The period of the year when groundwater supplies can be replenished is set to reduce from between five and seven months to between three and four months because of climate change.
That’s according to a report from the Environment Agency which says water supply is under threat as changing rainfall patterns are expected to reduce groundwater replenishment each year coupled with increased risks of flooding in winter.
The report – called National groundwater recharge assessment under climate change, also notes that by the 2050s heavier rainfall in winters will have implications for the water resource management in areas more heavily reliant on groundwater for water supplies.
The report suggests the changes in groundwater recharge are expected to be felt by the 2080s.
Historically the recharge season has been between September to April, but the report expects higher temperatures with hotter drier summers lasting into September and October, meaning the recharge period is reduced.
It shows an east-west split with heavier rainfall and drier summers in the west due to the nature of UK weather systems.
Despite these fluctuations, the recharge volumes will be “broadly stable”, which the report suggests show groundwater resources being maintained.
The condensed recharge season could lead to variable groundwater levels and greater vulnerability to drought.
It suggests that during the reduced window of recharge the country would be left more prone to drought if rainfall was lower than predicted in any of the ‘wet’ months.