The Eastland Group, owners of the troubled Waihi Dam, say they are co-operating with the "appropriate body" in regards to the alleged damage caused by a broken sluice gate.

This comment comes in the wake of Green Party MP and water spokeswoman Catherine Delahunty calling on Environment Minister Nick Smith to question why the group has not been prosecuted over the alleged environmental damage caused by a broken sluice gate.

A spokeswoman for the Group said they were "co-operating fully" with the Hawke's Bay Regional Council, which was conducting an investigation into the matter.

"At the moment they are the appropriate body to be making those decisions."


The Eastland Group-owned Waihi dam, which was damaged during a severe weather event in September last year, has now been repaired and will shortly resume full function as a hydro-electricity station generating enough power for 1600 homes.

The damage to the dam, which is 26km north-west of Wairoa, resulted in silt being released into the Waiau River system.

The council's resource management group manager Iain Maxwell said in earlier reports that no decision had been made as yet whether a prosecution would be pursued in relation to the silt discharge at the dam. He said there were statutory timeframes within the Resource Management Act stipulating that any prosecution against any party must be initiated, filed with the Environment Court, within six months of the regional council becoming aware of the incident.

The Eastland Group had not received any substantive claims for damages, the spokeswoman said. "If we receive such claims they will be dealt with responsibly," she said.

"It is hard to determine whether there has been any ecological damage to the Waiau river system although mullet were observed in the Waiau River in the vicinity of the Waihi powerhouse earlier this week."

She said it was important to note that these were normally high sediment river systems and, with the winter rains coming, any residual sediment was likely be moved through quite quickly.

The spokeswoman said a team of engineers, divers and other expert personnel, has been on site since the council issued a consent allowing repair work, and that team has worked in arduous and dangerous conditions to ensure repairs took place as urgently as possible.

"Temporary gabion baskets were also installed downstream from the dam to catch sediment prior to entering the Waiau River, with silt collected in the area transported to council approved clean-fill sites on nearby farmland," she said.

She said Eastland Group has consistently maintained open lines of communication with all key stakeholders including local and regional councils and members of the farming and local community, with a view to supporting affected parties where possible with up-to-date information. She reiterated the group "sincerely regret" the sediment releases.