About 10,000 homes and businesses are without water for a second day following a burst main.
Severn Trent said repair work to a broken pipe in Tewkesbury was “extremely difficult” and had proved more complicated than they had hoped.
A third bottled-water collection point is being set up in the town.
The supply has been off since the early hours of Friday. The water company said it was still unknown when the repairs would be completed.
“The burst has happened on a 36-inch pipe, which is one of the biggest in the area, and it’s located in a flooded field which is making the repair work extremely difficult, particularly in darkness,” a spokesman for Severn Trent said.
“We’re continuing to try and move water around the network in different ways to keep people on supply and we’re using as many tankers as we can to inject water into our pipes as quickly as we can.”
Two bottled water collection points have been set up at Morrisons in Barton Road and at Tewkesbury School in Ashchurch Road.
A third collection point that was set up at Gloucester Road car and coach park is being closed and moved to a new location, the spokesman said.