Removing obsolete dams brings rivers back to life
10/6/2016 Volume XLIX, No. 39
When officials gather to announce a public project, it’s usually a new building, park or bridge.
But on Sept. 8, officials and community members came together to commemorate the de-construction of the obsolete 125-year-old Hughesville Dam on the Musconetcong River. U.S. Secretary of the Interior Sally Jewell and New Jersey Department of Environmental Protection Commissioner Robert Martin were on hand to tour the project that will restore the 42-mile Musconetcong – a federally-designated “Wild and Scenic River” – to a free-flowing state.
The 150-foot-wide dam is 3.5 miles upstream of the confluence of the “Musky” and the Delaware River and was originally built to provide power in the days before rural electrification.
Beth Styler Barry, executive director of the Musconetcong Watershed Association, said dismantling the dam will improve water quality for human and aquatic life, reconnect fisheries and provide kayakers and canoeists with safe passage free of portages and hydraulic traps below dams. “Following the dam removal, fishermen will enjoy a greater variety of native fish to catch, possibly including shad,” she said.
Hughesville is the fifth dam along the Musconetcong to be removed, and one of dozens of old and obsolete dams in New Jersey that have been taken down or proposed for removal.
The Raritan River, the largest waterway entirely in New Jersey, has also benefited from dam removals. Three dams along the Raritan in Somerset County – the Nevius Street Dam, Robert Street Dam and Calco Dam - were taken down in recent years to help migrating fish, and more dam removal projects are proposed.
According to American Rivers, a national group that has worked on more than 200 dam removal projects across the United States, dams can damage river health. Here’s how:
- Dams block rivers, preventing fish migration. They limit the ability of fish to access spawning habitat, seek out food and escape predators. Fish passage structures can enable some fish to pass around dams, but their effectiveness decreases depending on the type of fish and number of dams to be traversed.
- Dams slow water flow. Aquatic organisms, including fish such as salmon and river herring, depend on steady flows. Stagnant reservoir pools disorient migrating fish and can significantly increase the duration of their migration.
- Dams alter habitat, changing how rivers function. Dams can trap sediment, burying rock riverbeds where fish spawn. Gravel, logs, and other important food and habitat features can also become trapped behind dams.
- Dams degrade water quality. Slow-moving or still reservoirs can heat up, resulting in abnormal temperature fluctuations which can affect sensitive species. This leads to algal blooms and decreased oxygen levels.
And as dams age and decay, they can also become public safety hazards, posing downstream flood risks in the event of failure.
American Rivers believes that many, or most, of the more than 90,000 dams throughout the United States are no longer serving their original purpose. “There is no faster or more effective way to bring a river back to life than removing a dam,” the group asserts.
Kudos to Musconetcong Watershed Association and the other partners in the Hughesville dam removal project. Thanks to them, the beautiful Musconetcong River will become an even more wild and scenic place! Next up on the Musconetcong Watershed Association’s proposed removal list is the Warren Glen Dam, the largest on the Musky.
To learn more about the Musconetcong River dam removals, visit the Musconetcong Watershed Association website at www.musconetcong.org. For more on Raritan River dam removals, go to https://thewatershed.org/science/dam-removals/.
To see a national map of dam removal projects, go to https://www.americanrivers.org/threats-solutions/restoring-damaged-rivers/dam-removal-map/.
And for more information on preserving New Jersey’s land and natural resources, visit the New Jersey Conservation Foundation website at www.njconservation.org or contact me at email@example.com.