Chesapeake Bay restoration experts know that one of the biggest threats to clean water in the Bay and its rivers is stormwater runoff -– the rainwater that runs off all the rooftops, streets, parking lots, and lawns in the Bay watershed’s six-state region, washing toxic pollution directly into local streams, rivers, and ultimately the Bay.
In fact, the sheer volume of stormwater runoff and its toxic brew of oil, grease, bacteria, fertilizer, dirt, and grime threaten to overwhelm the pollution reductions made over the years by farmers, wastewater treatment plants, and other Bay pollution sources. Pollution from these other sources is gradually getting better; stormwater runoff pollution is getting worse.
That’s why Virginia’s Chesapeake Bay clean water blueprint -- the state’s plan to reduce pollution and restore the Bay by 2025 -- puts an emphasis on better managing polluted runoff from Virginia’s cities and towns. And that’s why localities across Virginia are grappling with how to capture, slow, treat, or otherwise reduce the stormwater runoff in their communities.
Like many localities, Arlington, Va., a busy urban county adjacent to Washington, D.C., is employing lots of innovative and cost-effective greenscaping projects to address its stormwater challenges. The county showed off three of them during a recent “green stormwater tour” for statewide conservation groups.
Tour stops included:
• The Four Mile Run restoration project, a joint effort with the City of Alexandria and the U.S. Army Corps of Engineers to restore stream channels, wetlands, native vegetation, and recreational opportunities along Four Mile Run, a 7-mile creek flowing through Arlington to the Potomac River (top photo). The project not only ensures continued flood protection but is improving water quality, wildlife habitat, public access, and recreation along the creek.
• An 18,000-square-foot green roof atop the county’s Walter Reed Community Center that absorbs rainwater like a sponge to nourish the colorful plants on the roof. Studies show green roofs can reduce runoff from a building by 50 percent or more. Among other features, the Walter Reed Community Center also has a rain garden to absorb runoff from the center’s parking lot.
• Donaldson Run stream restoration, an on-going project to reduce flooding and erosion, restore and beautify a favorite neighborhood creek, and produce cleaner water for the Potomac River. By reconfiguring the creek channel and creating gentle meanders and rocky “step pools,” the project allows runoff-fed stream water to slow down, spread out across the natural flood plain, sink into the ground, and settle out much of the dirt, flotsam, and jetsam so typical of urban streams. To learn more, watch this quick video about the project.
That such green, holistic approaches can greatly reduce runoff pollution and improve local water quality is clearly demonstrated by before and after photos of the Donaldson Run restoration project. Especially striking is this image, taken during a heavy thunderstorm. The water coming down the restored branch of Donaldson Run on the left is markedly cleaner than the muddy, silt-filled water coursing down the unrestored branch on the right.
“There are so many compelling reasons to restore our urban streams using these greenscaping techniques,” said Aileen Winquist, Arlington’s watershed outreach program manager. “They reduce sediment and other pollution, a major focus of the Chesapeake Bay restoration effort. They protect county infrastructure from erosion, restore healthy streams for fish and other aquatic creatures, and re-create natural areas for wildlife and public recreation and education.
"And perhaps best of all from a local government perspective, they can be more affordable than traditional concrete and pipe solutions.”
Sound like winners.
Chesapeake Bay Foundation
Photos courtesy of Arlington County