Residents question timing of dam spill

By RENEE KIRIONA and ELIZABETH BINNING

Eastern Bay of Plenty residents are questioning why TrustPower did not release water from its Matahina Dam earlier.

Rising flood waters forced the power company to spill water from the big hydro dam on the Upper Rangitaiki River on Sunday afternoon.

The huge volume of water breached banks as it moved downstream, flowing through the towns of Te Teko and Edgecumbe.

Chris Kerr, of Edgecumbe, claimed that the damage to his town could have been lessened if the electricity company opened its floodgates earlier.

"We all knew a lot of rain was coming, but they especially should have been prepared for it. As far as I'm concerned they should have let some of the water out on Friday to leave more room for the lot [rain] that came in on Saturday night."

Elaine Croghen, whose home was flooded, said more planning needed to go into trying to prevent residential areas from getting damaged.

"In no way are we saying that it's TrustPower's fault. All we are saying is that we thought they might have been more prepared in such a situation.

"Perhaps we need to start working on these things in the future."

However, TrustPower spokesman Graeme Purches said the company's decision to open the floodgates on Sunday at 2pm would have prevented a lot of damage.

"If we opened the gates on Saturday night then people would have been swimming in their sleep. We did the best we could do."

Mr Purches said the flow of water through the Rangitaiki River peaked on Sunday, with company being forced to spill 740 cubic metres of water per second (cumecs) between 10am and 2pm.

Around 580 cumecs is considered a major flood in the river.

That discharge was reduced to 576 cumecs by 8am yesterday. TrustPower then agreed to reduce the flow even further between 10am and 4pm to allow Environment Bay of Plenty time to conduct work on damaged floodbanks.

Mr Purches said the dam level rose again during the time because the flow of water into the dam was higher than the outflow.

The water levels were now under control and no structural damage had been caused.

The earth dam, the largest of its kind in the North Island, was badly damaged in the 1987 earthquake. It was decommissioned for seven months to allow repairs including substantial strengthening of the dam to reduce it's hazard rating.