Pre-cast concrete slabs will be bolted on to the Mangakahia River bed to allow heavy traffic to access a forestry block but a water quality campaigner is concerned at the ease of which the plan was approved.

Millan Ruka, from Environmental River Patrol-Aotearoa, said he was surprised Northland Regional Council treated the consent process for a ford 6km south of Twin Bridges as a non-notifiable issue.

Mr Ruka described that status as a "have-a-chat consent", with no legal avenue for Maori to have concerns addressed in a hearing process. Those concerns include water flow, eel migration and the volume of traffic in the river and on local roads - all issues raised at a pre-consent, local meeting in November.

The consent was issued in January to Hancock Forest Management on behalf of Taumata Plantations, a majority offshore-owned company.


NRC land management officer Geoff Heaps said it was non-notified because the crossing is permissible in the Resource Management Act and the Regional Water and Soil Plan. Local hapu were informed but there was no need for further community engagement, he said.

Hancock Forests called a meeting at Tarai o Rahiri Marae, near Pakotai, last November to outline the plans for the ford and other forest management issues.

Mr Heaps said the concrete crossing, which would be level with the riverbed, was the most stable and low-impact option for permanent access to the 280ha landlocked Robinson' Forest block, where harvesting is due to start.

Trucks already cross the river to access the plantation and a neighbouring farm but the ford was necessary to cope with increased heavy traffic, Mr Heaps said.

"With a big river like this you can't put in a culvert crossing and a bridge is out of the question. As far as we're concerned, it's the best option and it's at an existing crossing point anyway," he said

It is likely that after the current harvest and the land is replanted there will be minimal vehicle movement on the crossing "for another 30 years", Mr Heaps said.

But the consent has a five-year renewal period and the harvest plan is for five years.

The report says there will only be a slight increase in the number of logging trucks on Mangakahia Rd, the ford will be installed in two stages to ensure half the river channel stays open during the work, and log storage and landing points will be as far from the riverbanks as practical.

Mr Ruka said there was no determination of how many trucks would cross each day.

"There is scope to have a much bigger planting area so this river crossing opens up the whenua on the other side to be a busy highway across our river that no one will be able to monitor."

He also disagrees that the concrete slab was the best option.

"They could do much lower impact, such as fly-wire the logs over or float them to the next road below."