Transmission Gully is known to pose a real runoff threat to the sensitive Pauatahanui Inlet below it. Photo: RNZ / Angus Dreaver
The Department of Conservation (DOC) has not had any input into reports on Transmission Gully motorway's environmental impacts or what to do about them.
The motorway is being looked at over whether it has breached resource consents, damaging streams and native fish.
DOC earlier told the public it had worked to get good biodiversity outcomes at the road.
It now says it has been part of working groups during construction, and since the road opened. But it had "not had input to any reports" either during construction or after the opening.
"Since the opening of the road (March 2022) DOC has not been approached by NZTA for input or feedback as to environmental matters associated with Transmission Gully," its director of operations Alice Heather said in a response to an Official Information Act (OIA) request.
Waka Kotahi / New Zealand Transport agency has held the motorway project up as a model of good environmental practice for a decade.
However, it was unclear who was responsible for its environment management because legal action over whether the construction has been completed fully was dragging on between the agency and the builders.
RNZ was seeking records of what DOC has done, especially considering the motorway was known to pose a real runoff threat to the sensitive Pauatahanui Inlet below it. The inlet is silting up, partly due to the road.
The response from the department showed there was a dearth of records.
DOC looked three years ago at the plans for water and earthworks to restore Wainui and Te Puka streams and resolve fish passage issues, and visited the site, Heather said.
"Initial comments were provided, stating DOC agreed in principle with the plans but suggesting more robust fish passage options be explored," she said.
The consent breach allegations include that some fish passages have not been set up or monitored properly since the road opened.
The department was part of a working group to protect native fish set up in 2018, and this group had been re-established since the road's opening, Heather said.
"DOC is amenable to continued engagement with lead agencies to continue to advocate for biodiversity and fresh water."