Hello and welcome to this Local Land Services training on-demand workshop. My name is Rob Campbell. I'll be hosting today and sitting with me is Alison Elvin from Natural Capital, presenting on how to get a healthy farm dam and your property.
We're delivering these training sessions to complement the workshops and events that are happening in the paddock. So this workshop is supported by Local Land Services with funding from the Catchment Acts in New South Wales and the Australian Government's National Landcare Program. We hope you'll find it valuable and worthwhile and enjoy the process.
So presenting today is Alison Elvin. Alison is a real trainer with a long history in working with farmers. She's a farmer herself in the area and also a director of Natural Capital Project Limited.
I had the pleasure of attending one of Allison's workshops earlier in the week and was just fascinated by her depth of knowledge and her ability to be able to describe things which are fairly technical but in a very practical and pragmatic sense.
So welcome Alison.
Thank you very much Rob and it's lovely to be here with you all and welcome to this webinar. I'm going to talk about water and healthy water.
It's a strange thing that you might think about water as being healthy. Here's a whole lot of us out near Wellington looking at healthy water the other day and thinking, well what is this thing called water?
We all need it for life. Every living cell on Earth needs water to undergo all its living processes. And yet water is not just hydrogen and oxygen. Water is able to dissolve more substances on Earth than anything else. It is a universal solvent.
Water has the ability to flow. Not many other things flow like water does. Water has a surface tension. As you know, you can see insects walking across water. That surface tension is very important and often needs to be broken by surfactants that we add to things like our herbicides in order for the active part of the herbicide to enter the cell of the plant to kill the plant.
Water also has high specific heat. That means it warms up and cools down relatively slowly. Water moderates temperature in a landscape if given the opportunity to do so.
So because of all of these wonderful and unique characteristics about the H₂O molecule, it means that water is able to attach to all sorts of other molecules biochemically or chemically. Also, many substances dissolve in this water and are carried across the landscape because water flows.
Water is also a medium in which such a huge range of living organisms are able to live. The organisms that we can't see—the bacteria, the algae and some of the fungus that live in water—are critical to making that water healthy or not healthy.
Also of relevance to all of us on the land is the fact that unhealthy water—water that can contaminate our livestock and make their lives very unhealthy—means that we can lose up to 20% of our productivity.
There's been a lot of research conducted in North America and Canada and now in Australia looking at things like the live weight of an animal when it leaves the farm, the overall health of the animal, the veterinary visits to the farm, the ability of the animal to undergo successful lactation and birth, the disease burden, the parasitic burden in the animal.
And we've found that there's about a 20 percent drop in your productivity—and so your profits—by giving those animals unhealthy water to drink.
So it's very, very important that we all begin to understand what we can do about the water in our dams and our creeks and our rivers to make it a much healthier environment.
We're not looking to get so-called pure water—that's just distilled water, which is hydrogen and oxygen. We are looking to get healthy water.
In this next photograph you see a typical farm dam. Farmers put a fence through it. The fence has corroded out. He wasn't then able to use it to water both paddocks.
Around that farm dam is pasture and bare banks. Another farm dam—very similar conditions—bare banks, eroding pasture, fairly heavily grazed, nothing else around that dam.
Cattle around a dam—we see that everywhere because of course, why are the dams there? Just to water our livestock. Well, why would we keep them out of it?
Here's a dam where livestock have been given unlimited access to the edge of the dam. They've grazed very heavily, as you can see in this picture. They've grazed down the tussock-forming grasses to little stumps.
There's real erosion and the light-coloured soil is actually salt that's starting to appear on the surface. You can also see some dried cow manure there. That's the pugging effect that cattle have on the edge of water, where you can see they're compacting the soil.
They're shifting sediment into that water by trampling in it. And of course, although it's not obvious in that photo, there is manure, there's urine and there's saliva all happily spread into the water by the cattle drinking that water.
And this is what that dam really looked like on that day—a beautiful blue-green algae film across the water, so toxic that nothing could drink it any longer.
