Moutoa floodgates to get upgrade later this year

Moutoa floodgates were built in 1962 and are getting a few improvements this year.

The Moutoa floodgates, opened whenever the water level in the Manawatū River upstream gets very high, are due for an upgrade, a Horizons Regional Council official says.

When the floodgates are opened water goes down a 10km spill way, down a shortcut directly to sea. This happens whenever the water levels in Palmerston North go above 5.2m and the level at the floodgates is expected to go over 8.2m.

“The Moutoa floodgates, completed in 1962, are the biggest piece of river management infrastructure in the Horizons region,“ the council’s group manager catchment operation, Dr Jon Roygard, said.

“They are regularly tested and are operational. However, like any asset, the gates need maintenance and upgrades to ensure their continued reliability and effectiveness for years to come.”

Roygard said that from October 2024 the gates will be getting a range of improvements. This work is co-funded by the Government as part of Horizons’ suite of infrastructure climate resilience projects.

The Moutoa floodgates

For all these infrastructure climate resilience projects, which include the work on the floodgates, the Government has invested $26.9 million, with Horizons contributing $9m.

“There are three general areas of work: mechanical, structural and electrical upgrades. The mechanical upgrades involve replacing existing gear with new components, integrating winch gear frames into a pre-fabricated steel base, and ensuring minimal outage time for flood risk mitigation.

“Structural upgrades include remedial repairs to dividing piers and installing new capping aprons. The electrical system upgrades encompass relocating the main switchboard, extending circuits, integrating energy meters and modifying PLC codes.”

Roygard said these changes will provide added resilience to the Moutoa floodgates, which is a key asset in the lower Manawatū scheme, providing important flood protection for those living near the Manawatū River downstream of the gates.

To see how the Moutoa floodgates work: https://vimeo.com/912798414.