The failed dam threatening Wairoa's drinking water has been brought under control.

Hawke's Bay Regional Council says it is pleased the Eastland Group has regained control of the Waihi Dam, which has been discharging silt into the Waiau River since before Christmas.

The discharge began after a sluice gate was damaged in a storm late last year.

Sediment levels1000 per cent higher than normal were detected in the river, causing costly mitigation by the Wairoa Water Treatment Plant..


The regional council issued an abatement notice on Christmas Eve and January 6th but the damage to the dam gate was prevented it being fully closed.

Council manager of resource management group Iain Maxwell said Eastland Group completed repairs and all three sluice gates were now closed.

The reservoir was filling and, once full, power generation would begin again.

"The closure of the sluice gates means the sediment discharge down the river has stopped, however there is still a large amount of sediment that needs to move through the river system," Mr Maxwell said.

The council would soon start discussions with the Eastland Group around the future management of the dam to ensure the situation would not happen again.

He said a thorough investigation, into how the situation occurred and its effect on the community and the environment, was continuing.

A decision on whether any party will be prosecuted would be made once the investigation was completed and all facts known.