Insights from an Earth Dam Specialist - S2E4

Join us for an insightful conversation with Belinda Boer, an Earth Dam and DAMFIX specialist, as we explore practical solutions for reducing water loss and improving on-farm water conservation. From dam maintenance and sealing techniques to the future of agricultural water management. Belinda shares valuable experiences and advice for farmers looking to make every drop count.

You can find Belinda on LinkedIn: linkedin.com/in/belindaboer

Email: belinda@dampro.co.za 

2026 South African Institute of Agricultural Engineers Symposium Announcement 

The 2026 SAIAE Biennial Symposium will take place from 21 to 23 October 2026 at the Protea Hotel by Marriott in Upington, Northern Cape. Hosted by the SAIAE, the event theme is "Driving Agricultural Growth through Engineering Excellence."  

To register and abstract submissions contact: Mr Senzo Masikane at senzo@saiae.co.za

Transcript

Announcer: If you work in agriculture, agriculture engineering, biosystems engineering, research, or academia, then this is for you. The South African Institute of Agricultural Engineers Biennial Symposium 2026 is back. It is scheduled to take place from the 21st to the 23rd of October in Upington, Northern Cape. Under the theme "Driving Agricultural Growth Through Engineering Excellence," the symposium will bring together engineers, researchers, industry professionals, and students to share ideas, showcase innovations, and tackle real-world agricultural challenges. Whether you're presenting research, exploring new technologies, or looking to expand your professional network, this is the place to connect, learn, and collaborate. Abstract submissions and registrations are now open. And if you can't join us in person, you can participate virtually from anywhere. Visit the SAIAE website today to register, submit your abstract, and be part of the future of agricultural engineering. We look forward to seeing you in Upington this October.

Introduction

Dr Udhav Maharaj: Hello, and welcome to the Agricultural Engineering Podcast. This podcast covers all aspects of agricultural engineering. It is produced by the South African Institute of Agricultural Engineers. We encourage you to tune in and explore the exciting world of agricultural engineering with us.

My name is Dr Udhav Maharaj, and I'm the host for today. Our guest today is Belinda Boer, who is a specialist in earth dam maintenance and on-farm water conservation. She works closely with farmers across South Africa to identify sources of water loss and implement effective strategies to improve dam efficiency. As a DamFix application specialist, Belinda provides practical, hands-on solutions to seal earth dams and enhance water retention, helping producers to maximize their available resources and improve long-term sustainability.

Interview: Part 1

Dr Udhav Maharaj: Hi Belinda, welcome to the South African Institute of Agricultural Engineering Podcast. I'm Idaff Meraj, and I'll be the host for today.

Belinda Boer: Good morning, and thank you for having me.

Dr Udhav Maharaj: Yeah, no, it's good to have you. I'm quite keen to get into the conversation. Maybe before we start, if you can give us a quick intro to who Belinda is, how did you get to this point, and yeah, then we can get into the interesting conversations.

Belinda Boer: I am Belinda Boer. I am quite busy within the dam sealing industry. Getting to this point, let's say I've basically been always involved in the agricultural industry. I grew up on a farm, my father was a farmer, and I experienced with him all the good stuff and all the bad stuff that farming can give you. So I've got a really good background with regards to that and the frustration. And I actually saw and experienced his frustration with water—keeping that water. And that was back in the 80s and in the 90s. Now I'm sort of giving my age away here! But yeah, that is more or less where I grew up.

In the meantime, a lot has changed with regards to water retention and the technology on how you farm with water. But seeing how he struggled back in those days to farm, to make sure water is widely available all over the farm, that is where the interest has started. So then, further on in my life, career-wise, I've always been... my larger background is more with regards to marketing. That is where I come from, a really good and strong marketing background. But then I started to work for somebody who was sealing dams and got exposed to this polymer way of sealing dams, and that's where everything changed for me. It's just been an amazing journey.

After that, I started my own business because there is really a lack of application specialists with regards to polymer dam sealing business and so on. So I started my own business. The people who manufacture the DamFix products, Cannar Earth Science, they approached me. They saw what we were doing, and they said, "Listen, we can manufacture this for you right here in South Africa." And then a lot has changed again for me! So we can very proudly say that this dam sealing polymer that we call the DamFix range is the only polymer dam sealer manufactured right here in South Africa. We work very good hand-in-hand. Our business name is DamPro. So from DamPro's side and from Cannar's side, in terms of development, in terms of observations, studies, just anything and everything surrounding dam sealing polymer, we've got this awesome working relationship. I think we have done some very, very interesting and incredible stuff with regards to the dam sealing polymer industry.

