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Last updated on April 23, 2014 at 21:24 EDT

Old Hydro Dam Back on Stream; Popular Recreational Activities Protected

July 15, 2008

By MAETZIG, Rob

THE go-ahead has been given for a century-old Taranaki hydro power scheme to be recommissioned — despite concerns it will hurt popular recreational use of the river.

The Taranaki Regional Council hearing committee has approved an application by Normanby Power Ltd to restart the Normanby hydro scheme on the Waingongoro River.

The decision follows a hearing last month when recreational users of the old scheme — including those who operate the dam-dropping tourism venture — opposed the plan because of the effect it would have on water flows.

But the committee has ruled that since the scheme, including the 6m-high weir used for the dam- dropping, has been there for 106 years and local ecosystems have adapted to its environmental impact, the effects of the scheme’s recommissioning will be minor.

“Arguably the river’s ‘natural’ state could be determined to include the weir structure,” the decision says.

But it adds had the proposal involved building a new weir, the decision may have been different because of the high value placed on the Waingongoro River by the community.

The decision also imposes a series of special conditions to ensure the recreational use of the river and the weir can be maintained. These include a minimum flow of 3000 litres of water a second over the dam at all times, regular “flushing” flows and a three-hour “recreational flow” over the dam — involving the whole of the river’s flow — up to 12 times a year at a request of canoeists. The decision also requires the bottom of the dam to be regularly monitored to ensure there is no sediment build-up that may affect the safety of the dam-dropping tourism venture.

The scheme is centred at the beginning of a 3.1km meandering loop of the Waingongoro which is known locally as the Normanby Loop.

The 33m-wide weir diverts water via a 1.8m diameter tunnel to a powerhouse, which then discharges it back into the river at the end of loop about 50m away.

Those opposing the recommissioning project included several canoeing clubs, the dam-dropping business, Fish and Game New Zealand and the Director-General of Conservation.

Recreational users submitted the Normanby Loop was an area of high importance for kayakers, canoeists and swimmers, while the weir itself was perfect for dam-dropping. Anglers argued the recommissioning would affect trout habitat in the most popular and productive trout fishery on the Taranaki ring plain.

But the committee ruled the positive effects of the recommissioning — the generation of sufficient electricity to power up to 500 homes — would outweigh the adverse effects, particularly given the weir has been in place for more than a century and local ecosystems have grown used to it.

“The adverse effects of the activity are limited to a 3.1km length of river and those effects can be adequately mitigated,” the decision says.

“While the proposed scheme is small, it has benefits that need to be recognised — and these benefits have additional weight because they are based on renewable energy.”

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(c) 2008 Daily News; New Plymouth, New Zealand. Provided by ProQuest Information and Learning. All rights Reserved.