High capacity water pumps deployed on the Somerset Levels have had to be switched off because of damage to the riverbank.
The pumps at Dunball, which have been brought in from the Netherlands, were installed by the Environment Agency.
A spokesman said the River Parrett's bank had been damaged due to the volume of water being discharged from the King's Sedgemoor drain.
Engineers are working on a plan to get pumping started again, he added.
A total of 13 Dutch pumps were brought in by the Environment Agency to divert water in a bid to reduce levels in the River Tone and River Parrett.
Eight of them were installed at Dunball and five at Beerwall, near Bridgwater.
The original plan was to run the pumps at Dunball for a few days before levels had been reduced enough for the ones at Beerwall to be turned on.
The agency spokesman said the pumps were switched off on Saturday evening.
"We will be working round the clock on alternative options so that pumping can start as soon as possible," he said.
"In the meantime we expect levels in the drain to continue to drop naturally."
Engineers were looking at stabilising the bank by adding ballast and extending the pipes so they pump water further into the estuary, the spokesman added.
He hoped the pumps would be turned back on again "at some point" on Monday.
Up to a million tonnes of water has already been pumped out, the spokesman added.
About 65 sq miles (41,600 acres) of the Somerset Levels have been flooded for several weeks.