Notice all the animal manure—the cattle poo—around the edges and the trampling effect on those edges.
When we look at water quality, if we were to do chemical tests on water quality, we would look at such things as: what is the acidity or the pH of that water?
There are many, many sorts of chemical tests that you can do. As well as pH—you want a pH around about 6.5 to 7.5. You can get a bit more acid or a little bit more alkaline, but not too much. Otherwise you start to have problems with the health of your animals drinking that water.
You also want to look at the temperature of your water. This paddock—sorry, this dam—that you're looking at on the screen at the moment, the water temperature was warmer than your blood. It was about 38 degrees.
It was very warm—the perfect conditions to brew up the algae together with all the manure that had gone into it and the sediment.
You want to look at the turbidity of the water. On the previous picture you could see that you couldn't see down to the bottom of that dam because there was so much sediment suspended in that water.
The reason is it's being trampled all the time and the sediment is carrying many chemicals and many pollutants into that water column.
You also want to know how much nitrate and phosphate might there be in your water. In that dam there, there would be a lot of nitrates and a lot of phosphates, allowing the blue-green algae to start growing and blooming.
Are there heavy metal concentrations in your dam? If you've been using a lot of fertiliser, many different types of herbicides and pesticides that run off into your dam—some of them will be carrying some heavy metals that could be attached to the sediment and thus polluting your water.
And also, what organisms are living in your dam? Many of them are called faecal coliform organisms—E. coli—that in higher concentrations can cause a great deal of ill health in animals.
So there's a lot of things that you can look at in your farm dam to know what the quality of that water is. But one of the simplest tests that you can do is to look at what insects live in and around that water.
I would suggest that you look up on the web Stream Watch or Water Watch guidelines for using insects and macroinvertebrates, as they call them, as indicators of water quality condition in your dam.
This is a farm dam that had a fair bit of an algal bloom in it. This algal bloom was dependent on iron in the water. It was extremely contaminated water and the smell was so awful it drove the owners to go and stay in town for a few days.
Don't let your dam get like this. This is a typical creek on so many farms where stock have unlimited access to that water. You can see that there's animal tracks on both sides of the water. There's a bit of a blue-green algae bloom starting up. There's slumping of the banks towards the edge of the water and there's no protection between where that sediment is and where the water body begins.
So I keep talking about sediment. One of the biggest things that we have in our dams is sediment. Many of us have to dredge our dams every 10 years or even more often because there is nothing protecting the dam from runoff from the paddock.
When it rains and the surface flows of water go across your paddocks, they run straight down into the dam carrying the manure, carrying leftover chemicals, carrying pathogenic diseases that could be in your animals' manure straight into the dam.
There is nothing to capture that sediment. That sediment bonds with the water molecule. So one of the first remediation things that you can do is manage your stock access to the dam and allow the inflow areas of your dam to be built up with reeds, rushes and sedges.
Like this picture you're looking at now, the water runs through those reeds before it ever gets into the dam. So it runs off the smooth edges of the pasture around it, carrying with it the contaminated sediment. As it hits those reeds and rushes, the water slows down, drops a lot of its sediment, and that sediment is cleaned in those—what we would call—a sedimentation trap before the water ever trickles down into the dam, much cleaner than when it first entered those reeds and rushes.
This is another example of inflow reeds. These are actually not reeds, these are sedges that are growing in the inflow area to a dam. There's a good depth to them. You need much more than one row of them if possible. If you could have a depth of even as big as 30 metres, you would be guaranteed you're cleaning all of your water before it runs into your dam.
There's another type of reed that grows actually at the water's edge that similarly will start to contract and buffer and filter the water running into your dam.
In this picture here, it's a farm in the Southern Tablelands, but not so different from some of the country in the Central West. You'll see down the bottom half of the picture there are some lighter coloured tussock grasses. They're Poa tussock and sedges, and they are protecting the water running off that hill down the catchment into the dam that you can just see the beginning of on the left-hand side of the screen.
