The leak in a Marlborough water main has been identified after about 3000 cubic metres of water was lost.
About 750 residents in rural Marlborough were asked to conserve water after the major leak was discovered late on Tuesday night.
The council said the location of the leak was identified on Wednesday afternoon in the 225mm water main, about two kilometres southwest of Seddon on Marama Road.
Marlborough Waters chief executive Richard Coningham said the good news was that the leak was not under the Awatere River bed as previously thought, making the repair much more straightforward.
“However we are not through the woods yet and it is still important that people in Seddon and on the Awatere Rural network conserve their water use as much as possible.”
Council engineers are investigating whether there are any other leaks on the network.
Water had been trucked into the Awatere area since 8.30am on Wednesday after about 3000 cubic metres of water, more than the volume of an Olympic-sized swimming pool, was lost.
Residents around Seddon were asked to urgently conserve water after the Rural Awatere water supply storage tanks ran dry and the Seddon water supply tank fell to about 40 percent capacity.
The additional water was helping to maintain supply, but conserving water remained extremely important because of supply constraints, Coningham said.
“Trucking water into the area means we can begin replenishing both the rural Awatere tanks and the Seddon tank while crews continue working on the leak,” Coningham said.
“However, we still need everyone connected to these supplies to use as little water as possible. Please keep water use to essential drinking, cooking and hygiene needs and avoid all non-essential use.”
People in Seddon are advised to boil water as a precaution and those on the rural Awatere supply remain under a long-standing boil-water notice.
Coningham said the precautionary boil-water notice was necessary for Seddon because, while the trucked-in water was safe, some of it was food grade and not classed as potable grade under water regulations.
Water should be brought to a rolling boil for at least one minute and allowed to cool naturally before use. The notices will remain in place until the council advises otherwise.
The council will continue trucking water into the area as required and is closely monitoring storage levels.
The pipe supplied Seddon, Seaview, Grassmere and rural areas south of the Awatere River.
People were being asked not to water gardens or wash vehicles.