Auckland's water savings have improved, but they're still just short of the target set by Watercare.

People are being asked to save 20 litres a person per day, to avoid a boil water order.

402 million litres went through the taps yesterday and the council-owned water company says it has managed to increase the output of the treatment plant by 10 million litres.

Even so, the savings call is expected to last two to three weeks.