Councillors are calling on Yorkshire Water to leave water levels in reservoirs around flood-hit parts of Calderdale permanently less full.
Members of Calderdale Council’s Flood Scrutiny Panel discussed progress in trials begun to investigate whether or not keeping levels lower than normal at reservoirs above Hebden Bridge can be a useful flood attenuation tool and the potential for Ryburn reservoirs in the same way.
Levels would be kept at ten per cent lower than capacity, 90 per cent rather than full, allowing them to have more capacity to hold water in flood conditions.
The view among councillors was that they did believe this would help and called for all reservoirs affecting flood-hit areas be kept permanently at lower level.
Yorkshire Water Action and Strategy Manager Granville Davies had spoken to the committee about issues concerning leakages and reservoirs, while a separate agenda item covered the attenuation trial.
He had outlined how Yorkshire Water was able to move water supplies around the region in times of shortage.
In terms of the Hebden Bridge reservoir trials, the problem had been a dry year in 2018 slowing progress following its start a year earlier.
“Clearly last year was a very dry year and that saw reservoir levels drop.
“We are still in a position where we are trying to recover levels rather than taking out,” said Mr Davies.
Councillor Steven Leigh (Con, Ryburn) said the Flood Board should be lobbied by the panel that irrespective of difficulties, there were special reasons why some Calderdale reservoirs should be kept at lower levels.
“If they run out there are others full that can help us out,” he said.
“The only fly in the ointment would be if there were drought conditions.
“In that case we can get water to drink through the network.”
Councillor Josh Fenton-Glynn (Lab, Calder) agreed and if the network generally was well supplied said: “Surely if we have got water levels everywhere it is relatively easy to keep the levels lower around Hebden Bridge?”
He also asked questions, answered by Helen Batt of the Environment Agency, about what impact lower levels would have on flooding and hoped pathfinder trials would continue.
“I would feel quite strongly we would like you to do that,” he said.
Panel chair Coun Geraldine Carter (Con, Ryburn) had raised issues relating to the affect two reservoirs had on the Ryburn Valley, including the run-up to the Boxing Day floods of 2015 when she said they had overflowed every day for three months.
“It becomes a problem as soon as it gets into the watercourse.
“Why on earth aren’t you pumping it out and using it for drinking water?” she said.
She said what councillors were asking for is that the reservoir issue would be looked at again.
Mr Davies said it was not as simple as keeping levels reservoir lower or moving water, .
“There is a while level of complexity. I’m hearing some very simplistic solutions to what are very complicated things,” he said.
Even if capacity was full reservoirs still had some attenuation protection, he added.
In the case of Boxing Day 2015, it followed one of the wettest winters on record.
Even if Hebden Bridge reservoirs had been ten per cent down in October they would fill up in winter and other reservoirs would also be full.
There were limits to the structures in place to move water, he said.
Councillor Carter replied: “It’s important to us that you explore it.”