Ruamāhanga River resilience work finally set to make a start

Nearly four years after announcing central government funding for flood resilience in areas of Wairarapa and Wellington, Greater Wellington will finally start work to protect a section of the Ruamāhanga River along River Rd where the road, a sewer line, Wai Rua Junction, and three private properties are at risk of erosion.

The $11 million government funding was announced in August 2020 as part of the government’s post covid-19 infrastructure fund and was designated to two main areas of development in Wairarapa and Lower Hutt.

A rock groyne [rock boulders] and a 150 metre rock revetment [rock wall] are being built into the Ruamāhanga River as preventative measures, and the work is expected to run through until July 31 this year.

Greater Wellington’s delivery director Jack Mace said the upcoming work follows on from erosion work already completed downstream to protect the river from an old landfill.

“Access to the site will be through the Masterton Recycling Centre via Nursery Rd,” Mace said.

“A haul road will be built through paddocks owned by Masterton District Council [MDC], allowing access from Nursery Rd through to the Waipoua and Ruamāhanga confluence.”

While work is completed, it is expected that there will be no lane alterations or traffic management.

When the funding was announced, Wairarapa Councillor and Greater Wellington deputy chair Adrienne Staples noted the need for flood protection infrastructure due to the “devastating consequences for communities flooded as a result of not doing so”.

“The Wellington Region is a beautiful place to live with our mountain ranges, winding rivers and many ocean-side cities and towns – we are lucky to call this place home. But we also know there is a flip side to enjoying that beauty, in the form of environmental hazards and risks posed to us and our properties,” Staples said.

“We manage flood risks from the rivers that flow across our region. We know how devastating flooding and erosion can be to the land, livestock, and homes. Rivers wind their way through public and private land, so we work with communities and land owners in places like Ruamāhanga to manage the risks and impacts of flooding and erosion.”

Flooding of the Ruamāhanga River dates back to the 1930s when settlers to the region suffered damage and loss when the river overflowed its banks into pastures.

A river control scheme was implemented in 1953 where, over 20 years, bank edge protection and river alignment helped reduce instances of flooding.

Previous work to combat erosion on the river included the installation of six rock groynes next to the closed landfill site on Nursery Rd to prevent landfill eroding into the river.

This work was funded as part of the Wellington Region’s Climate Resilience Programme, with funding coming from central government’s Kānoa fund, Greater Wellington, MDC, and the Hutt City Council [to support Manor Park’s improvement project].