One of the biggest single things, as I've already said, that you need to do—we all need to do—to protect the water of our dams and make it more healthy is to control stock accessing the dam.
There are many ways to do it. We can fence the dam off, obviously leave a gate in it, plant vegetation. When that vegetation is big enough to withstand stock pressure again, we can let the stock back in occasionally for short periods of time.
Another option is that we can do the same thing and reticulate the water out of the dam to a holding tank and then down to a trough system. Many people do this.
Some people have got steep enough land where they can just deliberately immediately gravity-feed water from a pipe down to a trough without having to have a pump.
And if you have an intensive grazing operation—a grazing rotational system like a holistic cell grazing management system—and stock are in that paddock for a very short time with great long rest periods, you may not need to do any fencing at all.
The important thing is to get the vegetation in your inflow and around your body of water up and growing to slow and filter the contaminated water coming into your dam.
Here's another picture of a farmer who has simply started rotating his stock. As a result of that, all of this inflow tussocks and sedges and reeds have started to grow back.
He has not added any additional fencing, but he's allowed those to grow. On the right-hand side of the picture, you can see that out of the blue—brought in by birds—the seeds of a native reed have started germinating and growing.
And for the first time ever, water birds have landed there and started to make nests, which was very exciting.
This is the same dam. You can see those reeds colonising the edge, actually protecting the erosion up above and also stopping the water coming to the base of that eroded slope and eroding it further through the wave action of the water.
In the foreground of the dam, you can still see there's manure. The cattle have still got access. It would be preferable if they had less access, but this is the beginning of the dam starting to heal and to produce much healthier water.
Another dam—photo taken by the side of the road. This dam has rotational grazing practised on the farm so that the edges around the dam aren't trampled into exclusion, and so they're offering some filtering—but not enough.
They need to go back probably as far as where that blackberry bush is in order to be really efficient in filtering the water.
This is a dam with no exclusion on a very hot summer's day and was constantly accessed by all the stock on this farm.
The owners were very keen to do something about the water quality because their stock were getting sick, and so they agreed to fence it out all the way around.
Eighteen months later, this is what the dam looked like all the way around. Reeds and sedges had started to come in of their own accord because there were no animals trampling and eating them any longer.
The reeds that you can see into the water on this photograph are critical to grow around what we call the toe of the bank and the toe of the dam, which is where the water meets the earth—where the water meets the sides of the dam.
If those small reeds are able to grow there, they break up the effect of the wave action and they stop sediment coming from the sides of the dam going into the water and contaminating it.
They planted some trees and shrubs. They electric-fenced the edges of the dam. As you can see, the panic grasses really got a go on in the foreground there.
And notice the reeds at the very edge again came in of their own accord. None of those were planted.
This is a photograph provided to me by Dave Hunter from the Office of Environment and Heritage, who very kindly allowed me to use this picture because it illustrates another feature of the vegetation that you really want to grow in and around your dam.
When you look at those frogs—that's a lovely picture—but look alongside them and you will see a whole lot of gunk growing on the leaves and the stems of the plants that the frogs are holding on to.
That gunk is something called a biofilm, and it's created by a gelatinous coat extruded by a whole range of microbes that live on those stems.
As the water flows past those stems, it's slowed down by those stems. The water and all the pollutants and sediment it's carrying is attached and attracted to the jelly-like coat—what we would call slime.
The organisms that live in that slime often are capable of then taking apart the polluting molecules and detoxifying them.
In other words, it's a wonderful natural cleaning system in water—quite aside from the fact that frogs need it to hang on to to mate.
Here's a picture of reeds that are also accumulating biofilm underwater. You can see the sediment with its attachment.
You can't actually see the pollutants, of course, because they're microscopic, but you can see the sediment attached to those stems underwater.
The water around them is beautifully clean. There's another type of plant that grows in water that also cools the surface of the water down and, by reducing the temperature, increases the available oxygen in the water—which is another critical indicator of water health.
