The future of outdoor swimming at the Canberra Olympic Pool complex is in doubt as the ACT government investigates how to stop serious leaks first detected in August 2013.
Territory and Municipal Services Minister Shane Rattenbury said about 19 million litres a year had been leaking, including from an outdoor diving pool and a children's swimming pool, equivalent to the loss of the entire volume of an Olympic size pool every two weeks.
The leaks, thought to date back to 2012, are costing about $100,000 per year.
Already more than $260,000 has been spent trying to stop the water leaking into Canberra's stormwater system.
Both pools will be closed for public use from March 31 as part of annual winter shutdown arrangements, but their reopening won't be confirmed until leak investigations and repair strategies are completed by a leak detection expert.
The government will also advertise the operating contracts for Canberra Olympic Pool and the Lakeside Leisure Centre in Tuggeranong this week, after ending the contracts two years early by mutual agreement with the operators.
The Assembly passed new laws modernising pool management in the ACT on Thursday.
Until now both pools have operated under a single management contract, but they will be split after June 30. A request for proposal periods for the contracts will open this week, ahead of a full procurement process for new management contracts.
Mr Rattenbury conceded the ageing outdoor pools at the Constitution Avenue site, built in 1955 ahead of the Melbourne Olympic Games, might not reopen if the leaks can't be fixed or their repair is deemed too expensive to the taxpayer.
The closure will impact summer swimmers as well as water polo teams, underwater rugby and the ACT Diving Academy.
"It is my preference that we can reopen the outdoor pools next summer but we have to be realistic about the possible cost, the age of the facility and the difficulty of identifying where the leak actually is and whether repairs can be undertaken," Mr Rattenbury said.
"I have serious concerns about not only the financial impact that this leak has on government budgets, but also about the environmental impacts.
"There are obvious environmental concerns due to the loss of such a large quantity of water. An initial concern raised by the Environmental Protection Authority, who identified that chlorinated backwash water may be running into the stormwater, has been remedied through changes to the backwash system that now divert expelled chlorinated water into the sewer.
The indoor 50-metre pool, health club, and other facilities will remain open throughout the winter months, with the possible exception of a number days associated with the investigative works.
Tuggeranong Pool will be closed for a period of weeks in July and August for repair works. The dates are yet to be finalised.
Mr Rattenbury said he would hold meetings with pool-user groups in coming weeks to discuss the city site's future.
The government wants to build a new aquatic centre next to Lake Burley Griffin's west basin shore as part of its City to the Lake infrastructure plan, as well as a new pool in Molonglo.
A new city stadium planned for the civic pool site and the new aquatic centre plan have both been delayed as the government faces a deteriorating budget situation caused by the Mr Fluffy asbestos buyback scheme.
"Final decisions on timing of the new pools have not been taken but certainly the Molonglo facility has a more definite timeframe of works getting underway in the 2016-17 budget year," Mr Rattenbury said,
Last year the ACT Heritage Council decided not to list the Canberra Olympic Pool site for heritage protection.