Infrastructure manager Andy Finch said showers had brought some relief to parts of the Far North in recent days, but the need to conserve water remained urgent.
"Our Kerikeri and Kaitaia water treatment plants are working at maximum capacity to keep up with demand and recent rain has had little impact on consumption. We're asking all residents to take steps to reduce consumption now."
The situation in Kaikohe was particularly serious, he said.
"The recent rain will have no immediate impact on the Monument Hill water bore, which is dangerously low, and will not substantially increase flow rates in our primary water source, the Wairoro Stream."
Finch also urged residents and businesses with rain tanks to conserve water, because most bulk water carriers filled up from council supplies. People buying in water shouldn't use it to fill swimming pools or for irrigation.
If there was no reduction in demand the council would be forced to stop bulk water carriers sourcing water from the Kaitaia, Kaikohe and Kerikeri water treatment plants, Finch warned.
Kaipara District Council will impose level 3 water restrictions across the whole district from Tuesday next week, which bans sprinklers, irrigation systems or hoses to water gardens; and no filling swimming pools from the reticulated supply.
The council has also banned the use of trigger or hand held hoses and water blasters for washing windows, vehicles, buildings or paths. People should only use water in a bucket for gardens or to clean windows, vehicles, buildings or paved areas. There are no water restrictions in Whangārei District.
Simple conservation measures included only washing clothes with a full load, turning off the tap while brushing teeth or shaving, putting a plug in the sink when washing vegetables, and mulching gardens with grass clippings or compost to reduce water loss through evaporation. Go to bewaterwise.org.nz for more tips.