Prince William Conservation Alliance

Your Address: Occoquan Watershed

(Article printed in the February, 2003 Gainesville Citizen)


Western Prince William is a special place. With rolling hills across Nokesville gently rising to the historic Bull Run Mountain, this area is relatively undeveloped by Prince William standards. Horses, emus and even a zebra are part of the growing farm community. Many areas still have a scenic appearance provided by west Prince William’s many natural resources. Stream corridors, forests and wetlands are enjoyed by birders, butterflyers and photographers. We like to ride horses and bikes, hike and jog. Families enjoy exploring the woods together and picnics on stream banks.

As we travel through Prince William on our way to work, school, soccer fields and grocery stores, we notice the wooded areas and other open spaces. These give our community a scenic appearance and help make west Prince William a terrific place to live. Streams and other natural resources, such as wetlands, forests and prime farmland soils, support healthy communities where people want to live and work. West Prince William is fortunate that, despite the intensive development pressures, many high quality streams and natural resource areas still exist. This is especially good news because the entire area drains to a significant regional water supply, the Occoquan Reservoir.

What is the Occoquan Reservoir?

The Occoquan Reservoir is important to Prince William. About 172,000 Prince William residents (more than half the total county population) depend on the Occoquan Reservoir for nearly 17 million gallons of water each day. And Prince William is important to the Reservoir. Nearly 40% of Prince William land drains directly into the Occoquan Reservoir, largely from western Prince William. The Occoquan Reservoir is also important to the region and serves over one million people in Northern Virginia.

The initial recommendations to safeguard the reservoir included restricting the population within the watershed area to 100,000 people. Growth has instead far surpassed this limitation and as of the 200 Census 363,00 people call the Occoquan Reservoir watershed home, with 38% of the population in Prince William alone. Growth and development means that many acres of wetlands and forests are replaced by roads and rooftops. Natural filters are replaced with land surfaces that feed pollutants into the air, water and soil. The land uses in a watershed have considerable impact on water quality: Changes to as little as 2% of the watershed area can affect water quality. Today, growth within the Occoqouan Reservoir watershed continues at a steady pace. The result is an ongoing loss of important natural resources, and degradation of waterways that drain to the Occoquan Reservoir.

In 1989, 60% all stream miles in the watershed were classified as high-quality streams. But a 1996 study by the Center for Watershed Protection warned that, given current land use trends, by 2005 only 22% of streams could retain these high-quality conditions and by 2020 over 80% of streams in the watershed would be heavily impacted. Considering the importance of this drinking water supply to the Northern Virginia region, relatively little management attention has been directed toward addressing the cumulative impact of urbanization on the streams that feed the Occoquan Reservoir.

Can Natural Resources Really Make a Difference?

While the recreational values of west Prince William’s natural resources are obvious, they also have economic value. Stream corridors act as buffers for stormwater runoff and urban pollutants. Forests reduce erosion, protect watersheds and have a substantial stabilizing effect on the world’s climate by releasing oxygen and absorbing carbon dioxide. Weltands filter pollutants, allow rainwater to filter through to the goundwater supply and prevent flooding. Our air is cleaner. Soil is formed and enriched, nutrients are recycled and crops are pollinated. All this helps keep waterways clean and safe for drinking, swimming and fishing.

We know that forest and wetland functions are important for good water quality. When these natural buffers are either eliminated or overwhelmed, their functions must be replaced by constructed stormwater systems and filtration facilities. Real dollars are needed to construct alternate systems to replace natural functions. Although the economics of open spaces have seldom been translated into dollars and cents, there is growing interest in calculating these values. At all levels, the numbers are startling. For example, in 1997 an international team of environmental scientists and economists estimated that the cost benefits received from natural systems worldwide to be $33 trillion (Nature, 1997). The thought of replacing these services with technology boggles the mind.

Another example comes from New York City, where rapidly degrading watershed conditions threatened the water supply to the point where it fell below Environmental Protection Agency (EPA) standards. Charged with providing over one billion gallons of water every day to New York City and the surrounding communities, officials were faced with hard choices and initiated a review of available options. New York City’s analyses focused on two scenarios: technology vs. nature. Estimated costs to build a new filtration plant exceeded the costs to restore the watershed area to something close to its original cleansing capacity by a factor of eight. The choice was clear to New York City voters, who strongly supported a bond to begin purchasing forested lands, restoring stream corridors and upgrading septic tanks in the watershed area.

