- Flora, fauna and significant tree inventory wand survey
- Flora, fauna and habitat assessment and management
- Assessment of ecological significance and threat status
- Vegetation management plans (VMPs) - Environmental Risk Assessments & Management Plans
- Revegetation and ecosystem restoration
- Detailed vegetation survey
- Waterway and wetland condition assessment
- Fish Passage and Fishway Design
- Waterway habitat assessment
- Riparian crown land assessment and management
Completed Fishway Passages at McQuades Bend and Frost Crossing, Ovens River
The Warby-Ovens National Park, 240 km north east of Melbourne and 10 km west of Wangaratta provides an important connection between the alpine foothills, the Murray River and floodplain. In 2012, two entry points to the Warby-Ovens National Park were impacted by flooding. The gravel and rock crossings at McQuades Bend and Frost Crossing required upgrading, this presented an opportunity for the North East CMA to improve the waterway connectivity for fish as the crossings were a barrier to fish migration.
Water Technology, working in conjunction with Gordon Gibson Nominees and the Arthur Rylah Institute, was involved in the preparation of detailed design plans for the construction of the fishways, all the relevant approvals and construction to enable fish passage at Frosts Crossing and McQuades Bend Track at low flows, across the Ovens River floodplain.
The objectives of the project were to provide:
- Improved fish passage and floodplain connectivity at low flows at Frosts Crossing and McQuades Bend Track.
- Detailed design and construction to enable fish passage at low flows across the Ovens River floodplain at the two project locations.
- An improved crossing arrangement on Frosts Crossing and McQuades Bend Track that minimises the alteration to flow characteristics surrounding the crossing, minimises erosion potential surrounding the crossing, minimises maintenance requirements and provides for fish passage in consultation with Parks Victoria.
- Construction, site layout and supervision for both fishways at Frosts and McQuades Crossings, to be carried out in consultation with North East CMA and Parks Vic.
|Before fishway||After fishway construction|
An article on these crossing is available in Water Technology’s Waterlines
In the news:
- The Border Mail – McQuades Bend, Frost Crossing passages a win for people, environment
River regulation and the presence of instream barriers are known to impact natural river processes and the movement of fish. This can produce environmental conditions that benefit some of the most invasive species on the planet, such as the common carp, and interrupt natural migratory and breeding cycles of native fish.
The Murray-Darling Basin (MDB) in eastern Australia has over 3,600 instream barriers, which generally consist of dams, weirs, and flow regulators. Recognising the impacts of these barriers on native fish, the Murray-Darling Basin Authority (MDBA) instigated a fishway construction program (the Sea to Hume program) in 2001 to mitigate the impacts of major instream barriers on fish movement. This ambitious program has now re-established longitudinal connectivity to some 2,235 km of the Murray River, catering for the migration of native fish species within the MDB.
Catchment Management Authorities, water authorities and councils are now working towards a similar goal, to re-establish longitudinal and lateral connectivity at instream barriers within their respective jurisdictions. The North East CMA specifically is aiming to improve fish passage at a number of instream barriers by constructing fishways and fish friendly structures to facilitate passage along the Ovens and Mitta Mitta Rivers. Both riverine systems are known for their recreational fish species, such as brown trout, Murray cod and golden perch, all of which require unhindered movement to complete various aspects of their life-cycle. These riverine systems also harbour threated species such as Trout Cod and Macquarie perch, while Blackfish and various Galaxias species are also present.
Water Technology has designed fishways at three locations on the Ovens River (Tea Garden Weir, Frosts Crossing and McQuade’s Bend crossing) and one on the Snowy Creek at Mitta Mitta. The development of the designs required Water Technology to work in multidisciplinary teams and consult with local communities to ensure that their needs are also met with the design of the fishways.
Ovens River Fishway Design at Tea Gardens Creek Weir
River regulation and the presence of instream barriers are known to impact natural river processes and the movements of fish. This can often facilitate environmental conditions that benefits some of the most invasive species on the planet i.e. common carp and interrupts the natural migratory and breeding cycles of native fish.
