Karaaf Wetlands info session: questions and answers

Doug Frood’s response:

I think we need to see this as a process rather than a specific action.  In the top north to west corner, there are a lot of areas with 30% - 50% dieback or mortality of salt marsh shrubs. If it doesn’t pond deeply with freshwater, we’ll get recoupment pretty soon, a few years to reach maturity.

Where we have 100% mortality, there’s a question of do we actually have a state change – a tipping point reached where there’s a lens of freshwater and it’s flushed saltwater out of the system. I’m hoping that’s not the case over the most of it, but what I think you’re going to see is a process of recovery in from the edges, so it’s hard to put a timeframe on that.

Where you’ve got remnant plants, you’ve got a lot more seed fall, it’s a lot more available to regenerate.  Where you’ve got a big dead area, it may take a lot more. Where you’ve got intertidal action, that should recover pretty well – I think to a level that reflects the current tidal regime.

Because there is excess freshwater, it requires getting the western end of the Karaaf to dry out again and hoping that salinity levels will re-establish.

The ideal solution for me is to not have stormwater going in there at all, and I’m purely talking from a botanical viewpoint.

Doug Frood’s response:

Depends what you mean by original.  It certainly can’t go back to 1750.

Doug Frood’s response:

You always have values, and parts of that saltmarsh are probably resilient, and could be elevated enough.

Or also, they’re getting the intertidal flushing, which will work.

Other parts, who knows, with the cumbungi (or Typha, an invasive plant), how long it will take for the western part brackish wetland to convert back again or whether we do have a tipping point.

The cumbungi should die out if it’s kept dry. Cumbungi does not like sustained dry conditions over summer.

We can see this more an in indicator of change, rather than a problem in itself.

Doug Frood’s response:

It’s hard to know where the dieback level is. If you’ve got 50% dieback, I can’t see why that can’t fill in again.  That can just be a blip in time.  Because if the remaining plants are still healthy, that means the event has passed.

If you’ve got 70% and the plants are looking really sick, maybe you’re getting close to that turning point.

Doug Frood’s response:

There’s two perspectives; one’s process which is related to things that happened across time and pattern which is related to the arrangement of plants across space. So we’re concerned about the pattern – and people often try and change patterns without changing process, so to me we’ve really got to look at the processes here and many aspects of pattern will resolve themselves.

If we get the Karaaf dry over summer and stop the freshwater inputs to the places where the Typha is occurring, it’s going to cease to be problematic.

Some introduced plants such as Water Buttons we may just have to live with. Many weeds can’t survive in the intertidal zones – they don’t survive full on emersion from seawater. So we may have weedy fringes.  But I think if we can restore the salinity, a lot of those (invasive) things will disappear from the currently modified areas.

Doug Frood’s response:

I think it’s a good idea to have a holistic management approach, but many of those things should be seen as symptoms rather than essentially problems in themselves.

Doug Frood’s response:

Typha will burn when the foliage is dry (after summer), however that will not kill the plant and is not actually addressing the issue which is changes to salinity and water regimes.

Council’s response:

We need to understand our options for diverting water in the short-term, while we work towards long-term plans to re-use the water 

The surplus of stormwater presents an opportunity. We are working with Barwon Water on a concept to divert the stormwater away from the Karaaf Wetlands, to mix it with recycled water from the Black Rock Water Reclamation Plant, and to use it to support high value agricultural activities in the Thompson Valley.

Council’s response:

At a broad level, it’s a clear opportunity.

Currently the infrastructure that it relied upon is not functioning anymore.  There are some pump systems and power to those pump systems that no longer function. 

We also need to look at the volume of water that we would be sending to a new catchment, so that work is about to commence.

We need to look into making sure this would not create other environmental issues.

We know that there were environmental issues in the past, and that’s part of the reason the water was diverted.

Council’s response:

Historically there was flooding around that Esplanade area, and we’ve got to be mindful of not bringing back a problem that seems to have been successfully addressed, so that may prove to be an issue in terms of the holding capacity of the Esplanade wetland.

There’s also a strong relationship to the Sands.

Based on the data we have, the Sands only use a little bit of the water that’s going in.  They generally use water they capture from their own setting.  Part of our discussions with the Sands will be on their future water needs, because at the moment the Sands is a thoroughfare, and unlike housing estates, a golf course has a lot of capacity to take water but depending on the climate and the time of year too.

