Prospective students

The WERG are an interdisciplinary group of hydrological, ecological and geomorphological researchers, with strong links to Melbourne Water through the Melbourne Waterway Research Practice Partnership (mwrpp.org). We offer a stimulating, collegiate environment for students interested in applied research in river science, with strong links to management practice.

A list of potential projects is provided below (with further detail on each project provided below that). Most of these projects are offered at PhD, Masters and/or Honours level. We encourage prospective research students to contact us to discuss the project they are interested in. While the project descriptions identify the primary contact(s), projects will be supervised by a number of WERG staff, to encourage interdisciplinary thinking.

  1. Understanding urban subsurface flow pathways from stormwater infiltration (PhD)
  2. How do upland stream ecosystem processes respond to urban stormwater runoff?
  3. Investigating the effects of riparian restoration on basal resources, fish and foodweb structure.
  4. Restoring habitat for our critically endangered state faunal emblems.
  5. Optimising revegetation success for effective critical habitat restoration.
  6. Spatial prioritization of stream restoration activities.
  7. No eye deer? Developing revegetation techniques to outsmart introduced deer in Australia.
  8. Infiltration systems, groundwater, and salinity
  9. Where upland flow lines meet streams.
  10. Unaccounted costs of conventional urban development on streams.
  11. Sediment processes
  12. Limitations to recruitment
  13. Modeling the effects of different climate change scenarios on the catchment scale performance of stormwater retention measures in the Little Stringybark Creek catchment.
  14. Effects of urbanisation on groundwater quality and movement.
1. Understanding urban subsurface flow pathways from stormwater infiltration (PhD)
Stormwater infiltration basins are among the most widely applied stormwater control measures worldwide, in part for their ability to intercept stormwater runoff and allow it to infiltrate into the ground, with the assumption that this will recharge groundwater and help restore clean, filtered baseflows to urban streams. Stormwater infiltration basins provide substantial localised (point-source) additions to the subsurface water store, with the potential to generate major contributions to groundwater and/or lateral seepage to streams.
There is increasing concern however, that infiltration basins may, in some situations, fail to restore stream baseflows (in terms of both flow regime and water quality), due to the gross disturbance of subsurface flow paths caused by urban underground infrastructure (e.g. water, sewer & gas pipes, communications conduits) and their associated gravel-filled trenches (collectively referred to as the ‘urban karst’). These highly-permeable trenches potentially lead to ‘short-circuits’ that could rapidly transmit water and pollutants to streams, undermining the objectives of infiltration systems. Therefore, it is important to understand the potential for infiltrated stormwater to mobilise pollutants in urban soils and subsurface flows to surface waters such as streams.
This PhD project aims to understand the fate and pathways of infiltrated urban stormwater and associated pollutants, and the implications for the flow regime and water quality of urban streams, by developing a very detailed physically based model of a selected site. The student will develop advanced subsurface flow and transport simulations to represent both the field study site and a range of typical generalised situations. This will contribute to a better understanding of the spatial design of infiltration systems (i.e. improved siting of such facilities). The ideal PhD candidate will enjoy numerical analysis and problems, have experience with CAD, an understanding of groundwater hydrology and transport simulation as well as some programming or data analysis experience.
Primary contact: Tim Fletcher (tfletcher@unimelb.edu.au)
2. How do upland stream ecosystem processes respond to urban stormwater runoff?
Small upland drainage lines are important retainers and transformers of nutrients and other contaminants, while they retain their natural form. A number of such drainage lines in the Dandenong Ranges have received different degrees of stormwater runoff over different periods. How does their morphology and ecological structure and function change with increased urban stormwater flows? Depending on the interests of the student, this project could focus on geomorphology (how do drainage lines/channels respond to changes in catchment flow regime?), ecological function (how are biogeochemical processes such as nutrient retention affected by different land practices?), or ecological structure (how is the biodiversity of small drainage lines affected by changes in land practices?)
Primary contact: Chris Walsh (cwalsh@unimelb.edu.au)
3. Investigating the effects of riparian restoration on basal resources, fish and foodweb structure.
Each year significant financial resources are allocated to riparian restoration. Despite this there is limited understanding of the effects of these management approaches on basal resources, food web structure and fish biomass. This project will use a combination of fish surveys, stable isotopes and gut analysis to investigate these and other key questions.
