Waimak dam upset continues
Opposition to a 13-metre high dam in the Waimakariri district continues, despite it being out of the limelight for a couple of years.
Catherine Ballinger of the Eyre Community Environmental Safety Society (ECESS) residents’ group said although the matter had been before the Environment Court for the past two years, many people were unaware of the group’s efforts, which was why she wanted to ‘‘ring the bell again’’ and rally the troops.
‘‘We need the whole community behind us,’’ she said. ’’We want to do some fundraising and get our voice heard again.’’
In essence the group is opposing Waimakariri Irrigation Ltd’s (WIL) building of a large dam on the grounds of safety concerns. With about 1,800 people now living downstream of the proposed dam, Ballinger said residents were concerned about the lack of a workable evacuation plan.
‘‘Nothing has been built like this before, with no natural water course for it to flow to if it breaks or floods,’’ she said. ’’The only course of action we could take was to appeal, which we are doing now.’’
Ballinger said public meetings had been held with WIL and GNS scientists attended by ‘‘lots of unhappy people’’.
Concerns were heightened after last year’s earthquake, she said, however there had been no change to the dam plans to take a potential natural disaster into account, despite building standards having been changed in recent years.
‘‘We are not anti-dairying, and we are not against water storage. It’s just the safety issues. There are other alternatives — farmers could put their own ponds in, underground storage could be put in. By all means have your water, but store it safely.’’
WIL general manager Brent Walton said there were certainly some farms which already had onfarm storage, however the dam was necessary to protect against the ravages of drought.
Currently farmers in the area had a 75 per cent reliability on being able to take water, but for the remaining 25 per cent of the time the Waimakariri River level was too low and restrictions came into force.
With the dam, this reliability would be up between 92 and 95 per cent, he said.
Alternative sites had also been researched, but there would always be a population beneath any proposed dam.
As for the safety concerns, four different flood scenarios had been modelled. While the ECESS group argued they would not hear warnings over loud speakers or sirens, the modelling showed there would be plenty of time for an evacuation.
The water would take at least two and a half hours to reach Downs Rd, and a further two to five hours to reach Two Chain Rd.
In the event of a major earthquake, which was the only realistic risk to the dam’s structure, the quake itself would be the trigger for the area to evacuate, Walton said.
In terms of a fault with the structure, there was a three-tier emergency management plan with checks and balances in place, including weekly inspections, water level checks and seismic triggers.
The design of the dam, which would be built to the highest standard, had been extensively peerreviewed.
In addition, it was important to note there were shareholders in the irrigation scheme living in the flood path who would be unlikely to be investing if they believed it was going to burst in five years, he said.
The next step in the process was for the matter to take its course in court, with a hearing anticipated before Christmas, he said. After that, a construction contract and price would be negotiated before it went to the shareholders for approval. Only then would construction go ahead, Walton said.
Catherine Ballinger of ECESS is concerned about evacuation plans.