Omakau Irrigation Company general manager Roger Williams said the company voluntarily set a minimum level at Falls Dam to hold water for fish.
In the 35 years he had been there the dam had never been completely empty.
"We have run out of storage but never run dry," he said.
The water level of the Falls Dam, 10km east of St Bathans, was almost as low as it had been since 1999 but rain earlier this week had the level rising.
Water flowed naturally into the dam from the Manuherikia River and creeks, so there was always water going in.
The irrigation company managed the outflow.
At the moment, farmers were voluntarily restricted to 25% of their full take because all the creeks had dried up and the storage was essentially gone.
"We are just managing it with what is coming in is essentially coming out and that is working very nicely for the 25%. It’s in a lovely wee balance," Mr Williams said.
The Central Otago District Council has imposed a red water warning in Ranfurly, Ophir/Omakau and Naseby. Garden sprinklers are banned.
The Pisa area and Patearoa were on an orange warning with restricted garden watering and reduced water use urged.
