WATERLINESIssue 3 2017Waterways, weeds and wetlandsAustralian Water Environments joins Water TechnologySTOP PRESS:2 : WATERLINES : ISSUE 3 2017October 2017 marks the tenth anniversary of the addition of waterway management and ecology to Water Technology’s services. This was an important phase in our company’s evolution, as the introduction of these skills complemented what was then our more traditional water quantity and water quality capabilities. This provided us with a greatly enhanced capability to assist our clients overcome the on-going challenges and often competing demands of managing their catchments and waterways. As such, it is appropriate that this issue of Waterlines should focus on some of our more recent waterway and ecological projects where we have been working with our clients to provide expert advice and assistance in managing complex ecosystems.Whether it is studying urban bushland billabongs, monitoring wetlands or designing new fishways, the range of integrated and multi-disciplinary skills required by these projects highlights the depth and breadth of experience that can now be brought to complex water management challenges by Water Technology.Some of the main articlesthis in that issue may be of interest include:• Fishways for reducing barriers to fish migration• Waterway and geomorphic assessments in Queensland• Iconic wetlands of the Lower Ovens floodplain• Aquatic weed assessmenst• New HydroNET and Guardian (Disaster Management Application) collaboration• Urban bushland ecology and integrated water managementThank you for taking the time to read Waterlines. Please do not hesitate to contact me or any of the Water Technology team if you require any further information.ANDREW McCOWAN - Managing DirectorWelcome to the latest issue of Waterlines WATERLINES : ISSUE 3 2017 : 3Since European settlement, major land use changes have occurred across many catchments in South East Queensland. The clearing of land, changes to riparian vegetation and consequent increased catchment flows have resulted in greater erosive power in the waterways. The investigation and assessment of erosion and stability issues within waterways across South East Queensland and the recommendation of mitigation options to stabilise streambank erosion has been an important part of a variety of recent projects conducted by Water Technology.Key projects have included:• Waterway Crossing Assessments Expert review of bridge design and erosion protection for 6 sites along the Toowoomba Second Range Crossing involving geomorphic assessments and other advice. • Lockyer Valley Sub-Catchment Assessments Geomorphic condition assessments and management recommendations for 9 sub-catchments in the Lockyer Valley. • Bank Stabilisation Design Geomorphic and hydraulic assessments of sites along the Caboolture River for bank stabilisation to offset nutrient inputs from an upstream sewage treatment plant. Waterway and Geomorphic Assessments in QueenslandContact Michael Cheetham michael.cheetham@watertech.com.au +61 7 3105 14604 : WATERLINES : ISSUE 3 2017Managing aquatic weeds is a challenge in many regions which requires ongoing vigilance in the identification of impacted waterways and the implementation of targetted management plans and strategies to control the weed infestations.Cabomba is listed as a Weed of National Significance and is regarded as one of the most invasive aquatic weeds in Australia due to its potential to spread, and subsequent economic and environmental impacts. Cabomba is a submerged aquatic plant that grows quickly, reproduces readily and establishes in new locations via stem fragments that break from the parent plant. Aquatic habitats are damaged when infested, with Cabomba competing against and outgrowing native vegetation, displacing native fish and invertebrate populations and impacting recreational use of waterways.Isolated infestations of Cabomba were first identified in Lake Benalla, Victoria, in 1990. By 2009, the weed was well established in the Lake and had also been carried down the Broken River, infesting Casey’s Weir Pool some 12km downstream. Jamie Kaye has completed six comprehensive Cabomba survey and mapping audits of the Broken River system since 2010. The assessments are assisting the Goulburn Broken Catchment Management Authority understand the effectiveness of control methods, the rate and extent of spread, and how best to control weed throughout the system.For more information about the impact of Cabomba or to find out more about waterway and riparian vegetation assessment, mapping and management contact Jamie.Aquatic weed assessment in Lake Benalla and the Broken RiverContact Jamie Kaye