Doug Frood’s response:

I think the drowning and becoming more fresh is clearly the issue. Also for example, Typha does love nutrients, so the volume and pollutants are not independent.  To me, the largest impact is coming from the volumes of water. 

Jason Sonneman’s (Design Flow) response:

No, the volumes are too great. Also the sewer system does not remove many nutrients through the process, so this is not an option.

Council's response:

We believe there are feasible options to redirect some level of stormwater directly to the ocean instead of through the Sands and Karaaf. These are being investigated as part of the next stage of the project.

Options to reduce stormwater inflows to the Karaaf include stormwater re-use and diverting/pumping stormwater runoff to alternative discharge points (i.e. Deep Creek). The feasibility of these options will be considered by Council in the next project phase.  The manipulation of the constructed wetland water regimes would have no impact on the stormwater volume discharged to the Karaaf.

Council’s response:

This option would be unlikely to be viable as at first glance the only way to achieve this would be to run a stormwater pipe through the middle of the Karaaf. The construction for this would likely cause significant damage to the wetland. 

Council’s response:

As the majority of the subdivisions upstream have already been developed this would only be an option for the section of development yet to proceed and would likely have minimal impact overall.

Council’s response:

The next stages of the overall project are focussed on looking at both improving the stormwater quality and reducing the volume to the Karaaf. 

As Barwon Water has commissioned this report it’s to them to determine what information will be shared publicly.  We can then share this information with approval from Barwon Water.

Council’s response:

The constructed wetlands have generally been built to the requirements set under the 2010 plan. We now know a lot more about how stormwater systems need to be designed, and we are applying what we know to future developments.

We have strengthened our processes for planning, approving and monitoring constructed wetlands.

Jason Sonneman’s (Design Flow) response:

No, an inspection of the gross pollutant traps was not undertaken. Generally speaking, there are some gross pollutants getting through the system and into the wetlands, but not the sorts of volumes we’d expect to see if those systems were grossly failing.

Jason Sonneman’s (Design Flow) response:

We identified a number of rectification actions that will help make the wetlands work harder and function better than they are currently (these are outlined in the wetland assessment report).

Jason Sonneman’s (Design Flow) response:

In future developments, the most recent guidelines for wetland design should be adopted (i.e. Melbourne Water wetland design manual). The designs for the existing wetland systems were based on older wetland design guidelines, which weren’t quite as robust as the current Melbourne Water wetland design manual. We recommend, going forward, that Council adopts the design guidance provided in the Melbourne Water wetland design manual. It provides a rigorous design process to ensure that the wetlands are correctly sized and configured.

Council’s response:

This will be considered as part of the next stage of the projects. There are a number of options that can be looked at including modifications to the wetlands, adding non-wetland treatment devices and increased cleaning regimes.

Jason Sonneman's (Design Flow) response:

A range of issues associated with the constructed wetland designs were identified including wetland size and configuration, sediment pond performance, vegetation cover and wetland storage depths. Although little can be done to increase the size of the wetlands, it is expected that Council will undertake works to rectify many of the identified issues to optimise wetland functional performance.

Council’s response:

We acknowledge that it’s part of a wider system, and in terms of the management plan, whilst there’s benefit in focusing solely on the Karaaf, a better understanding of the hydrology of the wider area is going to be an input to that.

We’ve got all the agencies sitting around the table, recognising the issues and committed to working on it.

In some respects, Council is a bit limited in terms of the extent of our boundary and knowledge, so that’s where the other agencies are going to really important in understanding the best way to develop a management plan that focuses on how the entire system works.

Corangamite Catchment Management Authority's response:

There are 28 estuaries in the Corangamite region, only 10 need to be artificially opened through a permit and CCMA if the regulator of those openings.

The only 10 that are permitted for opening are the ones that have a human interface, so where there’s some sort of human interaction with that system.  All of the rest, where there’s no human assets as play, they’re just left alone.

The systems are dynamic and it’s important to leave them alone, which is overwhelmingly the scientific evidence.

In this situation, we’re dealing with human interactions, such as increased stormwater entering the system and a weir on the lower Thompson Creek, and when there’s that human interaction with the system things get a lot more challenging.

It is possible through some of the short-term measures that are looked at through the agency partnership that estuary openings could be considered to make sure factors are protected in the short-term, whilst those longer term actions are considered.

