Transcript
Ivy Jensen
Welcome to Talking Water with GMW where we discuss all things water.
Today we are joined by the North Central CMA's Peter Rose and the Victorian Environmental Water Holders Keith Chalmers.
Peter and Keith discuss how their organisations are looking to revitalize northern Victoria's waterways to support the native plants and animals that call them home. They also talk about the methods being used to reduce carp populations and how we can ensure native fish prosper instead.
We have episodes on a range of topics on our website, so there is plenty more to listen to. When we're finished with this one.
Klaus Nannestad
Peter, can you tell me a bit about your role and also the role of the North Central Catchment Management Authority?
Peter Rose
Yeah, so my role, I'm project manager for the Native Fish Recovery plan in the Loddon region. In terms of the North Central CMA, our Catchment Management Authority area covers about 13% of Victoria. The main river basins we look after the Loddon, the Campaspe, the Avoca and the Avon-Richardson. And the main mission of the CMA is to create natural resource management partnerships and programs that deliver lasting change. Basically working with our community to improve the catchment health.
Klaus Nannestad
Thanks Peter.
And Keith, would you also just like to tell me a bit about your role and the role of the Victorian Environmental Water Holder?
Keith Chalmers
Yes, so my role is focused on the planning and delivery of water for the environment. A lot of what I do is in northern Victoria, but the Victorian Government will hold a statewide organization. So we're an independent statutory authority that has the role of managing the water that's held by Victoria for the environment and working with our partners like the Catchment Management Authorities and others, to use that water and deliver that water to the best possible environmental outcomes that we can get.
So it's a bit of a niche organization, not quite as broad and wide ranging as what the Catchment Management Authorities do. But Victoria has a fair amount of water for the environment across the state and our role is to manage that water.
Klaus Nannestad
Yeah, and can you elaborate a bit on what it means when we talk about water for the environment?
Keith Chalmers
Yeah, so water for the environment is water that's held in storages – a bit like the way water is held for irrigators or for urban supply – so that water is available for us to deliver in our rivers, across our floodplains and wetlands for the benefits of native plants and animals. So we plan to do that each year, working with our partners and working with the conditions that we've got at the time and using that water as effectively as we can to support those environmental outcomes.
Klaus Nannestad
Yeah. I might go back to you Peter, because you mentioned that the floods last year had impacted your area, but can you tell me a bit about the main effects of the floods?
Peter Rose
Yes, the flooding had negative and positive impacts for our rivers. When you look at communities like Rochester, there were quite devastating impacts there. But our rivers also took a bit of a hit. Some of the areas in the rivers were impacted by erosion of the banks, and in some areas there was a lot of deposition of silt. One of the main impacts from the floods was water quality. So because the floods were really large and got right down to the floodplain, and were following a wet season where there was a lot of crops doing really well, a lot of organic matter and nutrients washed into the river system and that caused some anoxic backwater which resulted in some fish deaths in some of our systems up north. So places like the Lower Loddon and the Little Murray were pretty heavily impacted by that.
But, you know, on the flipside, flooding is a natural part of our environment and that plants and animals are really adapted to that. And we don't get a lot of the small and medium floods that we would have before European occupation. So there was some obviously great benefits to native plants and animals, for example, the higher kind of areas with blackbox woodlands and river red gum forests up north got good drink water.
Birds will be doing pretty well because of the floods and despite the anoxic blackwater, bigger picture native fish will do really well and boom because the carbon that does flow into the rivers from flooding is their food source, essentially. So, you know, we expect them to do pretty well in the next couple of years because of it.
Klaus Nannestad
Yeah. And Keith, has it also changed operations for the Victorian Environmental Water Holder?
Keith Chalmers
Yeah. So we plan on what we'd like to do each year under a range of conditions, anything from drought, dry, average and wet. The same way that the Victorian Resource Manager announces potential water availability under different climate scenarios. But the floods were, as Peter said, a really, really big, really significant and it means that we need to go back and look at what we're doing and why we're doing the environmental flows that we had planned.