Dr Udhav Maharaj: No, that's an interesting background. And it sounds like many of us in agriculture where the lifestyle chooses you. You're always born into it, and then that's where that passion comes in. And you can hear it from the way you speak, like you're really passionate about the industry and what you do. But it's also good to hear that DamFix is manufactured right here in South Africa, which is good. It's exactly what we need—products for South Africa, made in South Africa, by South Africans, which is not very often you see things like that. But maybe before we get into the technical details, I'm quite keen to know, if you had to explain to me what DamFix is and just the range of products that you have. Because I know behind you, you've got DamFix Wet and Dry, but I've also seen that there's other products out there. It'd be good to just get a sense of what the range of products are before we speak about how they actually work.

Belinda Boer: Yes, so currently there are three products. I'm going to start with the DamFix Wet. It's a very, very fine granular polymer powder. It looks like white sugar, almost. So please don't add this to your coffee! Because if you are going to add it to your coffee, the moment it becomes wet, it's going to turn into that gel. That is what DamFix Wet looks like when it has activated. And basically all our other dam sealing polymer products work on the same principle: the moment it becomes wet, it hydrates, then it starts to swell.

So this polymer powder, it is so easy. We do the application while an earthen dam, a soil-based dam, is filled with water. If you see clear seepage for instance on the other side of your dam wall, you can spread this on the side where the dam water is. On the water, from there it's going to descend, it's going to find itself on the bottom floor of the dam, and it's going to bond with the soil. But with this product, hydrostatic water pressure is extremely important because it bonds with the soil. And if the water pressure is not there, if it's like shallow dams, you're not going to have the bonding process. So that is extremely important for all these dam sealing products—it requires really good water pressure.

And then what we see is there's results where we see within two to three days, where we've got clients telling us, "Look, the water is drying up on the other side of the dam wall." But other dams you see within weeks, others in a month or so, because not every single dam is different. You cannot compare any dam with each other. But yeah, it's phenomenal that you can actually seal a dam without the need to drain the water. So that is the main important part of DamFix Wet.

Dr Udhav Maharaj: Yeah, 'cause you eliminate that need to stop your operations on the dam, especially if you're irrigating out of it. You don't want to drain your dam, you don't want to have to build a coffer dam to store that water. And then we all know earth moving equipment and moving earth costs a lot of money, so if you can avoid that, this is a no-brainer for farmers.

Belinda Boer: That's exactly the point a client of ours made in the Marble Hall area. We went to seal his dam about a month ago. It's an irrigation dam and he's got very, very big operations going on there. He cannot afford downtime on an irrigation dam. And the dam actually seeped right through into his fields where he's planting his crop. He called us, we went in, did a really good dosage, and then he actually said within four days, he sent us a video and it all completely stopped. All gone. And he was able to plant his crop and continue. And where his pivot was also moving, usually it would get stuck there in the field, and no more of that as well. The pivot can freely move in that area.

Dr Udhav Maharaj: It's... I think that's exactly the problem that lots of farmers have. It's either your dam seeping or there's lateral movement from your dams going outwards, and that affects your everyday operations. You can't plant, you can't harvest, you can't irrigate your center pivots. So if you've got a solution that can sort that out, I think many farmers will be your friend.

Belinda Boer: Yeah, there's another example that I can use in the Delmas area. It was also an irrigation dam and the maize fields were also positioned right around that dam. And if you go look at the Google Earth historical data, you can see every single year during the rainy season, when that irrigation dam is filled to capacity thanks to the rain, the floor can't carry the weight of the water anymore, then it starts to leak, also into the maize field. The client would usually tell us every year harvesting would be a massive problem because they would have been done more or less with the rainy season, but because the dam is leaking into the maize field, the soil is just completely saturated with water. Basically, harvesting with his big harvesters, they would always get stuck in that specific section. And they started harvesting last week, and I got the phone call for the first time since he's been farming there, which is about eight years now. He's not getting stuck in that area anymore because the dam has been sealed and the issue has been sorted out.

Dr Udhav Maharaj: It's good when you hear the impact of your work, and the positive impact, and you can see the difference that it makes in people's lives and especially in agriculture. And apart from just the harvesting side of things, it also helps reduce your water losses. 'Cause it's a precious resource, people are struggling to actually conserve that water. And now if you can reduce the seepage losses, that's a big win as well.

