Weir removal, lowering and modification: a review of best practice
Environment Agency report which looks at the impact that removing or changing a weir (a low dam built across a river) has on rivers and their ecosystems.
Removing, lowering and modifying weirs can have beneficial effects for rivers and their local environments, and these improvements can also help satisfy the requirements of the EU Water Framework Directive (WFD) – European legislation on integrated river basin management introduced in 2000.
However, there was very little information available about such weir projects in England and Wales, so this report pulled together the available scientific evidence on weir removal to inform best practice and identify gaps in our understanding. The study made use of a literature review, the National River Restoration Inventory, an online survey of people involved in specific projects, technical experts and a series of case studies covering a range of issues experienced in different projects.