Primary contact: Sam Imberger (Samantha.Imberger@unimelb.edu.au) and Nick Bond (Nick Bond (n.bond@griffith.edu.au)
4. Restoring habitat for our critically endangered state faunal emblems.
Both Victoria’s faunal and avifaunal emblems, the Leadbeater’s Possum and the Helmeted Honeyeater, are critically endangered. Threatened Eucalyptus camphora (Mountain Swamp Gum) swamp forest within Yellingbo Nature Conservation Reserve in the Yarra Valley is home to both species. This habitat is currently under threat from the dieback of mature E. camphora trees and lack of natural regeneration. Research is required on: the potential causes of the dieback, such as the role of waterlogging due to altered hydrology, and excess nutrients from agricultural run-off; and effective means of promoting natural regeneration. There are a range of potential projects that could contribute knowledge aiding the conservation of these species and our understanding of wetland forest restoration in general. Potential projects could involve both nursery and field based studies.
Primary contact: Joe Greet (joe.greet@unimelb.edu.au)
5. Optimising revegetation success for effective critical habitat restoration.
Revegetation is a common approach to restoring habitat for our native fauna. However, plantings and vegetation trajectories are often compromised such that the resulting vegetation community may not provide appropriate habitat. Hundreds of thousands of dollars have been spent (and will be spent) revegetating Yellingbo Nature Conservation Reserve in the Yarra Valley to provide habitat for the critically endangered Helmeted Honeyeater and lowland Leadbeater’s Possum. A range of factors affect the success of these plantings, including weed control measures (or lack of), as well as protection (or lack of) from browsers (deer, wallabies) and other environmental factors. There are a range of potential projects to assess the effectiveness of revegetation efforts at Yellingbo that could contribute knowledge aiding future restoration efforts.
Primary contact: Joe Greet (joe.greet@unimelb.edu.au)
6. Spatial prioritization of stream restoration activities.
Spatial prioritization of stream restoration activities Each year Natural Resource Management Agencies invest millions of dollars managing and restoring riparian and catchment vegetation, controlling weeds and addressing stormwater impacts to improve waterway health. A fundamental challenge is how to most efficiently allocate this investment to achieve biodiversity and river health outcomes at the whole-of-system level. We are currently working with Melbourne Water on a large project to develop improved prioritisation approaches to support this investment. Activities within this project are focussing on using biological data for a range of taxa (e.g. macro invertebrates, fish, platypus), species habitat models and systematic spatial planning tools (Zonation) to develop cost-effective restoration strategies. Within this broad project there is scope for a number of student projects looking at more targeted research questions, including: i) can species distribution models for aquatic biota be improved by combining presence-absence and presence-only data? ii) are there useful heuristic rules of thumb about how much and where to revegetate to maximise ecological outcomes?; and iii) novel approaches to validating species distribution models.
Primary contacts: Nick Bond (n.bond@griffith.edu.au) and Yung En Chee (yechee@unimelb.edu.au).
7. No eye deer? Developing revegetation techniques to outsmart introduced deer in Australia.
Australian forests contain introduced deer species, which cause considerable damage to vegetation through browsing, trampling and thrashing. Attempts to restore these sites through revegetation are repeatedly hampered by deer, and excluding them through fencing and guarding can be cost-prohibitive. Alternative methods have been proposed in Australia and overseas, such as reduced plant nutrient levels, topping, deer repellents and co-planting of palatable and non-palatable species. However there is considerable uncertainty around their success and cost-effectiveness. Greening Australia has revegetation sites across Victoria that are deer-affected. Last year for example, they planted 280,000 plants at Yellingbo Nature Conservation Reserve where there are known populations of deer with variable levels of success. Next year they will plant similar numbers of plants as part of the high-profile Twenty Million Trees restoration project. Greening Australia is keen to improve the science of restoration in the presence of deer. This project provides an opportunity to work with Greening Australia staff on a large restoration project and improved revegetation outcomes in the face of browsing pressure from deer.
Primary contact: Joe Greet (joe.greet@unimelb.edu.au)
8. Infiltration systems, groundwater, and salinity
Infiltration systems, groundwater, and salinity Interactions between surface and ground water are inherently complex, but much more so in the urban environment, where the ‘urban karst’ (the network of underground infrastructure and associated trenches) perturbs subsurface flow paths. While we have observed substantial reductions in nutrient concentrations in LSC (see above), salinity has remained high in the stream and its tributaries. We are seeking a PhD student to test if this lag in salinity response is a result of interactions between infiltration flows from SCM and groundwater. The project will assess (i) contributions to baseflow (ii) sources of salinity in baseflows and (iii) the fate of infiltrated water in urban catchments and its effect on transit times.