The Murray-Darling Basin (MDB), in eastern Australia, has over 3,600 instream barriers which generally consist of dams, weirs, and regulators. Recognising the impacts of these barriers on native fish, the Murray-Darling Basin Authority (MDBA) instigated a fishway construction program (termed the Sea to Hume program) in 2001, designed to mitigate the impacts of major instream barriers on fish movement. This ambitious program has now re-established longitudinal connectivity to 2,235 km of the Murray River, catering for the migration of native fish species within the MDB.
Similarly, Catchment Management Authorities, water authorities and councils are now working towards a similar goal, to re-establish longitudinal and lateral connectivity at instream barriers within their respective jurisdictions. The North East CMA specifically, is aiming to improve fish passage at a number of instream barriers by constructing fishways and fish friendly structures that facilitate passage along the Ovens and Mitta Mitta Rivers. Both riverine systems are known for their recreational fish species, such as brown trout, Murray cod and golden perch, and all require unhindered movement to complete various aspects of their life-cycles. These riverine systems also harbour threatened species such as trout cod and Macquarie perch, while blackfish and various galaxias species are also present.
Ovens River Tea Garden Creek Weir Fishway Design
The Tea Gardens Creek Weir on the Ovens River delivers irrigation, stock and domestic water to entitlement holders on the Tea Garden Creek system. The weir is owned and operated by Goulburn Murray Water and was updated in 2016 to extend the weirs operating life and support their water supply objectives. While the update in 2016 met distribution needs it remained a barrier to fish movement.
It was identified that a fishway was required to improve fish connectivity end ecological function. The new fishway design was required to meet the following core criteria:
- Achieve fish passage without compromising weir functionality
- Meet with Goulburn Murray Water and community needs regarding safety in design
- Be resilient to flood events (including total submersion)
- Minimise future maintenance requirements; and
- Where the final design allows, include provision for PIT-tag reader installation for monitoring fish movement through the structure.
|Before||Rock Ramp Fishway Design|
|Ovens River, Tea Garden Creek Weir.|| Ovens River, Tea Gardens Weir
Water Technology has design a partial width rock ramp
fishway to replace the right side of the weir.
Water Technology has designed fishways in three locations on the Ovens River (Tea Garden Weir, Frosts Crossing and McQuades Bend crossing) and one on the Snowy Creek at Mitta Mitta. The development of the designs required Water Technology to work in multidisciplinary teams and consult with the local communities to ensure that their needs are also met with the design of the fishway.
Working on these projects Water Technology has utilised the following skillsets:
- Waterway Engineering
- Fluvial Geomorphology
- Vegetation Ecology
- Fishway Detail Design
- Project Management
- Community Consultation
Ecological and water quality experts from Water Technology and Monash University joined forces to assess the water quality and ecological processes of the Gippsland Lakes.
The Lakes have suffered recurrent summer toxic blooms of cyanobacterium Nodularia spumigena since 1985. Diatoms and dinoflagellates also commonly form blooms in the Lakes. Nodularia has the ability fix free nitrogen and is typically found during periods of low freshwater inflows in brackish waters near the inflowing rivers. Growth of Nodularia is controlled by a combination of biological, chemical and physical drivers which are impossible to simultaneously assess through physical experiments.
Whilst the key drivers of the growth of Nodularia (intermediate salinity, stratification, bottom water hypoxia and sediment phosphorus release) are well understood, there was a lack of quantitative tools to predict bloom formation and assess management options to mitigate them.
A 3-D fully coupled hydrodynamic biological ecological model was used to explore the interaction between the physical and biogeochemical controls over Nodularia blooms. The hydrodynamic model included turbulent mixing within the water column, whilst the ecological component of the model contained over 40 state variables and 200+ processes, parameterised by 176 constants to describe the biological/ecological and chemical reactions occurring in the water column and sediment compartments.
