Suburban backyard green waste helps rehabilitate Kogan Creek mine levee

Kogan Creek

If you live in South East Queensland and love gardening there’s a chance your raking, mowing and clippings may have ended up in the mix of organic materials used in the recent rehabilitation of a levee at CS Energy’s Kogan Creek Mine.

The Kogan Creek Mine supplies black coal to the neighbouring Kogan Creek Power Station, which is also owned by CS Energy.

In late 2018, the levee walls surrounding the Kogan Creek Mine pit were raised and extended to deliver increased flood protection to the mining operations.

Following the revegetation of the new levees, the Kogan Creek Environment team applied the lessons learned from that project to revegetate the old mine levee.

Trucking in composted green waste from local councils in South East Queensland is just one of the innovative techniques employed for the project.

Kogan Creek Acting Environmental Business Partner Lisel Dingley said they developed a custom plan for the rehabilitation, working with Ipswich based business NuGrow Revegetation Services.

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“It was the first time we have incorporated native species into site rehabilitation – not just a native species but those that are locally endemic to the area,” Lisel said. They were collected by a custom built quad bike native seed harvester from the local area.

“We also included a wide variety of grass and legume species. Legumes naturally provide nitrogen to the soil, which keeps plants growing and enables them to create their own nutrient cycling system, reducing the need to add fertilisers.

“And we took the composted green waste from local councils, so if you live in Brisbane or Greater Ipswich, your yard work could have ended up on the levee.”

Lisel said the team reduced rehab costs by working directly with the subsoil layer, turning it into topsoil with compost and by adding microbes – kind of a probiotic for soil – to hydrocompost.

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It wasn’t until the rain in mid-January 2020 that all this work came to fruition – within a week the levee was green and thriving, thanks to all the preparation in the months before.

Since the rain started on January 16 the area has received 250mm, which is more than they received in 2019 alone.

“2019 was a terribly dry year for the region, with only 221mm received, and 127mm of that was in March 2019,” Lisel said.

“Compare this to an average rainfall of 630mm and you can get a sense of how tough the region has been doing it, and how essential rainfall was to help bring this project to life.”