Lessons from the largest river works program in Australia; refining erosion-control construction techniques to maintain healthy working rivers. (10692)
While rivers are utilised to meet Australia’s demand for food, energy and water, it is inevitable that they will continue to experience adverse impacts arising from regulation. Appropriate river works programs are critical to maintain and enhance the condition of working rivers, such as the River Murray, to ensure they continue to provide this vital nexus into our uncertain future.
The Hume to Lake Mulwala River Works program is the largest of its kind undertaken in Australia. To date, over $20M has been invested in physical works along a 200km reach downstream of Lake Hume. The program was implemented to mitigate the detrimental geomorphic impacts of regulation arising from Hume Dam; the powerhouse of the regulated River Murray system. The works program commenced in 2000 and has been progressing ever since, making it the longest running major river works program of its kind.
The scale and continuity of the Hume to Mulwala river works program, together with contribution and strategic direction from a range of experts in the field, has allowed a considerable body of knowledge to be developed. The program has refined a range of established river works techniques and construction methods through extensive trials including engineered logjams, log revetment, pile fields and re-snagging. This is significant given that the majority of other river works programs within Australia are short-term reactive programs, limited in geographic scope and funding. This paper outlines and evaluates these techniques in detail, providing river managers with a way of accessing this information for practical implementation within a geomorphic context.
In addition to erosion mitigation and bank stabilisation techniques, other practical advice for project managers is presented. This includes advice on monitoring, undertaking condition assessments, landholders consultation, contractor engagement, working with animals (domestic, feral and wild), and utilising native plants in conjunction with river work techniques.