Woodslake is perhaps the most culturally significant site in the closer Burketown locality. Traditional owners once relied on this pristine freshwater ecosystem as their water, food, cultural and recreational source. Since then pressures and impacts from road construction, pastoralist activities and other forms of infrastructure have created major erosion and sediment control problems in and around the lake. The adverse impact to water quality and general loss of biodiversity over this time, as seen through the eyes of Gangalidda and Garawa Traditional Owners, has been alarming.
For many years the Carpentaria Land Council Aboriginal Corporation (CLCAC) viewed the rehabilitation of the Woodslake as a priority project but it was not until this year, in partnership with Southern Gulf Catchments and Burke Shire Council that the vision was realised. The strategy for the rehabilitation of Woodslake, which will continue to require long-term project commitment, was structured in three focused stages.
Stage 1 – Consultation
The CLCAC contracted Dr Hugh Pringle, a renowned landscape ecologist specialising in managing landscape patterns and processes, to work with rangers and Traditional Owners to investigate and prepare a plan of management for the rehabilitation strategy. Dr Pringle used an Ecosystem Management Understanding (EMU) process to ensure Traditional Owner leadership and project direction, through the compilation of their historical and cultural knowledge and their sound understanding of the local hydrological influences impacting on the lake.
Using maps of the area rangers created overlays delineating all the uses and impacts the lake was and is subject to, from past hunting practices to current weed and feral incursion. At all times the maps and the pens where firmly in the hands of the rangers both young and old and all had stories and knowledge that prescribed from the mouth to the page. This was the EMU process in its true form.
This consultation was coupled with an extensive field survey and an aerial charter flight, which resulted in the rangers, with Dr Pringles guidance, identifying 17 areas of concern in and around the lake. Based on their level of impact the rangers then prioritised these sites for management. Larissa Lauder from Southern Gulf Catchments attended this week-long workshop presenting an appreciated funding commitment and welcomed NRM partner in this important project.
Stage 2 – Technical training / Soil Conservation techniques
It became obvious that wet season culvert discharge, cattle pads, secondary roads and tracks all played a major role in forming the gullies, gully heads, top-soil loss and general erosive nonsense that was sending vast amounts of sediment up and into the lake system each year.
Rangers received theory training in the construction of various structures to slow, spread and re-direct this angry sediment laden water. With Dr Pringles simple terminology rangers grasped the principles of the causes and effects impacting and degrading the Woodslake system.
This week culminated in the rangers delivering a presentation to the partners and community in outlining the outcomes and planning strategy for the commencement of the on-ground works.
Stage 3 – On-ground soil conservation works
The first culvert gully on the main road west out of Burketown was identified as the number one priority works site. This culvert was acting as a wet season downpipe, forcing a significant torrent of flood water to rip through the gully carrying a vast amount of sediment to discharge into the lake.
Dr Pringle accompanied by earthworks specialist Mark “Sharkie” Fran, returned to Burketown for a week to support this first stage of ground works. Burke Shire Council partnered on the project supplying heavy machinery, gun grader operators Kasey McGrath and Benny Kumsing, as well as rock supplies needed for the construction works.
Over the following weeks, with Head Ranger Billy Jackson as Project Manager, the Rangers achieved more than first thought possible, resulting in:
- The opening, grading, reshaping and battering of 100 metres of gully from the culvert discharge point, required to effectively spread the water over a wider and deeper area, dramatically minimising the force of water;
- Construction of two rock wall drop structures approximately 50m long x 1.2m high x 2m wide (set precisely on a base of geomatting) with wire mesh armoured notch openings to further reduce water force and catch sediment;
- Four grader formed ‘whoaboys’ and a check bank to either side of the old detour road to slow and control overland water flow;
- Additional works included contour ripping to the perimeter of the entire site and some minor gullies to the northwest; and
- The first of many ‘filter’ traps installed with many more required at strategic points along the gully running into Woodslake.
To look at the site on completion of these works a significant feat of engineering is evident and it is a major achievement for the Gangalidda and Garawa Rangers and the partners involved.
The CLCAC looks forward to continuing this community partnership and seeks additional funding support to initiate planned works on the next priority site.
The upcoming wet season floods will be the real test on determining the success of this initial project and will be monitored closely. However, by design, theory and the hard work involved its purpose is assured.
By Shane Bailey, Gangalidda and Garawa Ranger Coordinator.