Natural systems are complex, heterogeneous and diverse, and every aquatic ecosystem is unique with many variables co-existing and providing feedback to this complex system. The study of these many co-occurring and interacting physical, chemical and ecological processes in a dynamically changing environment cannot be easily simulated or studied in conventional field and laboratory experiments.
Water Technology has an extensive and complimentary range of technical skills to provide a variety of environmental services from the catchment to the sea. Our multidisciplinary team are adept in the design and implementation of monitoring and modelling programs for water quality, contaminant tracing, erosion severity, vegetation establishment to improve ecological health of any aquatic system.
We combine leading edge technology with out-standing project experience to deliver economic and environmentally sustainable solutions.We pride ourselves in the creation of innovative solutions to technical environmental issues. We have been involved in the technical work and development required for numerous Environmental Effects Statements (EES), Environmental Impact Assessments (EIA), Environmental Management Plans (EMP) as well a range of other projects culminating in effective and sustainable environmental management solutions.Capabilities
- Contaminant modelling
- Nutrient load management
- Sedimentation studies
- Dredging impact assessments
- Water quality forecasting
- Hydrological/hydraulic analysis
- River Stability Assessment & Design
- Environmental Flow Assessment
- Monitoring Program Design & Implementation
- Water Quality Monitoring and Modelling
- Agent Based Modelling for Fish Response
- Algal Bloom Modelling and Management
Shoreline Erosion: Aligning management strategies with community aspirations
Main image: Rodney Wiley
Located on the north-west corner of North Stradbroke Island, the township of Amity Point enjoys a rich diversity of seascapes and landscapes – providing extensive recreational and lifestyle opportunities that are considerably enhanced by local cultural, heritage and environmental values.
The historical development of Amity Point has focused on the shoreline – as residents and visitors seek to enjoy the unique character of this coastal precinct. However, the dynamic nature of the coastal environment means that local foreshores are experiencing erosion which is threatening these values, as well as endangering essential infrastructure.
Water Technology was engaged by Redland City Council to develop the Amity Point Shoreline Erosion Management Plan which included a framework for the sustainable use, development and management of this vulnerable foreshore that was acceptable to both the residents and the relevant management authorities.
Previous recommended approaches to shoreline management at Amity Point (including an earlier SEMP completed by another consultant in 2014) did not allow for Council and the local Amity Point community to appropriately and proactively plan for suitable erosion management along the vulnerable foreshore.
This project therefore focused on developing an approach that was consistent with the community aspirations and the polices of the Commonwealth and State Governments, and Redland City Council. Technically, the Shoreline Erosion Management Plan considered various strategies in response to the erosion processes and associated risks at Amity Point and, importantly, it involved considerable engagement with the local community and other stakeholders, and has delivered a unique solution to the considerable erosion hazard at Amity Point.
Key Services Provided:
- Physical Process Analysis
- Erosion Threat Risk Assessment
- Shoreline Erosion Management Plan
- Stakeholder Consultation and Engagement
- Shoreline and Erosion Management Optioneering and Recommendations
Presentation by Paul O’Brien (Water Technology) and Tim Mitchell (Redland City Council)
at the 6th Queensland Coastal Conference 2017 (5-7 September 2017).
The Latrobe River estuary is located at the interface between the Latrobe catchment and the Gippsland Lakes. It is a part of the Gippsland Lakes complex, recognised as a wetland of international significance. Upstream freshwater reserves have been set aside for ecological flows, but the environmental flow requirements were unknown. The water resources are also shared between agricultural, industrial, and domestic use. Water Technology was engaged to address the gap developing environmental flow recommendations for the lower Latrobe River estuary.
1D and 3D models were developed to characterize the hydrodynamic regime of the estuary. The 1D model represented river and floodplain flows and was used to examine the interactions between the river and the floodplains. The 3D model was used to provide more detailed information about the hydrodynamic properties of in-stream flows, including interactions between flows, lake levels, and salt wedges.
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.
Water Technology was commissioned by Groote Eylandt Mining Company (GEMCO) to undertake a river sedimentation analysis for the Angurugu River, Groote Eylandt.
Groote Eylandt is situated on the western side of the Gulf of Carpentaria, approximately 50 km from mainland Australia. The Angurugu River flows between the main GEMCO mining leases, and is fed by a total catchment area of approximately 117 km2. The river discharges into Milner Bay and the tidal influence is known to extend as far up stream as the Haul Road Bridge.
Concerns have been raised that increased sedimentation in the river is occurring as a result of changes associated with the Haul Road Bridge and/or mine operations. In order to understand the sedimentation processes in the river, this assessment focussed on analysing the river planform, flow characteristics and sediment transport potential prior and post construction of the Haul Road Bridge.
Work undertaken included a geomorphic assessment, combined with hydrologic and hydraulic modelling along with sediment transport modelling through the river system.
