Blackmans Bay Beach South

Blackmans Bay Beach has been given the all-clear

Council’s water quality task force has carried out significant work over the last two years and we are now in a position where the public health advisory signage can be removed and are confident that the water quality is and will remain good for swimming.

This has been a priority issue for us with a strong focus on public health and stormwater management to ultimately ensure that the high community value placed on recreational use at this site can be restored.

Council worked closely with the Department of Health and submitted details of all actions undertaken to date for their consideration and support prior to lifting the public health advisory.

Investigations

Council’s investigations and actions have included:

Extensive monitoring program

An extensive monitoring program has been undertaken since November 2018 involving five marine sites and four stormwater outfalls. Since July 2019, a considerable improvement in results has been demonstrated.

Source tracking

A number of source tracking initiatives have been completed at Blackmans Bay.  This has included DNA phylotyping, sterol sampling, sand sediment sampling, and the use of ammonia testing.  The increased presence of seagulls has been reviewed with no confirmed indication that they are a significant contributor to water quality at the site.

Stormwater management

We have given an increased focus on stormwater management and appointed a permanent full-time Stormwater Investigation Officer.  A vast amount of work has been done in identifying and rectifying domestic cross-connections, infrastructure failures, and response to sewer spills.  Two low-flow diversions have been installed at southern and middle beach stormwater outfalls.  These divert dry weather low-flows from the stormwater system to the sewer and only bypass and discharge from the outfall during periods of rainfall.

Communication and engagement

Working collaboratively with TasWater, the Derwent Estuary Program (DEP), the Department of Health and the Environment Protection Authority (EPA) on source tracking and joint investigations has been critical to the success of the work.  Strategies have been developed for proactive and integrated management approaches to recreational water quality.

Where to from here

We will continue to monitor the stormwater outfalls, identify and investigate any issues in the catchment, and work collaboratively with relevant agencies.

Our weekly sampling program will start in November 2020; a month before the official start of the summer sampling season. We are also looking at appropriate signage around stormwater outfalls.

Whilst we are unable to give the site a long-term grading at this stage (as that is based on five years’ worth of data), our extensive monitoring program has demonstrated that this end of the beach has returned to having good water quality at this time.