Kai Iwi Lakes Public Toilet and Wastewater Treatment Upgrade
The details
Taharoa Domain is a 538ha recreation reserve 35km northwest of Dargaville, home to three ecologically significant freshwater lakes known as the Kai Iwi Lakes. Kaipara District Council (KDC) established the Taharoa Domain Governance Committee to include kaumatua from Te Kuihi and Te Roroa into the management of these precious lakes.
Taharoa Domain is increasingly popular with both Pine Beach campground users and day visitors, and KDC wanted to develop the campground facilities while protecting this sensitive environment. With support from Te Kuihi and the Tourism Infrastructure Fund upgrades were commissioned for the 2025/26 summer season.
We were contracted in March 2024 to support KDC with developing the existing design, obtaining consents, community engagement, procurement and contract supervision.
The challenge
The Taharoa Domain Governance Committee were concerned that the proposed new public toilet, two ablution blocks and associated wastewater treatment system would increase demand on the existing lake water take. There were also concerns about the location and design of the wastewater treatment upgrade.
The Domain is within an outstanding natural landscape area, and parts of the site are subject to flooding and erosion hazards. Coordinating with the contractor was essential to meet resource consent conditions around engagement with Te Kuihi and Pouhere Taonga Heritage New Zealand.
Our approach
We worked with KDC to develop a staged design that could be delivered over several years as funding became available. Stage 1 delivered the public toilet, reticulation and wastewater treatment upgrade, while setting up the site for the ablution blocks planned in Stage 2.
We provided practical recommendations for Stage 2, including grease traps and water saving devices to reduce pressure on the wastewater treatment plant.
Close collaboration with KDC’s Community Engagement Team, designers, contractor and the Governance Committee ensured the design met their needs. We carried out condition assessments on the campgrounds’ piped network, then modelled it to ensure the wastewater tanks and dripper fields were correctly sized. Multiple treatment options were considered including electrocoagulation.
Outcomes
Construction was completed in compliance with consent conditions and on time for the 2025/2026 summer season. Visitors to Taharoa Domain no longer have to use Portaloos, they now have a purpose-built accessible three-pan toilet facility. The associated rainwater collection system and proactive installation of future water and wastewater reticulation set the site up well for Stage 2 and sustainability in the long-term.
