FAQs

Wattle Range Council, District Council of Robe, and District Council of Grant are undertaking a process to develop coastal adaptation strategies for 11 townships located in the Limestone Coast region. The Limestone Coast Local Government Association, the Coast Protection Board, and Kingston District Council are also stakeholders in this project.

The District Council of Grant will be specifically focusing on investigating adaptation strategies for the following townships:

• Carpenter Rocks;
• Pelican Point;
• Blackfellows Caves;
• Nene Valley;
• Cape Douglas;
• Port MacDonnell;
• Racecourse Bay;
• Eight Mile Creek; and
• Donovans.

Adaptation seeks to proactively manage or avoid harm or make use of beneficial opportunities. This process recognises that careful planning combined with a forward looking approach can reduce economic losses and response costs, preserve biodiversity, and provide a strategy to maintain the long-term viability of coastal communities. 

There are many different options that are considered during the adaptation planning phase and not all are appropriate for each location or context.

Natural coastal processes such as short- and long-term erosion and inundation shape coasts. These processes are often referred to as coastal hazards when they impact on coastal values or uses. These values may be environment, or related to our use of the coast, such as for settlements or infrastructure. Coastal hazards considered in this adaptation planning project include coastal erosion, temporary inundation and permanent inundation. Improving our understanding of coastal processes and expected changes in climate allows us to be better informed to make decisions on short term actions, and plan for the future.

Coastal hazard risk is the potential for coastal hazards to impact on things we value, where the outcome is uncertain. To assess risk, we undertake a Risk Assessment. 

A Risk Assessment is a systematic process of evaluating the potential risks (likelihood and consequence) of coastal hazards, helping to inform a risk management response and adaptation actions.

Likelihood x Consequence = Risk

Temporary inundation is the flooding of low-lying coastal land due to a locally elevated sea level (storm tide) combined with waves impacting the coast.

Permanent inundation occurs when low-lying areas become regularly inundated as part of the regular tidal cycle, up to and including the Highest Astronomical Tide.

Erosion can occur when winds, waves and coastal currents shift sediment away or along the shoreline, sometimes just offshore. Short term erosion (storm bite) is often associated with big storms.

During calm conditions, wind and waves transport sand onshore, building up the dune. For a stable beach, a lot of the sand moved offshore in a storm will eventually move back onto the beach.  

In some cases, changes in sediment supply or climate conditions (such as bigger or more frequent storms), means the beach may not rebuild fully between storm events. With less sand retained on the beach over time, long-term erosion (recession) may occur. The shoreline position then tends to move landward.

Over geological timescales (thousands of years), softer sediments are eroded away, exposing hard rocky coasts. These coasts are common throughout the region. 

Hard rock cliff slopes are susceptible movements such as cliff falls that may be initiated by a combination of surface processes (rain, surface runoff) and/or due to marine influences at the base of the cliff (e.g. toe undercutting). Hard rock erosion can occur with little or no warning. Where a sandy beach is ‘perched’ on a rock platform at the base of a cliff, increasing sea levels and wave energy often result in sand loss, due to limited sand volumes and little to no sand supply, as well as increased wave reflection off the rocky coast. 

Some rocky coastal areas have softer, more erodible rock. These coasts can be more vulnerable to erosion from both surface processes and cliff toe undercutting. Erosion of soft, rocky coasts can occur as both cliff falls and slumping (material movement down its slope). Unlike sandy coast, rocky coasts do not ‘recover’ after erosion. However, they also tend to erode at a slower rate.