Water restrictions are being introduced in Palmerston North and nearby Linton after the driest March on record has left dam levels dangerously low.
Rob Green, Palmerston North City Council water and waste disposal manager, said after last summer's drought the council invested in the city's two artesian bores, reducing reliance on the Turitea dam.
But he said with no significant rain in the last eight weeks, the dam will run dry in 30 days at current rates of consumption.
"The main worry is that if it keeps drying like this ... there might not be enough time for it to fill over winter, unless we curtail demand now."
He said because of the seriousness of the situation, the council has jumped straight to level 2 restrictions, with a complete ban on unattended hoses, sprinkers and garden irrigation systems. Hand-held hoses are restricted to alternate days between 5pm and 7pm.
The council is also cutting water usage at council facilities, gardens and lawns.
If the dry weather continues, Ashhurst, Longburn and Bunnythorpe may also face water restrictions.
Mr Green says two dry summers and autumns in a row are bringing home the reality that water is a finite resource and everyone needs to conserve it.