Homeowners have been urged not to use water at night in a bid to conserve supplies.
Severn Trent, which supplies water to thousands of households in the East Midlands, urged people not to leave hosepipes or sprinklers running overnight.
Marcus O’Kane, of Severn Trent, said: “Because some customers are leaving hosepipes or sprinklers running overnight, we are not seeing reservoirs refill as much as we’d like, which means there’s less water available in the morning.
“Therefore, some of our customers are seeing lower pressure than normal and there is more risk if we have a problem somewhere on our network.
“So please help your fellow customers by avoiding the use of sprinklers.”
Despite the warning, Severn Trent said said stocks were “healthy” and a hosepipe ban was not expected.