Ad Break

Announcer: Let's take a quick break. If you work in agriculture, agriculture engineering, biosystems engineering, research, or academia, then this is for you. The South African Institute of Agricultural Engineers Biennial Symposium 2026 is back. It is scheduled to take place from the 21st to the 23rd of October in Upington, Northern Cape. Under the theme "Driving Agricultural Growth Through Engineering Excellence," the symposium will bring together engineers, researchers, industry professionals, and students to share ideas, showcase innovations, and tackle real-world agricultural challenges. Whether you're presenting research, exploring new technologies, or looking to expand your professional network, this is the place to connect, learn, and collaborate. Abstract submissions and registrations are now open. And if you can't join us in person, you can participate virtually from anywhere. Visit the SAIAE website today to register, submit your abstract, and be part of the future of agricultural engineering. We look forward to seeing you in Upington this October.

Interview: Part 2

Belinda Boer: Absolutely. Yes. So, the other products that we have is the DamFix Dry. DamFix Dry is a two-part sealing process. There's a Part 1 and then there's a Part 2. So the mythology with regards to this is... not all dams you can seal with the DamFix Wet way. Sometimes you have to reset the dam and do a complete renovation. Because remember, each and every dam is different, not one is the same. And also especially if you've got a brand new dam. Set it up perfectly well from the start! We see so many dams that is not being built correctly from the start. There's no proper compaction being done. They don't even install a seal, even bentonite or anything for that matter. Many people are under the impression you just go in and dig a hole and you've got a dam. So we see quite interesting scenarios.

But yeah, if we look at DamFix Dry, the Part 1, this is very, very fine. The reason it looks like this—this is a polymer clay sealer. If you've got an existing dam where you are applying DamFix Wet, you already have got like a sediment layer. The polymer bonds quite well with it, it loves it. Where you've got if you are renovating your dam or if you are... if you've got a brand new dam, there is no sediment, there is no holding capacity yet. You must also think of a dam that has got a settlement period. Because every single new dam has got a settlement period which is about one to two years. And that's also something that people are... they do not want to acknowledge the fact that a dam has got a settlement period.

So what we see with DamFix Dry—or let me first explain the application process because this is not as straightforward as your DamFix Wet application. DamFix Dry, obviously you do it while the dam is empty. You till it into the soil, about 150 mil deep. No deeper than that, because you want, the moment this starts to hydrate, you want the polymers to link with each other. That is very, very important. And then after we've tilled it into the soil, we do a proper Bomag compaction. Because you have to compact your dam floor. I cannot stress this enough—compaction is really... you're setting up your dam for longevity if you are compacting the dam floor. That is such a crucial part of a dam renovation or a brand new dam, you have to compact. So after we've done the compaction, then the dam is set. You can start to fill it with water.

What we then discovered, if you just do a very mild application of the DamFix Wet component on the water, then it's like it's locking with the DamFix Dry Part 1 application. And we've seen the dam settle actually within two to six months. That is how quick it happens. So this one is now specifically for the Part 2. This is not DamFix Wet by the way, it looks a lot like DamFix Wet, but this is DamFix Dry Part number two. So we spread it evenly on the water, it also goes down and it locks with this part that we've worked into the soil. And then this is, this is crucial for settlement. It's like it just activates and the dam is just on a roll, it starts to activate. We've done a dam in Waterfall Country Estate. It was like river sand, it was horrible, horrible soil that we had to work with there. And that dam settled within two months on the DamFix Dry application process. That's how quick it was. And I was just completely amazed at the results that I saw there. But yeah, it is crucial to assess each and every dam unique to its own. You cannot compare two dams to each other. You have to talk to us first, let's see what we can recommend.

Dr Udhav Maharaj: Okay. No, that's good to know. And at this point I'm sure our engineering colleagues will probably be itching to hear all the technical details. So I have to ask, in terms of the soil types that DamFix is compatible with, is it across the range or is there certain types of soils that you would recommend where you can actually use DamFix, and some where you'd propose an alternate solution? And then the second part to that question is on the ecology side of it. When you mentioned the crocodiles and hippos, there's also lots of farm dams that have a wide range of fish species in there. So I wanted to find out how does DamFix play with the ecology of the dam?

Belinda Boer: Yeah. Okay, so DamFix, we've seen the polymer work on basically on every soil type. We've worked on very bad soils, very sandy soils, and then we've also worked with very awesome clay-like soils. We've worked on turf-like soils, even on... we've sealed dams with G5 soil in it. So I think it's obvious, if you look at the scale of very clay to very sandy, the polymer bonds extremely well with clay-like soils. Another thing that we have discovered just as we went on with it: polymer loves the sediment that has formed on the soil. So it seals extremely well when there's organic matter present on the dam floor. It likes that a lot.

