The news came as irrigation restrictions were imposed in parts of the Wakatipu. Hampden and Moeraki residents are being urged to use water for domestic and stock purposes only and not for activities such as garden watering and washing vehicles.
Waitaki District Council water facilities contracts engineer Michael Goldingham said a conserve water notice was issued last week and levels had been monitored each day by the council.
''It came to a head [on Monday] when we weren't getting enough water at the intake,'' Mr Goldingham said.
The Big Kuri Creek flow has reduced significantly, severely affecting the water supply intake, he said.
Water use at Moeraki at the weekend had been ''absolutely flat stick'' with an increase in visitor numbers.
''There's high usage all around the district, but the rest of the supply seem to be coping,'' he said.
In December 2013, long-term rainfall in Oamaru was 75mm, compared to just 23mm in December 2014.
''It goes back to the fact we haven't had a decent rainfall since June,'' he said.
Mr Goldingham said he hoped some of the rain forecast in the catchment would eventuate.
''It [often] doesn't come to anything ... it just disappears, the catchment just doesn't get the rain,'' he said.
He said the council apologised for any inconvenience caused and thanked customers for their patience over this period.
Updates will be posted on the Waitaki District Council website at www.waitaki.govt.nz.
• Irrigation restrictions in parts of the Wakatipu came into force last night.
Queenstown Lakes District Council communications manager Michele Poole said the restrictions covered Lake Hayes, Lake Hayes Estate and Shotover Country.
The continuing hot weather and low rainfall had coincided with peak demand on the Lake Hayes water supply and the council had placed signage in the three communities to remind residents of the need to conserve water by reducing irrigation.
Mrs Poole said the restrictions meant there should be no irrigation at all between noon and midnight; sprinklers and irrigators with timers fitted could be used for 30 minutes between midnight and 6am; and hand-held hoses could be used between 6am and noon, provided they were ''being held at all times''.
Watering lawns and gardens used more water than any other domestic activity - on average, a sprinkler used 1300 litres an hour, while hand-held hoses used an average of 400 litres an hour.
