Water restrictions continue in Tauranga because of low flow in the streams that supply the city's drinking water.
Tauranga City Council said the "unprecedented situation" reflects the knock-on effect of three unusually dry summers for the Bay of Plenty.
Stephen Burton, council director of city waters, said despite recent rain the stream flow rates have not improved.
"The situation is a first for Tauranga. Never have city-wide sprinkler restrictions been necessary beyond the first week of April.
"Also, historically, restrictions have been necessary due to water treatment capacity constraints during peak summer periods.
"What we're looking at now is a potential problem sourcing water due to unprecedented drought in our region and the need to protect stream health.
"We are working to bring additional source water and treatment capacity into service for Tauranga as soon as possible.