Sediment composition was silt at channel edges and sand at mid-channel. Rates of change in channel geometry versus sediment composition indicate different temporal scales of recovery after dam removal. While low-head dams substantially alter channel morphology, recovery following removal appears rapid for some physical and chemical attributes. Doyle, M.D., J.M. Harbor, E.H. Stanley, and T.S. Hooyer. A Conceptual Framework for Recovery of Fluvial Systems Following Dam Removal.
Dams are perhaps the most limiting factor for restoration of American rivers.
Dam removal as a river restoration alternative represents a significant change in policy, and raises questions about costs and benefits of this management option. Two dams in southern Wisconsin over 100 years old were breached in summer 2000 as a step before complete removal later that year. Geomorphic and biogeochemical data were collected prior to breaching. Both impoundments were trapping suspended and bedload sediments prior to drawdown. Suspended-sediment loads downstream increased dramatically following dam breaching while bedload remained unchanged.