Cambridge Coastcare has been awarded a grant of $8868 by Coastwest, a branch of the WA Planning Commission, for its project titled ‘Cambridge Coastcare helicopter car-park dune restoration project’. The project aims to restore vegetation cover for approx 200m of dune fronting Floreat Beach Park south of our Coastwest 2020-1 Project. Erosion in this area is threatening infrastructure as identified in Department of Transport’s 2019 report ‘Coastal Erosion Hotspots in WA’. We plan to fence the dunes, mat bare areas, plant with native species and control wind blowing across plantings with plant shields and windbreak fencing. The helicopter car-park is the nickname we apply to Floreat Beach car-park with its elevated position overlooking the ocean between the boardwalk and the Floreat Kiosk area.
The stretch of dunes fronting the Helicopter car-park has been severely degraded over a number of years by storm erosion and by human access reducing vegetation cover. Over a decade ago, Cambridge Coastcare matted and planted the dunes along the face of the helicopter car-park, and, whilst erosion has left no trace of that work today, the well-vegetated slope of the dunes resulting from our work would have delayed erosion until storms in 2020. Human access from the car-park is a problem caused by a lack of paths due to the steep dune frontage – Town of Cambridge has recently formed and fenced a new path leading from the southern end of the helicopter car-park down to the beach to provide better access and hopefully reduce erosion caused by human access to the steep dune faces.
In a report issued in July 2019 prepared for the WA Dept of Transport by Seashore Engineering P/L, Floreat Beach is noted as one of 55 WA locations identified as ‘hotspots’ where coastal erosion is expected to impact on public and private physical assets and require management and adaptation action within 25 years. Town of Cambridge is preparing a Coastal Hazard Risk Management and Adaptation Plan (CHRMAP) which will address the risk to public and private assets from coastal hazards, in particular the Floreat Beach coastal hot spot.
Vegetated sand dunes have been identified in studies as the best and most cost-effective manner of protecting coastal infrastructure. This project should see an improvement in vegetation of the dunes after several years of management and will hopefully strengthen resistance to ocean storm damage. However it is only likely to delay (hopefully substantially) the need to move infrastructure landwards if forecast increases in sea level and weather severity prove correct.
The objective of the project is to build up wind-blown sand along the dune frontage to increase its resistance to winter storms, to deter and reduce human access to these dunes and to increase vegetation cover so as to:
- stabilise these dune areas,
- rehabilitate the areas, and
- to manage coastal erosion by preventing erosion of steep dune faces which could undermine parts of the helicopter car-park and boardwalk.
Significant erosion of the dunes took place in storms in May 2020 and removed about 2m or more of sand from the base of the sand cliffs. Any further erosion is likely to cause some collapse of these cliffs, leading to loss of parts of the car-park. Engineered solutions will involve substantial cost so, whilst it may not be a permanent solution to erosion issues in this area, wind-break and exclusion fencing followed by matting and planting will hopefully defer the need for an engineered solution for some time.
Cambridge Coastcare will:
- Install or repair exclusion fencing and install windbreaks as needed to protect approx 200m of dune frontage south of designated path CMB25 past the southern end of the helicopter car-park to a point where we hope that it will be possible to build a new beach access path to reach the beach at the end of our fenced off section.
- Install lateral fencing where needed to manage wind erosion and sand transfer into restored areas.
- Acquire matting and pins with which to secure the matting to the sand.
- Arrange for volunteers to lay and secure the matting.
- Obtain native plants to revegetate the matted areas.
- Arrange for volunteers to put in the plants with fertiliser tablets, soil wetter if needed, and plant shields.
Whilst the project is underway, weekly visits will be made to attend to any minor maintenance issues such as matting becoming loose. Note that we are vulnerable to damage to wind-break fencing from winter storms and that these may remove any sand accreted during the summer months. We are looking at the two Coastwest projects – our 2020-1 project for the surf club and kiosk area and the 2021-2 project for the helicopter car-park as taking a protracted period to achieve completion, depending on having mild winters in the short term. This is comparable to the 4-year period it has taken to make progress with the Floreat dog-beach restoration. Some dune faces in the project areas are too steep for planting at present, but this will be re-assessed in April 2022 when plans for 2022 matting and planting are finalised.