Powell's Creek Restoration

 

from Prince William County

The Prince William County Department of Public Works has just begun a project to restore a portion of Powell Creek. This project is the largest project Public Works has taken on, and will include clearing along the creek, temporarily rerouting Powell's Creek, removing existing sediment, channel relocation to restore the streambed, stream bank reinforcement and replanting with native plants and trees to finish the project and connect this section of Powell's Creek with its wetland system.

All the improvements will create a meandering creek with riffles, where water runs swiftly over rocks to introduce oxygen into the water, along with pools to bring equilibrium to the stream to control sediment. Once established, the new trees and native plants will stabilize the stream bank at the same time they provide shade and reduce algal growth. "Even though you're impacting the wetlands temporarily, they're going to be improved ... because we're reconnecting to the flood plain," said Prince William County Environmental Engineer Tom Dombrowski. "What we're trying to do is restore it to what it was, which is wetland forest. We're changing it to be what it was, the way nature intended it to be," said Tom Dombrowski.

The project will encompass nearly one-mile along part of Powell's Creek, just off Cardinal Drive and Merrily Way, behind the Montclair and Four Seasons subdivisions. The two-year project will establish wetlands along the boundaries of Powell's Creek to act as buffers against flooding. According to Tom Dombrowski "It is actually going to store the water in the wetlands that are on the flood plain and prevent any major flooding downstream ...”  

The Powell's Creek project will also improve degraded bank conditions that threaten a sanitary sewer main transmission line and reduce sediment and nutrient runoff to meet the U.S. Environmental Protection Agency (EPA) mandated reduction in these pollutants. The Chesapeake Bay and its tidal waters are impaired by  the release of excess nitrogen, phosphorus and sediment. These pollutants cause algae blooms that consume oxygen and create dead zones where fish and shellfish cannot survive, block sunlight that is needed for underwater grasses, and smother aquatic life on the bottom. The US EPA has taken control of the situation and has developed a federally mandated total maximum daily limit, TMDL, to restore the Chesapeake. 

The TMDL allocates a pollution budget among the states and localities including Prince William County that limit the daily amount of sediment, nutrients and other pollution going into their waterways. Deforestation decades ago, and ongoing development, continue to impact streams and make restoration necessary. If it's out of whack, it's because of how we developed the land around it. Stream restoration is one of the better ways to solve the problem," Dombrowski said.

While the primary goals of stream restoration are to protect infrastructure, clean up the watershed and protect property, completed projects create environments for a wide range of water-dwelling macro-invertebrates, fish, birds and mammals. Residents will be able to enjoy walking around the restorations. Once fully established, the riparian zone, or areas surrounding the stream, will not only protect the stream bank from erosion, but also take up nutrients before the nutrients can enter Powell's Creek, which runs to the Potomac River, which in turn, flows to the Chesapeake Bay. "By making these changes, we're achieving a goal of preventing pollution from going into the Chesapeake Bay. These goals are multi-faceted" said Prince William County Environmental Engineer Tom Dombrowski.