The Murray CMA needed to understand the condition of riparian vegetation for the Yanco, Colombo and Billabong Creeks to assist with identifying investment priorities for the system in the future. Water Technology and the Murray CMA developed a method for assessing the riparian condition, vegetation composition, potential threats and condition trajectory.
A limited budget allowed only 20 days to field assess 1,000km of creek network vegetation and hence we had to develop a method that was:
• Rapid enough to allow a ‘reasonable’ sample size
• Repeatable (method able to be applied by trained CMA/LLS staff and well documented)
• Useful in meeting the project aims
• Capable of assessing the key vegetation condition attributes
• Able to inform investment direction.
A range of condition assessment parameters were mapped and graphed by reach including Habitat Quality, Riparian and Instream Health, Canopy Health, Weed cover and Condition Trajectory. More than 1200 photos were taken across the project area and these were provided digitally in a GIS hotlinked project file. This allows the viewing of photographs across the project area at the click of a mouse on a map.
The final report provided a baseline condition assessment of riparian vegetation across the project area and included recommendations for future work to maintain or enhance that condition.
Water Technology has been involved in two major State wide projects assessing the condition of waterways and wetlands across Victoria for the Department of Environment, Land, Water and Planning (DELWP). These projects provide a State wide snapshot of condition to determine the progress made towards condition targets and to assist in the setting of priorities for action to improve or protect these natural assets. These projects have also been driven by Regional, State, National and International reporting obligations.
Victorian State Wide Rivers LiDAR Project
DSE recently developed a method to assess components of the Index of Stream Condition (ISC) using LiDAR (Light Detection And Ranging) in conjunction with aerial imagery. Water Technology was commissioned to provide the ground validation assessment of remotely derived riparian vegetation and physical form ISC condition metrics. This involved detailed field assessment and analysis of 200 validation sites across the 26,000km of Victoria’s ISC stream network.
State Wide Index of Wetland Condition (IWC)
More than 350 wetlands were assessed by Water Technology staff across the State in collaboration with the relevant Catchment Management Authorities. All field assessment data, mapping and photographs were collated and entered into the online IWC Data Management System (IWCDMS). This important project has provided the first State wide ‘baseline’ condition assessment of wetlands across Victoria.
The Ovens River floodplain is one of the many within the Murray-Darling Basin that has been subject to anthropogenic changes, negatively impacting on the condition of floodplain and wetland environmental assets. The lower Ovens River and its floodplain wetlands are in much better condition than many other rivers in the basin due to the absence of major water storages and extractions from the upper catchment, with less impact on the magnitude, frequency and duration of flooding. However it still has a number of issues to manage; namely vegetation clearance, pest species, the operation of the Murray River and backwatering from Lake Mulwala, and the construction of levees, channel banks and roads, some of which have disconnected wetlands from the river.
The Lower Ovens Connectivity Study was a landmark project which integrated complex floodplain hydraulics, catchment hydrology, advanced spatial analysis, ecological assessments and environmental outcomes. Detailed 1D/2D hydrodynamic models were used to understand the flood behaviour across the floodplain at a range of different magnitude flow events. Extensive condition assessments of the significant ecological assets within the floodplain were also conducted. The study identified and mapped over 380 potential barriers to flow and produced a number of highly valuable datasets which relate areas such as wetland connectivity, frequency of wetland inundation and ecological condition that could serve as a benchmark for floodplain managers across the Murray-Darling Basin. The knowledge gained from the study was incorporated into a geodatabase that linked flood behaviour to connectivity and ecological assets within the floodplain.
The study concluded that much of the lower Ovens floodplain is in excellent condition and that there are few barriers which significantly reduce wetland connectivity, with 90% of the wetlands found to be inundated on average at least every two years. The approach developed in this study could easily be applied to other river systems across the country to improve understanding of the ecological condition and connectivity of floodplains and improve management of key environmental assets. The study has developed a number of tools that will significantly expand the North East CMA’s capacity to engage key stakeholders in identifying options for improving the management of unregulated flows to key environmental assets through the design and management of environmental infrastructure.