Britain’s biggest water company has recorded its highest ever demand, due to a “perfect storm” of hot weather and the coronavirus lockdown.

Last month was England’s driest May since records began 158 years ago and householders are being asked to help conserve supplies.

A striking aerial photo showed part of Howden Reservoir in Derbyshire looking like a near-dried-up river on Tuesday.

Owner Severn Trent said the reservoir is at just 51% of its capacity.

Thames Water, with 10 million customers, said it is processing an extra 35 million gallons a day as demand hit its highest level in the firm’s 31-year history. It added: “The challenge for us right now is keeping up with demand.

“A great many people are at home and the weather has been very hot, creating a perfect storm.” Water companies say above-average rainfall last autumn and winter makes hosepipe bans unlikely.

How Howden reservoir in the Derwent Valley looks when the water levels are higher
How Howden reservoir in the Derwent Valley looks when the water levels are higher

Instead their problems centre on “unprecedented” daily usage, with millions of workers at home rather than the office.

Some areas have suffered pressure drops at peak times, including evenings when many people water their gardens.

Industry body Water UK has urged them to help at peak times by “ditching the evening sprinkler”.

Thames Water advised people to take shorter showers and re-use supplies if possible – for example by giving plants a drink from children’s paddling pools.

The firm, operating in and around London, said a massive fall in commu-
ters to the capital has put pressure on its outer networks. But it added that the “overwhelming majority” of customers are unaffected.

Other main suppliers also reported that most reservoirs are full and hosepipe bans are not on the horizon.

Affinity Water, which serves the South East, has handed out bottled drinks to vulnerable people among its 3.6 million customers after low-pressure issues.

The firm said: “The problem is not about water resources, as there’s plenty in the ground, but demand is unprecedented as more people are staying at home.”

Severn Trent said it is operating at 85% capacity overall. It added: “Howden is the smallest of three interconnected reservoirs in Derbyshire and these are currently two-thirds full in total.”

Yesterday cloud and cooler temperatures reached Britain after the sunniest spring on record. Some areas had heavy rain with more forecast in the next few days, offering hope that demand on supplies will ease.

Met Office expert Steven Keates said the new weather front will be a “big change” for many regions. He forecast sunshine and showers “that may be on the sharp side” today, adding: “If you are out, maybe take a brolly.”