Water services investment for Horowhenua
In the Long-Term Plan 2024-34, Horowhenua has committed to spending more than $550M to meet demand for growth and responsibly plan to maintain existing assets – replacing pipes, treatment plants and other infrastructure.
Horowhenua is one of the fastest-growing districts in the country. Its population of 37,500 is forecast to grow to over 66,000 by 2054.
The district needs to provide drinking water, wastewater and stormwater to all its residents and businesses. But at the same time as its population is growing, much of its infrastructure is aging and needs to be refurbished or replaced. Some of the major projects are listed below.
Levin Wastewater Treatment Plant
The Levin Wastewater Treatment Plant is now more than 70 years old, is deteriorating, and needs repairs and upgrades to ensure it meets current needs and is able to accommodate future growth in the district.
The plant will be upgraded in a staged approach. This significant work is estimated to cost $68M over the next 10 years and a total of $111M by 2053. The investment is largely funded by development contributions and debt funding.
The first stage of the project is to replace the main inlet pipe with a larger and more durable pipe. The next step will be to upgrade the headworks, which is the first stage of treatment when wastewater enters the plant.
Replacing the inlet pipe and headworks is estimated to cost $12-17M.
Total investment in wastewater assets between FY 2025/26 and 2033/34 is budgeted at $132M.
Extra drinking water capacity
Levin and Ōhau currently have less than 24 hours emergency drinking water storage capacity at the treatment plant on Gladstone Road.
To address these capacity issues, as well as changing water regulations, the impacts of climate change, and the need to improve resilience against natural hazards such as earthquakes, the council is planning to build a new water reservoir.
The 740,000 cubic metre reservoir will be located near the Levin Water Treatment Plant, on council-owned land between Poads Road and the Ōhau River.
It will give Horowhenua a critical buffer in times of water shortage, allowing it to take water from the river when flow rates are high and store it for times when the river is running low.
The council has budgeted $65.7M for the project and applied for resource consent.
Horowhenua is also looking into building an 8-million litre reservoir for treated water at the plant and is continuing to upgrade water treatment plants in Foxton, Foxton Beach and elsewhere in the district.
Total investment in drinking water assets between FY 2025/26 and 2033/34 is budgeted at $115M.
Stormwater consent and infrastructure
Work is progressing to secure a long-term consent for Levin’s stormwater discharge, a key step in protecting the health of local waterways and Lake Horowhenua. The council is preparing a full consent application, addressing Horizons Regional Council’s compliance requirements and providing the requested supporting information. This includes a detailed assessment of stormwater effects on water quality, monitoring results, and a proposed long-term monitoring plan. Engagement with iwi owners is ongoing.
Recent stormwater improvements include fitting ‘downstream defenders’ – essentially giant filters – at several key points to improve the quality of stormwater run-off going into Punahau – Lake Horowhenua. A further treatment device will be installed on Queen Street this year.
Total investment in stormwater assets between FY 2025/26 and 2033/34 is budgeted at $17M.