Coir logs protect Wirraway’s natural wetlands

Erosion control logs

Project Snapshot

Back in November 2014, construction giant Daracon was engaged to develop the Wirraway residential area for Defence Housing Australia. Located in NSW’s Hunter region, Daracon was tasked with the construction of a $40M subdivision. The project included earthworks, retaining walls, road and stormwater drainage, a range of utilities work and landscaping.

The development’s elevated site overlooked a natural water corridor, which needed protecting during and after construction. For the wetland areas that ran adjacent to the subdivision, Daracon chose COIRmasta Coir Logs to act as a silt barrier.

The challenges

The Wirraway subdivision was situated alongside a sprawling natural wetland area. In the construction phases, Daracon had the challenge of working within a drainage corridor throughout wet weather periods. This included excavating 1500 sqm of fill from the corridor, which was removed and treated. Plus, with the construction of 511 lots spanning 58 hectares, it was critical to managing the substantial volume of construction silt in order to protect the natural wetland environment.

The construction phase was completed last year however a subsequent inspection noted the wetland banks needed extra protection from silt and sediment. The project managers approached the GEOmasta team and it was decided that long borders of coir logs would provide an effective barrier and protect the sensitive wetland environment.

Jaybro's solution

Jaybro’s GEOmasta landscaping team supplied 285 COIRmasta Coir Logs as an environmentally friendly solution for redirecting silt flow. Additionally, we supplied Daracon with a significant quantity of 450mm timber pegs to fix the coir logs in position.

Coir logs are also ideal for constructing check structures, managing changes in stream flow velocity, shaping channels and stabilising shorelines. They can also be stacked to form a natural barrier in areas where tidal changes or wave movement are present.

A natural planting medium for vegetation, they are manufactured from 100% coconut fibre compacted into an outer mesh of bristle coir twine. This totally biodegradable material lasts up to 5 years and is biodegradable within 5-10 years. Our 3m coconut coir logs are available in 200mm or 300mm diameter for different applications.

KEY DATA

• System Used: COIRmasta Coir Logs
• Quantity Supplied: 285 logs and 25mm x 50mm x 450mm pegs
• Install Length: 855m
• Customer: Daracon
• Time Period: July 2019
• Project: Wirraway Thornton Residential Development