The Broadacres Target Stream Augmentation project
Establishing aquatic habitats and augmenting stream flow in the Selwyn water zone.
Safeguarding habitat for native aquatic species
The Raywell Farm tributary of the Waikirikiri /Selwyn River is historically a lower Selwyn Waihora stronghold for Canterbury mudfish (Kōwaro).
Canterbury mudfish are the most threatened of New Zealand's mudfish species and have a conservation status of Threatened (Nationally Critical) under the NZ Threat Classification System. Kōwaro are also considered a taonga species by Ngāi Tahu.
Unfortunately, no live specimens have been recorded in Raywell Farm Stream since the 2014-16 drought. This project involves proof of concept testing of a solar powered groundwater supply, weir, and enhanced aquatic habitat.
The aim is to repopulate the tributary with Canterbury mudfish and safeguard them against future droughts by pumping groundwater into the spring-fed Raywell Farm Stream when flow is limited or absent.
Achieving restoration outcomes through collaboration
Together with the landowner, EOS Ecology and Ellesmere Sustainable Agriculture, the project team constructed a solar-powered bore in 2016-17 and planted some 2,400 natives along the upper reaches of the tributary.
Next steps involve lining the wetland near Raywell Farm Stream spring to establish a suitable aquatic habitat and then transferring mudfish until the local population is self-sustainable.
These collaborative restoration efforts may also benefit other precious species, such as Freshwater crayfish (Kēwai) and Freshwater mussels (Kākahi).
Photo credit: Ellesmere Sustainable Agriculture
A key part of our water management strategy
The Broadacres TSA project is an integral component of the Canterbury Water Management Strategy (CWMS) and Canterbury Land and Water Regional Plan (Policy 11.4.22). Together with other augmentation schemes, such as the Waikirikiri/Selwyn Near River Recharge project, it forms part of the CWMS Environmental Infrastructure workstream.
The project was recommended by the Selwyn Waihora Water Zone Committee as of their Zone Implementation Programme Addendum (ZIPA) (PDF file, 6.55MB).