Berms and Swales 101: What They Are, What They Do, and When NOT to Use Them

Added: 2026-05-08

[00:00:00]We are standing right now at the top of one of our berm and swale systems that we have here. It's really a agroforestry system. One of the key elements in that are berm and swales.

[00:00:12]So, we're going to talk about like what is a berm and swale, how to distinguish that from certain other types of harvesting features, and why we chose it, and why you should not use it in certain circumstances.

[00:00:25]For Should I look directly at the camera? Yeah. It takes we have karst geography. Like Damn it. The karst geography strikes again. Karst geology cutting into the slope of a landscape, and then you are Uh sorry, hold up.

[00:00:42]Yeah, it's gorgeous, man.

[00:00:45]WHY AREN'T YOU USING BERKELEY BEAR?

[00:00:48]WELL, LOOK AROUND, BROTHER.

[00:00:50]It's everywhere.

[00:00:54]All right. So, when I first came into this site, you know, one of the things that you notice is we have a challenge, which is we're going to be trying to establish some sort type of food production in this almost pure rock, this very rocky caliche soil.

[00:01:12]I was just walking around with a client earlier today, and they were saying like it's hard to fully capture it on video.

[00:01:18]When you look at it, it's like you're standing on rock.

[00:01:21]Um so, we have a few challenges.

[00:01:23]The soil condition is one. The other challenge is erosion. You know, this material that has not being [music] vegetated very well, it's not covered by anything growing in it, which thank you weeds, that's what weeds are typically trying to do.

[00:01:37]Um that leads to the loss of the little bit of soil that you do have. Nutrients, organic matter, the seed bank, all that's getting washed away. Um so, we also have a third problem, which is when we grow anything in Central Texas, we need to be thinking about water flow. We need to be thinking about systems that are very conscious of water usage, and are going to leverage whatever moisture we do have as much as possible.

[00:02:01]>> [music] >> Yeah, so one of the potential solutions to the problems that I mentioned are some kind of obstacle [music] that we're putting into the landscape that is going to capture and hold water. So, it's really a water capturing >> [music] >> system of some kind.

[00:02:18]In this particular context, we used something that is often referred to as berms and swales.

[00:02:24]So, berms and swales, you can think of it as basically we are constructing a little valley, and on the downhill side, a little hill. So, what we've done is we have placed a speed [music] bump in the landscape that is going to slow down and capture water, and concentrate it in our little valley, which is the swale.

[00:02:41]The reason that we do that is that moisture is then going to passively [music] irrigate anything that we decide that we're going to grow on the berm. That could be just native vegetation, it could be an orchard like we have in this particular context. Um just some kind of living root in the ground is going to be an important thing to establish. We're also going to be conserving soil.

[00:03:04]So, as this continues to erode, um it's actually going to start capturing and filling in slowly over time, and that's a feature, not a bug. Um this is going to continue to revegetate. As you're seeing this frog fruit is starting to grow all the way up into this, you know, pure [music] rock area, and you know, put roots into the ground. And you can also probably see there is some moisture in this swale right now. It hasn't rained in like a week, but this swale is holding this moisture, so it's allowing for better revegetation of the area.

[00:03:36]Berm and swales are a Really, they are I would consider a traditional ecological technique. Um sometimes it's referred to as low-tech traditional ecological knowledge.

[00:03:47]And there is examples all over the world of various types of water harvesting structures that indigenous people used for agricultural productivity. So, we're leveraging that ancestral knowledge, and creating something very, very simple, honestly.

[00:04:04]Um it's just a mound and a hill, but creating it in this particular fashion that we did here, and in the right context, is going to be passively irrigating plants, but also one of the beautiful things, you know, we just came from [music] doing a wonderful tour with the Edwards Aquifer Authority, and they have some of the only research that I'm aware of in the world on how much water these berm and swale systems are infiltrating. And, you know, as good scientists, they would say they don't have a statistically significant data set yet, but the evidence is suggesting that there is significant additional infiltration happening in these swales that is continuing to flow underground in this [music] plume type concept, which is basically the idea is water is concentrating here. It is getting more time to percolate into the ground, and then it is continuing to travel underground downhill.

[00:04:57]And in that process, the water quality is actually being improved cuz the water's being filtered [music] by the body of the earth itself, and then it pops up in seep springs further down in the landscape where it has enough pressure to do so.

