Christine Colvin, of the Rivers Trust, said: “We did feel that these bans were coming in quite late. Given that we were experiencing an incredibly dry July off the back of a low-rainfall year, I think a lot of these emergency measures should have been announced in mid-July and implemented into the latter half of July rather than leaving it into mid- August.
“That’s a whole month’s worth of use at the hottest time of year when we could have actually been saving on the supply side.”
The Environment Agency has warned much of England is heading for drought if dry weather continues. Very warm weather is forecast again for southern England next week, with temperatures in the mid-30s expected.
July was the driest on record for the south east of England and East Anglia, with just 10 per cent of the average rain falling in the South East.
In Cornwall, 40 firefighters tackled a grass fire near Truro on Saturday, while in Norfolk the River Wensum stopped flowing through a historic watermill for the first time in a century.
On Friday, Scotland moved to a “red alert” for drought, prompting the Scottish Environment Protection Agency to implement its first ever water bans, restricting use for industrial users including distilleries and golf courses.
Addressing the need for action from water firms to plug leaks, Mr Eustice said: “The onus must be on companies to do more to reduce leakage, building on progress made in recent years.
“We expect water companies to step up, to adapt, innovate better in their approaches to reducing demand, and better support customers with measures to reduce water consumption. If we don’t see the changes we and the public rightly expect, I won’t hesitate to step in and take further action.”