It's important to get back on track
Good progress continues to be made for some of the Strategy targets. However, results from the mid-term review highlight just how important it is for us to refocus our efforts and get back on track in key areas.
The 2022/23 year is the third consecutive wet year in the region. While this is likely to have been largely positive for most environmental values there are clear indications that warmer and drier conditions lie ahead.
Tracking Healthy Waterways Strategy targets annually keeps us focused on the things that matter most
Of the 58 catchment scale targets
were
on track
were
slightly off track
were
significantly off track
continues to be
under review
Vegetation extent and maintenance, environmental water and stormwater are the main targets that are behind where we need to be.
Progress has been made on all 45 Regional Performance Objectives
Mid-term evaluation nearing completion
The mid-term review commenced in 2023, assessing progress of the strategy and identifying areas for improvement. It also provided a valuable opportunity to look at how changes in the operating environment may impact the ability to meet strategy targets.
Findings from the review provide valuable insights into where we need to focus our efforts to get strategy targets back on track.
Over the coming months, Melbourne Water and the Region-wide Leadership Group will host a series of forums to share findings and recommendations from the mid-term review and collaborate with delivery partners to develop a Response to the recommendations. These forums are an opportunity for delivery partners to work together to re-assess where we collectively need to focus effort and what work needs to be prioritised, as well as consider new ways of achieving strategy targets and performance objectives.
Regional Catchment Strategy released
The new Regional Catchment Strategy (RCS) for the Port Phillip and Western Port region was approved by the Minister for Water in February 2023. It is the fourth RCS for the region and brings together planning and information on land, water and biodiversity, demonstrating how these connect across the region and identifying targets for the future health and resilience of our environment. The RCS is founded on the principle that collaboration by many organisations is vital to achieve environmental improvement for our region.
The Healthy Waterways Strategy forms part of the RCS and focuses on waterway management targets.
Melbourne Water is now the Catchment Management Authority for the region and the custodian of the RCS.
Recycled water guidance
In May 2023 Environment Protection Authority Victoria (EPAV) updated Guidance for environmental and human health risk assessment of wastewater discharges to surface waters (publication 1287) which helps industry, businesses and local governments understand their responsibility when seeking permission to discharge wastewater to the environment.
Additionally, EPAV undertook a study and published a report in June 2023 characterising Emerging contaminants in recycled water (publication 2054).
This work will inform the increasing focus on recycled water as a valuable resource.
Progress highlights
Reinvigorating efforts in the most important areas!
Almost 2,000 hectares of new vegetation has been established in priority areas along waterways across the region since the strategy began in 18/19 and 8 sub-catchments are exceeding the 10-year targets. Even though this is great and efforts have ramped up significantly since last year, it’s not enough to stay on track to meet the ambitious 8,000 hectare target required by the end of the strategy. This year only the Dandenong catchment is still on track to meet the 10-year targets for establishing new vegetation. We remain significantly off-track in the Werribee, Maribyrnong and Westernport catchments and slightly off-track in the Yarra catchment. Working with landholders on private land is increasingly challenging so opportunities to keep work progressing has led to an additional 480 hectares of new vegetation being planted outside priority areas, most of this in the last year.
Over 10,800 ha of vegetation was maintained this year and the Yarra, Werribee and Dandenong catchments are all well on their way to managing the areas required to maintain good habitat quality. However, the Maribyrnong catchment is slightly off-track and Westernport is significantly off-track, particularly for managing areas of high-quality vegetation. Some of the reasons for this is that we need to increase the area of vegetation we manage each year and finding ways to work safely in remote areas where high quality vegetation occurs has been challenging.
This is important because the mid-term review has highlighted that grant programs to revegetate riparian areas on private land are facing some issues that are limiting what can be achieved in priority areas. This is consistent with what has been found by other catchment management authorities elsewhere in Victoria. The mid-term review has also highlighted that establishing new vegetation requires long-term maintenance to ensure outcomes are achieved. Vegetation planted today will take several decades to reach the maturity needed to support in-stream values such as platypus and fish. In order to offset some of the impacts of climate change it's very important that we get back on track now and keep planting and maintaining vegetation in priority areas!
Next we need to use the information outlined in the mid-term review to refocus efforts. We need to make sure we get back on track in critical areas in particular, and the mid-term review Response will identify opportunities for improved implementation such as exploring new strategic approaches to working with private land holders so that priority areas can be accessed.
We also need to improve the information we have on weed and deer threat present in high value vegetation areas to better understand how frequently maintenance works are required. Additionally we will investigate how contributions to vegetation targets that are delivered by strategy partners can be included in the target achievement. Currently only Melbourne Water-funded projects are counted towards the target achievement.
Stormwater... are we getting closer to the change we need?