Just a big rule: the product will not bond with any stones or rocks. If there is like a rock bed that's involved in the dam floor somewhere, it does not bond with any rocks or stones. Sometimes if there is also like a... you know these old dams, farm dams has got a concrete wall built, it will not seal or bond with the concrete. It will only bond with soil. So always keep that also... remember that. So we've got bombing methods. If there is like a concrete wall, I always say "Just give the product soil to work with." As long as you give it soil, it is going to bond with something. So what we do is usually the DamFix Wet, while there's water in the dam and they do not want to drain and do all kinds of repairs on that concrete wall, we would do a mixture of DamFix Wet with soil, and then that soil we dump all along the dam... the concrete dam wall. Then it will stop all that seepage that's going through the wall, underneath the wall. Because that's a lot of... we get a lot of inquiries with regards to the concrete walls that are leaking and aging and it's not going well. So there's various methods that we use these polymers. As long as you give it soil, it's gonna bond with it.

In terms of your question with the fish and the plants and all of that, so we've had the DamFix sealers independently tested by WSP. They've been awesome in that whole process, and they found the product to be non-toxic. It is not going to have any negative impact on your eco life. We've done many applications where the fish are present. We've actually seen if the water is nice and clear, we actually see the fish, they are quite nosy. They want to come see and inspect what's going on in their dam. And the... when you see the polymer is making a blanket, then it's starting to fall like that. So when it's falling, we've seen fish that are playing through the blanket. They're going in and out, in and out of the blanket as it's falling. And nothing happens to them! People are worried that it's gonna get stuck in their gills or wherever. It's... it's a gel, it's... it's like a... and it's interesting to them, that's... that's what I'm summarizing it as.

We always follow up with the client. Many times we go back to the dam in the next day or two, and then there is no... we don't see anything that has died or... Obviously, there is a factor with DamFix Wet, where dams that are 2,000 squares and smaller, in the first 24 hours there will be a fight for oxygen between the polymer and the fish. So with dams of 2,000 squares and less, we just say you must seal the dam in sections over a week, just to bridge that. But other than that, it is non-toxic, it's not bad for your plant life, your animals, your cattle, the sheep, whatever you farm with, they can come and drink the water. And my team, if you go look on our Facebook for DamPro, you will see many videos and photos, and even my own Facebook, Belinda Boer, you will see us on a dam working with this stuff almost every day. And I've been now non-stop, consistent, myself, inhaling this... this stuff, because when you spread it, there's very fine powder of this that do go up in the air. It falls on your skin. When you start to sweat or anything, it will activate into the gel. Sometimes it comes into my eyes. So if something had to happen with somebody, it had to be me. Yeah. And I'm sitting here and I'm alive and kicking. So... and yeah, I don't feel sick, I don't feel there's anything wrong with my lungs, I'm all good. So, yeah. No, the product is definitely eco-friendly and there won't be any negative effects to your fish or plants or your animals.

Dr Udhav Maharaj: Okay. No, that's good to know. And I think just from my side, one last technical question is around the time that you may need between applications of either DamFix Wet or Dry. And then a follow on to that is, does it also work on your dam walls, or is it mainly for the flow of the dam?

Belinda Boer: The dam walls is the most of our inquiries. It is with regards to dam walls, especially because there are two things that usually go wrong in a dam wall. You either... we see people have not built it correctly, construction was not done correctly. People do not build a key into the wall. And when I ask them, "Have you built a key into the wall?", they actually asking me, "What is a key?" So people are uneducated in terms of the importance of constructing a key into the wall. So that is one of the reasons, main reasons basically why a dam wall would start to deteriorate and the integrity of the structure is not going to... it's not going to go well with that.

The other thing we see is people want their dams to look nice. The ones who are using it for aesthetic purposes on lifestyle estates, golf courses, the game lodges, they want their dams to look nice and they want trees situated in and around the dam. And another thing I want to touch on, everybody wants an island in their dam to have that also look nice. And I would say, "Listen guys, do not have an island in your dam. That thing is just going to cause problems." Again, an island is not being constructed properly, they do not compact it well, and they plant a tree on the island.

