Route picked for Kaituna divert

Bay of Plenty Regional Council has chosen its preferred option for its plan to re-divert the Kaituna River and create new wetlands in the area.

The Regional Council has chosen the second of two options, which maximises the flow into the Ongatoro/Maketu estuary while keeping Te Tumu cut open for flood protection. The Option 2 concept design has been modified to take into account feedback from the community.

Regional Council project manager Pim de Monchy said the preferred option would likely lead to significant ecological improvements and reduced sedimentation in the estuary.

"The preferred option would increase the mauri [life force] of the area by allowing up to four times more water from the Kaituna to flow into the estuary. Some private land will need to be used to complete the project," he said.

"The Maketu community has been concerned about degradation of their estuary, largely due to opening of Te Tumu Cut in 1956. This made the estuary more saline, leading to the loss of 95 percent of estuarine wetland area and reducing the estuary's ability to flush out sand and mud," he said.

The project aims to re-divert more of the Kaituna River's flow through Ongatoro/Maketu Estuary while keeping Te Tumu Cut open, and to re-create at least 20 hectares of wetland habitat.

The project team had consulted with landowners, tangata whenua and the community over the past few months on the two options, holding public meetings, drop-in sessions and meeting with individuals. Of the responses received, almost three quarters supported the project, six percent were opposed and the rest were neutral, he said.

"More than half did not choose between Options 1 and 2, but those who preferred Option 2 were concerned about erosion of Papahikahawai Island and Maketu Spit. Issues included navigation and erosion, landscape and access, cultural and social issues, ecology and natural hazards," he said.

Modifications from the proposal include moving the proposed intake for the re-diverted flow further upstream to maximise the amount of fresh water and minimise salt water on the incoming tide entering the estuary through Te Tumu Cut. The preferred option will be modelled and assessed to determine environmental effects in detail, as well as the cost and risk.

Mr de Monchy said the Regional Council expected to lodge resource consent applications and a Notice of Requirement in mid-2014 to designate land required for the project, with construction planned to start by the end of 2015 once all consents and requirements were met.

The project team would be talking with the community about the next steps in the project, negotiating with landowners, assessing technical requirements, planning, construction, operation and maintenance costs and assessing environmental effects and alternatives, he said.