Greymouth was close to running out of water yesterday after a connection break prevented the Coal Creek reservoir from refilling.
Residents were asked to conserve water after the connection failure during work to hook up the reservoir to the new pipeline that will service Taylorville and Dobson.
Grey District Council assets manager Mel Sutherland said they were "very close to draining the Greymouth reservoir."
The break occurred when work was being done to install a t-valve. A rubber ring on the connection failed, causing water to burst through.
Supply to the reservoir had to be turned off meaning it could not be refilled while repairs were done.
Mr Sutherland said the valve installation had to be done without any bypasses, so the reservoir had been "as full as we could make it" prior to the work.
Contractors needed to pump water out of the hole to access the valve, which was fixed by 6.30pm. However, demand on the supply meant the council asked people to continue conserving water up to midday today.
A straight pipe was put in meaning the t-valve would need to be redone at a later date.
The reason for the failure was still to be identified and the council would be investigating the rubber ring, Mr Sutherland said.
Despite the break, the council was on track to connect the Taylorville and Dobson supply on time.