So if you look at what happens in a... with a tree, there's actually a photo of myself, you can also go and look on my Facebook, where I stand in a dam wall that has broken, and you can see how the tree roots are just hanging there. It has just blown my mind how a tree can take over in a dam wall, and that creates cavities, and the integrity of the dam wall is being completely depleted. So incorrect construction method of a dam wall and tree root systems establishing itself in a dam wall causes it to leak, and if you are not going to give attention to it or even integrate a maintenance plan into your dam, you are going to see a dam wall breaking.

So we also see a lot of people for some reason building their... whatever building it is they want to build... I've actually been last week at one where I was mind blown, they had a full restaurant shop and everything just below the dam. So if that dam wall is going to break, the restaurant, everything's gonna be gone. So you must really plan if... when you've got a dam, you must plan on what you're going to have where. Do not build a building below a dam wall, it's really not a good idea. Because if that dam wall breaks, you're gonna sit with a lot of problems. So in terms of DamFix Wet, we have seen quite... I was astounded by several instances where I thought actually it's not gonna work, and the product has done miracles. I've got a... one of my colleagues Ryan, he actually says "DamFix heals the soil." And the cavities. So that when the polymer is being... is finding itself on the dam floor, and the hydrostatic pressure is gonna push into that dam wall, you're gonna see any... anything that's porous, it's gonna bring it together. Um, and that's where you see the leak is stopping.

Dr Udhav Maharaj: Yeah, no, that's really good advice for the farmers out there. And just in light of the recent events that we've been having with climate variability and extreme weather events, droughts, floods, that sort of thing. Have you noticed the farmers taking more interest in that, or like the farmers becoming more conscious in terms of water use and water use efficiency?

Belinda Boer: I've seen immediately with those heavy floods we've seen earlier in the year by the Kruger National Park, there by Hoedspruit. All those areas, we got an immense amount of phone calls with... now that they've got all this water. There was many dams who had half the capacity to empty and all of a sudden those dams was bombarded with mass amounts of water. And then it was like, "These walls was like, but what's happening? I can't believe all this pressure that's happening." And dam walls that was really battling to keep the water.

So we've seen a lot of movement with regards to that, and product moving into that area. And then also over the last month, the heavy rains that we've now seen in the Eastern Cape and into the Free State, the same then happened as we experienced in the Hoedspruit area and the same type of calls. All of a sudden these dams was bombarded with a mass amount of water. So when you've got the opportunity to retain your water, do it, because it seems now if we look at the weather predictions, the weather patterns for the upcoming season, the next summer, it seems like El Niño is coming back. So right now with all the good rains we've had, and if you see your dam has got seepage issues, you can actually now retain that water without going into all the work of restarting your dam. So yeah, I am concerned about this next rainy season, doesn't seem like it's gonna be there. So while you've got the chance, keep the water. That's what I'm saying.

Dr Udhav Maharaj: Yeah. No, I think that's... everyone has to be aware of that and be very conscious about the fact that we could be going into an El Niño and it could be a long one. So yeah, if you've got any leaky dams, I think Belinda's the best person to speak to. And if anyone wants to reach out to you, just to confirm, it's @DamFix or @BelindaBoor for all the interesting stories and pictures?

Belinda Boer: Yes, absolutely. And yeah, all our contact numbers are there, various agents' numbers are there, my number is there. There's many numbers there. So somehow you must, you must get sorted with your dam.

Dr Udhav Maharaj: We also have a lot of listeners that are still in school, some are still studying, so students at university. So I wanted to find out if you've got any bits of wisdom or advice to our younger listeners out there.

Belinda Boer: Always be curious, always be open to learn, never stagnate. You have to be interested, or find your purpose. I found my purpose when I was 40! So never, ever give up. You will find your way, but you need to explore, you need to try everything, and somewhere something is going to pop up that's going to be like, "Okay, this is it. This is what I'm going to do now." So yeah, I think the main rule especially in my life: never, ever give up. You must always search, you will find the answers. And always give your best. Never ever... even if you're gonna work for somebody who is really not good for you, still give your best. Because somewhere somebody's gonna see you and they're gonna take you. And then a lot of other doors are going to open for you. So even if you are in an environment where you feel you are stuck, always give your best.

Dr Udhav Maharaj: Yeah. No, that's really good advice. Thanks so much, Belinda, and it's been really great chatting to you and yeah, I really enjoyed this conversation and I'm sure we'll be in touch in future.

Belinda Boer: I really appreciate it. Thank you for having me on your podcast. I appreciate it, and all the best. May you guys also just move forward and go from strength to strength. Thank you, be well.

Dr Udhav Maharaj: Okay. Thank you, and hope you have a good day.