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 NSW Office of Water is required to assess the ecological response of the Snowy River and Snowy Montane River Increased Flows. The Office of Water 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.

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)

Environmental water allocations to the Snowy River 2002-10 and constraints to Recovery.
This presentation was presented at the Australian Society for Limnology in 2011 (Stage 3).
Response to environmental flows in the Snowy River and factors limiting Recovery.
This presentation was presented as a key note address to the Australian Water Association.
Snowy River and Snowy Montane River Increased Flows.
Implications for environmental water delivery to the Snowy River Estuary.

Response of periphyton to environmental flows in the Snowy River below Jindabyne Dam.
Relating vegetation response to flows using aerial photography and hydraulic modelling, Snowy River.
Functional responses to environmental flows: Linking benthic metabolism and dissolved organic carbon in the Snowy River.
Can tributary flows improve dissolved organic carbon delivery to a regulated snowmelt river?
Habitat response to a flow release, bushfire and flood in the Snowy River below Jindabyne Dam.
This presentation was presented to the The Australian Society for Limnology Thredbo Conference 30 Nov – 2 Dec 2010.
Thermal and chemical stratification response to environmental flows in the Snowy River.

Snowy Montane River Increased Flows (SMRIFs)

The impacts of the Snowy Mountains Scheme on the invertebrate assemblages of the Montane Reaches of the Snowy River.
This presentation was presented at the Australian Society for Limnology in 2009 and describes the impact of the Snowy Scheme below Guthega Dam and Island Bend Dams.
Preliminary results from the spring 2011 flows to the Murrumbidgee and Snowy Rivers.
Presentation to a joint workshop with ACTEW, SHL, NOW and the community in March 2012 (Stage 3).

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.

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.

Images

Images of scientists working in the waterways of the Snowy Mountains. Click on the image to view or download larger version.

Autosampler Water quality sampling Upper Snowy
Topographic survey Topographic Thredbo River at Cascades fire Trail
Thredbo River Spatial analysis Snowy Delegate junction spring 2011
Sediment sampling Loggers Logger download
Jindabyne Dam Hydro-survey Hydro-Survey
Freeze core Drift sampling Cultural Water
Snowy Science Foodwebs Fish sampling Willis
Periphyton Periphyton Periphyton

A tour of the Snowy River

Take a trip down the Snowy River from the unregulated montane reaches via Guthega Dam, Island Bend Dam and Jindabyne Dam to the river mouth at Marlo.

The following presentation contains a series of photographs taken at key locations along the Snowy River by staff from the NSW Office of Water and the former Southern Rivers Catchment Management Authority (now Local Land Services).