Why Remove Dams Around the Chesapeake Bay?
Last month, I had the pleasure of speaking to a group of engaged, intelligent people at the local Patagonia store here in Washington, D.C. as a follow-up to a June screening of DamNation. Have you seen the film yet? It’s pretty explosive, isn’t it? However, as I’ve said before, this film only gives a tiny glimpse into the world of dam removal. Below, I share part of that presentation and discuss what removal looks like in the Chesapeake Bay by highlighting a few completed and ongoing projects that we’ve been engaged in.
Why do we remove dams? Huge drivers for dam removal in the Chesapeake are migratory fish, such as American and Hickory Shad, river herring and American Eel. It’s hard to believe, but the American Shad fishery was once the largest in the bay— surpassing oyster, crab, and rockfish harvests.
Historically, river herring (Blueback Herring and Alewife, collectively) and American Shad were a major fishery resource throughout the Chesapeake Bay, and a common food staple for Native American tribes. Besides being important for human use, river herring and shad are important contributors to many freshwater streams and provide important forage for other recreational and commercial fish species like Striped Bass.
The commercial harvest for American Shad peaked in 1890 when landings in Maryland exceeded seven million pounds. Unfortunately, the absence of policies to manage this fishery resource at the time contributed to the rise in commercial exploitation of American Shad and river herring, not only in the Bay, but also along the entire Atlantic seaboard. As a result, river herring and American Shad landings began a precipitous decline. By 1979, these fisheries were near collapse, as evidenced by only 18,000 pounds in American Shad landings in Maryland.
Commercial exploitation was not the only factor contributing to the decline of anadromous fish in the state. The proliferation of mills and dams prevented shad (American and Hickory, collectively) and river herring from migrating upstream to their spawning grounds, thereby limiting the habitat available to them. Once restrictions on commercial fishing were in place, states could begin restoring habitat and rebuilding the shad and river herring fishery.
The decline of this commercial and recreational fishery is a major concern for natural resource agencies in Maryland, Pennsylvania and Virginia, as well as federal agencies such as the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Fish and Wildlife Service (USFWS). This collective concern has contributed to the establishment of the Chesapeake Bay Agreement—a multi-state agreement to restore the health of the Bay and its tributaries—and goals for restoring habitat connectivity for migratory fish. This is just one of several reasons why we remove dams, but it’s an important one to consider in the Chesapeake Bay.
What do dam removals look like in the Chesapeake? Dam removal in DamNation was big and explosive, but you’ll find this isn’t always the case. Do you know how they say that serial killers could be your nice, quiet neighbor? This idea totally applies to dam removal! The smallest, most unassuming dam can have just as significant an impact on aquatic populations. Let’s examine a few.
We kicked off removal of the Harvell Dam in Petersburg, Virginia, on July 15th, after more than a decade of legal wrangling with the Federal Energy Regulatory Commission (FERC).
The project will re-open 127 miles of upstream habitat for migratory fish and is the sixteenth dam removed within the Chesapeake Bay drainage in Virginia since 2004.
Less than 24 hours after removal began, tiny elvers (baby eel) started to wiggle over the dam once a section was breached and water began to trickle through.
One month after construction crews began to break up the concrete dam the Appomattox River flows freely through Petersburg, Virginia, providing unencumbered passage for paddlers and fish alike.
Potomac Industrial Dam
Hidden from the highway, but right below the iconic “Blue Bridge”, is the Potomac Industrial Dam on the Potomac River in Cumberland, Maryland. Originally built for industrial water supply in the 1950s, it now serves no purpose other than to provide a bit of backwater for the pumps that water the C&O Canal. This potential removal is part of a grander vision for the city that includes restoring habitat for aquatic species, improving flood attenuation, eliminating a safety/liability issue, and growing Cumberland’s economy through increased recreation-based tourism. The project is currently in the study and design phase.
Heistand Sawmill Dam
The Heistand Sawmill Dam in Marietta, Pennsylvania, is the 1st blockage on Chiques Creek and is located approximately 600 feet upstream from the confluence with the Susquehanna River. Historically, American Shad, Hickory Shad and American Eel entered the Chiques Creek Watershed, but these fish are currently impeded by the presence of the dam. Removal of the Heistand Sawmill Dam will reconnect more than 13 miles of streams.
Heistand Sawmill Dam currently impounds water for nearly a mile upstream on Chiques Creek, and creates a backwater condition in the lower reaches of Donegal Creek. This situation has led to a localized siltation problem, which interferes with natural sediment transport processes and decreases the availability of quality habitat. Removal of the Heistand Sawmill Dam will restore the free-flowing river, improve habitat conditions, directly address non-point source pollution by eliminating a hydrologic modification, and encourage the natural movement and processing of sediment and nutrients.
Currently, American Rivers has approximately 20 restoration projects in various phases of development throughout Maryland, Pennsylvania and Virginia. Add The River Blog to your RSS feed and ‘like’ us on Facebook to see more of what we’re up to throughout the year!