Collaroy Seawall Faces First Real Test
Environmental vandalism or gross negligence?
At what point do we put an end to this insanity.
The Collaroy Beach seawall project was put to the test for the first time today with the arrival of a moderate to large east-northeast groundswell from ex-Tropical Cyclone Seth, coinciding with a king tide.
It didn't last long and within 12 hours the sand that was built up against the near finished first wall was 2/3rds washed away. It never stood a chance.
In their natural state, sand dunes are dynamic and in a constant state of flux. Building up during periods of low swell energy, while being transported into the surf zone during periods of high swell energy, acting as a buffer to the incoming surf. When a hard structure is introduced to the equation we see an increase in reflective energy and turbulence, slowing the accretion of sand while also accelerating erosion in storm conditions.
Adjacent a second wall constructed just to the north, the half finished revetment was torn to rubble with dangerous rebar, boulders and cement being washed into the surf zone.
The beach is now too dangerous to walk along and it's one big eyesore. Further to the north, sand that was built up in front of properties has been scoured away leaving an eight foot drop-off. If anyone was to slide down the edge during one of these high-tide swells there would be a high chance of being washed off their feet and dragged out to sea.
Comparing the swell to those of last year it wasn't of any major significance but it shows the futile efforts trying to protect property with a hard structure.
The only feasible way forward without wasting any more council and tax payers money to protect the properties in question is to acquire the properties at any cost and return them to a naturalised stated.
Over the coming fortnight there's a couple more swell forecast from the east-northeast and that'll really put the structures to the test.