So it’s really important to make that distinction between a natural system and a system that’s impacted by humans and how the action taken will be different in those situations.

Corangamite Catchment Management Authority's response:

If a FLOWS assessment is undertaken it would inform an understanding of the hydrological requirements of the whole Karaaf-Breamlea wetland system. However, the first step is to assess if opening the estuary mouth is likely to increase the salinity in the saltmarsh affected areas identified in the vegetation assessment. A more comprehensive FLOWS assessment would only be undertaken if salinity could potentially be increased in the impacted areas.

Council's response:

The focus of our initial assessments within the Karaaf has been on vegetation extent and quality to understand the direct impacts stormwater inflows is having on the wetland system, however we know that altered conditions in the Karaaf has the potential to impact on fauna species as well.   

Increased total volumes of freshwater and freshwater inputs over the summer when the saltmarsh was naturally drier, leads to changes in vegetation composition which in turn can impact the suitability of the habitat for saltmarsh dependent fauna.  Similarly, the increased frequency and extent of prolonged inundation within areas of the Karaaf may also change the availability of specific habitats for fauna species throughout the year.

Council's response:

There are many factors which influence mosquito numbers. Some of these include the way wetlands are constructed and the mosquito predator population (such as fish and frogs).

Mosquito numbers are not expected to increase if changes are made in accordance with ‘mosquito risk assessment and management in constructed wetlands guidelines’ and fish and frog numbers remain healthy.

Council's response:

In terms of the quality of the stormwater, the primary concerns are the nutrient levels e.g. phosphorus and nitrogen bound to sediment particles, fertilisers and treatments from gardens and sport facilities and the like.  Impacts to fauna from changes in water quality have not been assessed, however there are no known chemical concerns with the stormwater inflows beyond altered nutrient and salinity levels.

Council’s response:

The Sands acts as a buffer between the stormwater system and the Karaaf.

There are five lakes, and evidence of the upstream impacts is more visible in the lakes that are closer to the Torquay north development than the Karaaf, so it’s clearly playing some kind of role.

One of the challenges we have here is where do we best invest our time, effort and money in the first instance – is it downstream or upstream?  The Karaaf is well and truly the focus.  We’ve got a list of actions that can be taken in the constructed wetlands to get them working as well as possible to prevent any downstream impacts.

However we need to understand more about the role and the condition of the Sands amenity lakes as they are part of that system.  

In the short-term our focus is upstream, but let’s also keep a close eye on how the Sands performs as part of that system.  We are committed to improving the overall system.

*Please note, we received several variations of questions about the Sands lakes system, which we have tried to consolidate here, but please let us know if you know if you feel your question hasn't been responded to.

Council’s response:

We are assessing our options to improve the quality of stormwater from our network and will begin implementing some of the actions identified in the North Torquay Constructed Wetland Assessment to improve the effectiveness of the constructed wetlands.

Council’s response:

The section 173 agreement is 20 years old.  It doesn’t make the Sands responsible for the stormwater passing through, just that it has to allow it to pass through.

As part of the overall project, we will look at the agreement given how much has changed, and the role of the Sands and Council.

We will have the conversation with the Sands Owners Corporation about what the appropriate agreements are to have in place now.  

Council’s response:

This is an option that will be considered as part of the next stage of the project. There are challenges as this area is currently considered unencumbered open space. If a wetland were to be constructed in this location Council would be required under the planning scheme to replace the equivalent open space elsewhere within the area, which will increase the cost of such an option.

Jason Sonneman’s (Design Flow) response:

Constructed wetlands are designed to capture sediments from stormwater runoff from the developed urban catchments. Construction sites such as Stretton estate are subject to erosion and sediment control plans which dictate that all sediment associated with stormwater runoff must be captured onsite. The construction of additional wetlands within the reserve between the Dunes Wetland (Horseshoe Bend Rd) and the Zeally Sands Wetlands would be difficult due to site slope (in excess of 6m), existing underground infrastructure and the narrow width of the reserve.

Council’s response:

The quality of stormwater needs to be improved and the volume entering via The Sands lakes system needs to be reduced. We are now exploring options that are better for the Karaaf Wetlands and will improve our community’s future water security.

We’re working with Barwon Water on a concept to divert stormwater away from the Karaaf, mix it with recycled water from Black Rock Water Reclamation Plant, and use it to support high value agricultural activities in the Thompson Valley.

