Declaring the sediment buildup behind Conowingo Dam a growing threat to the Chesapeake Bay, Maryland Gov. Larry Hogan announced Tuesday a pilot project to dredge up a tiny portion of the accumulated silt and sand.Sell it to jurisdictions worried about sea level rise, to raise their own height.
Speaking at a press conference at the dam, Hogan said the state later this month would issue a request for proposals to dredge 25,000 cubic yards of sediment by next spring from the reservoir upstream of the hydroelectric facility on the Susquehanna River.
The intent, he said, is to pin down what it would cost to dredge massive quantities of sediment from the Conowingo “pond,” as the reservoir is called, and to find out if there are viable markets for reusing the material. He said that he hoped the project would help the state determine whether large-scale dredging is feasible - even though an earlier study concluded that dredging the built-up sediment would be costly and provide little overall benefit to the Bay.
Since its completion in 1928, the 94-foot high dam has been trapping millions of pounds of sediment, as well as the nutrients attached to the particles, keeping them from flowing into the Bay 10 miles downstream. But the pond has been slowly filling, and a study led by the Baltimore District of the U.S. Army Corps of Engineers found that it has reached capacity and now does little to prevent material from reaching the Chesapeake.
Another concern is that major storms, and even heavy spring rains, can scour large quantities of the deposited sediment from the river bottom and flush it into the upper Bay.
“Much of our efforts to protect the Bay and safeguard our environment for future generations could be wiped out by the effects of one bad storm,” Hogan said. “Simply put, this is a growing threat which must be addressed.”
Wednesday, August 9, 2017
Gov. Hogan to Dig Out Conowingo Pond
At least a little. For the past 30 or so years, the sediment building up behind Conowingo Dam was like the weather; everybody liked to talk about it, but nobody did anything about it. Gov. Hogan proposes to break the mold and actually try it: Pilot project planned to dredge Conowingo sediments