Dredging the Conowingo Dam Still Makes Environmental Sense

Press Releases Jul 24, 2017

ROCKVILLE, MD (July 24, 2017) – Scientists working for the Environmental Protection Agency have reportedly confirmed what the Maryland Public Policy Institute first argued in 2014: that sediment pollution piling up behind Maryland’s Conowingo Dam poses a grave threat to the Chesapeake Bay’s health. The Institute’s 2014 study, linked here, concluded that an innovate dredging solution to remove the sediment would be an environmental and economic success story for Maryland. 

The Washington Post and The Baltimore Sun this month reported that scientists believe that the reservoir behind the Susquehanna River’s Conowingo Dam has filled with sediment pollution far sooner than previously predicted. If a storm surge pushed the sediment over the dam, it could cause catastrophic harm to the Bay’s ecology and the industries that depend on it.

“Our 2014 research underscores that dredging the dam will protect Maryland’s natural resources and aquatic life while strengthening our green collar economy,” said Christopher B. Summers, president and chief executive officer of the Institute. “We are pleased that the scientific community now appreciates the threat posed by the dam and we commend the Hogan Administration for soliciting creative, private sector proposals to address this challenge.”      

The Institute’s 2014 study estimated that removing all 172 million tons of sediment pollution behind the dam would dramatically improve the Bay’s health at a fraction of the cost of other Bay cleanup efforts.  The dredging effort would cost an estimated $4.2 billion – significantly less than the $14.4 billion the State of Maryland plans to spend on Bay cleanup efforts – while removing one of the principal threats to the Bay’s water quality, wildlife, and economic potential.

Periodic storms transform the Conowingo Dam into a large-scale source of pollution. When Tropical Storm Lee hit the Mid-Atlantic in September 2011, nearly 19 million tons of Bay-killing sediment were released from the dam over just five days – that’s 26 times greater than Maryland’s average annual Bay sediment load.  The upper Bay’s oyster harvest plunged 95 percent that year, demonstrating that failure to dredge the dam can devastate Maryland’s aquatic life.

 About the Maryland Public Policy Institute: Founded in 2001, the Maryland Public Policy Institute is a nonpartisan public policy research and education organization that focuses on state policy issues. The Institute’s mission is to formulate and promote public policies at all levels of government based on principles of free enterprise, limited government, and civil society.  Learn more at mdpolicy.org.