Restoration of fluvial connectivity through the removal of structures responsible for impoundment is an increasingly considered option to mitigate environmental impacts of river engineering. In Europe, dam and weir removal has become a commonly proposed restoration strategy, particularly as a high density of structures exists, and morphological pressures are considered to be one of the most important reasons for why ecological status of water bodies are failing under the Water Framework Directive. In many cases the small-scale historic dams and weirs, e.g. built for milling, no longer fulfil the purpose for which they were originally constructed.
In North America, dam removal is a popular restoration option under some scenarios, especially when decisions to do so are supported by other non-ecological factors, such as safety and the economic and legal considerations of relicensing, renovation and maintenance. ICER has been involved in providing advice on the potential to remove the Mactaquac Dam on the Saint John River in New Brunswick, Canada.
In developing nations dam removal has not yet become a commonly considered river restoration strategy, although ICER is collecting information and providing advice on the feasibility of removing the Pandeiros Dam in Minas Gerais state, Brazil. If this dam removal goes ahead it will likely represent the first project of its kind in South America.