What’s Happening in the Occoquan Reservoir Watershed Today?

The land area that affects the Occoquan Reservoir lies in four jurisdictions: Fairfax, Prince William, Fauquier and Loudoun Counties. Cooperative efforts and investments from each locality are needed. Some efforts to protect land in the reservoir watershed area have been made by other jurisdictions. One noteworthy contribution came in 1982 when Fairfax County downzoned 41,000 acres of land to protect the Occoquan Reservoir. This also created a buffer area for the Reservoir and an important recreational amenity managed by the Northern Virginia Regional Park Authority. Unfortunately Prince William no longer has the option to protect the land area along our side of the reservoir, as Fairfax did in 1982. A variety of residential densities already line this area and the remainder is scheduled for development, including a golf course, with no long-term requirements for water quality monitoring, and residential homes, with septic fields instead of sewer connections.

Many high quality streams still exist in west Prince William. But the area is becoming increasingly pockmarked by a hodgepodge of sprawling low-density residential uses and isolated high-density developments. These uses will eventually overwhelm area streams and increase pollutants that flow to the reservoir.

What Should Be Done?

Here in Northern Virginia we face two choices: rely totally on technological fixes or preserve Prince William green spaces. The pressure to develop appears overwhelming. We need the schools, offices and homes. We need grocery stores, book stores and restaurants. What can we really do?

The first step is to recognize that continued development without consideration of environmental conditions is foolhardy. The natural environment is an important part of our communities, with economic and recreational values. We require our buildings to be functional and attractive. This same standard can be applied to the natural ecosystems that support our needs.

We need to be aware of the subtle balance between land use and water quality. Converting even seemingly insignificant percentages of the watershed to roads and rooftops will impair water quality conditions. Stream buffer restoration and land conservation efforts applied to the same area can prevent or offset damage to water quality from development. Long-term planning efforts that evaluate development needs comprehensively at a watershed-wide scale should provide the framework for development. Development blueprints that recognize natural resources values and incorporate protections for these assets result in sustainable communities. The resulting development will be more attractive, creating healthy communities that people take pride in.

Our proximity to the Occoquan Reservoir means that Prince William has an important role to play. As the primary stewards of Prince William’s natural resources, we are first in line to receive the benefits. When the balance between human uses and natural systems is upset, Prince William community members will be the first to notice the problems that result . . . and the first in line to pay the costs required to restore what has been lost.

Thoughtful decisions now would save taxpayer dollars down the road. Conservation of water-sensitive natural features and important natural resource areas is the critical component of preventative efforts. There is potential for conservation design, low impact development and other ways to protect natural resources, if Prince William were to go this route to make the most of the current situation. And establishing and funding a purchase of development rights program would be a significant step forward for Prince William. Citizen support to protect existing public lands and acquire new lands is needed. When all is said and done, choices in the types and amounts of conservation options available is up to the local community.

The first step is to get involved and find out more. The Prince William Conservation Alliance hosts monthly programs on land conservation and natural resource protection opportunities. We sponsor the Potomac Waterfront and Occoquan Watershed Working Groups, where citizens, businesses and government share ideas and promote productive activities. Prince William water quality monitoring programs need volunteers. Participation with this program helps you learn how to ‘read’ our local streams and helps document current water quality conditions within Prince William. Training for this program is provided free of charge by the Audubon Naturalist Society. Volunteers are especially needed in west Prince William.

Only a strong body of active citizens can exercise the political will to change from the business-as-usual approach. Doing things such as learning more about Prince William, becoming active in our own communities, talking to local representatives can help you make an impact. Take advantage of local opportunities to participate in Conservation, Restoration and Preservation efforts – CPR for Prince William. We look forward to seeing Prince William people everywhere . . . in the woods looking for birds, restoring a creek bank, sharing ideas government or participating in local stewardship opportunities. There’s lots to do and you can help. Indeed, it can’t be done without you.

Kim Hosen, Executive Director
Prince William Conservation Alliance
9118 Center Street, Manassas, VA 20110
703.367.0069, www.pwconserve.org


Occoquan Reservoir
Resource Management Issues
Prince William Conservation Alliance