In the meantime we are starting a new project to assess our options to improve the quality of stormwater from our network and to divert some water away from the Karaaf Wetlands.

We will also begin implementing some of the actions identified in the North Torquay Constructed Wetland Assessment to improve the effectiveness of the constructed wetlands.

We are partnering with Wadawurrung Traditional Owners Aboriginal Corporation, land managers (including The Sands Owners Corporation) and agencies responsible for the Karaaf Wetlands on a holistic and adaptive management plan.

We need to make sure that any actions we or others take are effective. This means that all agencies and partners will also need to gather more information before making any decisions that might change the way the Karaaf Wetlands functions.

Council’s response:

Council’s master planning of the stormwater network from over 10 years ago focused on managing peak flow rates rather than total volume.

Therefore the plans underestimated the amount of water that would be generated from north Torquay developments and did not identify the potential for it to affect the vegetation in the Karaaf Wetlands.

We know a lot more now than we knew then and are committed to learning from and addressing this.

Council’s response:

We will provide regular (at least monthly) updates about progress of this work to both key stakeholders and the community through our website, emails to subscribers, media releases and project meetings. We will establish a community reference group.

Council’s response:

As part of the scoping of the next stages of work, we will be seeking advice from other agencies and experts in the appropriate fields who specialise equally in both the ecological complexities and engineering complexities to ensure we have the right balance and spread of expertise to achieve the best possible outcomes.

Council’s response:

The easier modifications and maintenance work in constructed wetlands can be done now. But we need to know exactly what those things cost as the money that’s available could be burnt through really quickly and remove the opportunity to do anything else.

But there are things like the weed removal that could be done within weeks.

In terms of the discovery work (such as diversion options), this will take some time, more into the months.

And in the even longer-term – the opportunity to work with Barwon Water to reuse the stormwater - we could be looking at a multiple years timeframe.   This solution appears to be the silver bullet to the worst of the problems.

But there’s a decision point in the next six to 12 months: what do we invest in now versus waiting.

A sign of success will be an improvement in the condition of the Karaaf Wetlands, particularly at the western end. Ongoing monitoring of its condition as part of a management plan will be crucial.

Council’s response:

We’re grateful for the federal government’s support with the commitment of the $1.9 million, and we’re finding out more about the timing.

We know there’s money in the program spread across four years, and we’re hopeful that it’s in the 2022-23 budget.

We need to draw on the findings of the next pieces of work to determine the best use of this money.

We acknowledge that we need to reach agreement with the federal government on the exact scope of works it will fund.

Doug Frood’s response:

This is outside my brief, but hopefully that sort of money could go a long way towards protecting the Karaaf from stormwater inputs as the most immediate concern.

Council’s response:

There’s expertise that lives within our community, and we’re really blessed to have this. So if there is knowledge that can be contributed that supplements what we know, then we would love to have that.

We need to look at what kind of reference groups or advisory groups can be established to maintain that connection to the work that’s been done. If we can create the forums for healthy debate and critiquing the information that’s developed, that would be really helpful.  We’re open to ideas on the form this takes.

Council’s response:

Council is undertaking measures in this space, including increased street cleaning and monitoring of building sites with education and, if required, issuing of warnings to builders.

Council’s response:

No infringements have been issued to date. We have increased surveillance and issued a number of warnings. So far, builders who have been warned have complied to those warnings. Our preference is to warn and educate in the first instance before resorting to fines.  

Council’s response:

The legal framework referenced in the Karaaf program refers specifically to the Sands development and in particular, the drainage and environmental obligations agreed to when the Sands development occurred in the early 2000s.

At a local level, the existing legal framework includes local planning scheme provisions and a legal agreement (and by extension, approved management plans). 

The composition of a new legal framework will be heavily dependent on the proposed solutions coming out of stage 3 of the project.  While it would be would be premature to speculate on what those proposed solutions might be, we do not expect it to be necessary to advocate to the State Government for reforms to the state planning provisions.

We assume that the second part of the question posed around developer responsibilities, refers to water quality related to construction management rather than where stormwater is directed.  These kinds of developer obligations are set out in planning permits (and by extension, any endorsed documents and legal agreements).  It is therefore, unnecessary to rely on a change to the state planning provisions in order to alleviate pressure on the Karaaf wetlands.  

