwchlan • Uwchlan • Valley • Wallace • Westtown • West Whiteland

Boroughs:
Downingtown • Honeybrook • Modena Parkesburg • South Coatesville • West Chester

E:[email protected]
W:www.brandywinewatershed.org