Will Shad Put the Kibosh on Conowingo?

Probably not, but that doesn't mean that they won't be an issue in the relicensing.

Dismal shad run puts Conowingo Dam in crosshairs

"This is a once-in-a-generation opportunity," said Mark Bryer, Chesapeake Bay program director for The Nature Conservancy.

Exelon has applied to the Federal Energy Regulatory Commission to renew its operating license for Conowingo and is in negotiations with officials from Maryland and Pennsylvania and with federal fish and wildlife agencies. Until those talks are resolved, all parties have agreed not to discuss publicly what the Chicago-based power company might do to improve passage of shad. But Kimberly Long, environmental program manager for Exelon Power, pointed out that shad runs up and down the East Coast are down, suggesting that the troubles may not be limited to Conowingo.

"I don't think anyone has pinpointed one reason for the decline in the American shad population," she said in an interview last week at the dam
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No one's seriously proposing to remove Conowingo Dam, though, as its 572 megawatts of power-generating capacity help balance out electricity supply to the Mid-Atlantic grid, particularly when demand is at its peak. Moreover, the 14-mile-long "pond" of water backed up behind the dam furnishes cooling water for the Peach Bottom nuclear power plant, also operated by Exelon. And it's a backup source of drinking water for Baltimore, which has tapped it occasionally when severe droughts drained the metro area's reservoirs.

Conowingo's removal "would cause a number of impacts to other users," Bryer acknowledged. "If we can strike a better balance and get ... better environmental performance out of the lower river while getting electricity generation, I think that would be a solution many would be excited about."

As far as environmental effects, Conowingos most important effect is as a sink for sediment coming down the Susquehanna River, preventing much of it from entering the Bay.  This function is declining as the pool behind the dam fills with sediment.  If they don't manage to solve that problem as part of the relicensing, they might at well just dynamite the dam, and manage the sediment by other means.

While dams are an impediment to shad, it is really not clear whether the dam is the problem in this instance. However, a new iteration of the dam should provide for adequate fish transport above the dam.