Wellington City Council says it has had about 100 calls dobbing in people who are breaking the ban on using water outside.
A ban on using water outdoors covering Upper Hutt, Lower Hutt, Porirua and Wellington came into force on 16 March and includes sprinklers, hoses and even hand-watering of gardens.
The council said most calls over the weekend were about people washing their car or watering the garden with a hose.
Some have complained about petrol station car washes but the council is satisfied these use recycled water.
Council spokesperson Richard MacLean says the regional council is still very concerned about water levels in rivers despite rain on Sunday and Monday and the ban remains in place.
People who contravene it are given a formal warning that they could be fined up to $24,000 for serious repeat offending.
Greater Wellington Regional Council's general manager of water supply, Chris Laidlow, says demand for water has dropped but people can still make more savings inside the home, for instance, by taking shorter showers.
"The sort of numbers we're looking at in terms of reduction is about 30 litres per person per day," he says. "It doesn't take a great deal of effort to actually achieve that - it's probably four flushes of your toilet or the three-to-four minute showers."
Mr Laidlow says if supply remains at a target level of about 130 million litres a day the region should get by for the coming weeks.
The region got between 13 and 36mm of rain on Sunday. Residents reduced water usage from about 160 million litres a day to 131 million on Saturday and 123 on Sunday.