Te Ahuriri Wetland

Client: Environment Canterbury

Overview of Te Ahuriri Reserve prior to works.

Overview of Te Ahuriri Reserve prior to works.

Morphum Environmental has recently completed the detailed design of the 5 hectare Te Ahuriri Wetland for Environment Canterbury (ECan). The wetland is a flagship project being delivered as part of the Whakaora Te Waihora programme, which is a joint ecological and cultural restoration programme and an operational programme, being developed collaboratively with Te Rūnanga o Ngāi Tahu, ECan, Selwyn District Council, Christchurch City Council and the Department of Conservation. These parties are collectively working as Te Waihora Co-Governance Group, with a vision to restore and rejuvenate the mauri and ecosystem health of Te Waihora and its catchment.

The project has involved stakeholder engagement, site analysis, options assessment, design documentation and preparation of the Assessment of Environmental Effects (AEE) for consenting. With funding from the Ministry for the Environment’s (MfE) Freshwater Improvement Fund, timeframes were tight and Morphum Environment was required to work effectively with all stakeholder groups, including the Co-Governance group, consultants developing Matauranga Maori monitoring plan, NIWA and local landowners to ensure that the project delivers on multiple objectives.

The final design involves a controlled diversion for the Huritini/Halswell River, re-engaging a 500 metre long relic river channel prior to discharge into the 5 hectare wetland, which is being constructed within the historical footprint of Te Waihora/Lake Ellesmere. The wetland will function to attenuate nutrients and sediment and improve biodiversity and mahinga kai across the ecological and culturally important site. Long-term monitoring by NIWA will enable the project to demonstrate the role of well- designed constructed wetlands in addressing some of our current freshwater quality challenges.

Construction of the wetland is to begin in January 2019, with over 120,000 eco-sourced aquatic and terrestrial plants to be planted by the end of 2019. Morphum Environmental has been engaged to assist ECan throughout the consenting and tendering process and will provide supervision and technical advice throughout construction.

Footage of the restoration journey for Te Ahuriri Wetland.

Key deliverables:

  • Options Assessment

  • Detailed Design Report

  • Ecological Report

  • Construction Specification

  • Construction Drawings

  • Assessment of Environmental Effects (AEE)

  • Ongoing technical support

Stu Farrant

Southern Sector Manager