Water in dozens of small coastal settlements in Northland could soon become too salty to drink due the drought.

The Northland Regional Council is set to declare water shortages in 23 communities, including Russell, Tutukaka and Matapōuri, it announced on Monday.

More than two dozen aquifers were nearing record low levels and shallow coastal groundwater systems were expected to drop to significantly lower levels than normal during the next few months, council water and waste manager Ali McHugh warned.

That could lead to the freshwater becoming too salty to drink – or to no water at all – as shallow bores became unable to pump water and deeper bores were impacted by saltwater moving inland.

READ MORE:

*Northland drought: Residents say council knew of water issues for years

*Northland drought: Call goes out to dob in water wasters

*Northland drought: More Far North towns in desperate water savings plea

*Top 10 ways to save water at home, as drought hits Northland and Auckland

If too much saltwater made its way it to the freshwater system, it could be months before bore water could be safe to drink again, McHugh said.

The council was likely to restrict water to essential use only in coastal areas "in the very near future".

The affected areas are Russell/Tapeka, Ngunguru,Tutukaka, Matapōuri North and South, Taipā, Coopers Beach/Cable Bay/Mangonui, Whangaumu Bay, Kowharewa Bay, Church Bay, Pataua North and South, Bland Bay, Ōākura, Teal Bay, Moureeses Bay, Sandy Bay, Taiharuru Bay, Taupo Bay, Tauranga Bay, Whananaki North and South, Woolleys Bay, Matauri Bay and Te Ngaere Bay.

The council said Ruawai, Whatitiri/Poroti, Maungakaramea, Maunu/Maungatapere, Mangawhai, Tara, Kaikohe, Glenbervie, Three Mile Bush and Matarau were likely to be impacted soon.

Meanwhile, Whangārei District Council has put in place further water restrictions.

From 8am on February 26, residents will no longer be able to use sprinklers and irrigation systems, while businesses will be banned from them on gardens, lawns and private fields, filling public fountains from water mains, taking construction water from water mains and watering sports fields except for those with approved watering plans.

The restrictions come after Whangārei residents were asked to cut their water use by 20 per cent.

DAVID WHITE/STUFF Northland is experiencing a drought.

McHugh urged people in coastal areas to save as much water as possible.

"In these conditions, it's best to pump slowly from a groundwater system into a tank, which allows more recovery time for the aquifer and acts as a buffer if any issues arise with the bore," she said.

In small coastal settlements heavily reliant on aquifers, people did not need resource consent to take reasonably small amounts of bore water for daily domestic and stock drinking needs.

But McHugh said during a drought, most people using groundwater were just as much at the mercy of the lack of rain as those relying on surface (stream, water and lake) supplies.

During the past 18 months, Northland has had very little rainfall. Rivers are below drought levels at 93 per cent of the council's flow monitoring stations.

For the next two weeks, people in the 23 small coastal communities should only use water when it was "essential" for domestic or stock welfare.

Water could not be used for irrigation, garden watering, car washing, water blasting and filling swimming and spa pools.

The council would be monitoring water use and people found to be using is for non-essential tasks could face enforcement action, McHugh said.

The water shortage direction could be extended.

The council recently issued a water shortage direction for the whole of the Awanui River catchment and has been issuing general advice about the dry weather, minimal rainfall and dwindling groundwater for months.