Primary contacts: Matt Burns (Matthew.Burns@unimelb.edu.au) and Tim Fletcher (timf@unimelb.edu.au)
9. Where upland flow lines meet streams.
A recent masters student with the WERG showed that directing runoff from roofs and roads into stormwater pipes that drain to hillslopes causes channel incision and weed invasion in forests of the Dandenong Ranges. The extent of channel incision varies from place to place, in some cases extending to the stream at the bottom of the hill, in others, stopping before reaching the stream, which is likely to provide protection for the stream headwaters. These interfaces between hillslopes and stream headwaters are little studied, and the extent to which intact hillslopes protect streams, and eroded hillslopes degrade them has not been studied. This project could involve a number of possible investigations- e.g. comparison below hillslopes in different states of degradation: of invertebrate assemblages in headwaters; of water quality or flow along the flow lines.
Primary contact: Chris Walsh (cwalsh@unimelb.edu.au)
10. Unaccounted costs of conventional urban development on streams.
With urban sprawl and conventional drainage in suburban developments there is an associated increase in stormwater runoff. This can result in problems such as localised flooding, degradation of receiving waterways and the transfer of pollutants to bays and estuaries, to name a few. An alternative is for stormwater control measures that may assist in addressing these problems, as well as providing benefits such as alternative water sources and increased urban cooling. Yet, a comprehensive cost-benefit analysis comparison has not yet been developed and published. This project would seek to develop case studies that account for the costs and benefits of stormwater management for urban developments considering both the local and system-scale. Background reading
Primary contact: Geoff Vietz (geoff.vietz@unimelb.edu.au)
11.Sediment processes
Sediments are the primary site of nutrient processing in small streams, providing habitat for microbes that cycle and transform nutrients, and for macrophytes. While these processes are well understood, in-stream processes have not been linked to catchment-scale restoration of hydrologic processes. Sediment processes and associated macrophyte growth can influence nutrient availability, dissolved O2 concentrations and the transfer of basal resources to higher trophic levels and thus ecosystem function. We have observed greater reductions in dissolved P and N in LSC than predicted by relationships between nutrients and reduction of urban stormwater impacts, and greater than can be explained by mass-balance estimates of tributary inflows. We hypothesise that observed N and P reductions are in part a result of sediment processes and macrophyte uptake promoted by reduced hydrologic disturbance. We are seeking a PhD student to investigate (i) coarse sediment retention rates, (ii) macrophyte biomass and productivity, and (iii) reach-scale nutrient processing and uptake to test this hypothesis.
Primary contacts: Sam Imberger (Samantha.Imberger@unimelb.edu.au) and Geoff Vietz (g.vietz@unimelb.edu.au)
12. Limitations to recruitment
We are yet to observe any change in macroinvertebrate or algal assemblage composition in LSC, although a minor change in assemblages is indicated in Dobsons Creek (DC), a second creek which has also had extensive stormwater control measures implemented in its catchment. These trends lead to a hypothesis that invertebrate colonisers are more available in sites with forested uplands (DC) that permit rapid downstream drift of colonisers, compared to sites with urban uplands (LSC), in which the primary vectors for colonization are upstream and aerial dispersal (for species with flying adults), which are likely to be slower. We are seeking a PhD student to investigate colonisation pathways, barriers of stream biota in our study streams, to assess the degree to which availability of colonisers is a limit to biotic recovery following the mitigation of abiotic stressors.
Primary contact: Chris Walsh (cwalsh@unimelb.edu.au)
13. Modeling the effects of different climate change scenarios on the catchment scale performance of stormwater retention measures in the Little Stringybark Creek catchment.
A large number of stormwater retention works have been installed in the Little Stringybark Creek catchment, which have been monitored and modeled. This large set of models provides an opportunity to model the effect of climate change on the performance of the systems, and the hydrologic consequences for the creek. You will work with the MUSIC software to develop and test the scenarios
Primary contacts: Sam Imberger (Samantha.Imberger@unimelb.edu.au), Chris Walsh (cwalsh@unimelb.edu.au) and Tim Fletcher (timf@unimelb.edu.au)
14. Effects of urbanisation on groundwater quality and movement.
The effects of urban stormwater drainage infrastructure on water quality and hydrology in streams is well studied, but little is known of the effect of urban land use on the quality and movement of ground water. This project, working as part of the Waterways Ecosystem Research Group’s Little Stringybark Creek project, will assess groundwater quality in well-studied catchments across an urban gradient, and use isotopes (14C or tritium, and Radon) to trace groundwater age, transit times and contribution to stream flow.
Primary contacts: Sam Imberger (Samantha.Imberger@unimelb.edu.au), Tim Fletcher (timf@unimelb.edu.au) and Matt Burns (Matthew.Burns@unimelb.edu.au)