Terms of reference, membership and other administrative matters were still being finalised, but Foster said he intended mana whenua and some members' independent from the council to be included.
"We understand the high public interest in this issue and so will ensure the taskforce's work is open and transparent.
"In the meantime, we will continue to work with Wellington Water to ensure that specific current problems are dealt with efficiently and that communication with the public about them is improved.
Furthermore, Southern Ward councillor Fleur Fitzsimons has today also called on the council's chief executive to launch a "detailed and wide-ranging inquiry" into the operation of Wellington Water and its relationship with the council.
"Residents deserve better than the defeatist excuses that have been coming out about our city's infrastructure. Our call for a wide-ranging inquiry is about ensuring that we all know the extent of the problems, how they came about, and how much investment is required to fix the problems," she said
The notice of motion has been seconded by councillor Jill Day.
"Water is a taonga for Māori and the council and Wellington Water must comply with Te Tiriti o Waitangi in the delivery and maintenance services for water in our city, this inquiry will ask important questions to ensure this happens. I am asking the CEO to ensure that mana whenua are actively involved in the inquiry," Day said
Eight councillors originally signed the notice of motion and now Foster and three others have added their support. It will be tabled at the council's Strategy and Policy Committee.
At a high-level meeting yesterday Wellington Water bosses admitted they did not have a complete understanding of the state of the water network, and proposed an "enhanced" programme to assess its condition.
They stressed it was not only a matter of past underfunding, but a change in community expectations around the prevention of pollution in streams, the harbour and coastal waters.
Wellington Water tabled several proposals at the meeting to deal with the city's problems, Mayor Andy Foster said.
"Many of the ideas proposed would require additional funding if agreed, which the Council would need to consider carefully. The council already invests around $180 million per year [averaged over 10 years] on the three waters, and that figure is scheduled to increase in coming years. So our first obligation to ratepayers is to ensure that money's being efficiently spent," he said.
Foster acknowledged Wellington Water was under pressure from both projects in the city and across the region.