Sandridge beach at Port Melbourne will be declared off limits for swimming today after the Environment Protection Authority forecast its water quality to be ''unacceptable'' after the Christmas Day storm.
The warning, made yesterday afternoon, came as the EPA promised that its online reports on bay beach water quality would be kept up to date over the new year holiday period, after the site failed to warn swimmers of polluted conditions during the Christmas break.
For the first three days after Christmas, the EPA's Beach Report website carried out-of-date reports advising that conditions were ''good'' at beaches that should have been downgraded to ''poor'' because of the effects of stormwater.
Sandridge, the beach between Princes Pier and Webb Dock, gained today's unacceptable rating after two bacteria tests in as many days came in above health triggers. The Port Phillip City Council will put up notices telling people not to swim at the beach today. The EPA will today decide whether to give the beach the all-clear for what is forecast to be a hot new year weekend.
The 35 other bay beaches monitored by the EPA are rated ''fair'' or ''good'' for swimming today. EPA spokesman Simon Frost said the authority always recommends beachgoers use judgment and local knowledge.
''As a general precaution, we advise people not to swim near stormwater drains, rivers, streams and other outlets into the bay during rain and for at least 24 to 48 hours afterwards.''
The EPA was forced to alter advice on its Beach Report website on Wednesday after water quality was incorrectly forecast to be ''good'' at all beaches earlier in the day, when instead 13 Melbourne beaches had ''poor'' conditions. The incorrect advice resulted from long-term predictive forecasts put in place days before because no EPA staff were rostered on for the Christmas public holiday period.
A spokeswoman for state Environment Minister Ryan Smith said he had had assurances from the EPA that a water quality expert would update the beach report website over the long weekend. ''The EPA is always looking for ways to improve how they provide information to Victorians and we urge beachgoers to use common sense and care,'' the spokeswoman said.
Environment Victoria chief executive Kelly O'Shanassy said:
''If there is a system that is meant to tell the public whether it is safe to swim or not, it should be accurate and updated every day whether a public holiday or not.''