Residents were left without water in Croxley Green this afternoon.
Properties along Norwich Way suffered problems to their water supply as engineers from Affinity Water carried out work in Little Green Lane.
Sue Pavey, a spokesman for Affinity Water, said: "We have been carrying out work on the water supply distribution system in the Little Green Lane area.
"Because a valve we were due to use was inaccessible to us, we had to shut a different valve which unfortunately affected some customers in Norwich Way. We apologise for the inconvenience caused and the supply should be restored just after 4pm this afternoon."