RESTON, Va. — A recent U.S. Geological Survey (USGS) study reported that the Conowingo Dam, located on the Susquehanna River, is at approximately 92 percent capacity for sediment storage, according to a press release.

Sediment and nutrients have been building up behind the dam since its construction in 1929 and released periodically down river into the Chesapeake Bay, especially during high flow events, stated the release.

Previous research revealed that the water is depleted of oxygen needed to maintain healthy populations of oysters, fish and crabs due to excess levels of nutrients in the bay, reported the release, and these nutrients, along with sediment, also cloud the water, disturbing the habitats of underwater plants that are critical for waterfowl and aquatic life.

At full capacity for sediment storage, the Conowingo Reservoir will be about halfway filled with sediment with the remainder, around 49 billion gallons, flowing water, continued the release.

This amount, added the release, could fill about 265,000 rail cars that could stretch over 4,000 miles when lined up.

“Storage capacity in Conowingo Reservoir continues to decrease, and ultimately that means more nutrients and sediment will flow into the bay,” said Mike Langland, USGS scientist and author of the study. “Understanding the sediments and nutrients flowing into the bay from the Susquehanna River is critical to monitoring and managing the health of the bay.”

The Susquehanna River, the largest tributary to Chesapeake Bay, transports approximately half of the total fresh water input — along with significant amounts of sediment, phosphorus and nitrogen — to the bay, noted the release.

Read the entire release here.

You can find the USGS study here.