The planned rediversion will direct 20 per cent of the river's flow back into the estuary while maintaining existing flood protection levels and channel navigability at Te Tumu cut.
Regional council Kaituna Catchment manager Pim de Monchy said the council was grateful to iwi, landowners, environmental groups and the wider community for their support for the project so far.
"There are lots of interested parties. It's a complex project involving more than 100,000cu m of earthworks in a sensitive environment, both ecologically and culturally. We need to make sure we get it right."
The council lodged its application for resource consent and associated land designations in July last year.
A panel of independent planning commissioners approved the application yesterday, following review of 46 public submissions at a hearing in May.
The consent approval is subject to 40 pages of conditions designed to manage the potential environmental effects of the project. Mr de Monchy said his next task was to do a cost analysis on the consent conditions and check that the project is still affordable.
"After that we'll respond to any appeals and start the process of detailed design and construction planning. If land acquisition processes go smoothly and there are no appeals, construction could start by September 2016."
A copy of the full consent decision, including conditions and the commissioner's report, is available at www.boprc.govt.nz/kaitunamaketurediversion.
A public meeting will be held at Maketu in August to discuss the decision and what it means.