A water firm is releasing millions of litres of water into the River Wolf to keep salmon healthy in the heatwave.
Water releases help salmon migrate upstream to safety
South West Water is releasing 19 million litres of water from Devon's Roadford Reservoir every day this week.
The company says it has done this for the past two years and is advised by the Environment Agency when to act.
The move comes as parts of England face their worst drought for 30 years, leading several water companies to bring in hosepipe bans.
Fish deaths fear
South West Water says the releases are normally made when high tides coincide with very hot weather.
At such times oxygen levels in the estuary decline to dangerously low levels for salmon, which often results in deaths.
Making releases from the reservoir ahead of the high tide encourages salmon to migrate upstream into the river and safety.
South West Water will start releasing water, which is on top of the normal releases for public supply, at midday.
Roadford is one of South West Water's five main reservoirs and is currently more than 70% full, with about 34 billion litres of water.
Sutton and East Surrey Water was the first English water company to impose a hose pipe ban in May.
It gets most of its water from underground aquifers which have been diminished by two winters of exceptionally low rainfall.
Sutton and East Surrey spokeswoman Liz Thorne said: "If only we had the same resources as you, but unfortunately life is not like that.
"It's not envy, just a fact of life."
The drought order means that owners of commercial fish farms have to apply for special dispensation to replenish stocks, however owners of domestic fish ponds can replenish levels if wildlife is at risk.