The company was first incorporated as Wellington Water Management Limited on 9 July 2003. The name was changed to Capacity Infrastructure Services Limited in July 2009, and in September 2014 the name was changed to Wellington Water Limited, when Capacity Infrastructure was merged with the water supply group of
Greater Wellington Regional Council. The South Wairarapa District Council transferred the management of their water infrastructure to Wellington Water, as from 1 October 2019. Wellington Water manages the three waters assets owned by five councils including
Hutt,
Porirua,
Upper Hutt and
Wellington City councils,
South Wairarapa District Council plus Greater Wellington Regional Council. Wellington Water is jointly owned by all six councils, but the individual councils retain ownership of their assets, and set their own rates and user charges. Each council is represented on a regional Wellington Water Committee that provides overall leadership and direction for the company. The Chairman of the Wellington Water Committee from its establishment in 2014 was Hutt City Councillor David Bassett. In March 2021, Bassett announced his intention to step down from the role. The mayor of Hutt City,
Campbell Barry, took over the role of representing Hutt City on the Wellington Water Committee in May 2021. Governance of Wellington Water Limited is provided by a board of independent directors. As of November 2023, the Chair is
Nick Leggett. In June 2021, Wellington City Council (WCC) announced the resignation of the council's chief infrastructure officer, Tom Williams. This role was responsible for the working relationship between WCC and Wellington Water. Williams was originally appointed after an independent report commissioned by the WCC chief executive in December 2019 found that the relationship between the two entities was lacking trust, and that the management services agreement had remained unsigned for over three years. In a comment about Williams resignation, the WCC chief executive said that Williams had "built a strong working relationship with Wellington Water."
Replacement In late June 2025, the
Upper Hutt,
Porirua,
Lower Hutt,
Wellington City Councils and the
Greater Wellington Regional Council announced that Wellington Water would be replaced by a new water services entity that would own and manage the various councils' water infrastructure. The new entity would generate its own income independent of council funding and manage its own debts. This new entity is expected to come into existence on 1 July 2026. In early February 2026,
Radio New Zealand reported that Wellington Water would be replaced by a new regional water services entity called
Tiaki Wai from 1 July 2026. Tiaki Wai assumes Wellington Water's drinking water, wastewater and stormwater functions and services. The entity will be jointly owned by the Wellington, Porirua, Hutt, Upper Hutt and Greater Wellington councils. ==Asset management challenges==