jamie.kaye@watertech.com.au +61 3 5721 2650 WATERLINES : ISSUE 3 2017 : 5The Lower Ovens floodplain, in north-east Victoria, is one of the healthiest in the Murray Darling Basin largely due to relatively natural flow regimes. It still has many issues to manage, including vegetation clearance, exotic pest species, operation of the Murray River and backwatering from Lake Mulwala. Constructed levees, channel banks and roads have also disconnected wetlands from the river.In 2014, Water Technology completed the Lower Ovens Connectivity Study, a landmark project which integrated assessments of complex floodplain hydraulics, catchment hydrology, ecology and environmental issues all underpinned by advanced GIS based spatial analysis. Further work has recently commenced on theL ower Ovens floodplain to implement several of the key recommendations from the original study, including:• Commencing a monitoring program of selected wetlands to verify the water regime and inundation frequency. This has involved the installation of gauge boards or water level pressure sensors on 15 wetlands with a good geographical spread and a range of commence-to-flow thresholds. • Capturing new bathymetric survey to improve the accuracy of modelling in areas where survey data was previously limited. • Updating the Lower Ovens geodatabase, developed as part of the original study, which contains a wealth of information related to the ecology, hydrology and hydraulics of the Lower Ovens floodplain. Significant winter rainfall provided the first decent flow events system the in since the monitoring program began. Data will be gathered in coming weeks as water levels allow and beused to verify the findings of the original study regarding the water regime and wetland inundation frequency. Water Technology is proud to partner with the North East Catchment Authority in helping to improve and maintain the health of this iconic Victorian floodplain. Iconic Wetlands of the Lower Ovens floodplainContact Julian Skipworth julian.skipworth@watertech.com.au +61 3 8526 08006 : WATERLINES : ISSUE 3 2017Fishways: reducing barriers to fish migrationRiver 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 MacquarieP erch, 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. Contact Julian Skipworth julian.skipworth@watertech.com.au +61 3 8526 0800Contact Julian Martin julian.martin@watertech.com.au +61 3 5721 2650Contact Jamie Kaye jamie.kaye@watertech.com.au +61 3 5721 2650 WATERLINES : ISSUE 3 2017 : 7Frost Crossing: BeforeFrost Crossing: AfterMcQuades Bend: BeforeMcQuades Bend: After8 : WATERLINES : ISSUE 3 2017Integrated ecological, hydrological and hydraulic assessments for improved bushland management plans.An urban refuge WATERLINES : ISSUE 3 2017 : 9Bushland reserves in urban areas can act as refuges for native flora and fauna. These are often actively managed by Councils to protect and promote biodiversity. Councils must control many threats to such areas including weeds and feral animals to protect native ecosystems. In growth corridors, many of these reserves are inherited by Councils as offset reserves, gifted to local government to compensate for vegetation loss due to permitted development. The health of these indigenous ecosystems is declining due to fragmentation and water stress - specifically because land use change and the construction of drainage infrastructure alters the natural hydrological characteristics of a reserve. Water Technology is using hydrologic and hydraulic modelling to assist in the management of native ecosystems. As an example, we are using TUFLOW - software generally used for larger scale drainage and waterway assessments – to identify flowpaths through a bushland reserve in Dandenong to inform future planting programs. As part of a Melbourne Water funded Living Rivers project, we are also investigating the hydrologic regime of a billabong in an urban reserve using monitoring and modelling to assess its ability to support riparian vegetation. This work required the modelling (and calibration) of major rainfall events in December 2016 which caused significant damage across Greater Melbourne. This work will inform future bushland management plans for a local council. Our in-house ecological skills were utilised to monitor vegetation changes over time within the billabong, and to recommend enhancement plantings, with indigenous species, suitable to the billabong profile and the modelled hydrology. If you want to find out more about how to bring ecology into your integrated water management project, please contact Bertrand Salmi to discuss.Contact Bertrand Salmi bertrand.salmi@watertech.com.au +61 3 8526 0800Next >