Northland Regional Council says it cannot allow the dumping of treated effluent into Kaitaia's drought-stricken Awanui River.
Kaitaia's sewage treatment ponds are almost full, and the Far North District Council has said it would have to discharge into the river next week.
But the regional council says that is no longer an option.
Operations manager Tony Phipps says the Awanui is running very low and the sewage ponds have an algal bloom that could poison stock downstream.
He says the objective is to keep contaminated water out of what is left of the river, and protect the health of downstream water users.
Mr Phipps says the district council will have to lease land near the Kaitaia sewage ponds, and use the treated effluent to irrigate it.
Not about to relent on restrictions
Meanwhile the regional council says it is not about to relent on water restrictions in Kaitaia. It has reduced the volume of water the Far North council can draw from the Awanui.
The district council says unless it can boost its water take, Kaitaia's reservoirs will run dry in a matter of weeks.
But Mr Phipps says that the answer is not to take more water from what's left of the river and that, with a little more conservation effort, Kaitaia could balance its water use with the allowable intake.
The Far North council says it needs only another seven litres of water per second from the river to keep Kaitaia safe.
The local fire brigade says the drop in mains pressure has compromised its ability to fight fires and could affect sprinkler systems.