Those water ribbons appear to our eye often to make the water look dirty, but if you look underneath the jetty, you can see how clean that water is. You can see down to the bottom of that dam.
Another picture to show you how clean water can be—by the biofilm on the debris at the edge of a dam.
A catfish in a dam—one of our dams at home—following me around, wondering whether I'm going to let her ever lay her eggs in the nest that she's made out of a small amount of pebbles that I put down by the side of the dam a few years earlier.
Not at that time knowing that catfish will use those pebbles to make nests along the edges of where the water and the
Never put deep-rooted plants onto your dam wall because they can ultimately cause that wall to break open. These are shallow-rooted Lomandras somebody has planted on their dam wall, holding them in place at the time of planting just with a few logs. Over time they will colonise the whole dam wall as well.
This plant—native, named Happy Wanderer or Hardenbergia—that will spread out and colonise the wall together with a grass. The couch grass—the native couch and the exotic—are both very good at covering dam walls.
This is an inflow into a dam with actually a kangaroo grass understory, and through the kangaroo grass come all the spring wildflowers down the inflow into the dam, which makes it a very pleasant place to be.
Another thing about creating a healthy farm dam is to have differences in water levels in your dam. Create shallow edges, like putting some rocks at the edge. Shallow edges will allow insects and a whole range of other organisms to breed, which will feed the food chain of everything else living in your dam, which will make your water much healthier.
Another type of shallow edge—and here is something else to know about planting out farm dams—is that every species of plant in and around water grows in its own specific zone. Some like to be inundated with water all the time. Some grow in depths of water only to a few centimetres. Some like water around their roots only some of the time. The rest of the time they like to be dry.
Some like to be set right back from the high-water mark, where they've got very deep roots that will eventually access the subsoil moisture. It's worthwhile getting information from your LLS officers to find out which plants to plant where, if you do plant any at all.
You can make all kinds of islands in dams. These are reed islands. Foxes aren't real keen to swim out to those to eat whoever's living on them. They will do it, of course, if they're starving, but if they've got a bit of other tucker they'll leave them in peace.
You can also have islands with trees on them. And this is just a photograph to show the zones of some of the plants that will live around the edges and then back from the high-water mark.
This is a sedimentation pond designed by the Urban Services people in Canberra to capture sediment off a major highway.
This is a chain of ponds that quite accidentally happened when grazing pressure was changed in a farming system. As the stock were rotated and kept out of the paddock for longer before they came out to the paddock, the water couch that you can see at the front of the photograph—the brownish-coloured stuff—started to grow in abundance, holding the water back into a pond.
And the water, as it filled up, trickled through the couch. Of course, it was being cleaned at that time. Also, the banks of that pond started to grass in and reduce erosion.
That water has become sweeter and sweeter over time, and now there is a chain of ponds going through that landscape, where once upon a time it was just water that ran all the way off and down the creek and out the other side.
This is a picture to talk about one of the other values of dams that nobody ever talks about, because all we ever mention is profitability and how we're going to make more money or make more profit or more production from our land.
And we very rarely mention the aesthetic pleasure—and, if you like, the deep emotional pleasure—that water and what lives in and around water can give us and be a real solace to us in very difficult times through our lives.
And I don't think that it's something that should be overlooked.
And the last picture is an equivalent picture of an Australian male. There are some of our native water lilies. The photograph was taken in your central region or town of Dubbo, in one of your parks here.
And I think we should submit this to the National Gallery to be hung near a Monet—not this photo, but a good photo of the wetlands that we have and the water plants that we have that clean our water and make it really healthy.
Thank you.
Great, thank you Allison. And yeah, that was fascinating. I really enjoyed listening to you talk about obviously something you're quite passionate about and knowledgeable about as well. So really appreciate you coming on and talking to us, and I hope people out there enjoyed it as well.
Thank you very much Rob, and thank you for giving me the opportunity.
Now, great, thank you Allison—and thanks for listening as well.
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