2023 Potomac River Report Card
#PotomacReportCard
Land
The Potomac River’s health is intimately tied to the 14,600+ square miles of land that surround it. From upland forests and farms to the densely populated Washington, DC metro area to the low-lying stretches of the tidal region – the Potomac’s varied landscapes and how they are managed play a huge role in water quality.
Densely forested lands and wetlands act as natural filters between pollution and our local waterways. When forests and vegetation are cleared and paved over, we weaken the land’s ability to naturally absorb rainwater. As a result, streams and drinking water sources become overwhelmed with polluted runoff. (Head to our Pollution section to learn more about polluted runoff.)
An increase in the adoption of best management practices (BMPs) throughout the region signals important progress in the reduction of land-based pollution, though rural and urban BMPs are still falling short of implementation goals. Land placed under protection has improved, with the region nearly achieving a goal of 20% land protected.
Sustainable land use is one of the most effective and affordable ways our community can reduce water pollution and strengthen natural defenses against the impacts of the climate crisis. (Learn more about local climate impacts in our Rising to the Challenge series.) It is incumbent on our local, state, and federal agencies to prioritize responsible growth plans, forest and wetland protections, and incentives for best management practices. Tree plantings, wetland restoration, low-impact farming techniques, rain gardens, and more nature-based solutions are simple, scalable, and cost-effective.
Urban Best Management Practices (BMPs)
Adopting best land management practices (BMPs) in populated urban areas is one of the most effective strategies to reduce polluted runoff and meet pollution reduction goals. Examples of urban BMPs include permeable pavers, rain barrels, green rooftops, and rain gardens. All of these measures effectively capture rainfall and prevent excess stormwater from washing street oils, chemical fertilizers, and litter into local waterways.
Since the last Report Card in 2020, urban land improvements have seen a slight increase in the Potomac region. However, while overall implementation is headed in the right direction, marked differences in individual state implementation still persist. The District of Columbia has made a strong push to further incorporate nature-based infrastructure and BMPs thanks to leadership from local organizations and the District Department of Energy and Environment (DOEE). Maryland’s city centers, likewise, saw a great improvement in urban BMPs, while Virginia fell behind when compared to the successes of DC and Maryland.
As impervious surfaces (e.g., roads, rooftops, and parking lots) expand throughout the region, it is vital that local and state decision makers prioritize forest protections and BMP implementation to combat pollution. A recent comprehensive study of forests in Maryland showed a slowing but alarming rate of tree loss in the state, contributed largely by development. Nearly half (46 percent) of tree loss from development is happening in Montgomery and Prince George’s counties. Encouragingly, there is an opportunity to mitigate some of this loss; Baltimore, Prince George’s, and Montgomery counties are found to have the most plantable space in the state.
Urban-Suburban Land Use Improvement (percentage meeting 2025 goal)
Source: Chesapeake Bay Program
Rural Best Management Practices (BMPs)
Agriculture has been a dominant source of pollution to the Potomac River for decades. While excessive sediment and nutrients continue to flow into local streams and waterways, marked progress has been made in reducing agricultural pollution. Thankfully, due to an increased effort from farmers and local watershed organizations, more best land management practices are being adopted which better help reduce the impact and severity of polluted runoff from agriculture. Better sediment control practices, use of cover crops, livestock fencing, tree plantings, and other management methods are increasing as cost-share funding for these important practices allows farmers to implement them economically and public awareness surrounding their benefits to both farm and water quality alike continues to increase.
The amount and distribution of farm and forest land management BMPs are headed in the right direction but this measurement is still falling below restoration benchmarks set in state watershed implementation plans (WIP). Maryland currently leads all Potomac states in reaching their state WIP goals at 85 percent, with West Virginia not far behind at 70. Virginia, however, is lagging behind in their rural BMP implementation, reaching only 36% of their 2025 implementation goal. On average these states are collectively meeting 64 percent of their rural BMP goals, a positive increase from our last report and a sign that farm and forest land BMP implementation is still on the rise across the watershed.
Rural Land Use Improvements (percentage meeting 2025 goal)
Source: Chesapeake Bay Program
Protected Lands
Protected lands are vital to a resilient and healthy Potomac River. These natural, often forested, lands are permanently conserved through public parks and wildlife management areas, conservation easements, and development right transfers. Preserving natural ecosystems safeguards wildlife habitat, but it also significantly benefits public health and our quality of life. Wetlands and forests clean our air, provide us with safe water, and protect our communities from flooding, rising water levels, and other impacts of the climate crisis.
Currently, 19 percent of the Potomac River watershed is protected, just shy of the region’s 20 percent conservation goal. With 1.77 million acres in permanent protection, the Potomac region is 94% of the way towards meeting the goal according to the Chesapeake Bay Program Partnership's Protected Lands Database.
Learn how Potomac Conservancy, a nationally accredited land trust, works to conserve forests, streams, and river-friendly farms in the Potomac River region at potomac.org/lands.
Protected Lands (in acres)
Source: Chesapeake Bay Program
Current Land Use
Land use in the Potomac River region is highly variable due to the diversity of landscapes and land use types. Just over half of the watershed is forested (53 percent), but that portion is decreasing as developed land (15 percent) continues to increase over time; in suburban and rural communities, new building often replaces farms and forests.
As of 2019, agricultural lands have remained steady at 25 percent land cover reflecting successful land conservation efforts centered around preserving our region’s farmlands. Agriculture remains a top source of pollution to the Potomac, but encouragingly, it is on the decline as public programs have supported river-friendly farming practices that reduce runoff. As development encroaches on rural communities, it is essential for us to focus on protecting healthy farmland and forests as essential tools in cleaning our waterways.
Through river-friendly growth planning, our communities can prioritize redevelopment, preserve large natural and forested areas, and cluster mixed-use, low-impact building. And we can preserve agricultural communities that are vital for food security, wildlife corridors, cultural heritage, and farm economies.
Our land use score is tied to the percentage of forested lands in the Potomac River watershed. Conserving our natural and forested lands ensures a legacy of clean water for future generations.
Current Land Use (percent land cover)
Source: National Land Cover Database
Resources and Methodology
Urban/Rural best management practices (BMPs) and their grades in this report are directly linked to benchmarks established in state watershed implementation plans (WIPs). Data for urban and rural BMPs is reflective of the whole state and/or municipality from which they are reported. For this reason, the data may include BMPs outside of the Potomac River watershed. Individual state progress was calculated using CAST data for individual BMPs for the year 2020 compared to WIP 3 goals. Individual BMP progress for 2020 was aggregated and calculated for primary BMP unit (acres, animal units, etc.) and then a weighted average calculated to determine each state’s overall progress. Local and state reporting of BMPs can vary by location, therefore values may not be a full accounting of all BMPs across the region.
Land use data is provided by the USGS National Land Cover Database for the most recent 2019 dataset.
Protected lands data for the whole Potomac River watershed was supplied by the US EPA Chesapeake Bay Program. The data is reported in terms of acres of protected land and reflects the most recently reported data from local and state agencies. Reporting for this data can be variable and sometimes inconsistent meaning that protected acreage values could be higher than presented. Additionally, “protected lands” includes all lands legally protected from development but does not factor in level of environmental protection (e.g., lands in conservation easement can be protected from development but landowners aren’t required to implement any BMPs).
Data for the Land section was provided by the Chesapeake Bay Program, the Chesapeake Bay Program’s Chesapeake Assessment Scenario Tool (CAST), and the National Land Cover Database (NLCD).
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