Transcript
Ivy Jensen
Welcome to Talking Water with GMW where we discuss all things water. Today we are joined by our very own environmental maintenance coordinator, Danielle McMillan. Danielle discusses our most ambitious weed treatment program to date and some of the interesting innovations happening around how we approach weed management. We have episodes on a range of topics, including Winter Works, which is running alongside our weed treatment program, so be sure to tune in to those after this one.
Ivy Jensen
I wanted to start with you actually and just wanted to get a bit of a background on how you came to be ay GMW
Danielle McMillan
I grew up on a dairy farm in the Murray Valley Irrigation District as a child and then went off to AG College to study agriculture, and then from there went into mainly research, so cropping research, chemical research. I lived in the Mallee for five years. I was at the Birchip Cropping Group over there doing some trials and then moved back closer to home in 2015. From there I sort of wanted to do something new and the aquatic weeds is something that's very niche. There aren't a lot of jobs that sort of operate or a lot of people that have a lot of knowledge around aquatic weeds. So yeah, it was a nice little thing that I just fell into in the end.
Ivy Jensen
I was going to ask you about that, Danielle. It is a very niche area and I'm guessing a lot of people wouldn't know that that is an industry that they can get into. How did you get into that?
Danielle McMillan
I think at the time GMW was running some trials with where I was working and yet sort of just evolved from there. I had a lot of chemistry like herbicide knowledge through trials that I'd been running and whatnot but not a lot in the aquatic weird space. But yeah, there was another fellow that worked at GMW, that certainly had a lot of knowledge in the aquatic space, and then it sort of just built up from there. But it is a very niche area. It's a good side area to work in and there's certainly other people within other irrigation organisations that work in the aquatic space. But it's relatively tricky when you don't have a huge community to rely on, that's for sure.
Ivy Jensen
But you need a fair bit of lead time to plan that out. So when do you start planning for winter works?
Danielle McMillan
So two years ago, we sort of recognized that we had a massive problem with submerged weeds throughout the GMW irrigation channels, and chemicals that we had, I guess tools in the toolbox is how we refer to it, weren't working. We were very reactive in the way that we were treating weeds. Yeah, just trying to fix problems as they arise rather than preventatively trading channels. So I guess we sort of canvased a few chemical companies to see what was up and coming products that then have available that we could sort of tailor make to suit what we were doing. So I guess that sort of started some work in this space, which was pretty exciting given we haven't ever had that before in terms of proactively out there trying to seek new alternatives.
So last year I think we ended up doing 240 kilometres. And then off the back of that, we've been able to change sort of application types, really tailor my programs that we set out, look at weight types specifically. And then this year our plan is to roll out across all three irrigation districts in Central and West. So we kicked off two days ago and we've gone out pretty hard and fast given we're up against the weather next week. It's been a bit wet, but we're hoping to get high ranked priorities in each irrigation district. It's a bit over 320 kilometers I think on the wish list, I guess we are calling it. But yeah, just weather dependent. We're inspecting as we go as to where we find weights and whatnot.
Ivy Jensen
So can you just explain the process of how you go about treating these weeds?
Danielle McMillan
Yep. So we work with the areas pretty early to identify channels that they're having trouble with in terms of weight load. Then we go about doing some inspections just to identify species and any other types of problems that we might come up against when we are trading. But we have a fleet of vehicles, trucks and utes that are set up for spraying across the day. We obviously have our full time staff that are trained with chemicals and we basically work with the area. So there's different application types that we can do with this product. We can either dewater the channel fully, surface, spray the soil and get the chemical directly onto the plant. We're also treating the water volume in channels so we're not having to dewater, which works for other weed types. We have found we had really good results with that last year. The other application type that we have on our permit is we can do a flowing injection so we can inject at a regulator, draw the water down over the target area and then pull the water up. So where access is really bad that becomes another good application tool.
So they're out basically manually buying these products, whether it be direct, injecting into water, using the booms or surface spraying by hand.
Ivy Jensen
Yeah. So it's not just a one size fits all approach, is it?
Danielle McMillan
So for every channel, we've basically got to do an inspection to work out whether we've got access, because on a lot of channels we do have very poor access, which makes our life quite difficult. But every channel has to be inspected and we write an individual application for every channel based on application type. And then other factors come into play like the width of the channel, the depth of the water, because it's treated on water volume and certain factors.
We're adding some surfactants and a few other things this year to try and increase the uptake by the plant as well. So certainly a lot of effort in the set up, but once we get rolling, it probably will take three or four weeks in total without any weather interruptions and then that could be slightly longer. But given aquatic weeds go dormant over the winter period, June is really sweet spot before the plants go too dormant towards the end of July, once we've had a lot of cold weather.
Ivy Jensen
So this year, we're using a herbicide that has minimal effect on fish life. Can you explain a bit about that?
Danielle McMillan
So these products main target is for natural waterways. So it's registered for natural waterway use, and has minimal effect on aquatic life. So with other products we do see toxicity by fish and other products are harmful to them. We have trended towards something that's a little bit softer. So we're seeing great results in terms of weed control. Plus last year we recorded zero fish death. So it's is a good move by GMW to move towards something that's a little bit more environmentally friendly. Submerged weeds affect water flow and obviously promote the silting of the channels and wear and tear on our regulators because they're always trying to overcompensate by the impact on the flow. So the weed treating itself is really critical to the way that we run water and water delivery to our customers.
But we do deliver a lot of environmental water now. So there's a lot of risk around treatments and a lot of channels to end up in the natural area. So trying to reduce products that are harmful to fish and other aquatic life is high on our radar at the moment and certainly something that we're conscious of and products that we have used in the past.
There's still a tool that we can use. It's just something where that's a very reactive way to treat weeds and it doesn't control the weed, just burns off what is present there. So we're not actually getting control by using those products, just trying to take away a problem that we have in that space of time. So this is more trying to shift towards prevention to really trading weeds and increasing the health of that channels.
Ivy Jensen
So you would have seen a lot of changes in herbicides are used and in what is put in the herbicides over the years is that technology's still building. And what do you see the future of weed management?
Danielle McMillan
It's tricky because it all comes back to there being an investment, I guess, by the companies. So the aquatic weed space is a very small one. We have a few companies now in the space, and it's really gaining a lot of traction because there is such a big weed problem. There's a push from the irrigation companies to try and reduce fish deaths and a few other things.
There's a lot happening in the background. I guess this time we're working with this chemical company. We've said 'these are the weed species that we do have in our channels. This is the way that we have a winter maintenance period where we shut down, able to treat weeds, where people don't have access to water,' so they understand sort of what we're up against. So it's a very proactive way, I guess, to get something that's really useful and a product that we're able to use in a constructive manner going forward.
Ivy Jensen
Yeah. Is there anything you'd like customers to know about what's happening in the next month or two?
Danielle McMillan
We've notified customers that will be directly impacted by these treatments and certainly, and are fielding a lot of calls. If anyone needs any more information, I'm happy to provide that to people. But while it's sort of short term pain, I guess it's the long term gain. So we are really putting a lot of effort into increasing the health of our channels, controlling these weight so that down the track that basically is a direct link to customer delivery and them being able to get their water on time.