Traditional approaches to stormwater management in urban growth areas is the most significant near-term threat facing the region. The strategy set out ambitious, but critical, targets for harvesting and infiltrating stormwater in order to reduce impacts to waterways. The targets are aligned with the current state of knowledge set out in the new Urban stormwater management guidelines released by the EPA in 2021 under the new General Environmental Duty framework. In addition to protecting waterways, harvesting stormwater presents an opportunity to service future water needs in a growing population.
Urban development is occurring at a rapid rate and since 2018 over half the area of land expected to be subdivided by 2028 has occurred. The Maribyrnong catchment is currently the only catchment on track to harvest and infiltrate enough stormwater to offset new urban development because significant harvesting projects are planned and committed to. In particular, good progress has been made in the Sunbury Sustainable Water Futures project in the Maribyrnong River catchment where stormwater from new developments will be harvested to prevent damaging flows entering local waterways (e.g. headwater streams and Emu Creek). Stormwater will be transferred to storages and released to Jacksons Creek in a controlled way to address some of the shortfall in this system. Melbourne Water is investigating options to optimise the two outcomes. While this is a great outcome for the Maribyrnong River system development is occurring more rapidly than estimated in 2018 and while long-term predictions have not changed, the ten-year target needs to be reviewed.
The Westernport catchment is slightly off-track because of limited evidence of sufficient commitment to projects. The Werribee catchment is also slightly off-track. While some progress has been made towards a significant harvesting project in the Werribee catchment to mitigate stormwater impacts from the growth of Melton it is still in the planning stage. The Yarra catchment is also slightly off-track because planning for projects in the Upper Merri Creek has not progressed as quickly as expected. In addition unmitigated in-fill development around Croydon poses risks to the iconic Yarra main-stem. Infiltration targets are still significantly off-track in the Werribee, Westernport and Yarra catchments despite some good initiatives, such as mandated passively watered street trees in Melton.
This is important because the mid-term review highlighted that macroinvertebrates improve when stormwater is disconnected from waterways but that more broadly in our region declines are predicted from un-mitigated urbanization that has occurred since 2018. Planned harvest and infiltration projects are not being delivered quickly enough to mitigate impacts and in some catchments sufficient projects are not yet in place to offset planned development.
Next we need to fast track the Melton stormwater harvesting scheme and increase the number of projects in the Yarra and Westernport catchments that will harvest and infiltrate in priority areas. We also need to develop technical guidance for construction and maintenance of stormwater assets in order to improve industry capacity and investigate further options for passive infiltration.
Flows from harvested stormwater – a win-win for river and creeks
The targets for additional environmental water for Maribyrnong, Werribee, Yarra and Westernport catchments remain significantly off-track as there has been very few new entitlements created since 2018. This will hopefully change soon with new directions for the use of manufactured water and improvements to water efficiency as set out in the Central and Gippsland Region Sustainable Water Strategy (CGRSWS). The CGRSWS aims to return a total of 31.3GL to Traditional Owners and the environment across the region by 2032. This target is aligned with strategy performance objectives and is driving progress in several areas.
The environmental water reserve in the Werribee system is expected to increase through irrigation modernisation works completed in the Werribee and Bacchus Marsh districts. The water savings are currently being verified through an audit process prior to formalisation in the Environmental Entitlement and the increase in volume is expected to be around 2 GL per year.
Modelling over the past year demonstrates that the Werribee River Reconfiguration Project is theoretically able to meet the environmental shortfall. The project is a collaboration between Melbourne Water, Greater Western Water, the Department of Energy, Environment and Climate Action and Southern Rural Water that aims to return water to Traditional Owners and the environment through reconfiguring the way water is delivered across the catchment. The Melton harvesting scheme mentioned above is also part of this broader reconfiguration project.
In the Maribyrnong catchment, 2023 investigations demonstrate that controlled delivery of harvested stormwater can reduce the shortfall in Jacksons Creek by 1.6 GL per year and improve environmental flow compliance year-round, in addition to protecting streams from the impacts of urbanisation.
Also, urban water corporations are considering how to reduce reliance on river water for urban supply to enable this water to be returned to the environment and Traditional Owners. Options developed by water corporations are due to be sent to the Victorian Department of Energy, Environment and Climate Action (DEECA) by the end of 2023.
This is important because the mid-term review examined trends in the key values and the likely causes of declines. It also looked at updated climate change predictions and impacts on environmental values. This work, coupled with the declining water availability outlined in the Long-term water resources assessment, (2020) indicate that it is even more important to secure water for the environment to support environmental values such as vulnerable populations of platypus. The use of manufactured water such as desalinised and fit-for-purpose recycled water as well as stormwater will be an important part of preparing for the future.
