Lake to be damned
Friday, 7th January, 2011
By Andrew Robertson
The future of Imperial Lake as the city’s emergency water supply is in doubt after a review found part of the dam deficient.
Country Water said yesterday the issue with the lake related to the spillway, which releases floodwater so as to prevent damage to the dam.
Group Manager Travis Nadge told the BDT the NSW Dam Safety Committee found the design of the spillway was “deficient” and needed upgrading.
He said while preliminary costings were yet to be done, the cost of upgrading the spillway so it complied would run into the millions of dollars.
“The issues surrounding Imperial Lake are pretty significant in terms of the spillway.”
He said Country Water was now investigating other options, including decommissioning the dam or turning it into a wetland, which could possibly see it once again open to the public.
“We’re just looking at designs and different options.” The lake, which was built to supply water to the city’s mines and is still on a mining lease, was a popular recreational spot before it was shut to the public in the 1980s.
It was almost re-opened about 10 years ago before public liability insurance and laws forbidding access to public reservoirs curtailed the plans.
Australian Inland, the city’s water utility at the time, spent an estimated $100,000 on landscaping, revegetating and cleaning up the lake foreshore.
Thousands of dollars worth of support was also donated in-kind by businesses and volunteers. Imperial Lake is by far the smallest of the city’s dams and is used only in times of critical water shortages.
According to Mr Nadge, water from the dam, which can hold 600 megalitres, has been accessed only two or three times for an emergency situation in the last 10 years.
But he said any decision on the lake was still months away and the public would be consulted as part of the process. “I’ve got no intention of rushing a decision.