Current growth trends suggest bleak future for farms and forests in DC region; 800,000 new acres will be developed by 2030, according to Chesapeake Bay Foundation study
April 30, 2002
At current growth rates and trends, 800,000 more acres of land in the greater Washington DC region will be developed by 2030, according to a new study by the Chesapeake Bay Foundation (CBF). That development represents an 80 percent increase over current development in the 5.2 million acre region studied. The great majority of the newly developed area--more than 700,000 acres—would be farmland, forest, and wetlands. However, the study also found that with improved management, the same growth could be accommodated using two thirds less land and preserving more than 550,000 acres of farmland, forests, and wetland.
At current trends, the Washington DC region will lose
“Growth in this region is inevitable,” said Lee Epstein, director of the Chesapeake Bay Foundation’s Lands Program. “However, this study clearly demonstrates that if we take strong steps to contain sprawl and manage growth, we can accommodate growth while protecting our quality of life and the health of local streams, rivers and the Chesapeake Bay."
The Chesapeake Bay Foundation study is the most detailed projection of greater Washington DC region growth patterns to date, thanks in large part to the use of the powerful the SLEUTH computer model of growth patterns conducted by the Regional Earth Science Applications Center at the University of Maryland's Department of Geography, funded by CBF.
The SLEUTH model projects future growth patterns based on past trends. Programmers fed SLEUTH 15 years worth of satellite imagery data to map different types of land use (developed land, farmland, forest, wetland, etc.) across the region. SLEUTH then divided the greater Washington DC region into a grid of cells each 45 square meters (about one third of a football field) and mapped development in each one. Next, the model projected where development could occur over the next 30 years if current patterns of growth continue. Finally, programmers adjusted the model to experiment with various growth-management tools and map their impact.
The total land area involved in the study covers 5.23 million acres, ranging from Fredericksburg, Va., to the Maryland-Pennsylvania line and from the Blue Ridge Mountains to the Chesapeake Bay shoreline. The area represents 12 percent of the Chesapeake Bay watershed (the region that drains into the Bay). The complexity of the model challenged the ingenuity of the researchers and required almost a full week of computer time at the U.S. Geological Services mapping center in Colorado to calibrate the model.
“This model allows us to predict with greater accuracy than currently is available, what will happen to the future of the region, depending on decisions we make now to manage growth,” said Epstein.
.“The success of our effort to reduce sprawl, traffic congestion and pollution is not only a question of how much growth the region will experience, but more importantly where that growth occurs,” said Epstein.
Forest, wetlands, and undeveloped land are essential to the health of the Chesapeake Bay, added Epstein. Undeveloped land serves as a natural water filter for the Bay and is home to many of the plants and animals that live in the region. The more of it we convert to roads, roofs, and parking lots, the more polluted our water will become and the more distressed our wildlife will be. Additionally, the more we spread out, the more travel by automobile we have to do, adding to an already serious air pollution problem.
The emphasis on carefully planned growth is consistent with goals outlined in the new Chesapeake Bay Agreement, signed in June 2000 by key Bay stakeholders, that seeks to reduce the rate of harmful sprawl on forest and farmland by 30 percent by 2012. Increased land development is one of the most pressing challenges facing efforts to restore and protect the Chesapeake Bay watershed. The conversion of green spaces to developed areas not only reduces the watershed’s vital natural filters, but also creates impervious surfaces (such as roads, roofs, and parking lots) that funnel pollution into the region’s waterways.
While the model is intentionally regional, results can be looked at on an individual county level, noted Epstein. For example, under current trends, outer-ring counties such as Stafford, King George, Fauquier, Calvert, Culpepper, Frederick, Carroll, and St. Mary’s would see an increase in developed land of 274,000 acres – a
“Residents in the DC region consistently say they value the region’s rural areas, but the way the region is growing belies that,” added Epstein. “A managed growth plan focused on conserving farms, forests, and stream buffers would protect both our environment and the region’s quality of life.”
According to CBF, key elements of better managed growth in the Washington DC region include: directing development away from important working and open lands, encouraging quality development and revitalization in and adjacent to existing towns and cities, and efficient use of current public investment in infrastructure.