Water Management
Snowy Flow Response Monitoring and Modelling program
The Snowy Mountains Scheme has had an impact on the ecology of Snowy Mountain rivers and streams. The Snowy Water Inquiry identified the need to increase flows to the Snowy River below Jindabyne and the Snowy Montane Rivers. The Department is required to assess the ecological response of the increased flows to these waterways.
The Snowy Flow Response Monitoring and Modelling program has been established to assess the changes in river conditions that could be attributed to the increased flows. The key river attributes that are assessed include:
- Riverflow
- Geomorphology
- Water quality
- Plants
- Water bugs
- Fish.
Other studies are also undertaken to assist in the:
- interpretation of the results from the main program
- filling key information gaps
- development of future environmental water allocations, including the generation of decision support tools for future water management decisions.
Snowy River below Jindabyne
Following construction of the Snowy Mountains Scheme between 1955 and 1967, flows in the Snowy River have been severely altered, with less than one per cent of mean annual natural flow (MANF) being recorded in the River at Jindabyne, or four per cent of MANF as measured at Dalgety, post Scheme.
To improve river health, water has been released to the Snowy River via the Mowamba River and/or Jindabyne Dam. Dependent on water savings in the Western Rivers of the Murray Darling Basin, it is anticipated that up to 21 per cent of MANF will be released to the Snowy River. The first stage of the increased flows occurred between 2002 and 2005.
Information Sheets
Four information sheets have been developed discussing the River attributes and outcomes being studied:
- River flow (PDF 247 KB)
- Physical and water quality response (PDF 890 KB)
- Water bugs (PDF 726 KB)
- Fish (PDF 593 KB)
Reports
- Response of aquatic macroinvertebrates to the first environmental flow regime in the Snowy River (PDF 2 MB). This report documents the effects of environmental flows on aquatic macroinvertebrate assemblages of the Snowy River and incorporates data collected from autumn 2000 to autumn 2005
- Hydraulic modelling of a fish barrier–Pinch Falls, Snowy River (PDF 2 MB). This study assesses the suitability of hydraulic modelling techniques to assess a possible causative factor in the decline of Australian Bass in the Snowy River
- Water quality in the Snowy River before and after the first environmental flow regime (PDF 1.2 MB)
- Changes in fish assemblages after the first flow releases to the Snowy River downstream of Jindabyne Dam (PDF 1 MB)
- Hydraulic modelling to estimate threshold discharges for sediment entrainment in the Snowy River, Australia (PDF 1 MB)
- Field manual for identifying and mapping channel units in the Snowy River, Snowy River Recovery: Snowy River Flow Response Monitoring (PDF 1.8 MB)
- Impact of the 2002-03 wildfires on the macroinvertebrate assemblages of the Snowy River catchment (PDF 1 MB)
- Representativeness and efficiency of a laboratory sub-sampling method for the Snowy River macroinvertebrate samples (PDF 666 KB)
Snowy Montane Rivers
The increased flows to the Snowy Montane are specified in the Snowy Water Inquiry Outcomes Implementation Deed (SWIOID) and the Snowy Water Licence (Schedule 3, Part 5, Table 1).
Increased flows are to occur from five Montane River release points, these being:
- Murrumbidgee River at Tantangara dam
- Goodradigbee River at Aqueduct
- Geehi River at Geehi Dam
- Snowy River at Gungarlin
- Snowy River at Perisher/Rams Flat.
When the water becomes available these increased flows will be the equivalent to 118 gigalitres per year. Like the Snowy River below Jindabyne, these releases are also dependent on water savings in the western rivers of the Murray–Darling River.
The first stage of increased flows have commenced in the Goodradigbee River and the Murrumbidgee River below Tantangra Dam. The Department has commenced ecological field studies in some of these Montane River systems.
Reports
Expert panel environmental flow assessment of various rivers affected by the Snowy Mountains Scheme (PDF 4 MB).
Snowy Scientific Committee
The Snowy Scientific Committee was established in 2008 by the NSW and Victorian Governments under the Snowy Hydro Corporatisation Act 1997. The role of the Committee is to advise the NSW Government on the regime for the release of environmental flows from the Snowy Hydro Scheme.
The independent, six-member committee will produce an annual public report into catchments affected by the Snowy Mountains Hydro-Electric Scheme, such as Lake Eucumbene, Lake Jindabyne and Tantangara Reservoir.
In October 2008 the Snowy Scientific Committee completed a report into the adequacy of environmental releases to the Snowy River (PDF 285 KB) downstream of Jindabyne Dam from 2002 to 2008.
In February 2009 the Department of Water and Energy prepared a Response to the Snowy Scientific Committee report on 'Adequacy of environmental releases to the Snowy River' (PDF 172 KB)
In June 2009 the Committee released its report Environmental Releases from Jindabyne Dam: Recommendations for 2009-2010 (PDF 276 KB). The Department has incorporated the Committee's recommendations into Snowy Hydro's Annual Water Operating Plan for 2009/10.
More information about the Committee including membership details can be found at www.snowyssc.org.
On this page
- Snowy Montane Rivers
- Snowy Scientific Committee