The low level of the Tamaki River and no significant rainfall forecast means Tararua District's water situation is critical.
Tararua District Council has issued an urgent plea for residents to cut their water use.
In a letter to all residents council chief executive Blair King said the water shortage had reached a critical stage.
"Drought-like weather conditions are forecast to continue and there is no significant rainfall forecast through the next four weeks."
The letter stated without urgent water conservation across the district, the council would be forced to move to an "Essential Use Only" restriction within the next five to 10 days.
Essential Use Only means no outdoor use of water. Water will be restricted to use for cooking, drinking and cleaning (personal hygiene).
"Council has a resource consent to draw raw water from the Tamaki River to supply the Dannevirke township and properties outside of the town boundaries with drinking water.
"The river is at its lowest on record since the 1970s and drought-like weather conditions have meant that Horizons Regional Council has now capped what the council can take from the river (capped at 54 litres per second).
"For the last three months, demand for water in Dannevirke has been more than what council is allowed to take from the river. To manage this the council has been supplementing supply with water from the Dannevirke impounded water reservoir on Laws Rd.
"Council is taking all practical measures to ration the water left in the impounded reservoir so we may continue to supplement supply. However, with no significant rainfall predicted in the next four weeks, even if these measures work we will empty the reservoir inside the next 30 days."
Among the actions taken by the council, but are not limited to, are active monitoring of the water supply and imposing a total hosing ban.
Leak detection services are actively scanning the network to find and report leaks to the council so they can be fixed.
The council has also been communicating with the community about the urgency of conservation via letter drops, signage and social media.
The letter outlined measures residents could take to conserve conserve water:
• Cook food in as little water as possible (this also helps it retain more nutrients).
• Shortening showers by a minute or two can save up to 500 litres per month – even turning off the water while washing your hair can make a huge difference.
• Turning off the water while you brush your teeth can save up to 15 litres a minute. That's up to 750 litres a week for a family of four.
• Be a leak detective. A dripping tap can waste up to 90 litres of water a week. Check all hoses, connectors, and faucets regularly for leaks.
• When you find yourself with really grubby hands, fill the basin rather than washing under the running tap.
• Use a broom instead of a hose to clean patios, sidewalks and driveways. • Know where your master water shut-off valve is located. Were a pipe to burst, this could save litres of water and prevent damage.
• Wait until you have a full load of washing before using your washing machine. A full load uses less water than two half loads.
• Water your garden with greywater (recycled water) eg, bath water, washing machine and dishwasher water.
• Watering the garden in the heat of the day can cause leaf burn and excessive evaporation, wait until a cooler time of the day before watering plants or gardens.
• Flushing the toilet uses between five and 12 litres every time – flush when you need to and avoid using the toilet as a bin.
King said the council appreciated the community's efforts to reduce water consumption so far this summer.
"However we must increase our collective water conservation efforts to try to avoid the need for more drastic restrictions to be imposed."
A fact sheet accompanying the letter says the council will be able to lift restrictions after river levels have returned to sufficient flow levels.
Small rain events will have very little impact and the rain will only help if it is a significant.
Under the resource consent, the council must prioritise drinking water usage, over stock. This means restrictors have been fitted to those on the raw water line and valves supplying water mains outside the town boundaries have had their flow reduced.
Anyone experiencing low pressure is asked to contact the council on 06 374 4080 or 06 376 0110.