As more people move into the Bay watershed, development of new homes, roads and businesses continues. We are choosing to move away from city centers and live in bigger houses on larger lots, causing forests, farms and other valuable lands to be transformed into subdivisions, shopping centers and parking lots—severely impacting the health of our streams, rivers and the Bay.
Development itself is not necessarily harmful to the Bay; it is the way we develop the land—where we locate new roads and buildings and how we build them—that can have a lasting negative impact on our natural environment.
Sprawling, low-density residential and commercial areas built far from existing cities and town centers require improved linkages and infrastructure: more schools, roads and shopping centers. Open areas between existing centers and sprawl eventually fill with more new development. This type of sprawl development chews up forests, shorelines and agricultural lands, and increases pollution and degradation of our land and water.
As we spread across the watershed and build away from existing infrastructure, we are using more land than we need. Between 1970 and 2000, the average household population decreased; however:
The amount of land we use relative to our population growth is also measured by impervious surfaces: roads, rooftops, parking lots and other hardened areas. Impervious surface data is used to gauge the rate of development across the watershed and identify potential sprawling development patterns.
Development has been the largest cause of forestland loss over the past 15 to 20 years. Between 1982 and 1997, the Bay watershed lost over 750,000 acres of forestland to development—a rate of about 100 acres per day and a total size equal to 20 District of Columbias. This loss of forestland is a permanent loss of air and water filters, wildlife habitat and other significant functions that forests provide.
In addition to forest loss, 60 percent of Chesapeake forests are divided by roads, subdivisions and farms into disconnected fragments surrounded by other land uses. Forest fragmentation isolates animal and plant populations into smaller areas, and makes forestland more vulnerable to development, fires and invasive species.
Conversion of farmland to residential and commercial developments can adversely impact the long-term sustainability of the agriculture industry, a significant part of the culture, heritage and economy of the Chesapeake region.
Water quality is inextricably linked to population growth: as we add more roads, septic systems, parking lots and disturbed areas of land, we create more pathways for pollutants to reach the Bay at an increasing rate.
Impervious surfaces that replace natural, vegetated areas do not allow precipitation to soak into the soil. Instead, water runs off the hardened surfaces and into local rivers, streams and the Bay, picking up pollutants like nitrogen, phosphorus and chemical contaminants along the way. Stormwater running off urban and suburban lands is now the fastest-growing source of pollution to the Bay.
As people move farther away from city centers, they often have to spend more time on the road to reach their destinations, increasing both congestion and pollution. Vehicle emissions are one source of airborne nitrogen—a type of air pollutant—that eventually falls to the ground and can add to excessive nutrient loads to the Bay.
The initial construction of new developments contributes substantial amounts of sediments to the Bay and its tributaries. Construction sites can contribute, on a per-acre basis, 10 to 20 times as much sediment as agricultural lands. Particularly in the 1960s, construction activities throughout the northeastern U.S. caused a sharp increase in sediment delivered to local waterways.
Building away from existing centers also dramatically changes the heritage and economic diversity of local communities. Development in small and rural communities can impact existing local industries, such as farming, fishing and forestry. New residential and commercial development in these areas can also alter the visual character and “sense of place” that make the Chesapeake region unique.
Headland breakwaters at the Virginia Institute of Marine Science serve practical purposes for wildlife and residents.
The Sustainable DC Plan outlines two decades of changes.
Chesapeake Bay Trust Grant program will fund 16 new projects in Maryland and Virginia.
This Potomac River stream winds through development-burdened Northern Virginia before ending near Great Falls Park.
Friends of Sligo Creek is a volunteer organization that has worked since 2001 to clean up this Potomac River tributary.