A problem of our own making

• Sticking drainpipes through the dunes isn’t helping the problem, just making it worse. 

CHARLIE NICHOLSON was born in North Fremantle and has been living there for the last 35 years. Along the way he had a job in coastal management up north with the Environmental Protection Authority. In today’s THINKING ALLOWED he says we should stop blaming storms for erosion at Port Beach and start thinking about how our poorly designed carparks might actually be the culprit.

MY rates are at stake in Fremantle council’s works at Port Beach, and I hope they will be well spent.

I have been keeping an eye on Port and Leighton Beaches for the last 35 years since moving back to North Fremantle where I was born. 

I have memories of Leighton Beach from my 1950s childhood. 

My assessment of what’s gone wrong at Port Beach is informed by my eight years’ experience as the EPA’s regional environmental officer in the 1980s guiding the coastal shires’ coastal management from Carnarvon to Broome – the cyclone coast where shire engineers habitually ignored the fundamental principle of coastal engineering: do not fight nature using hard structures in a soft environment, risking expensive replacement and remedial works. 

I do hope the council is not about to repeat the mistake in the existing carparks in the design of the new Port Beach carpark.

Much of the erosion immediately south of the lifesaving club building, at the path at the showers, and at the beach access north of the Coast building is due to storm water draining off the bitumen carparks into the remnant dune, scouring out the sand that should be available to buffer the sea.

Don’t blame the seas and the storms, it’s the work of previous councils that causes most of the immediate and costly problem. 

Sea level rises and the erosive effects of the Fremantle Port’s greedy sea grab are a different long-term problem to be solved. 

 • No beach erosion here, the run-off is trapped in the carpark.

The solution to these current erosion situations is not to simply dump more sand which will inevitably be eroded away by the next rain storm – at ratepayers’ cost – but to trap and infiltrate the rainwater as close to its point of fall as possible, before it builds up into an erosive force. 

Keep the water on land to recharge the freshwater aquifer and keep saline intrusion at bay! I wonder if the council knows about that aspect of coastal hydrology? 

The design of those old carparks is completely wrong. 

All run-off should be absorbed into swales in which the shade trees should be planted parallel to the beach.

The existing alignment of the parking bays and the casuarina tree plantings, surrounded by concrete chastity belts preventing any rainwater run-off from infiltrating, causes much of the beachfront dune erosion.

Council vaunts its ‘sustainability’ credentials. There is nothing sustainable about a heat-generating carpark that sheds all its precious rainwater into the ocean, costing ratepayers much money for constant beach repairs.

Definitely no drainage pipes shunting rainwater through the dunes onto the beach, eroding the sand that protects the coastline. And definitely no large lumps of rock in vain attempts to keep the sea at bay. 

I have offered and occasionally been accepted to conduct a beach walk with council staff over the years. 

Unfortunately nothing seems to come from it except the old Einstein mis-attributed saying that insanity is doing the same the same thing over and over again and expecting a different result.

  • The erosion pattern makes more sense when you view it as coming from the car park rather than the beach.

It’s time for the council to re-think its coastal mis-engineering. 

All the expensive coastal erosion studies fail to factor in carpark drainage. 

They also fail to consider cyclone storm surge. 

None of the council’s beach engineering consultants seem to have heard of Cyclone Alby and the council seems to have no corporate memory of our beaches. Some of us who have lived here do remember, you should listen to us.

If the council needs any help to ensure that the new carpark is ‘sustainable’ and won’t contribute to dune erosion, it should dig out its copy of Water Conservation Through Good Design, WA Water Resources Council 1986. It should be on the bookshelf. Check out “Water harvesting from carparks”, p64.

I conceived and steered the production of that design manual when I was the EPA regional officer on the cyclone coast. I can lend the council a copy if they can’t find it.

I would love to see an engineering design I would love to see an engineering design that satisfies me that my rates are being spent sustainably.

One response to “A problem of our own making

  1. Dear Chook, thanks for hatching my squawk about the Port carpark drainage that erodes the dunes. No response from Council. Being an un-deviced elder, I read your paper copy. I have only just discovered that you sit on an internet nest, your “Interactive” website. Unfortunately in my case you have hatched scrambled captions to the photos. First photo should have third photo caption. Third photo should have first photo’s caption. Second photo should have the caption “No beach erosion here, the run-off is trapped in the carpark.”

    Although it seems that only one blogger is interested enough to comment, I think it is important that future readers understand what I’m trying to explain if we want to enjoy our beaches in the future. Picture worth thousand words if caption correct. Can you correct the captions?

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