...In recent years, the silvery shad that Native Americans used to teach European settlers how to fertilize crops, that helped feed George Washington’s Continental Army, and that provide food to eagles and otters, have started to disappear in alarming numbers. The disappearance has started talk of extinction, mostly because of four giant dams that block the Susquehanna River in Pennsylvania, where the fish were once abundant, according to the U.S. Fish and Wildlife Service.This is more than fair. The dams have a major impact on a major fish species, and they should make all reasonable effort to accommodate the passage of the shad up to their spawning grounds.
Biologists say there’s one ray of hope for efforts to restore the Susquehanna’s shad — the looming expiration of operating licenses for two of the dams. Before granting a 30-year renewal, the Federal Energy Regulatory Commission requires the dam operators to study the environmental effects of their facilities. Based on the findings, the commission can require that conditions be greatly improved so that more shad can swim past them...
The commission confirmed in a statement that two dams, the Conowingo Hydroelectric Plant, built in 1928 and run by Exelon Power, and the York Haven Hydroelectric Dam, built in 1910 and run by York Haven Power, are in the “pre-filing state of the relicensing process,” meaning they must conduct environmental impact studies of the shad and other species affected by the plants. A decision is a ways off, with release of the studies, critiques and public comments pending over the next three years.
Research shows that only 33 percent of shad get by the Conowingo dam and only 8 percent make it past York Haven, said Hendricks, citing figures provided by Pennsylvania. Another dam, the Holtwood Hydroelectric Dam, owned by Pennsylvania Power & Light, passes 26 percent of shad. The Safe Harbor Hydroelectric Station, run by Constellation Energy, allows 72 percent of shad to pass.
I'm kind of surprised they're willing to file to relicense Conowingo Dam. Ever since I arrived in Maryland in 1985, there has been talk about how the reservoir was rapidly filling with sediments and would soon reach the end of it's useful life. But according to this article, they are considering plans for dredging the reservoir. Where the hack will they dump all that sediment? I guess they could take it back and put it on farm fields in Pennsylvania, where most of it came from.
Shad were introduced from the East Coast, to the Columbia River in the Pacific Northwest, where they are doing quite nicely, despite the fact that the Columbia is also heavily dammed.