Thousands of households in Northamptonshire have had their water restored after the hot weather caused a strain on the system.
Fifteen villages had supplies cut or reduced on Wednesday - but the water was back on by 2200 BST.
The use of sprinklers is being partly blamed.
Emma Rees from Anglian Water told BBC Northampton demand in the hot dry weather put a strain on an underground storage tank at Thorpe Mandeville in the south of the county.
Ms Rees said: "As soon as the water was going into the storage tanks, the surge in demand, which increased by 50%, was just pulling that water out immediately, leaving it very difficult to keep recharging the tank.
"Most times, recharge happens during the night, but it was only giving enough water for about four to five hours."
Anglian Water said 3,500 customers were affected in an area to the west of the M1 between Northampton and Milton Keynes.