Auckland's Watercare will be delivering its Huia 1 water pipeline under budget

The final four metres of the 15 kilometre pipe from Titirangi to Epsom, will be laid this morning.

Once fully completed it will allow for growth by increasing water capacity.

It's expected to serve about 20 percent of Auckland's population.

Capital Delivery General Manager Suzanne Lucas says there's also been a real discipline around price, with original estimates coming in around 143-million dollars.

She says through early intervention with contractors and methodology changes, they've managed to knock that down to 115-million dollars.