Slow The Flow Calderdale was set up to look scientifically at the issue of why and how the Calder Valley floods and to look at natural flood prevention measures and solutions to slow the volume of water which comes down the hillsides into the River Calder. We are a group of dedicated engineers, scientists, landscape experts, and those working in land management. We are working with Government, The Environment Agency, Calderdale Council, The National Trust, Natural England, Treesponsibility, The Source Partnership, The Calder & Colne Rivers Trust, Pennine Prospects, Calder Futures and the Flood Wardens along the Calder Valley to seek a solution to this continuing and growing problem.

Slow The Flow Calderdale members are mostly local and are all volunteers giving up their time to secure a future for the Calder Valley and all who live, work and visit here. We will not stop flooding events, but if we work collaboratively we can reduce the risk of serious flooding. Building walls are not the only solution. Our objectives are simple –to slow the flow from the upper catchment to the main river channel thereby reducing the flood peak and limiting out of bank flow where it matters, in our towns and villages. So far we have installed over 150 ‘leaky woody dams’ working with the National Trust in their Hardcastle Crags estate above Hebden Bridge as a pilot programme funded by the Environment Agency.

For more information visit their website ( or read the following article: STF March flood