Kaituna River Rediversion and Maketu Estuary Enhancement
The Kaituna River Re-diversion and Maketū Estuary Enhancement Project was established to significantly increase the volume of freshwater flowing from the Kaituna River into Te Awa o Ngātoroirangi/Maketū Estuary and re-create 20ha of wetland.
The project sought to address the long-standing negative effects of the 1956 Kaituna Cut and associated works on the health of the estuary and the local community. Re-diverting the rivers flow would restore freshwater connections in the upper estuary, stop the process of sand infilling the lower estuary, and significantly improve the ecological health of the middle and upper estuary.
Along with the re-creation of 20ha of wetland and increased opportunities for public access, the project would help to make the estuary healthier for people to swim and fish in.
In 1956, the Kaituna River was diverted away from its natural outlet, via Te Awa o Ngātoroirangi / Maketu Estuary, so that the surrounding areas could be drained and farmed. However, the new farmland came at a significant price - with the loss of freshwater flows the health of the estuary collapsed.
The estuary is now half full of sand, has lost 90% of its wetlands, and populations of both finfish and shellfish have crashed. Since at least 1979, the community have been calling for the Kaituna River to be re-diverted back into the estuary to address the environmental degradation arising from the 1956 diversion.
The large-scale project brought together the Bay of Plenty Regional Council, Western Bay of Plenty District Council, iwi and the community, working together to ensure its success.
The options developed for the project sought to maximise the ecological and cultural benefits (particularly wetlands and kaimoana) for the estuary, while limiting the economic cost and adverse environmental effects to acceptable levels.The partial re-diversion of the river’s flow would also maximise the benefits to the estuary while at the same time keeping the 1956 diversion at Te Tumu Cut open for flood protection and boating access.
The consented option for the project involved re-diverting at least 20% of the rivers flow via a new 650m channel and control gates, construction of new public boat ramp facilities, and re-creation of more than 20ha of new wetlands.
WSP was engaged in 2013 to lead the planning and consenting process, along with supporting stakeholder engagement, environmental and property services. Past attempts to address the situation by other agencies had been largely unsuccessful due to upstream water pollution issues, so there was significant community interest with a hunger for information about this project.
However, while there was broad support for the concept of re-diverting the river to the estuary, obtaining a consensus on the relationship and balance between environmental, social and economic matters put the scope, options and methodology for the project under intense public scrutiny during the planning and consenting process.
The consenting team needed to demonstrate that short term pains, such as the temporary loss of very popular recreational access during construction, would lead to the long-term gain of environmental restoration and improved access.
The decision to designate, and acquire land, for ecological restoration purposes associated with environmental infrastructure is rare. In this case, the designation was a critical statutory process that supported the acquisition of 20ha of farmland for wetland re-creation but also meant that the proposal faced intense scrutiny and legal challenges. This included an appeal to the Environment Court, where WSP provided expert planning evidence.
Community engagement and project transparency were major priorities for the Bay of Plenty Regional Council. A front-facing, multi-disciplinary team was formed that met regularly with the public throughout the project.
Significant time was put into using a range of tools to convey the highly technical aspects of the applications to the community. Collaboration with iwi to achieve cultural outcomes was critical to the success of the project, with seven iwi groups directly involved and four separate cultural impact assessments supporting the consent applications.
This approach ensured that the project would contribute to the restoration of cultural knowledge and the mauri (life-force) of the river and estuary. By staging the consent compliance requirements, some initial works were completed early. It ensured the community saw early changes, helping their understanding and ongoing support of the project. Staging allowed the health of the estuary to start recovering before the main tender was awarded.
The commissioning of the project in February 2020 has already resulted in numerous positive outcomes - the restoration of flow to the estuary and the wetland re-creation on land which was previously farmed has seen the return of finfish and bird species. This project demonstrates that true community collaboration can be a vehicle to enable significant change and positive environmental outcomes.
WSP planners have been an integral part of the project from inception through to completion, pivoting from community engagement and concept development in the initial phases, to the consenting process and subsequent legal challenges.
WSP Planners also acted as project managers and client representative during construction and commissioning.
This continuity ensured that the project was implemented in a collaborative way and managed with a holistic view of the environment. The project has also been an opportunity to build social capacity and knowledge throughout the community, so they can sustain and nurture the environmental benefits of the project. Over time, these positive outcomes are expected to increase and multiply, and additional benefits will become apparent as the estuary finds a new and improved balance.
The project has already resulted in numerous environmental benefits - the restoration of flow to the estuary and the wetland re-creation has seen the return of finfish and bird species. It was also awarded the 2020 Rodney Davies Project Award from the New Zealand Planning Institute.
Hectares of farmland designated and acquired for ecological restoration
pages of technical information and summary documents
wetland plants planted with help from community volunteers