Snowy science

The Snowy Mountains Scheme has affected the ecology of Snowy Mountain rivers and streams.

The Snowy Water Inquiry Outcomes Implementation Deed (SWIOID) 2002 is a legal instrument that the three partner governments entered into to give effect to the outcomes of the public Snowy Water Inquiry in 1998 and the corporatisation of the Snowy Scheme. The deed includes the water recovery targets for the Snowy, Murray and Snowy Montane Rivers Increased Flows programs.

Targets for the Increased Flows programs include returning the following volumes of water each year:

  • Snowy River – 212 gigalitres (GL), or 21 per cent of the average natural flow
  • Murray River – 70 GL
  • Snowy Montane Rivers – up to the equivalent of up to 150 gigawatt hours of forgone electricity generation, which equates to up to 117.8 GL.

The department is required to assess the ecological response of the Snowy River and Snowy Montane River Increased Flows. The department Snowy Flow Response Monitoring and Modelling (SFRMM) program was established in 2000 to assess the changes in river conditions that could be attributed to the Increased Flows.

Snowy Flow Response Monitoring and Modelling program

The Snowy Flow Response Monitoring and Modelling program comprises of five components. These components include:

Measurement of long term changes in environmental variables

  • Temporal changes in key variables are assessed (i) using a reference condition approach or (ii) where there is no suitable reference condition a time series analysis is undertaken.
  • The key river attributes assessed include river discharge, geomorphology, water quality, plants, water bugs and fish.

Targeted research to address specific management objectives / actions

  • Research is often undertaken over a 1-5 year time period to address specific water management questions.
  • These water management questions may relate to short term responses to specific components of the current releases strategy (i.e. spring high flows) or more strategic directions such as 'defining the role of unregulated tributaries in providing ecosystem services to regulated Snowy Montane Rivers'.

Development of models to assist with decision support

  • Models, such as hydrological, hydraulic and ecological models provide some key functions: (i) extending the predictive power of environmental data, (ii) assist with options analysis for water management decisions, and (iii) to communicate findings.

Reporting and evaluation

  • Report to the public, government and the scientific community on the outcomes of the implementation of the Increased Flows.
  • Evaluate water management strategies.

Adaptive management of environmental water releases

  • To provide scientific and technical support for the adaptive management of the Snowy River and Snowy Montane River Increased Flows.
  • Establish long-term objectives, ecological end-points and long term river recovery strategies.
  • Undertake experimental water releases to extend our understanding of environmental water delivery to Snowy Montane Rivers.
  • Co-ordination of water committees in the Snowy Mountains.

Reports

Hydrology/Hydraulics

Water quality

Macroinvertebrates

Fish

Other

Fact sheets

Snowy River Increased Flows (SRIFs)

Snowy Montane River Increased Flows

The role of tributaries

Presentations

Snowy River Increased Flows (SRIFs)

Journal articles

Brooks A.J., Russell M., Bevitt, R. and Dasey M. (2011).Constraints on the recovery of invertebrate assemblages in a regulated snowmelt river during a tributary-sourced environmental flow regime. Marine and Freshwater Research 62, 1407-1420.

Coleman, D, and Williams, S. (2016). Mobilising fine sediment in a highly regulated upland snowmelt river using hydrological scaled experimental floods. Marine and Freshwater Research, http://dx.doi.org/10.1071/MF15231

Hinwood, JB and McLean, EJ, (2014) Entrance changes in the Snowy River estuary in response to environmental flow releases. Australian Journal of Civil Engineering, Vol 12(1), Special issue on Coasts and Oceans, the Institution of Engineers Australia, 2014.

McLean, E.J. and Hinwood, J.B. (2015) Response of the Snowy River Estuary to two environmental flows, Proceedings of the Royal Society of Victoria, 125 (1).

Rohlfs, A, Mitrovic, S., Williams, S., and Coleman, D (2015). Can tributary in-flows improve the recovery of the dissolved organic carbon regime in a snowmelt river regulated by a large reservoir?. Marine and Freshwater Research, http://dx.doi.org/10.1071/MF14230

Rohlfs, A, Mitrovic, S., Williams, S., Hitchcock J., and Rees G. (2016) Dissolved organic carbon delivery from managed flow releases in a montane snowmelt river.  Aquat Sci (2016). doi:10.1007/s00027-016-0472-5.

Hydraulic modelling animation

The animation shows modelled river flows for the spring 2010 environmental flow release to the Snowy River downstream of Dalgety. The animation was derived from hydraulic modelling as part of the Snowy Flow Response Monitoring and Modelling Program.

Gallery

Images of scientists working in the waterways of the Snowy Mountains.