Environmental issues

Water

Daily bulletins

Availability

The daily bulletins are issued for ocean and harbour (Sydney Harbour, Botany Bay, Georges River and Port Hacking, Pittwater) beaches in the Sydney region only. During the summer swimming season (October to April) the bulletins are issued at 7.30am every day (including weekends). Outside of the swimming season (May to September), the reports are issued at 9.30am on weekdays only and a weekend forecast is issued at 4.30pm each Friday.

The bulletins are updated during the day as beach conditions change.

The daily bulletins are available on our website, on a recorded telephone information line (1800 036 677) and are emailed to a range of organisations including local councils, state government agencies, environmental groups and major print, radio and television media.

The daily bulletins provide predictions of pollution levels at Sydney's ocean and harbour beaches for that day and are based on rainfall in the previous 24 to 72 hours.

The bulletins contain information from a number of sources:

  • Bureau of Meteorology: air temperature, wind, swell, tides
  • Manly Hydraulics Laboratory: sea temperature
  • Local council lifeguards: beach closures due to dangerous surf conditions or pollution incidents, lagoon openings and presence of marine stingers
  • Sydney Water Corporation: pollution incidents such as sewage treatment plant bypasses and sewage overflows.

Why predictions?

One of the challenges facing Beachwatch is to provide the community with timely information on beach water quality when bacterial results are not available for 24-48 hours after sampling.

Beachwatch has overcome this problem by using rainfall to predict the likelihood of pollution at ocean beaches and harbour swimming areas. Each morning, we analyse rainfall data from a network of more than 20 rainfall gauges across the Sydney region. Pollution is predicted as 'unlikely' or 'likely' based on a known relationship between rainfall and bacterial levels developed from several years of data.

Because the relationship between rainfall data and bacterial levels is not exact, our predictions are not always correct. Our predictions err on the side of caution, so that we sometimes predict pollution as 'likely' when the beaches are clean, but rarely predict pollution as 'unlikely' when the beaches are dirty. This conservative approach ensures that the health of the community is protected.

We recommend that you also look out for the following visual indicators of pollution before entering the water:

  • Discoloured water
  • Fast flowing or strong smelling stormwater drains
  • Street litter such as drinking straws, food wrappers or leaves floating in the water or on the tide line

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Page last updated: 15 February 2013