So there's a few examples. So in some cases we were able to respond on the back of the floods. So once things had receded back into sort of channel capacity and we weren't going to impact on towns or farms with using water for the environment, we were able to do some small releases – working with GMW – in places like the Lower Broken Creek over sort of Numurkah way to try and provide some fresh water into that system, which had the same issue with low oxygen levels to try and protect the native fish. So we respond when we can. We can't do enough to sort of deal with the really big low oxygen levels in places like the Murray, it's just too big a scale for us to respond to.
But some of those smaller examples, smaller creek systems, we can, and then we look ahead as well. So we've certainly got events planned in autumn across the state. So we maintain sort of low flows in rivers as well as some freshers.
But one example is in the Lower Goulburn River, working with GBCMA, we had a planned autumn fresh there, but the monitoring and talking to the scientists and sort of showing that the objectives we had for that event for native fish, which is really a key flow for fish migration and movement of native fish, bank vegetation, some of the critters live in the river like shrimp and water bugs and that kind of stuff. All of those things we don't think we can improve by delivering that fresh.
So the bank vegetation is in great condition following the flood. Now we've had some low inflows. We think the water balance, there’s anecdotal evidence that there's lots of shrimp in the river from recreational fishing is giving us a bit of feedback. And fish migration for native fish on the back of a carp boom is not something that we think is something we can really achieve in the Lower Goulburn. So that event was planned is now not going to go ahead at the moment. So that's a significant event. It's quite a large one that we do and we do it in most years, but that's an example of where I'm working with the scientists, the Catchment Management Authority guys and even a bit of community feedback from recreational fishers and things like that, really sort of go to inform a change of plans for us on the back of this sort of flood event.
Klaus Nannestad
Absolutely. And you mentioned the carp boom there, Peter. I know that's been an issue in your region. Can you tell me a bit about in the aftermath of the floods, what's been done to try and prevent that and what sort of future actions will also take place to try and restrict the number of carp?
Peter Rose
Yeah, sure. It's really challenging, and it's not just a local issue. Carp boomed right across the basin because of the flooding. And unfortunately this is just what happens when it floods; where there's water getting out onto the floodplain and the warmer times of the year, you just get carp booms. Carp numbers usually jump, we've seen it before we'll see it again. But on the flipside, native fish are also expected to do pretty well out of that. Look, there's not a lot of strings in our bow in terms of what we can do to manage carp. Locally for some of the kind of more protected areas where we've got good native fish populations like Gunbower Creek, we were able to close the fish ways to prevent carp moving up from the Murray while there's heaps of juvenile ones around and we've done some fishway trapping as well at those fishways and being able to move some of those carp across to Charlie Carp to be used as a resource.
But really when it comes to managing carp, our best bet is managing native fish longer term. So that's all about, you know, fixing up the flows. So getting the flows right to benefit native fish like Murray Cod and Golden Perch, which are carp predators, getting the connectivity right for our native fish.
So putting in fishways so that fish can move around and breed and fixing up the habitat. Also, talking about improving riparian zones, getting in-stream habitat there, so our native fish can do well. I mean, there's obviously management strategies being discussed at a national level like the carp virus, which if it comes to fruition, won't be a silver bullet. So our focus is really doing what we can for native fish and getting the balance right, and that's how we manage for.
Klaus Nannestad
Yeah, thanks Peter. And Keith, has your watering program also been adapted in any way to sort of mitigate the carp effect.
Keith Chalmers
Yeah, so it's a tricky one with carp because they're just so robust and such generalists that they do well under a whole wide range of conditions, hence why it's such a pest in our rivers. But I guess the fish migration example's a good one. We often look at the opportunity to move fish around the system. We tend to have big breeding events of things like perch in particular locations throughout the Murray-Darling Basin and then using water for the environment, deliver flows that help those juvenile fish move.
But at the moment, with the number of carp in the system, with fishways closed, as we mentioned, that opportunity for fish migration has really decreased and therefore what would be a priority in autumn across many of our rivers really drops away.