[00:05:10]Um so, in a system like this, a multi-tiered system, we have this berm capturing water, and then it's actually still sending that water further down into the system, and eventually it makes its way into the Blanco River in this context. One aspect of a berm and swale type system that's going to be different from other types of terracing systems is this is on contour. So, what that means is basically the entire berm is level.

[00:05:35]So, when water hits it, it's all at the same elevation, so the water is not draining [music] in one direction or another. We're actually wanting the water to sit and be Some people may be concerned like, okay, you're creating waterlogged soil, you're creating stagnant soil. Particularly in our context, we have a karst geography.

[00:05:52]Uh Damn it. The karst geography strikes again. Karst geology.

[00:05:58]Um and uh the water's going to infiltrate.

[00:06:02]Generally, in these systems, I don't see them last in in here for more than 24 hours. So, you're not going to get mosquito production. They infiltrate really fast, and as they they revegetate, it's going to get even faster >> [music] >> than once they've just been created. Um and they're slowly making their way through little fractures in [music] the rock that we have here.

[00:06:19]Um so, again, water is sitting level on the landscape so that it [music] infiltrates. That's our number one goal.

[00:06:27]We're not necessarily directing it to a water body in this case.

[00:06:30]>> [music] >> There's no appropriate place for a pond on this property or something like that.

[00:06:34]So, we really just want to soak it into the ground.

[00:06:37]Um and a berm and swale is a great way to do that.

[00:06:39]>> Hey, you guys taking a quick break from the video. We're back in the office where all of our projects start as we analyze maps to give our clients good recommendations, and I wanted to show you something that I'm really excited about, our newest tool from LandScope.

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[00:07:23]There's a lot of other great stuff in here. Check it out. All right. So, regardless of what type of earthen structure you're creating, it's really important for us to revegetate any land that we are excavating, moving around, rearranging in any form or fashion. The star of the show on our systems in general right now tends to be frog fruit. Frog fruit and woolly stemodia in particular make excellent spreading ground covers. So, I personally am biased to living mulches. We did put a little bit of wood chips down just to like kind of cover the soil when we first excavated it, but what we're relying on long-term is a continuous living ground cover that's going to provide shelter for various types of insects. [music] It is also going to shade and protect the soil. It's going to nourish and feed the soil microbiome, and it's going to support pollinators, which we can see, you know, even on a cloudy windy day. I've been seeing different butterflies and things and bees buzzing around.

[00:08:19]>> [snorts] >> Um so, we've also located a syntropic inspired or a permaculture food forest on the berms, and there's a whole 'nother video that we're going to create all about that particular topic.

[00:08:32]Um but we have utilized to our advantage the the water that we're capturing to again passively irrigate plants. We've also created a non-erodible zone or an area that is very resistant to erosion.

[00:08:45]So, native seeds are expensive, so we've [music] done a reestablishment of the native seed bank. We planted a, you know, millions of native seeds across these berms. Um and we know now that they are going to stay in place. One of the problems we see with landowners a lot is they buy a bunch of native seeds, they spread it on the ground, and we have a big flood event, and it all just washes onto your neighbor's property.

[00:09:06]So, this is a really good place to reestablish prairie strips and native seed banks are these slightly raised berms that we've created. All right. So, right here is a good example of how we're also capturing soil. So, I mentioned [music] we're slowing erosion by capturing the erosion and creating a place for the soil to backfill rather than washing away. And it is backing up against an area that we're already revegetating, and we're already, you know, doing productive agriculture on. Um so, right here, you know, you see the soil that has been um that has eroded and is starting to settle in this place, and it's starting to revegetate with native wildflowers, which [music] is something that we would expect to see. And also, our frog fruit is expanded all the way out into this area.

[00:09:53]It actually, as I'm looking at this, this might just be occurring spontaneously or from seed cuz it's not actually connected to the frog fruit that we planted up there. So again, that is going to as we've seen on these berms, it's done an amazing job of creating a living ground cover. Same thing is going to happen to this whole swale. So we're basically extending our ecological restoration uphill from the berm that we've created. So our berm and swale systems do a great job of capturing and infiltrating water. But what happens when you're in a flood event? What happens when the berm and swale is at full capacity? So in that case, you need to intelligently design a spillway.

