Wairua

Wairua Oxbow Restoration

Wetlands – With Descriptor

About the project

This project aims to show best practice restoration of two oxbows on the Hikurangi floodplain.

The oxbow ‘lakes’ are the remains of meanders of the Wairua River. The meanders were blocked off in the mid-late 20th century as part of a large-scale government subsidised drainage scheme. The idea was that straightening waterways, building stop banks and installing pump stations would quickly drain flood waters from local farms. However, the drainage works ended up isolating the oxbow lakes disrupting habitats and having an adverse effect on aquatic flora and fauna.

The project area, which is adjacent to the Wairua River Reserve, had indigenous and exotic vegetation including two threatened native plant species: the Hikurangi swamp koromiko and heart-leaved kohukohu; copious weeds and animal pests; and was routinely grazed by cattle as part of a lease agreement.

Living Water contributed funding to Whangarei District Council and together worked with Ngā Kaitiaki o Ngā Wai Māori, Northland Fish and Game, and a neighbouring farmer to retire the 7.4ha project area and undertake restoration activities that would replicate vegetation cover from 1942 as seen in aerial photos pre-drainage works. 

Akerama Marae

Akerama Marae

Bittern
Oxbow 1 in 1942
Oxbow current
Wairua

Benefits

  • Increased ecological health and ecosystem function on a highly modified floodplain
  • Increased freshwater habitat supporting a wide range of flora and fauna
  • Creating a best practice demonstration site for others to learn from

Progress

  • Completed ecological surveys to establish baseline species and composition
  • 7.4ha retired from grazing with stock-proof fencing erected
  • Ephemeral wetlands created and a drain reinstated to connect the two oxbows and improve mudfish habitat
  • Revegetation completed
  • Plant and animal pest eradication ongoing
  • Project will be completed mid-2019
Ecology North

Ecology North

Restoration Consultants
Northland Fish & Game

Northland Fish & Game

Whangarei District Council

Whangarei District Council

PROJECT IMPLEMENTATION AND MONITORING

Completed 2019

Progress: 100%