By: Cyrus Chimento (Stewardship Intern)
Stream restoration projects have been a preferred tool for reducing pollution and gaining TMDL credits. However, it turns out that there is a shortage of data supporting the ability of stream restoration projects to reduce pollution, especially in the long-term.
The Bay Journal’s late October article, “Researchers examining effectiveness of stream restoration”, reported on the question of whether stream restoration, an expensive but favored tool of watershed improvement in Maryland, is resulting in ecological benefits that justify the investment.
Watershed improvement is focused on several ways of reducing pollution inputs and restoring ecosystems in and around our waterways. Water pollution is regulated by total maximum daily loads (TMDLs). TMDLs constitute a pollutant budget: a maximum limit on the amount of pollutant allowed into a water body. Projects that reduce the amount of pollution running into a waterway receive credits from the Chesapeake Bay Program.
Stream restoration projects have been a preferred tool for reducing pollution and gaining these credits. However, it turns out that there is a shortage of data supporting the ability of stream restoration projects to reduce pollution, especially in the long-term. This has some environmental construction professionals and scientists at odds: the environmental construction business is thriving due to the influx of public funding for these projects, but data do not exist to support the projects’ long-term utility in improving water quality. The dearth of data also raises questions: if we cannot quantify the water quality benefit of stream restoration projects, how are they assigned credits for reducing pollution?
Despite the conflict, everyone agrees that the solution is more data. To that end, the Chesapeake Bay Trust has started funding research projects to determine the ability of stream restoration projects to address watershed pollution and ecosystem degradation. One of these research projects is the restoration of Muddy Creek at the Smithsonian Environmental Research Center (SERC), in Edgewater, MD. Scientists hope to monitor this project, along with several others in the area, to gain a better idea of the downstream effects of stream restoration.
Focusing solely on stream restoration, however, can obscure the bigger picture. The reason these streams need restoring in the first place is because of the changes to the land around them: watersheds covered in impermeable asphalt and cement, development over floodplains, and removal of wetlands and forests. With these changes, water travelling in the watershed moves quickly through drainage systems and into the streams, causing powerful surges that erode stream banks into deep, narrow trenches that keep water, and pollutants, moving quickly towards the bay.
The key, which stream restoration is trying to accomplish, is to slow the water down long enough to avoid erosion and let pollution and sediments fall out or get filtered out of the water column along the way. However, if stormwater is not slowed before arriving at the stream, we will have paid dearly in tax dollars to end up with the same problems: eroded streams and polluted waterways.
How can we slow down the water before it gets to these streams? We should use a diversified and holistic strategy for watershed restoration. Pairing stream restoration with efforts to increase permeable surface area in the watershed will slow water down before arriving at streams. Preserving natural resources, such as wetlands and forests, increasing low impact development (LID) efforts like green roofs and rain gardens, and expanding natural stormwater infrastructure will all allow water to seep slowly through the watershed, and will ensure that those stream restoration projects do their job: leave pollutants behind, regenerate ecosystems, and let clean water flow to the bay.
Increasing low impact development (LID) efforts like green roofs and rain gardens, and expanding natural stormwater infrastructure will allow water to seep slowly through the watershed, and will ensure that those stream restoration projects do their job: leave pollutants behind, regenerate ecosystems, and let clean water flow to the bay.
Ultimately, the goal of restoration is to have cleaner water traveling downstream. At the moment, stream restorations can do their job best in the upper reaches of a watershed. In these upper reaches, stormwater pressure will be relatively low. Therefore, danger of stream erosion will be at a minimum, lowering the chance of erosion in the future, and allowing the benefits of restoration to play out over time. As these projects get executed, time, and data, will tell whether they are indeed restoring streams or merely stabilizing the areas for the near future.
In the meantime, the Anacostia Watershed Society is doing its best to take a diversified approach to stormwater management. We have a wide range of programs that improve the physical capabilities of the watershed to reduce pollution. These efforts include RiverSmart Communities, which provides assistance to homeowners to install green infrastructure like green roofs and rain gardens, and restoration projects of our own, like building or maintaining wetlands, meadows, and streams.
Advocacy is also part of our work. We are part of the data collection process, keeping an eye on the natural resources in our watershed and making sure that local policy decisions are supporting a fishable, swimmable Anacostia. Anacostia Watershed Society monitors stormwater, pollution, and water quality. We track and clean up trash, and record the diversity of wildlife found in and around our waterways, release an annual report card that assesses the health of the river.
Good watershed stewardship goes beyond just the infrastructure: we educate people about how to improve the watershed. Anacostia Watershed Society works in schools to let students be part of our efforts in hands-on environmental education programs. These include Rice Rangers, where students grow wetland plants and eventually transplant them into marshes, and Watershed Explorers, a course that lets older students delve into the historical and scientific components of the Anacostia watershed. These programs are amplified by programs like RiverSmart schools, which combines education about low impact development best practices with action- implementing stormwater management projects and creating green space on school grounds. Adult education like teacher training and the Watershed Stewards Academy, for aspiring community leaders and activists, ensure that everyone in the community is involved in making the Anacostia watershed healthy.
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