$41.5m dam tagged for Lee Valley

BY ALICE COWDREY

The committee behind the Lee Valley dam project has expressed preference for the biggest and most expensive dam model, which comes with a price tag of $41.5 million.

Three cost scenarios for the dam have been presented to the Waimea water augmentation committee by engineering and environmental consultants Tonkin and Taylor, which recently finished the second stage of a feasibility study.

The committee's preferred model allows $4.2 million for a hydroelectricity generation set-up.

More than 50 people who gathered at the Brightwater School Hall last night were told that 70 per cent of the dam will be owned by water users in the Waimea Basin. These people will pay between $420 and $580 a hectare each year to fund the scheme's construction, depending on the number of users who join.

The remaining share of the dam would be owned by the community and will cost between $1.9 million and $2.2 million each year. It is yet to be determined where the money will come from.

Tonkin and Taylor consultancy team project manager Sally Marx said the $41.5 million cost would cover the hydroelectricity set-up, land purchase, access replacement, construction, cost of resource consents and "environmental mitigation".

"This includes a 20 per cent contingency. We are not into detail design yet, but still in a feasibility stage so there's potential for savings."

The water augmentation committee is planning to have the dam finished in four years' time.

The dam will catch water during high rainfall and release the water back into rivers in dry periods.

This will enhance the natural flow of water in the Lee and Waimea rivers during drought and recharge the underground aquifers across the plains.

The dam would provide water for an area equivalent to 5850 hectares which includes adjoining irrigable land, current and future urban and industrial water supply, and future regional water demand.

"At the moment 3800 hectares are irrigated," Ms Marx said.

The Tasman District Council would be contracted to provide the administration and management service and also guarantee the scheme debt. Users of about 1275 hectares outside the Waimea Plains will be able to hook into the supply but will need to pay more for reticulation, Ms Marx said. This includes land in the Lower Wai-iti, Redwood Valley and Rabbit Island.

The dam has potential hydroelectricity generation capacity of 6.23 GWh each year, or enough to power the entire Brightwater township.

The one-off saleable value of the hydroelectricity set-up is estimated to be between $6.4 million and $7.7 million. If the hydro component was kept within the scheme it would create a regular income and reduce the cost of the scheme per hectare by between $25 and $35, Ms Marx said.

Ms Marx said the dam will "secure the area" against a 66-year drought and improve low-flow conditions in the rivers. About 27 hectares of native vegetation will be affected, and although most is on private land, it includes four hectares of the Richmond Forest Park.

"But there will be no significant effect on wildlife," she said.

A recent survey about the dam found 94.6 per cent of people surveyed supported it.

Richmond retiree Martin Thompson said there was $30 millon spent on the Maitai Dam, and in 12 years it was not big enough. "Why not double the size of the scheme and make it worthwhile. It's never going to be cheaper than now; it ain't big enough. We just can't seem to learn from history, can we?"

Committee chairman Murray King said he took the comment as positive support.

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