Reservoir trials continue in battle to stop future flooding in Calder Valley

Members of Calderdale Council’s Flooding Scrutiny Panel were asking questions about progress on the scheme to keep Yorkshire Water’s reservoirs above Hebden Bridge at a level ten per cent below full to help manage flooding emergencies, and whether the scheme could be extended to include reservoirs above the Ryburn Valley.

Granville Davies, Yorkshire Water’s Clean Water and Catchment strategy manager, said the third set of trials – there wree none in 2018-19 because levels that year were not higher than 90 per cent – would be taking place with results used to inform flood modelling and a summary paper to be prepared with Environment Agency partners.

Flood warden Katie Kimber said people had thought levels would be lowered by ten per cent at each reservoir above Hebden Bridge and did not know the ten per cent figure referred to the group as a while rather than individually.

It was a question wardens were frequently asked, she said.

Mr Davies said this was because is was not as simple as that because of the reservoirs’ infrastructure and the way in which they work together, for example water from Upper Gorple reservoir flowing into Lower Gorple making it harder to achieve that fall level in one of them.

Part of the trials had been understanding how this would work but ideally the ten per cent lower figure would result in each of the three sub-catchments.

This might mean people might see one or two reservoirs in a three reservoir group looking full but the level in the other would be down, he said.

Coun Geraldine Carter (Con, Ryburn), raising a number of issues relating to reservoirs, land ownership and drainage, said reservoirs impacting on Ryburn, for example Baitings Dam, had been full month after month with no room for any excess water to go.

Mr Davies said there were no plans to manage Ryburn area reservoirs differently at the moment as the Environment Agency were doing some modelling to look at the catchment in detail.

“We need to see what that means going forward,” he said.

Mr Davies said it was a case of balancing water resources and flood risk – drawing more out of Ryburn would mean drawing less out of Hebden Bridge.

He also stressed lowering reservoir levels alone would not be a solution to flooding issues.