Next we need to finalise the audit of the water savings from the Werribee Irrigation Improvement works and formalise the increase in Environmental Entitlement for the Werribee so that environmental flows can be delivered as soon as possible. We also need to keep working productively together to continue the good momentum of the CGRSWS and work to address the shortfalls in the Yarra, Maribyrnong and Westernport catchments. We will continue to investigate and act on opportunities to secure additional reserve volumes where possible. In 22/23 322 ML of unused irrigation allocations was temporarily traded in the Maribyrnong catchment and released as a series of winter low flows. For more information see Water for the Environment.
We also need to assess how unregulated waterways and their environmental and social values are being impacted by climate change. In 2023, Melbourne Water initiated a region-wide assessment of how water availability is changing across the region. Flow conditions have been quite good over the last year with good rainfall across the catchments but we are now entering a El Niño weather system where conditions are likely to be warmer and drier.
Wetlands in growth areas are still draining away
The need to retain and protect natural wetlands from urban development has been an area of focus since the Strategy began in 2018. This year we report that another wetland, Muddy Gates Lane Swamp Complex has effectively been lost due to pressures from urban development. This wetland is not one of the 123 HWS priority wetlands identified in 2018 but is one of the improved and updated regional priority wetlands that are being tracked as part of the Wetland Monitoring and Evaluation Plan (2020) and reported on under RPO 29. Additionally, 16 other regional priority natural wetlands are under imminent threat which is an increase from last year.
We continue to be on-track across all 5 catchments to achieve wetland buffer targets and control key weed and pest animal threats in wetlands but in future years it will be challenging to stay on track because the targets increase significantly. We also made some improvements to the social values conceptual models for wetlands that will allow us to characterise wetlands in the landscape, both natural and constructed, to improve our understanding of how people value wetlands.
This is important because natural wetlands in urban growth areas continue to be at risk. Analysing wetland data and reporting it annually and the efforts of the interagency working group in particular has led to raising the profile of this issue. As a result, efforts to protect wetlands are being considered more closely in the development planning stages. Some positive changes in development areas to precinct structure plans and developer services schemes has led to the protection of wetlands. However, to date a total of 5 priority wetlands have seen their values lost to urban development.
Losing natural wetlands not only means the loss of unique ecosystems and the habitat and value they represent, but also a loss at the landscape scale. As we lose 'stepping stones' in the increasingly urban matrix the ability for native fauna and plants to disperse and retain genetic connectivity across the region is threatened. Native species of wetland fauna and flora are adapted to cope with 'boom or bust' cycles driven by rainfall – with wet periods interspersed by dry periods. This means, while populations may contract to occupy the few remaining wetlands during dry periods, they require more natural wetlands during wet periods to allow their populations to disperse, breed and recover. So even non-pristine wetland habitat can play an important role in wetland ecosystem resilience.
Next we need to ramp up efforts to protect and manage increasing areas of wetland buffers as this will allow us to remain on track in future years. We also need to amplify efforts to ensure sufficient protections are in place for natural wetlands. This should include strengthening urban planning and policy processes and informing the development of the next Victorian Waterway Management Strategy to influence for the protection of function and form as well as wetland condition. We also need to update state-wide wetland mapping to reflect the best available information for the Port Phillip and Westernport region, that aligns with information on the 2018 Healthy Waterways Strategy and Regional Catchment Strategy websites. Melbourne Water is also investigating the potential to purchase wetlands at risk in key locations.
As we continuously improve the collection and analyses of wetland data and build our knowledge of wetlands we enhance both our current wetland reporting but also future strategy development. Noteworthy progress on the development of wetland habitat suitability models has continued this year that will improve our understanding of how best to support habitat for a range of values including frogs and wetland birds.
Untangling snags to fish migration is slow and steady
Ensuring fish can move unimpeded through the landscape is one of the most important factors in ensuring life cycle completion and breeding success for migratory fish and long-term population health for non-migratory species. Although no significant additional fishway projects were completed in 22/23, progress has been made on a number of fronts that should see the situation improve in future years.
The Dandenong and Maribyrnong catchments remain on-track because key fishways have been completed. The Werribee and Yarra catchments have multiple barriers to address and both catchments are still slightly off-track however good planning progress has been made. This year Melbourne Water re-evaluated and re-prioritised the remaining fish barriers across these catchments. Concept design and planning for three of the remaining upper Yarra River fish barriers on Armstrong, McMahons and Starvation Creeks has progressed that will inform the development of business cases for future projects. The CGRSWS outlines an action to improve fish passage in the Wirribi Yaluk (Werribee River) and progress with this action has been made. A concept design for the lower Werribee Diversion Weir, a key fish barrier on the Werribee River, has been funded by the Department of Energy, Environment and Climate Action (DEECA) and Melbourne Water. An inter-agency stakeholder working group comprising representatives from Southern Rural Water, DEECA, Melbourne Water, Parks Victoria and Traditional Owners has been formed to guide the project. This project will not only address a critical barrier to migration but seek to improve the way environmental water is delivered to the Lower Werribee River that will benefit fish and other values. Smaller barriers on the lower Werribee River near Bungies Hole have also been investigated and Melbourne Water are working with the Wadawurrung Traditional Owners Aboriginal Corporation on designs that will improve fish passage and minimise disturbances.
