The Northern Beaches Council has undertaken a mammoth effort to build temporary roads and sand walls to help protect the houses at Collaroy from further storm and high tide activity following this month's East Coast Low.

Before work could start on rebuilding the Collaroy beach front 1,200 tonnes of rock were placed at the end of a number of streets to protect their integrity and allow heavy machinery to access the beach front.

With access established, staff have been able to arrange for approximately 1,600 tonnes of sand to be brought into the area to construct a 110 metre long, five metre high wall made of specialised sand bags. Each sand bag is 2.5 cubic metres and weighs approximately 4.5 tonnes.

In addition to the sand bags, a five metre high sand berm has been constructed as a buffer while the wall is constructed.