Originally Posted by MS Fowler

Back in the late 1970s, or early '80s there was a failure of a dam that was impounding coal refuse sludge. It killed a number of people. Army Corps of Engineers was tasked to develop a program to have all small dams evaluated. Many states also adopted some minimum practices for the design and construction of small dams.
Biggest problem with old small dams is the lack of maintenance--trees growing on the embankment etc.
Some people caused a problem and now everyone with a dam has to pay a price.