Como Beach is showing more storm damage, just from the small events so far this season. You can click here for some photos that show existing and imminent collapse and erosion. I have included some explanations of how erosion happens, where relevant.
This is of serious concern beyond the City of South Perth, due to proximity to the freeway, a vital link in WA's economy. Storm damage here could stop car and train travel. The City of South Perth has been able to fund minor works. This entire section of the Swan river needs much more protective engineering.
The photographs show that waves and ripples extract fine sandy material from behind the protective limestone walls, drawing the grains out the drain holes and spaces between blocks, allowing collapse of the limestone blocks. The vertical walls are hit by the full energy of waves. Limestone blocks at the base of the walls are being drawn out, making it likely that sections of wall will collapse. There are alternative wall designs that would allow energy dissipation and less destruction. Funding for better protection is important to the economy of WA.
Erosion is also taking place in the Cloisters Reserve section, between the Canning and Mount Henry bridges. Sandbags have been placed as a temporary measure to prevent damage to the cycle path.
With the very large number of cyclists now using this path to and from the City, damage to the path at both of these locations can hinder many people getting to and from work. See blog below, about South Perth- Cycle City, to see how popular this method of transport is becoming.
