Long term coastal hazard report delivered

The City of Stirling has released its draft Coastal Hazard Risk Management and Adaptation Planning (CHRMAP) report, with some areas along the coast designated at extreme risk of coastal erosion subject to the City adopting adaptation measures around as early as 2045.

A CHRMAP is a strategic, long-term plan that guides the response to existing and potential risks of coastal hazards, assessed at 10-, 25-, 50- and 100-year horizons.

Beaches, dunes, jetties, footpaths, community spaces and amenities, services, utilities and major infrastructure (such as West Coast Drive) are at risk from coastal erosion and inundation hazards over the next 100 years, with risk increasing as projected sea level rise takes effect.

Mayor Mark Irwin said the report highlights the state of Western Australia’s coastline based on the latest scientific data and geophysical investigations. It makes several recommendations, including:

• establishing a fund for ongoing coastal adaptation and management
• exploring long-term adaptation measures for land expected to be at risk of coastal erosion by 2122, which contains major infrastructure such as:
  • West Coast Drive
  • The Esplanade, Scarborough carparks and the Whale Playground
  • Scarborough Amphitheatre
  • Scarborough Beach Pool
  • Scarboro Surf Lifesaving Club
• immediately implementing soft protection measures, such as dune restoration and sand-fencing
• conducting targeted beach nourishment of beaches that are vulnerable in the short term
• investigating the implementation of engineered measures that will help keep nourishment in place, such as nearshore reef(s) at Watermans Bay and Mettams Pool, and groynes at Scarborough Beach
• initiating a long-term coastal monitoring program incorporating ad-hoc storm and metocean monitoring, coastal asset condition assessments and geological risk monitoring.

“The City’s foreshore reserves support a variety of recreation, conservation, and commercial land uses, including substantial built infrastructure close to the shoreline,” he said.

“West Coast Drive, Trigg and Scarboro Life Saving Clubs, cafes, playgrounds, footpaths, and several carparks will all be subject to the impacts of coastal hazards at present or into the future, so the CHRMAP explores what measures could be taken to mitigate these impacts.

“At the 2022 COP27 climate change conference in Egypt, the nations of the Pacific asserted that a disaster recovery and mitigation fund needs to be established, and that contributions from all major polluting nations of the world was the only equitable way of dealing with the negative consequences of climate change.

“For the same reason, it would be inappropriate for coastal local governments like the City of Stirling to bear the full burden of adapting, mitigation and recovering from climate change-induced sea level rises and inundation events.

“This is not about protecting expensive beachside properties; the research makes it very clear that Australia’s coastline, our beaches, our reefs, our community assets, our public spaces, our dunes and native vegetation will be under threat long before sea level rises start to affect major coastal road infrastructure and homes.”

The CHRMAP report outlines actions under an adaptation hierarchy (avoid, retreat, accommodate, protect) and in line with triggers rather than set timelines to activate those adaptation pathways.

“This shows in stark terms the sheer volume, scale and complexity facing coastal areas in the future and why funding and planning are now essential to best protect the coastal assets that our community values,” Mayor Irwin said.

At the June 2022 Australian Local Government Association (ALGA) annual conference, Mayor Mark Irwin moved a motion calling on the Federal Government to provide funding to local governments who will need to prepare coastal areas for the increased risks of a changing climate. It was unanimously supported.