18 Aug Simon Williams
Simon Williams, Australia
Simon Williams has been managing the Snowy Water Initiative (SWI) for over 17 years, and been instrumental in the (i) development of Snowy flow science, (ii) operational water management, (iii) inter-governmental water governance, and (iv) has been a key figure in the interaction with the local and Aboriginal communities. Simon has had the unique opportunity to develop a new approach to environmental water management within an experimental adaptive management framework. Additional to his responsibilities on the SWI, Simon has directed and managed environmental water management and flow science programs in NSW on behalf of the NSW Government for over 20 years.
Presentation Title: The Snowy River flows again: Ecological process the basis for flow based river rehabilitation in the Snowy River.
The completion of the construction of the Snowy Hydro-Electric Scheme in 1967 resulted in the flow of the iconic Snowy River being reduced to 1% of Mean Annual Natural Flow (MANF). This reduction in river flow resulted in significant deterioration in river processes and thus river health. In order to reinstate these river processes and improve the health of the iconic Snowy, the Snowy Water Initiative (SWI) was developed by the three partner governments (i.e. Victoria, Commonwealth and NSW) and Snowy Hydro Limited (SHL). In 2002, the SWI partners agreed to re-instate 21% of the MANF (i.e. 212GLy-1) in the Snowy River, but this initiative required some significant changes in policy, legislation, infrastructure, scientific understanding, management paradigms and community involvement. The program attempts to develop a “smaller but healthier montane river within the former channel of the Snowy River”, and has implemented some very novel components. These include a flow regime based on the hydrology of a reference montane river, using hydrological flow scaling, and 21% of MANF; complementary flow management using tributary releases to reduce a-seasonal warm water by 4-8oC during autumn, and the delivery of basal resources of dissolved organic carbon and dissolved silica to provide energy for aquatic food webs; reinstatement of a high flow regime with five high flow events a year which have improved the in-channel habitat of the Snowy River; peak high flow events named by the Aboriginal communities of the Snowy Mountains, as a mechanism of cultural recognition of the first Australians and their link to rivers; management of the riparian zone, including the removal of exotic woody weeds, to allow improvement in the effectiveness of environmental water releases; and developing social and economic opportunities for the regional communities using the previous investment in the Snowy River by government.