This compartment encapsulates the wider Clifton Springs and Curlewis shoreline as shown in Figure 6-30.

Figure 6-30     Compartment 7: Portarlington to Point Henry

Much of the Clifton Springs shoreline is steeply cliffed, backed by a high plateau. There are narrow widths of sandy / rocky beach at the base. Further west towards Point Henry, the topography lowers significantly near the Sands Caravan Park. There are indigenous and cultural heritage sites along this coast.

North-east of the main settlement at Clifton Springs, there is a series of three groyne structures that extend into the bay at approximately a 60-70 ° angle to the shoreline. These were constructed to hold the beach in front of the cliffs near Edgewater Drive. The performance of these groynes is not ideal, and works have been undertaken recently to remedy issues with the centre groyne.

A number of geotechnical assessments have been carried out previously along this section of coast (Coffey, 2006; A.S. Miner Geotechnical, 2011). These have investigated the types of geotechnical hazards, slope instability mechanisms, risk and mitigation. The rate of cliff recession was determined using historical aerial images with rates ranging from 2 to 23 m over a 60 year period from 1947 to 2007 (A.S. Miner Geotechnical, 2011). Following on from these assessments, works have been carried out to address some of the instability issues.

Works were carried out in 2013 to stabilise the toe of the cliffed shoreline near the north-east (third) groyne, near Edgewater Drive. At the Dell, works have been carried out recently to stabilise the slopes and shoreline near the spring’s historic site. Some material sourced from Point Richards was used to renourish the shoreline. At the time of writing, the renourishment appears to be having the desired effect.

Further to the west, the Clifton Springs Boat Harbour and boat ramp is dredged sporadically to maintain the navigation channel due to sedimentation. Groynes were constructed either side of the harbour to aid in capturing longshore sediments to reduce the frequency of dredging required and create areas of beach. The effectiveness of these groynes depends on the direction of the sediment transport, which is primarily towards the east. The groynes are at capacity, and sand is bypassing and entering the harbour. Also, with seasonal variation, sand is also able to enter the harbour entrance directly, especially during prolonged northerlies and north easterlies. Thus, dredging is required yearly. An additional groyne was to be constructed near the tip of the rock breakwater; however, this was opposed by the local community as it was thought it may limit accretion of sand in the down-drift areas, particularly those fronting Bayshore Avenue and Clifton Street (east of the boat harbour).

Towards Curlewis and Moolap, the shoreline elevation lowers, making this area subject to potential inundation.