Port Phillip projects

Location: Black Rock foreshore

Timing: Detailed engineering assessment and design complete by mid-2023.

Details: The Black Rock seawall and promenade was built in the 1930s.

The seawall is an historic structure and requires regular maintenance to maintain its condition. A recent detailed engineering assessment has identified the areas to be repaired and a design to repair these areas is currently being developed.

Location: Blairgowrie Beach – two sections between Inverness Ave. and Revell St, Whitecliffs Beach, and Tootgarook – between Laura St. and Kevin St.

Timing: Completed June 2022.

Details: Sections of beach between Blairgowrie and Tootgarook are eroding through natural sand loss processes.

In partnership with Mornington Peninsula Shire Council (MPSC), Capel Sound Foreshores and Whitecliffs to Cameron’s Bight Foreshore Reserve Committees of Management, DEECA has delivered over 30,000 m3 of sand to Blairgowrie Beach, Whitecliffs Beach and Tootgarook.

The nourishments will protect the beaches for the community and public infrastructure including Point Nepean Road, the campground, walking paths and power poles.

These nourishments were delivered as part of the Port Phillip Bay Beaches Renourishment Program (now closed).

Location: Sunnyside Beach, Sunnyside Road, Mt Eliza

Timing: Interim repairs to be completed by mid-2023.

Details: A rock revetment protecting the car park, water station and public toilets has been eroded. DEECA is currently analysing repair options, including rebuilding the revetment and extending it by approximately 180 metres, or relocating/retreating the car park and public toilets.

In August 2022, staff identified a failing a drainage pit behind the revetment. This has allowed water to run around the outside of a pipe, undermining and causing a hole in the revetment.

DEECA, Mornington Peninsula Shire Council (MPSC) and engineers have collaborated on remediation and future adaptation pathways for this asset. DEECA and MPSC have developed risk assessments and are currently assessing future options. DEECA has also received quotes to repair the damage to ensure the area’s short-term safety.

Mt Martha North Beach erosion management

Location: Mt Martha North Beach

Timing: Geotechnical inclinometer report complete February 2023.

Details: Beach and cliff erosion occurs at Mount Martha North due to ongoing, natural processes.

Ongoing management of the erosion presents challenges in balancing the needs and safety of beach users, beach box owners, and the responsibilities of land managers, while protecting the natural environment.

DEECA has undertaken several actions to limit the effects of erosion in the short-to-medium term, including:

• 2010: beach nourishment and construction of a 100m long revetment at the northern end of Mount Martha North beach
• 2017: coastal processes study
• 2018: construction of a temporary rock revetment to protect the base of the cliff from erosion
• 2018: options analysis undertaken to model and cost other recommended coastal structures
• 2019–2023: geotechnical inclinometer monitoring carried out quarterly
• 2021: geotechnical report.

Coastal processes are complex, and actions taken in one location can have significant, often unintended impacts elsewhere.

The primary objectives for DEECA are to maintain public safety for the Mount Martha North beach and protect the natural assets and public infrastructure.

The issue continues to be monitored closely in partnership with MPSC. Keep up to date by visiting the MPSC website – Mount Martha North Beach and Cliff.

Location: Portsea Front Beach

Timing: Major repairs to sandbag seawall completed in mid-2020.

Details: Since 2009, Portsea Front Beach has experienced significant erosion due to ongoing swell waves.

Most recently, DEECA undertook major repairs to the protective sandbag wall that was constructed in 2010. This will extend the life of the structure and provide shoreline protection for approximately 10 years.

DEECA and Mornington Peninsula Shire Council (MPSC) have conducted several investigations and works since 2010. These include:

• 2010: sandbag seawall built, and pier stabilisation works.
• 2012: pre-feasibility study into management options. Sand monitoring program.
• 2014–2016: wave modelling and monitoring investigation carried out over two-year period by Worley Parsons.
• 2014: rock seawall constructed to replace retaining wall west of Portsea jetty.
• 2016: Portsea Front Beach Options Analysis study.
• 2020: major repairs to the sandbag seawall and geotechnical investigation on cliffs east of the seawall.

Despite several investigations, no long-term option to date is financially viable or technically effective in managing the coastal hazards, while meeting community expectations of restoring the beach condition. DEECA does not have current plans to install additional structures on Portsea Front Beach.

For more information visit the MPSC website – Portsea Front Beach.

Location: Sandringham Beach, Southey Street

Timing: 

• Groyne construction - October to December 2017
• Beach nourishment - December 2021

Details: The Southey Street and Royal Avenue rock groynes have successfully anchored the sand to the beach south of the groynes, thereby protecting the most vulnerable section of the cliffs.

However, the groynes prevent some northbound sand from reaching the Southey Street beach, resulting in a loss of the beach and some cliff erosion north of Southey Street during summer.

Following extensive community consultation the Southey Street groyne was shortened to encourage more sand migration.

The groynes were modified and the beach was nourished in 2021, with more than 20,000 m3 of sand to nourish two target areas, one main area at Edwards Street Beach, Sandringham, and another at Half Moon Bay.

Sandringham is now part of the Victorian Coastal Monitoring Program.