Raw Water Delivery Line Upgrade

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To future-proof Stratford’s water supply, we need to replace the approximately 100 years old raw water delivery line to the Stratford Water Treatment Plant. This includes upgrading our raw water intake system and installing a new grit tank.

While the Stratford Water Treatment plant is only about 10 years old, the intake and grit tank delivering the river water to the treatment plant were installed in 1922!


What does the grit tank do?

The grit tank provides the first level of treatment as well as protection for the treatment plant, filtering Stratford’s water supply as it’s taken straight from the river.

It’s a bit like a sand filter on a swimming pool, it helps to clean the water of bugs and other bits of muck before it goes into the treatment plant for final processing.

Why do this work now?

The current raw water line largely consists of an unlined hand-dug tunnel with a short length of earthenware pipe at both ends, leading into the concrete grit tanks. The tunnel as well as the grit tanks were kept in place when we replaced the water treatment plant about 10 years ago to reduce the complexity of that project and maximise the benefit derived from these assets.

However, both assets have reached the end of their life, parts of them are no longer serviceable and are failing to deliver the required service needed.

These are critical assets that ensure Council is able to provide safe and reliable drinking water for Stratford. Replacement is essential, and the new infrastructure is expected to have a useful life of another 100 years.

What's the budget?

Council set aside $4million to do this work as part of the Long Term Plan 2024-34.

Find updates on this project below, or reach out to us at StratfordDC@Stratford.govt.nz if you have any questions.

To future-proof Stratford’s water supply, we need to replace the approximately 100 years old raw water delivery line to the Stratford Water Treatment Plant. This includes upgrading our raw water intake system and installing a new grit tank.

While the Stratford Water Treatment plant is only about 10 years old, the intake and grit tank delivering the river water to the treatment plant were installed in 1922!


What does the grit tank do?

The grit tank provides the first level of treatment as well as protection for the treatment plant, filtering Stratford’s water supply as it’s taken straight from the river.

It’s a bit like a sand filter on a swimming pool, it helps to clean the water of bugs and other bits of muck before it goes into the treatment plant for final processing.

Why do this work now?

The current raw water line largely consists of an unlined hand-dug tunnel with a short length of earthenware pipe at both ends, leading into the concrete grit tanks. The tunnel as well as the grit tanks were kept in place when we replaced the water treatment plant about 10 years ago to reduce the complexity of that project and maximise the benefit derived from these assets.

However, both assets have reached the end of their life, parts of them are no longer serviceable and are failing to deliver the required service needed.

These are critical assets that ensure Council is able to provide safe and reliable drinking water for Stratford. Replacement is essential, and the new infrastructure is expected to have a useful life of another 100 years.

What's the budget?

Council set aside $4million to do this work as part of the Long Term Plan 2024-34.

Find updates on this project below, or reach out to us at StratfordDC@Stratford.govt.nz if you have any questions.

  • Saying goodbye to 100 year old infrastructure

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    It's had a good run, but we're ready to say goodbye to the current raw water delivery line, which has been serving the Stratford water supply for over 100 years!

    Check out the old grit tank design from 1922:

    The new Raw Water Delivery Line involves building a pumping station above the existing water intake, which will take water up to a junction box in the paddock above, where it will then enter a new large, 450mm heavy-duty plastic pipe.

    From that high point, the water will flow naturally downhill using gravity, traveling directly into the new filtration tank designed to remove sand and grit before the water continues through the treatment process.

    This is a drawing of the new pump station design:


  • Site blessed & work underway to future‑proof water supply

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    On 12 January 2026 Ngāti Ruanui led a blessing of the new grit tank project site at Stratford’s water treatment plant, joined by council staff and contractors. The ceremony marks the start of physical work on what is a significant water infrastructure upgrade for our district.

    While our water treatment plant is only about 10 years old, the intake and grit tank that deliver river water to the plant were originally installed over 100 years ago in 1922.

    The grit tank provides the first stage of filtering for Stratford’s water supply as it’s drawn from the river. Much like the sand filter on a swimming pool, it helps remove sediment, bugs, and other debris before the water enters the treatment plant for final processing.

    The $4 million project will be complete by July 2026, strengthening the district’s water resilience for the next century.

Page last updated: 16 Feb 2026, 10:34 AM