Yamba is a small coastal community on the northern beaches of New South Wales (NSW), Australia and is known as the “Jewel in the Crown” for Clarence Valley Council, a point which was reinforced when it won “The Best Town in Australia” in 2009. As a result, the Clarence Valley Council is keen to keep the usability and image of Yambe in pristine condition.
In early 2012, undermining in the southeast corner of Whiting Beach was exposing key infrastructure, including the footpath, road, stormwater pipe work and chamber, pressurized sewer and a car park.
Clarence Valley Council looked at a solution that could adequately protect this section while working within the restrictions of tide, fitting in well with the surrounds and providing a safe structure as it was in an area of frequent public access.
ELCOROCK® Geotextile Sand Containers were seen as an ideal solution to fit these criteria and were adopted after consultation with Geofabrics Australasia, Fisheries and Crown Land.
The installation of the structure called for a single month construction window of which only 4 hours per day were available on the beach due to tidal restrictions.
The design called for approximately 200 of the 0.75m3 ELCOROCK® geotextile sand containers laid out in a 40m long, 4.2m high structure that was integrated with a stormwater pipe exit, the installation window was considered to be quite tight to meet this, and was made worse by storm events within the window.
Clarence Valley Council devised an effective means of overcoming these time constraints by utilizing a separate site a short distance away to fill and close the containers and then placed in a tipper to be transported.
A sand pad was then built at the main site to unload the prefilled containers onto ensuring a smooth supply for placement at the site. This allowed for a full day’s work to complete this task and removed the time pressure that the tide placed on the beach access. From here the work crew could import the required containers as and when they were required to maximize efficiency of the installation.
Geofabrics played a supporting role on this project by providing expertise from both our local branch as well as the national technical team, educating the crew on best practice and instructions on operations for filling, closing, and placement of containers.
A DURABLE, READY SOLUTION
The installation of the structure was initially tricky due to geometry of the lowest point of the structure and as such had a slow start, that was further plagued by discovery of small boulders on the site that were there from a previous attempt at protection. At this low point of the site access was further reduced to only a few hours after which small waves made working on the site impractical. Once this hurdle was overcome, the work team did a fantastic job of constructing the wall within the confines of the job and within the allotted time frame.
The finished product shows a well-built ELCOROCK® revetment wall, utilizing mostly 0.75m3 vandal-deterrent containers, with a back facing of ELCOMAX® geotextile material to ensure retainment of fine material.
The structure has integrated well with the existing stormwater facilities at the location and all parties are pleased with the final outcome of the project.