Klaus Nannestad
Yeah, I'm glad you mentioned the fishways case because that actually reminded me of Peter. I wanted to ask you a bit about the fishways and the Native Fish Recovery plan. Can you tell me a bit about the NCCMA’s involvement for that program?
Peter Rose
Yeah. So our Native Fish Recovery plan for the Gunbower and Lower Loddon has sort of been in place since 2014. And it's it's a large scale, a long term plan. So we're looking at connecting up 530 kms of open flowing Murray River with over 400 kms of waterways and wetlands just in the NCCMA area. And that plan is really all about fixing up the flows, the habitat and the connectivity. And in the last three years there's been a real push towards getting those fishways constructed and really opening up fish passage. So there's been over $22 million invested in fish ways and fish screens and fish habitat over the last three years.
In 2021, fishways were constructed on the Koondrook Weir and Cohuna Weir in really great partnership projects with GMW and the VEWH and DEECA, so that's now opened up fish passage from the Murray River into Gunbower Creek.
So 144 kilometers of waterways opened up. You know, back in 2016 with the GMW Connections Project, fishways were built on Little Murray Weir and Fish Point Weir, down in the Murray River. A fishway in Kerang was upgraded and also the Box creek fish lock was constructed. So that sort of opened up the entire Loddon System to the Murray, and now we're at a point where we're about to go ahead with the construction of Taylors Fishway, which is a really important one, just upstream of Ghow Swamp. And with construction of that fish way that will connect up the entire Loddon system to the Gunbower Creek system and kind of create that whole loop for native fish to do their thing.
That's a really exciting project, that one. It's also good extra significance in that Ghow Swamp. It could be a really important productive area for Golden Perch in particular. And we know that when water is pushed down the Pyramid Creek, a lot of golden perch actually migrate up. Now they migrate past the Box Creek fish lock into Ghow swamp and they hightail it across, where they can get to Taylors Weir, and then they're on their breeding migration. So it is a really important opportunity opened up with the construction of this fishway, not just movement of things like Murray Cod and Trout Cod which occur in that system, but also an opportunity for things like gold and silver perch to really do well.
Klaus Nannestad
Yeah, thanks Peter. And Keith, does the VEWH also have a role in the fishways?
Keith Chalmers
Yeah, so one thing the VEWH has I guess given the water that we hold across northern Victoria, we can essentially do three things with it. We can deliver it, which is generally a priority to use that water for environmental outcomes, we can carry over from one year to the next and we can trade it.
So to trade there’s couple of things we can do. One of them is commercial trade sale of some allocation from year to year. When we do that, we invest the revenue back into things that improve the outcomes of the program. So we're always using our water to improve the program. And yes, as Peter mentioned, one example is we've been able to use trade revenue to invest in funding that fishway on request.
So, for us, we recognise the importance of those sort of complementary actions to just delivering water as well. So there's a whole lot of things that go into looking after our environment and that's one example where the revenue from our of allocation can sort of improve the effectiveness of our watering and the outcomes for that in this case native fish.
Klaus Nannestad
Yeah, fantastic. Thank you both. Anything else you'd like to add? Anything we haven't covered?
Peter Rose
I guess I've probably covered it a little bit, but I just want to recognize the value of really good partnerships and those partnerships with Goulburn Murray Water Water and with the Victoria Environmental Water Holder have been so important to be able to do these large scale infrastructure projects and I just want to thank you for those partnerships.
Keith Chalmers
I think along the same lines, we work really closely with GMW, with releasing water from headwork storages on the rivers, as well as delivering water through the irrigation district to key wetlands and places like Broken Creek and Gunbower Creek. So it's a really close working relationship as one of the water users in the system, and we do that to try and minimize their impact on irrigators through various ways.
But the ability to sort of look after the environment within that intensively irrigated district is really see it as a win-win both for the environment and hopefully for the locals and the irrigators in the district as well.