Wellington Water Limited

Pakuratahi Lakes Business Case Procurement

Over time, WWL anticipates a future need to progressively reduce the amount of water abstracted from Te Awakairangi (Hutt River), Orongorongo and Wainuiomata Rivers (Source Rivers) for the treatment and distribution of Bulk Drinking Water at its Te Marua and Wainuiomata Water Treatment Plants.

In order to maintain a resilient, responsible and sustainable water supply - demand balance whilst reducing maximum abstraction from 40% of Mean Average Low Flow (MALF) to 60% at 2036 at all Source Rivers, WWL has identified the need for:

• at least 3 gigalitres of additional, seasonal raw bulk water storage at Pakuratahi, Upper Hutt, Wellington;
• additional and or new pumping, equipment and piping to connect the existing weir at Kaitoke to Pakuratahi; and
• the potential need to augment, upgrade or amend operating and treatment systems at the existing Te Marua Water Treatment Plant to ensure quality and quantity of treated bulk drinking water remains appropriate during prolonged periods of taking from new and existing bulk lakes.

The predominant, amongst others, environmental benefit of this programme is to enable an increase of MALF from 40% to 60% on all Source Rivers from 2036. This means the operation of the Wainuiomata Water Treatment Plant would be suspended during times of low flow earlier and for longer than present, leaving the existing bore fields and the Te Maura Water Treatment Plant (bulk water lake source) to provide for Wellington’s water supply.

WWL is seeking expressions of interest by suppliers (or a consortium of suppliers) who are interested in being engaged by WWL to develop a Detailed Business Case for the Pakuratahi Lakes.

The Detailed Business Case needs to identify the appropriate application of new assets, change of operational process and procedures that will give effect to a sustainable and compliant supply of bulk water of responsible scale and resilience throughout changes in seasons and other things such as growth, climate change and long term seasonal variability.

This is a staged procurement process:
• Stage 1: During Stage 1 (this ROI) we will identify a short-list of preferred suppliers based on the responses received to this ROI.
• Stage 2: We will release a Request for Proposals (RFP) following on from this ROI to the short-listed suppliers, inviting them to submit proposals for the Detailed Business Case engagement for Pakuratahi Lakes.
• Stage 3: We will identify the preferred supplier(s) and award the Contract fo