A pent-up threat to the Chesapeake Bay: Editorial

Just a few miles from the Maryland- Pennsylvania border lies the Conowingo Dam, an 88-year-old power station stopping the massive Susquehanna River, which is the source of much of the freshwater flowing into the Chesapeake Bay. Since bay cleanup began, states in the Chesapeake watershed have relied on the dam to limit the flow of sediment and phosphorous further downstream, and the plan was to continue doing so for decades to come. But the dam's sediment pools are full, long before the cleanup plan projected them to be. Now Maryland, where the dam is located, and Pennsylvania, which is responsible for much of the pollution in the Susquehanna, have to decide what, if anything, to do about it.Maryland Gov. Larry Hogan announced last week that the state would conduct some limited dredging behind the dam, testing the feasibility of doing so on a larger scale and determining whether there could be some use for the material recovered.But Chesapeake environmental advocates are wary, concerned that diverting focus and resources to dredging behind the dam might undermine more important environmental initiatives, such as stopping pollution from entering the Susquehanna and other rivers in the first place. That is an argument for proceeding with care, not refusing to attend to the dam.