People camping close to the Waitaki Lakes are being urged to move away from the edges to higher ground following large amounts of rain in the main divide.
Waitaki rural fire officer Steve Couper said a severe weather warning was issued by Environment Canterbury on Monday.
Mr Couper said there had been 50ml to 100ml of rainfall overnight on New Year's, and another 100ml to 150ml had been expected last night.
Holidaymakers at the Waitaki Lakes could expect to see rising lake and river levels from tomorrow.
"A lot of the rain hasn't worked its way into the lake system yet," Mr Couper said.
"The lakes [levels] were down so hopefully there will be room for it."
People were urged to move their camps away from the lake edges.
"There will be a lot of people camped right down on the lake edge," he said.
"We're warning people just to shift to higher ground. Don't camp too close."
Mr Couper said any more rain in the high country could make a significant difference.
"If they get any more, that can make a big difference to the lake system.
"Hopefully it will be a good fill for the lakes but not too much to cause problems."
Go to Environment Canterbury website www.ecan.govt.nz for flood warning updates.
Weather updates are also available on the MetService website www.metservice.com