Legacy sediment is a hidden issue that plagues many of the eastern US watersheds where a combination of agriculture, mill dams and deforestation occurred in the 19th century. Much of the Rapidan watershed was deforested for agriculture causing massive erosion into stream valleys. There were also many water powered mills that trapped sediment on floodplains. A few dams still exist, but the legacy sediment is still apparent in incised stream channels.
A very good video on the topic may be viewed at https://www.sciencemag.org/news/2020/08/how-transforming-riverbanks-can-clean-contaminated-waterways#