A relatively dry winter and spring have Northland local bodies concerned that the region could be headed for its third drought in as many summers.
Northland's worst drought in decades was declared in January 2010. Another drought was declared in December last year, but it was over after a few days of heavy rain.
With the La Nina weather pattern firmly over the country this summer, local bodies are to keep a close eye on ground moisture levels and water supplies.
Northland water resources will be closely monitored over the next two months to prepare for what is shaping up to be a very dry summer, the Northland Regional Council says.
The region was generally very dry through September, with below normal rainfall varying from 30 to 85 per cent of normal. River flows were 15 per cent to 50 per cent of the normal September flows for the greater part of the region, but slightly higher (50 to 75 per cent) in some eastern areas from the Bay of Islands to Whangarei.
The council says groundwater levels at most of the NRC monitoring sites, except for the Aupouri aquifer and the Mangawhai area, were below their normal September levels and also below the levels recorded in September 2009 and 2010.
The National Climate Centre is predicting normal or below normal rainfall from October to December as a La Nina pattern reigns.
Whangarei District Council spokeswoman Ann Midson said the Whau Valley Dam was 98 per cent full but the Whau Valley catchment area had had the driest August since the 1970s.