This in from the NCA:
The National Capital Authority advises parts of Lake Burley Griffin are closed to primary contact activities following a sewage leak at Yarralumla Bay.
Yarralumla Bay, Yarralumla Beach, Weston Park East and Black Mountain Beach are closed to recreation activities that involve whole-body water contact or submersion of the head.
The NCA will monitor water quality and will re-open the areas as soon as clear test results are received.
Warning signs will be posted around the exclusion areas.
More information will be posted on this site as soon as possible. We apologies for the inconvenience.