[00:10:32]>> [music] >> And a spillway is basically just a place where we have decided the water is going to exit the system when we are at max capacity or we're in one of those flood events.

[00:10:41]So downhill of the edge of the spillway, we have placed all these rocks and this is an armoring. So what this does, as you can see, is one, this rock mulch, this lithic mulch strategy is allowing for revegetation of, you know, a lot of native ground cover including this frogner daisy which I love. Um it's going to protect this area from getting eroded by lots of water moving through this um system when we have those flood events.

[00:11:07]>> [snorts] >> So that's why we have a spillway and the spillway again is basically in a berm and swale context, just a place where we've dug a swale but no berm. So we have a little bit of a depression where water is going to be concentrated, but when the system is again full, there's no berm to hold it back. It slowly trickles out. And it trickles out level, so we're fanning out the water. It goes over these rocks. The rocks further slow it down and then it gently makes its way down the landscape, which is also protecting structures and things downhill. All right, so one thing that I want to distinguish is a berm and swale from a terrace. There's different types of terraces, but generally speaking, I like to think of the berm and swale as focusing on infiltration of water, keeping it level in the landscape, and also you're generating additional topsoil versus a terracing system where your goal is often going to be to move water across the landscape.

[00:12:04]A terrace essentially is cutting into the slope. Um you're cutting into the side of a of a hill or, you know, some sort of gentle slope on a landscape and you're creating a level um platform that has a 1 to 100 pitch.

[00:12:19]So what that means is you have a very very very gentle slope and you're creating a little bit of a lip, so you are slowing down water and you're keeping it in the landscape. Um and you are trying to maximize the amount of water that's going to stay right in that topsoil. So unlike a berm and swale, we are draining it, but we're draining it really really slowly. Um in this context, the [music] swales made more sense, I think, and we also needed as much topsoil as we can get. So mounting it up, I think, was the appropriate thing to do. You know, there there have been some cases where people have installed berms and swales without understanding the landslides. Um so there's certain types of soil conditions where you don't want to be holding a lot of water into the landscape. Like I said, we happen to live in a geologic context where that is very beneficial, but there are other contexts where you could be creating waterlogged soils or, you know, your berm and swales may not be yielding the results that you want. Um [music] I can't speak to all contexts out there, just that it's important to do experiments, to do small iterations of things, >> [music] >> to be humble and to receive feedback from the landscape itself. You know, oftentimes when I talk to clients, especially when I'm like locating ponds, you know, sometimes someone will say, "Well, I don't want the pond there."

[00:14:02]It's like, "I'm not determining where a feature should go in a landscape. I'm trying to read what the landscape is telling me is possible." Um and we have to be willing to accept when we're wrong. So again, just at a high level, berms and swales are about context. Are they actually solving direct issues?

[00:14:20]That's the number one thing. And then if it is, you know, are you placing it on the landscape in a in such a manner that you're going to see a return on your investment? So for reasons why you wouldn't do a berm and swale, I in my own house do not have any berm and swales. One of them is cost. Like it is going to be more energy intensive to create something like this. So if you have a really good, well-draining topsoil, this may be completely unnecessary, to be honest. Um this is solving a set of challenges and a set of a set of issues and if you don't have those issues, like if you don't have erosion happening on your landscape, if you got good infiltration already, if you got good soil, then a berm and swale, I'm not going to say there's no reason to do it, but um it's less of a priority and something that I would probably just completely skip and just focus on improving the quality of the soil that I have to promote better infiltration than reshuffling the entire landscape. So one reason is just you don't need to do it.

[00:15:17]The other is in a really rocky site like this, it might not be feasible. We have developed a particular expertise in this area. We had to bring in a rock mill.

[00:15:27]You know, there's a little bit more energy involved in creating a system like this. And if you're on a smaller scale, I don't know that it's necessarily worth it. If you're not able to get heavy machinery onto a steep slope, it may not be worth it to do it either.

[00:15:42]And you can achieve a lot of this the ultimate like reasoning for using a berm and swale, you can achieve that with different structures like one rock dams. All right, so right here we have a brush berm structure. This is one of the low-tech um options for passive water harvesting in a way that's going to encourage the um development of a potential orchard.

