Annapolis, MD – A draft report released Thursday, Nov. 13 indicates the much-maligned Conowingo Dam may not be the major culprit in the pollution of the Chesapeake Bay, environmental officials reported.

The report, the Lower Susquehanna River Watershed Assessment (LSRWA) was released jointly by the U.S. Army Corps of Engineers (USACE) and the Maryland Department of the Environment (MDE).

According to a press release from MDE, the report is now available for the public to review and submit comments. A public meeting and webinar on the report will be held in early December at Harford Community College. The public comment period is open until Jan. 9.

The Conowingo Dam is located in the lower Susquehanna River. The hydroelectric facility was built in 1929. It is currently owned by Exelon.

According to MDE, LSRWA “indicates that the reservoir behind the Conowingo Dam is trapping smaller amounts of sediment and has essentially reached its limit to trap in the long term. However, a large majority of the pollution to the Chesapeake Bay from the Susquehanna River comes from runoff from pollution sources from the upstream drainage area or watershed, as opposed to the sediment and associated nutrients collected behind the dam.”

Department officials stated in the press release that LSRWA “suggests that strategies to reduce nutrient pollution at its source from throughout the bay drainage area are more effective at addressing impacts to the bay.”

“The report concludes that attempting to dredge the 200 million tons of sediment behind the dam and relocate it safely could waste taxpayer money,” stated Chesapeake Bay Foundation (CBF) Maryland Executive Director Alison Prost. “The more effective strategy is laid out in the comprehensive, regional Chesapeake Clean Water Blueprint.”

Prost added, however, “Exelon should be held for its share of the problem. The buildup behind the Conowingo Dam is one source of pollution and the dam’s owner should be accountable for reducing that pollution and its impact on the environment.”

In a statement made prior to the release of the assessment, Prost called on officials from other Chesapeake Bay Watershed states, including Pennsylvania and New York, to implement their watershed plans.

The Conowingo Dam sediment has been identified by officials in several Maryland counties located along the shores of the Chesapeake as the bay’s most egregious polluter. After learning in late 2011 that Calvert County’s U.S. Environmental Protection Agency (EPA)-mandated Watershed Implementation Plan (WIP) would cost an estimated $1.3 billion, the county commissioners told MDE officials the dam’s owner and the larger jurisdictions were disproportionately overburdening the rural counties with responsibility for reducing water pollution. Later, a state consultant assured the commissioners the WIP cost would not be in the billions.

The EPA has mandated that amounts of nutrients and sediments entering the bay and its tributaries be reduced significantly by 2020.

Calvert County Environmental Planner Dr. David Brownlee said the commissioners will receive an update on the WIP after the new board begins its term.

The LSRWA can be accessed and comments may be made at

Contact Marty Madden at