Severn Trent Water has urged people to use water wisely despite the recent rain across the East Midlands.
The water company said recent rainfall should help boost reservoir-held water supplies, but it was still monitoring the situation.
Fraser Pithie, senior operations manager for Severn Trent Water, said: "It will take reservoir levels some time to recover.
"For that to happen, we need more rain over a period of days and weeks."
He added: "Of course the rain we've been seeing around our region in the last week or so will begin to make a difference, but we can't afford to be complacent.
"We're not out of the woods yet and we can all continue to play our part by using water wisely."