[00:16:07]We're in a canopy context where we basically just thinned the canopy, which means we removed some biomass um from lower-lying branches and non-photosynthesizing branches. And we instead of taking that all to a big burn pile, we layered it on contour to create these brush berms.

[00:16:23]Um and if you wanted to, if you took out a few of these trees um and you let even more light through the canopy, you could establish an orchard downhill of this structure.

[00:16:33]Normally we're planting our trees uphill of the berm, but with a a structure like this, I would probably place them downhill um because the water is getting slowed down and it's going to slowly trickle through and irrigate your plants. And also this is going to start gathering lots of topsoil. So you have a nice growing media for your plants, but you're not running the risk of your trees getting buried over time. Um because that, yeah, that extra soil is being kept up here by the brush berm. Um so you could do this with rock or you could do this with stumps, with branches, with entire tree trunks, but you can use the materials you have on site to basically, you know, create a system of slowing down the water for your trees.

[00:17:16]One of the interesting things about this site is the client, they already had the idea of putting terraces in. They put these nice rock terraces in to try to control some of the erosion that was headed to their house.

[00:17:27]It was helpful but not fully successful.

[00:17:31]Um however, I wanted to just mention that like a part of the context of this job was we integrated our agroforestry system into this rock terrace. So I think we just scraped a little bit of soil back up against the terrace. We didn't even bring in any soil. We amended it, improved it, and we planted our tree line right across this rock terrace. But this is also an example of something that you could do if you don't want to dig a berm and swale, you don't have local experts, you don't want to get an excavator, whatever. Um you can just pile up rocks and create a rock berm essentially and that can also help to um slow down soil erosion, capture water, and all the things that the berm and swales are like fundamentally attempting to do.

[00:18:14]So at a high level, what we've done [music] with these berms and swales is integrated them into an agroforestry system where [music] we have created a calorically productive landscape while restoring the ecosystem by adding lots of biodiversity. We have this Texas silingia here growing really well on this berm alongside, you know, Mexican [music] plum, fig, golden ball lead tree, mealy blue sage, all different copper canyon daisy. There are some adapted plants in here like ginkgo. Um but ultimately everything that we planted is either native or it has a strong benefit to humans and non-invasive tendencies.

[00:18:55]Um we are capturing the seed bank. We're slowing down erosion.

[00:19:00]Um and this agroforestry system leverages, you know, different principles from syntropic agroforestry, from the Miyawaki forest gardening method, you know, optimizing for high density. That's one of the ways we've returning the soil arable is we have a custom soil amendment blend. We have a whole video on that that we put down.

[00:19:20]Um it's a one-time application. It's more about structurally improving the soil. So a lot of our philosophy is typically, how can we improve the soil structure first [music] and utilize and um release lots of the nutrients and minerals that are already existing in the soil that are just locked up [music] um instead of focusing on bringing in all the inputs that the trees need, NPK >> [music] >> fertilizers. So as somebody who has designed and built many hundreds or thousands of linear feet of berms and swales, [music] it is just a tool that needs to exist in an ecosystem. I like to think of methodologies and ideologies and frameworks all [music] as like a part of an ecosystem. So, you don't take one tool and generalize it as a solution for everything. So, there are contexts [music] where berms and swales I don't think are the most recommended. You know, in this particular site, I'll start with the reasons why we did do it um because that also colors the reasons why we wouldn't do it.

[00:20:19]We need to develop topsoil. We have a house further downhill. So, we [music] are protecting that house as well from water just all going into the front door and the previous tenant [music] did a lot to try to avoid water. Like you could tell they were having erosion issues and they spent a bunch of money on it. So, we're solving an erosion problem. We're protecting [music] a structure. We're generating topsoil. Um and there wasn't really any other better places [music] to locate an agroforestry system. So, we're justifying this because we're capturing a lot of water.

[00:20:53]Um we are recharging, you know, the aquifer in doing so.

[00:20:56]>> [music] >> Uh we're in a contributing zone right now.

[00:20:59]We are doing ecological restoration and we are also producing food and reducing dependency on an energy intensive supply chain, which is the grocery store.

[00:21:12]All right. Hey, thanks guys.

[00:21:13]>> [music] >> Appreciate you watching. I hope you enjoyed it. And if you want to learn more about what we do, how we do it, why we do it, you can hop over to our website. There's tons of good articles.

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