Rivers naturally wash sediment downstream to wetlands and coasts, but dams disrupt this flow and over time the build-up of these muddy deposits gradually reduces the space for water.

The methane comes from organic matter in the sediments that accumulate behind dams. That knowledge led to questions about hydroelectric power's image as a green and nonpolluting energy source.

The two premises are actually much the same. There is a build-up of ice that keeps water behind it. Depending where that dam forms, and when it thaws, it can cause big problems.

Sediment trapped behind dams makes them 'hot spots' for greenhouse gas emissions Date: July 31, 2013 Source: American Chemical Society Summary: With the "green" reputation of large hydroelectric ...

Hydroelectric dams may be known as a relatively clean and low-cost energy source, but a new study says that the sediment trapped behind them makes them hot spots for greenhouse gas emissions.

Sedimentation threatens to steal capacity from nearly 50,000 dams Study shows the world’s dams could lose up to 28 percent of storage by 2050.

Sediment build-up can lead to safety and efficacy issues. The USGS created a new image to give operators a way to quantify a variety of changes in the future.

It’s an ongoing problem. The volume of sediment dredged to maintain shipping depths and clear out the build-up behind dams has the corps in constant search for new dumping grounds.

The giant sediment reservoirs at Conowingo Hydroelectric Dam — glorified sand buckets that collect millions of tons of grainy pollution near where the Susquehanna River enters the Chesapeake Bay ...

An environmental analysis of sediments behind Yarmouth’s Bridge Street Dam found a few spots of lower-level contamination but largely gave the stretch of Royal River a clean bill of health ...

The company that owns the Morrow Dam has begun the process of removing sediment build up in the Kalamazoo River. An excavator and other dredging equipment was brought into South Wenke Park in ...

Sediment, millions of tons of it, has flowed down the 440-mile Susquehanna River for more than 80 years and massed at the dam. And now a reservoir built to hold it is filling up.