About Tiaki Wai
Tiaki Wai is a council-owned organisation established by five councils in partnership with mana whenua iwi.
From 1 July 2026, Tiaki Wai will take over the delivery of drinking water, wastewater and piped stormwater services to people in the metropolitan Wellington area. It will absorb the current provider, Wellington Water.
Tiaki Wai will have more funding options, a regional focus and new leadership and governance arrangements to deliver improvements for current and future communities over time, while continuing the critical work done by Wellington Water to supply drinking water and safely remove wastewater and stormwater.
The region’s water assets, with a replacement value of almost $18 billion, remain in public ownership.
Tiaki Wai will cover the cost of building and maintaining essential infrastructure and delivering water services by borrowing against the assets and collecting revenue from business and residential water users, and from developers.
To be financially sustainable, Tiaki Wai has to be efficient and effective as possible.
Structure and oversight
Tiaki Wai is jointly owned by five councils - Hutt City, Porirua City, Upper Hutt City, Wellington City and Greater Wellington Regional Council. The mana whenua partners are Ngāti Toa Rangatira and Taranaki Whānui ki Te Upoko o Te Ika. It will be accountable to a Partners Committee of representatives from each council and mana whenua. The Partners Agreement is due to be finalised and the committee established in December 2025.
Regulatory oversight will be provided by the Water Services Authority - Taumata Arowai, the Commerce Commission and Greater Wellington Regional Council (as environmental regulator).
Tiaki Wai is being established and will operate within the legal framework of the Local Government (Water Services) Act 2025.
Board
Will Peet
Chair
Will is a Wellington-based independent director and advisor with deep experience in infrastructure, transport, technology, and public sector governance. A civil engineer, Will's career includes leadership roles as CEO of ONTRACK and Chief Operating Officer of the New Zealand Defence Force.
Currently, Will chairs Site Safe, is a director of Public Trust, a member of the Ministry of Education Risk and Assurance board, and serves as an external member on major project governance groups for a number of public sector organisations, including as independent chair of Te Wai Takamori o Te Awa Kairangi/Riverlink.
Will is a Fellow of Engineering New Zealand, Fellow of the Chartered Institute of Logistics and Transport, and Member of the Institute of Directors.
Jon Lamonte
Director
Jon has extensive experience in water services leadership, including being a former CEO of Watercare, and the Auckland/Northland Water Services Entity. He was also CEO of Sydney Metro, Transport for Greater Manchester, and Tube Lines Ltd (London).
Jon is a Chartered Director and Fellow of the Institute of Directors, a Fellow of the Royal Institute of Chartered Surveyors and Fellow of the Chartered Institute of Logistics and Transport.
Jon was also formerly an Air Vice-Marshal in the Royal Air Force, with director-level positions in defence procurement, logistics, and strategy.
Jon is currently a director on the Board of Waikato Waters Ltd.
Elena Trout
Director
Elena has extensive experience as a company director and professional civil engineer who has held a number of leadership positions in the transport, infrastructure and energy sectors over the past 30 years.
Elena is currently an independent director or chair of several boards including Citycare, Callaghan Innovation, the Energy Efficiency and Conservation Authority, Local Government Funding Agency (LGFA), WorkSafe, and has recently retired from Contact Energy. She has held significant roles as an independent chair and advisor to both central and local government.
Elena is currently the chair of the Board of Waikato Waters Ltd.
Elena is a Fellow of the Institute of Directors and a past president and distinguished Fellow of Engineering NZ.
Adrian Wimmers
Director
Adrian is a Wellington-based commercial and infrastructure advisor and public sector governance leader with more than 30 years’ professional experience across high-value infrastructure investment, complex commercial transactions and major public sector reforms.
Adrian’s career has included senior executive roles at KPMG, the New Zealand Treasury’s Crown Company Monitoring Advisory Unit and as an Acting General Manager at the New Zealand Infrastructure Commission. He has held governance roles with multiple departmental advisory boards and not-for-profit organisations including the Komiti Pasifika at Victoria University of Wellington and is currently Deputy Chair of the Fale Malae Trust.
Adrian is a Member of the Institute of Directors and a Certified Public Accountant (CPA) (Aust).
Leadership
Michael Brewster
Chief Executive
Michael Brewster is a senior infrastructure leader with extensive experience across Tasmania’s energy and water sectors and New Zealand’s water reform programme. He served as the inaugural Chief Executive Officer of TasWater, guiding the organisation through major transformation and strengthening its focus on safety, customer service, and environmental outcomes.
In 2023, Michael joined New Zealand’s Department of Internal Affairs as Chief Executive of the proposed South Island water services organisation, ‘Entity D’. Working with Ngāi Tahu, councils, and DIA teams, he helped shape the design and establishment plans for the new entity, gaining valuable insights into the opportunities and complexities of water sector reform in New Zealand.
Michael has held a range of senior executive roles in the electricity and engineering consulting sectors, including leading Tasmania’s Electricity Reform Business Transition Group. He has also contributed to public sector governance as a State Planning Commissioner and lectured in project management. He was formerly a Chartered Engineer (Electrical) and was a Fellow of the Institution of Engineers and former President of Engineers Australia, Tasmania Division.