IT is still too soon to comment on the role Grands Vaux reservoir could play in helping mitigate flooding affecting nearby properties, Jersey Water’s chief executive Helier Smith has said.
Next month marks the one-year anniversary of the flash flooding that forced the evacuation of 58 households, following heavy rain affecting the Island’s largest water catchment area, and work has been taking place since then between Jersey Water and the government.
Mr Smith said that an announcement would be made in due course when the work had been completed but he stressed that the situation was “not that straightforward”.
He said: “The context is really important. Grands Vaux is small relative to the volume of waters that come down the valley, so it’s unsuited to be a flood defence without significant modification.
“We’ve been working with the Government of Jersey since January, supporting their flood planning initiatives for Grands Vaux and that’s included an extensive piece of work around how the reservoir could be used in future.
“The challenge it’s had to overcome is how do you meet the flood requirements but also address the unsuitability of the reservoir from its design and size, given the volumes of rain.
“Twenty per cent of the Island’s water comes from Grands Vaux – a fifth comes from the catchment, and we can’t lose that resource. And to protect the water resources, we’ve got to manage water quality coming off the Grands Vaux catchment, and managing the reservoir for public safety is also very important during a period of flooding, so there’s a whole host of technical challenges around potentially using the reservoir for flood management.”
In September, the government published its latest “detailed plan of the intended multi-agency response to a surface water flooding event in Grands Vaux”, but the part the reservoir might play in future has been the subject of controversy since Infrastructure Minister Tom Binet suggested to a Scrutiny panel that Jersey Water should maintain a lower water level in the facility to help with flood management.
Mr Smith agreed that the reservoir’s water level was the “very essence of the work we have been doing with government”, but he said that it would be “premature to opine on that” before a formal announcement at the conclusion of the current work.
“That being said, we, as the water supplier, have a significant responsibility in terms of the water supply. We need to make sure we’ve got enough water of the right quality in the right place. Jersey Water’s perspective is that we need to make sure that’s protected, albeit we need to find a solution to the long-running flood issues in Grands Vaux valley,” he added.
