REJUVENATION IN THE WAKE OF DESTRUCTION

Formerly known as Granada TV Productions, ITV Studios Australia is the Australian arm of the UK TV company ITV studios. The studio has produced a variety of Australian TV shows including Dancing with the Stars, Australia’s Next Top Model, Talkin’ ‘Bout Your Generation and The Voice Australia.

In March 2017, Cyclone Debbie swept through the Studios’ site, greatly impacting the surrounding landscape and hindering future filming. With a limited timeframe before the filming of an upcoming show commenced, Australian environmental and landscaping service Total Environmental Concepts (TEC), in conjunction with Riparian Management Services, was engaged to repair the damage on two creek areas across four stages.

STAGE 1 | UPSTREAM FROM BRIDGE

Up the creek from the bridge at the area required the removal of approx. 2000 tonnes of river rock with 20 tonnes of imported rock groins to be placed, which will redirect the water. This stage also included the placement of logs in the creek bank, and the removal and construction of a new bridge.

STAGE 2 | TRIALS LAKE

Trials Lake is a concrete lined pool that was constructed in the bed of Dungay Creek in the early 2000s as part of the set used for filming. The flooding caused by Cyclone Debbie moved significant quantities of bed material into the pool. Erosion downstream of the pool crest wall also developed since floods from 2013.

TEC was tasked with restoring the pool to its original condition by removing the accumulated bed material. the accumulated bed material – silt, gravel and larger cobbles – were removed by a small excavator and by hand as the concrete lining is fragile. A pump located upstream released low-flor water around the works site to below the crest wall.

3000 tonnes of the silt and river rock material that flooded Trails Lake was removed and onsite creek rehabilitation works repaired the damaged area. This proved challenging as the palm trees provided small working space.

STAGE 3 | CASCADES

TEC was engaged to stop the erosion of the righthand bank downstream of the Trials Lake Crest wall. The team needed to create a constructed cascade to convey water from the Trials Lake to the natural channel downstream and, in doing so, repair the current erosion that undercut the right-hand crest wall of the lake.

The bank revetment was done using graded quarry rock with a geofabric underlay. The bank was shaped as required to position the geofabric. The upper bank batter was immediately revegetated in order to get cover on the erosion-prone surface.

STAGE 4 | NEW STAGE

The first order stream needed to be positioned into its former channel in order to protect the film set structure and nearby road, and allow for the rehabilitation of a newly formed gully system.

Four main components were proposed:

1. Rock revetment of the right bank at and downstream of the film set
2. The construction of a log training wall to re-establish the right bank commencing at the avulsion breakout point
3. Revegetation of the right bank to secure the creek’s position in the longer term
4. Backfilling of the gully system with bed material (gravel and cobbles) that had accumulated within the nearby Trials Lake on Dungary Creek

The revetment work was constructed by TEC using graded quarry rock with a geofabric underlay. The rock was carefully placed with existing large boulder worked into the structure.

The log wall consists of two tree trunks placed one on top of the other.

The creek had broken out of its natural course and severely eroded the outer creek surrounds. The work detail was for the use of rocks to protect the embankment and build a log wall to redirect the creek to erode in natural course.

TEC’s plan required logs to be recessed into a shallow trench with logs driven into creek beds on both sides and then bolted together under tension, allowing the deflection of water back into the centre of the creek.

The outside of the creek bed was lined with geofabric fill. Material and soil was added to revegetate and reinforces the outside of the bed.

Contact Total Environmental Concepts via the links below to find out more about this project and discover how it can help you with your revegetation project.