Horizons Regional Council has announced the completion of one of its largest ever suites of climate resilience and flood protection projects.
Council group manager catchment operations, Dr Jon Roygard says the Infrastructure Climate Resilience Projects, made possible with $26.9 million of central government funding administered by Kānoa – Regional Economic Development & Investment Unit since 2020, will have long-lasting benefits for multiple communities.
“Research shows every $1 spent on flood protection means between $5 and $8 of direct losses avoided* – an extremely strong ratio for large-scale infrastructure projects,” says Dr Roygard.
“While much of this work was in Horizons’ long-term work plan, having central government funding to cover 75 percent of the cost meant we could accelerate progress.
“This not only provided enhanced protection sooner, but brought money into our economy through local employment while also providing training opportunities for Horizons staff and contractors.”
The projects fit under four overarching workstreams: Palmerston North stopbanks; Lower Manawatū Scheme; Rangitīkei River climate resilience; and Te Awahou Foxton Flood Mitigation, says Dr Roygard.
“Many of the Lower Manawatū Scheme upgrades focused on protecting productive land. Work to upgrade a 450-metre-long stopbank along the Tokomaru River, which helps to protect 250 hectares of rural land, will give people who farm in the area more certainty.”
“Stopbanks along the Manawatū River near Te Matai Rd, between Ashhurst and Palmerston North, were given more resilience thanks to a new 440-metre-long section of armouring rock. This armouring rock will help to prevent erosion of the stopbank situated between the river and 360 hectares of land populated by people, businesses and productive land.
“The Lower Manawatū Scheme stream also included work to give the Moutoa floodgates their most significant upgrades since their construction in 1962, and the enhanced Hartley St rock armouring at Foxton Beach designed to help to provide protection to nearby homes and paths.
“The Lower Manawatū Scheme upgrades have created direct economic, social and environmental benefits for people living and working throughout the lower stretch of the Manawatū River catchment.”
The Rangitīkei River Climate Resilience project has aimed to create a more resilient approach – both economically and environmentally – to river management downstream of the Bulls Bridge, says Dr Roygard.
“We worked to give the river more room to move by giving it a wider corridor, increasing its capacity to handle larger flood events, and allowing for more natural dynamic changes.
“Dispersing water across a wider area during flood events through this wider corridor will help to take pressure off stopbanks and other infrastructure.
“This project had many social benefits, including ecological enhancements through putting Horizons leased land back into native vegetation, providing employment and training to local businesses and iwi, and creating new amenity such as upgrades to the Scotts Ferry access pathway.”
Stopbank upgrades throughout Palmerston North were wide-ranging, says Dr Roygard.
“A new 210-metre-long rock wall alongside the Manawatū River Shared Pathway has boosted protection to residents and businesses in Hokowhitu, as well as providing resilience for a main water line in the area.
“We also replaced deteriorating gabion baskets along the Mangaone Stream near Tremaine Ave with a secant pile retaining wall, replaced a timber retaining wall at Bisley St, realigned the Kākātangiata stopbank, and removed poplars along sections of the Manawatū River Shared Pathway.”
Addressing persistent flooding issues in Foxton was the goal of the Te Awahou Foxton Flood Mitigation Project, says Dr Roygard.
“While the scope of works changed over time due to a range of factors – including the COVID-19 pandemic and Cyclone Gabrielle – the establishment of a governance group in 2024 helped to find collaborative and tangible solutions.
“These solutions include sheetpiling along Kings Canal, stormwater work, and enabling pumping of surface water from Purcell St.”
With this suite of projects complete, Horizons will spend the coming years with a capital programme focused on Feilding, Palmerston North, and work associated with the Te Pūwaha project in Whanganui, says Dr Roygard.
“Asset maintenance and management will also be a core focus for Horizons, as this is an important part of keeping communities safe from the impacts of flooding.
“With 1,100 kilometres of drains, 500km of stopbanks, 54 dams, 24 pump stations and 755 floodgates to manage, along with a variety of other assets, maintenance and management will help flood protection infrastructure to perform when required.
“We are also well advanced on a regional flood vulnerability study, and hope to present the findings later this year.”
For more information about the Climate Infrastructure Resilience Projects, visit https://www.horizons.govt.nz/flood-emergency-management/infrastructure-climate-resilience-projects.
*Figures from Before the Deluge 2.0, a business case for co-investment in flood management infrastructure. The full report can be found on the Resilient River Communities website here.