Key Services Provided:
– Geomorphic Assessment
– Hydrologic and hydraulic modelling,
– Sediment transport modelling
The Living Murray Initiative and associated Environmental Works and Measures Program were established to improve the health of the River Murray system through recovery of water and effective distribution to the environment.
Water Technology has been involved in a number of eco-hydraulic projects through these initiatives to develop and assess water management options for improved environmental watering.
Water Technology undertook hydrodynamic modelling to assess proposed works and measures to significantly enhance the existing watering regime of the wetland systems around Lindsay, Mulcra and the Wallpolla Islands. This involved comparing flood extents based on historical, current and proposed infrastructure management. Prior to the development of environmental watering infrastructure, Water Technology undertook advection-dispersion model, investigated rates of mixing and turn-over times in the upper reaches of the system.
As part of Victoria’s Murray Darling Basin Plan Sustainable Diversion Limit Offset Works and Measure’s Program, the North Central Catchment Management Authority co-ordinated investigations to deliver environmental water to the Ramsar listed Gunbower Forest in an efficient and sustainable manner.
The objective of these investigations was to assess hydrological, ecological and structural feasibility of a range of water management options to deliver water to the Gunbower Forest.
Water Technology developed a number of 1D-2D hydraulic models of the system to evaluate the potential water management options and improve knowledge of the floodplain system, and worked closely with the CMA and ecologists to develop concepts of infrastructure and watering requirements for various target sites.
The Corner Inlet Environmental Audit was undertaken by the CSIRO (2005) in response to growing concern from natural resource managers and the community about the health of Corner Inlet. One of the key recommendations from the audit was to undertake a catchment audit to identify pollutant sources and develop targeted amelioration strategies. This project responded to this call by developing a comprehensive sediment and nutrient model of the catchments of Corner Inlet. Water Technology and Melbourne University worked closely with the West Gippsland Catchment Management Authority and the Steering Committee for this project to ensure the final outcomes were user friendly and appropriate for the site.
The method pursued was to develop SOURCE (catchment) and receiving waters (estuary) models (MIKE 21), which were calibrated to both existing data and field measurements taken as part of the project. The simulations of these two calibrated models were then integrated within a single software framework so as to produce a Decision Support System (DSS). The DSS allows scenario testing to plan and prioritise future investments in the catchments, and make decisions on what comprises appropriate development with a view to protecting and enhancing the integrity of the Corner Inlet RAMSAR site.
In 2012 Water Technology and GeoLink were commissioned by the Coffs Harbour City Council to undertake an Estuary Management Plan and Hydraulic Assessment of the Coffs Creek estuary which runs along the boundary of the main centre of Coffs Harbour.
The estuary is a tranquil oasis on the edge of the city and is utilised by residents and visitors in increasing volumes. An Estuary Management Plan was undertaken to identify and assess management options for the estuary going forwards. In addition, the free passage of flood flows through the estuary was identified as a potential contributor to the severe flooding experienced in the city centre during flood events.
A hydraulic model of the estuary was established and calibrated to measured water levels at the upstream and downstream ends of the estuary. Modelling of a range of management options, including reduction in fringing mangrove density and spread, dredging of the flood tide shoals and tidal entrance channel were assessed.
The runoff from the urban and industrialised sections of the catchments had been studied previously and the information from these works were used to determine potential improvements in the water quality which could be made by strategic upgrade of drainage and water quality systems.
The results of the Hydraulics Assessment were used to help prioritise the management options and to provide the Council and local community of Coffs Harbour with a wealth of information on the drivers of estuary health in their town.
Water Technology carried out detailed numerical modelling of the potential release of an abalone aquaculture contaminant into the Southern Ocean off the coast of western Victoria.
As part of the process, Water Technology undertook verification of the numerical model using fluorecene dye tests, released from the facility outflow drains. EPA risk assessments and notification of the local catchment manager and EPA prior to the tests were completed. Overhead shots from a light plane were taken and the images rectified and time stamped.
Numerical modelling of the dispersion involved hydrodynamic and wave modelling of the Southern Ocean, extending from South Australia, south of Tasmania to the Victorian /New South Wales border to the east. The model of the Southern Ocean utilised inputs from global models and was calibrated to predicted and measured tidal stations and recorded wave data. The dispersion of the waterborne abalone virus was verified against the results of the fluoroscene dye test and showed good correlation between the actual and modelled wave setup of water (and contaminant) inshore of the fringing coastal reef.
The model was used to determine the timing and concentration of the dispersion of the abalone virus along the western Victorian coast and through Bass Strait into Port Phillip Bay and Western Port. Scenario optioneering of different contaminant release points and concentrations were used to determine the likelihood of contamination originating at the subject site.
The results of the modelling were used in supporting arguments in the Supreme Court of Victoria and Water Technology was called upon by the court to provide an Expert Witness Statement and provide the presiding judge with additional comment during the hearing.