New Zealand Needs to Plan Dam Busting Says Consultant

New Zealand should be looking seriously at "dam busting" techniques, according to a Dunedin-based environmental consultant.

Bill Chisholm, manager of Chisholm Associates, said, following a six week study-tour of the United States to see "decommissioning" of dams, he was convinced New Zealand should be planning now for the removal of dams that inevitably would reach the end of their life. Technology in removal of dams in the US had considerable application to New Zealand, he said.

"In New Zealand there are many water supply, irrigation, hydro electricity and other dams, all which have a use-by date. There is a right way and a wrong way to approach their eventual removal.

The right way was to assess environmental issues and costs now. This was particularly important for the security of people who had aging dams upstream of their homes. The wrong way is to wait until environmental problems become apparent and then start arguing amongst each other as to whether dams should be removed and who is going to pay the clean-up costs.

Costs, both monetary and environmental, of decommissioning dams were often extreme, and should not be loaded on to future generations. Two dams on the Elwha River in Washington State, 70-80 years old and about the same size as Dunedin's Waipori dams, were scheduled for removal in five years time. The cost of environmental clean-up after decommissioning is calculated at over (NZ) $100 million.

"Basically, their grandfathers got the electricity, and now this and future generations have to pay the clean-up bill. The laws of compound interest are such that if we start planning for it now, future generations will have the money allocated and issues sorted out by the time the dams needed to come out," said Mr Chisholm.

In the light of current power reforms and transfer of assets, it was vital utility companies ensured they were not buying aged dams which could be a big financial burden to remove.

Mr Chisholm studied dam removal on both large and small dams in Wisconsin, Idaho and Washington. In Washington, two small hydro dams, and four dams larger than Benmore in the MacKenzie country, are earmarked for removal. Over 1000 small mill dams in Wisconsin were due for removal.

Contact:
Bill Chisholm, Chisholm Associates,
PO Box 5627, DUNEDIN.
Phone/fax (03) 4770215.
Email: bill@chisholm.co.nz