In relation to downstream impacts and pressure on the Sands drainage network, these matters will be further investigated in the stage 3 project.

Council’s response:

Council is the responsible agency.

For subdivisions, requirements are set out within planning permits, including preparation of a Construction Management Plan, which includes requirements for site management during construction.

For building sites, builders must comply with Council’s Community Amenity  Local Law No 1.

Under Council’s local law, the person in charge of a building site must deliver appropriate controls as recommended in the EPA’s ‘Civil construction, building and demolition guide’. This is an extensive document which includes many requirements on sediment control. Council has increased its proactive monitoring to help ensure compliance with these requirements.

Council's response:

A key part of the Karaaf program of projects has been the development of an overarching governance structure to manage its delivery in a structured and coordinated way following best practice project management principles.  The project is set up with a structure that sees the “program sponsor” General Manager Place Making and Environment as the key decision maker of the program who is supported by a Program Control Group (PCG) whose membership is made up representatives of key agencies and stakeholders. 

The PRCG provide a very specific support role to the program sponsor.  Their roles and responsibilities are outlined via an agreed terms of reference, which define their primary role as providing strategic oversight of coordinated planning and implementation of the project charters for each of the four projects including broader stakeholder engagement, procurement, budgetary strategy, and monitoring risks, quality, scope, issues and timeliness.

In addition, under the overarching program each of the four projects has its own subject matter specific project sponsor and project specific governance tailored to suit the size, scope and subject of the project.

For the first two projects that have been completed (projects 1 and 2: environmental assessment and stormwater assessment), both had their own project specific Project Control Groups which consisted of varying membership but broadly included members of the community, key stakeholders and agency representatives.

The role of the subject matter specific PCGs for projects 1 and 2 was to provide advice to the project sponsor of each project based on their expertise and areas of interest and stakeholder involvement. This included more specifically the following throughout the duration of the project delivery phase:

• Input and assistance into the development of the scope and brief for procurement of the specialist consultant services before it was sent out to market.
• Review of initial report draft and feedback for consideration by the specialist consultant.  The PCG members were asked to provide their feedback to the relevant project teams for each report.  This feedback from the PCG members was consolidated into a response which was sent to each specific consultant for consideration.

Feedback provided to the consultant was a combination of seeking additional clarity in findings and observations, charts, images and or general presentation. Clarifications on and or any amendments and adjustments to the report based on the feedback were at the discretion of the authors of both reports.

Changes made to the drafts by the author following their review of the feedback generated a new revision of the report to ensure ‘version control’ so that the latest information available was always clear. 

Updated versions of the reports were issued to the respective PCG groups for information following any updates as determined by the authors following feedback.  These were still considered ‘drafts’.

Before public release the reports were reviewed by Council for the purpose of accessibility, clarity, and publish readiness prior to public release with the Council agenda.  Approval of the reports for inclusion in the agenda and subsequent public release the reports changed the reports status from draft to final.

Council's response:

The initial communication plan proposed a small briefing of members from key environmental groups in addition to and prior to the public information session.  However it became clearer as the public information session was developed that there was likely duplication of attendees and that providing access to the expert consultant authors for all was going to provide a better outcome for both the environmental groups and broader community.  This would provide a better opportunity for everyone to have access to the same information at the same time and to observe different perspectives.   

Meetings were held as part of the communications plan and release of the reports for projects 1 and 2 with the current developers in north Torquay who are responsible for maintaining several of the constructed wetland systems and or have remaining stages to complete. 

These meetings were an opportunity to provide the developers with a summary of the audit information from the stormwater assessment report as well as the environmental report findings to start conversations about how we can progress and improve the outcomes from the system.  It also provided an opportunity to advise of the pending public information session and release of the full reports.

Council’s response:

It’s difficult to say as it’s very rare to have one staff member working on only one thing at one point in time.

Six months ago we didn’t have a stormwater co-ordinator, but now we do. We’re increasing our capability in this space.  There are other stormwater issues that this co-ordinator will be working on.

Importantly, we have funding in the program budget to draw on the expertise of others such as Jason and Doug who completed the stormwater and environmental assessments, because we don’t have all of the expertise in-house.

We have around a dozen staff working on this project including a project manager, engineers, ecologists, planners, communications staff, senior managers. In addition we have operational staff in our civil maintenance and open space maintenance, waste and local laws teams doing work to assist the project.