Rosslyn Beeby June 30, 2012
Water pollution and toxic algal blooms are costing the ACT around $25.5 million a year in lost revenue caused by closures of Lake Burley Griffin, a Canberra water scientist says.
''And that figure could be an under-estimate,'' University of Canberra urban water expert Professor Ian Lawrence told a business and ecology forum yesterday.
The forum also heard Canberra had ''fallen behind the rest of Australia'' in adopting smart urban design innovations to improve city water management, resulting in increased pollution of the lake from stormwater run-off, petrochemicals and garden pesticides.
A former senior bureaucrat with the ACT Office of the Commissioner for Sustainability and Environment, Warren Geeves said Canberra's ageing and leaking sewer system urgently needed an upgrade to protect the lake's water quality.
Professor Lawrence, who co-wrote the ACT government's recent report on the lake's declining water quality, told the forum the cost of annual closures of the lake exceeded its estimated value to the national capital's economy.
A preliminary economic assessment - which included tourism, recreational use, sporting events and water abstraction charges - estimated Lake Burley Griffin injected $23 million a year into the ACT's economy. But lake closures were estimated to cost the ACT between $16 million to $25.5 million a year in lost tourism opportunities, foregone water charges and cancelled sporting events. Rowing was the hardest-hit, with annual losses estimated at around $11 million.
''The lake is Canberra's soul. We should be taking better care of it,'' Professor Lawrence said.
Mr Geeves said faecal pollution from rural and urban run-off and algal blooms linked to ''an enormous store of phosphorous in the sediments of the lake'' were the most critical water quality problems. He said one of the most cost-effective solutions to lake closures could be ''sonic destruction'' of algal blooms, rather than water mixing systems or use of aquatic plants to improve water quality. The new technology, estimated to cost the ACT $200,000 to install and test, uses ultrasonic vibrations to rupture the interior of the algae cells, preventing the algae from growing and reproducing.
One of the forum's organisers, University of Canberra environmental law expert Professor Murray Raff called for a new catchment ''super-authority'' to bring federal, NSW, ACT and local governments together to fast-track a strategy.
''There is no magic solution for fixing water quality problems in the lake. It will require co-ordinated and concerted effort across jurisdictions and agencies,'' Professor Raff said.
Management of the lake would come under the provisions of the federal government's proposed Murray-Darling Basin water reform plan, which could impose tough new water quality guidelines.
''There is a temptation to focus on lake closure protocols, but really, the problem is far greater than that,'' Professor Raff said.