The Westernport catchment remains significantly off-track and even though no measurable progress has been made on a critical large and costly fishway on the Lang Lang River, an investment logic process has been initiated that could help to validate the significant investment needed for this critical infrastructure. Building a fishway at the Heads Road Weir would open up more than 204km of riverine habitat for a predicted six species of native fish including Australian Grayling, listed as vulnerable in under the Environment Protection and Biodiversity Conservation Act 1999. Few of the other 32 priority fishways identified in the Healthy Waterways Strategy open up more river length, and support more fish species in our region.
This is important because the movement and migration of fish past barriers is critically important for the long-term survival of fish species along our waterways which is even more important when coupled with pressures resulting from climate change. The mid-term review highlighted that investment in building and maintaining fishways is the management intervention that has the most immediate benefit for fish.
Next we need to complete the investment logic for the Lang Lang fishway to support progress of the business case. We also need to ensure the concept design for the lower Werribee diversion weir proceeds and we continue to work together across agencies to ensure all the needs of the community are considered. We also need to move to the detailed design phase for the three upper Yarra fishways to support these being delivered over the remaining years of the strategy.
Updated climate change predictions
During the mid-term review we used updated climate change predictions to re-run the habitat suitability models that were used to set strategy targets in 2018. Overall, new climate change predictions indicate even greater future impact on platypus and fish than was envisaged in 2018 but not a lot of additional impact for macroinvertebrates. Climate change can also amplify other events such as the intensity and frequency of storms and bushfires. The combined effects of event-based disruptions need to be integrated into planning for the future.
This is important because one of our key assumptions when we set the strategy was that changes in flow resulting from climate change could be mitigated in some areas, particularly where platypus were vulnerable to reduced flows. The new projections combined with evidence from the Long-term water resource assessment for southern Victoria (2020) indicate that reduced flows may already be contributing to some declines in platypus and other values and highlights the difficulties we face in overcoming this issue. Even the protected wet forested catchments in the east show significant predicted declines for platypus under the worst case climate change scenario.
Next we need to figure out smarter and faster ways to implement integrated water management solutions across the region to help to offset the declines we may see in the future. This includes innovative stormwater management solutions as well as implementing actions from the Central and Gippsland Region Sustainable Water Strategy that seek to return more water to the environment. The new analysis reinforced the need to get back on track across all targets in critical areas in order to build resilience for the future. We also need to investigate new ways of integrating event-based disruptions into future planning and target setting. New climate change predictions may mean we need to rethink our assumptions and target setting approach in future strategies.
Responding to the mid-term review
The mid-term review of the strategy has been a complex and rigorous process and the first time such an analysis has been conducted of a waterway strategy. It has been guided by an expert evaluation panel that has provided oversight and review along the way and we have continued to learn and build capacity throughout the process. The Science Inquiry and the Implementation Inquiry are nearing completion and will be made available in 2024.
The Science Inquiry assessed the trajectories of the key environmental and social values and conditions to determine whether we are on track to meet the long term target. It also revisited and updated the key threats and critical assumptions that were made when the strategy was set. It analysed and summarised the key outcomes from intervention monitoring programs and identified data and knowledge gaps.
The Implementation Inquiry assessed progress and evaluated factors influencing implementation and the likelihood of meeting 10-year performance objective targets. It also examined whether co-delivery of the strategy is leading to better outcomes overall.
Both reports will be released in 2024 as part of a suite of engagement events with delivery partners.
This is important because the mid-term review has provided an opportunity to reflect and check in on what's working well and what requires extra effort. It provides an evidence base on which to reset and reinvigorate efforts to get strategy performance objectives back on track and provides information on whats important to focus on.
Next we need to respond to the inquiry reports. Melbourne Water will lead development of a Response in collaboration with the Region-wide Leadership Group and delivery partners. The Response will outline how and where we will collectively focus effort and what work needs to be prioritised, as well as consider new ways of achieving Strategy targets and performance objectives. A suite of engagement events are planned for early-mid 2024, including online and in-person forums to communicate the findings and recommendations from the mid-term review and to facilitate input to the Response from delivery partners.