Swales for Drought: Is the Hype Real?

I'm thinking about having swales put in on a gently sloping 16 acres property. I've heard all sorts of fantastical things about them increasing water retention and helping during drought. I'm willing to give it a shot, as sometimes things that seem too good to be true really are true.

What are your experiences with this? A friend of mine (who's also a member on here) told me that she visited a site from the Conservation Corps built during the 30's in Arizona. She said it wasn't as good as it was made out to be, as the site was built at the base of a mountain range (not often included in discussion and photos) and therefore benefited from that runoff as well.

What are your thoughts and experiences with this? I would mostly be planting trees on the land

I’ve just read a whole shwack about “moving water across your land” in Ben Falk’s The Resilient Farm and Homestead so I’m all pumped to build some swales of my own.

The purpose of swales on contour, is to slow and spread the flow of water down a slope. When water builds against a swale, it will slowly permeate back into the ground, as it flows across the ground - directed by the contour of the swale. In theory they need to be positioned to catch the down-slope flow of water before they’ll be very helpful. Does the slope catch a lot of water?

Adding some ponds to store water into your earthworks/swale system might work? The two seem to be often intertwined!

The old swales on my land are very much like what your friend experienced. For me, they were installed in 1954 when two gales and a hurricane came back to back to back, and this being a potatoes farm, caused all that water to run down the hilled rows and cause severe erosion. Today, in this county, the swales installed during 1964 remain everywhere, yet on my farm they caused more damage than good. They never terminated the swales right, and so all it really did was divert water, and put erosion where they stopped.

But these were old swales, and this is Maine. We get a lot of water here, and in fact, over the last 20 years, we are getting MORE water, about 5 inches more of rain per year than 20 years ago. We also get a lot of snow, and with spring snow pact melt, it means our swales here get absolutely overloaded with water. We cannot just plan for 5, 10, and 50 year rain events. Spring thaw might be the equivilent of a 100 year flood, and that might happen every five years (a winter with a lot of snow).

But that does not mean I do not install new swales. I do, and have installed several miles of new swales on this farm, and intend to add more. For me now, I use a lot of erosion control rock check dams, and terminate the swales so they are more like sediment traps. So it is kind of a two prong approach. I am doing everything I can to prevent erosion, but I also know I am inevitably going to get some, and when I do, I know I can clean out my swale ends and at least capture, and reuse, the soil that has been eroded.

This was a swale end, a sediment trap just after construction in 2017, and will attest wholehearily that this works. The swales installed in 1954 have all been removed.

Just out of sight in the lower, left coner is a rock check dam. Then you see the swale formed as it goes down to what is a rock-bottomed field access ford. Then you see another rock check dam, marked by two grade stakes so that I can stay clear of it while bushogging high grass. Quite a ways farther still, you see another rock chck dam. Between the staked rock check dam, and the rock check dam farther down, is the sediment trap area. I designed this myself, but was checked and approved by the State of Maine USDA Soil Engineer, and was given a grant to do this swale work under EQUIP Conservation funding. Sadly, the payout was only $500, which is far less than what its real cost was, but it was done right. We had severe rain all spring, and the rock check dams, and sediment trap, are working as they were designed.

As a side note: this drains about 5 acres of a 9% slope of high erodable gravelly loamed field.

James Landreth wrote: A friend of mine (who's also a member on here) told me that she visited a site from the Conservation Corps built during the 30's in Arizona. She said it wasn't as good as it was made out to be, as the site was built at the base of a mountain range (not often included in discussion and photos) and therefore benefited from that runoff as well.

The swale was probably installed to mitigate flooding run off from the mountains.  We have mainly installed earthworks to mitigate flooding but we have certainly seen benefit from them in increased plant growth.  If you don't have surface run off or flooding, there's probably no benefit to installing swales, as they would have no water to collect.  

James, it really depends on your climate and the possible extremes of it. Also the size of the catchment area above your land matters.

We started of with swales, to switch to terracing later. Swales are tree growing systems, and on terraces you can grow anything you want.

We have designed our system to minimize erosion and maximize water infiltration. That's because we cannot afford to loose the excess water during the wet season. We need that in the ground. But we also designed all these systems for that once in a 100 years flood, where we get way too much rain to keep on our property. For that we need swales as water transport channels, to move it down bit by bit as calmly as possible. So you can find rock covered stairways everywhere on our land that double as waterfalls in severe weather events.

Swales are useful if installed for the purpose they can have: water control. I hope this is helpful.

Great question James. I too was a skeptic until I saw swales in an arid climate working with my own eyes...

A couple of years ago I took a Social Permaculture workshop at Quail Springs Permaculture in the arid Cuyama Valley in Southern California. There they have a series of swales & berms (installed by Geoff Lawton, if I'm remembering correctly) on pretty much what amounts to beach sand "soil" in the desert.
Downhill from their communal kitchen yurt they have their community greywater emptying into a small kitchen garden, then downhill to a willow grove that they use for basketry weaving workshops, then downhill of that, the rest of the greywater makes its way through several swale & berm food forest systems.

When I was visiting, the person who had originally designed & installed the food forests had left a few years earlier while some younger folks had moved into the community.
One day, I was wandering around in the lowest food forest swale & berm system, farthest away from the yurt & water source. I was glancing around on the ground & saw some almonds. There were many of them. I opened & nibbled on one of the almonds & it was by far the tastiest almond I'd ever had in my life!
I walked up back to the kitchen yurt & grabbed a bowl, walked back down & started collecting the fallen almonds. I went around to all the almond trees & shook them a bit, collecting more almonds. These trees were not being actively watered by any hoses, drip systems, nothing.... except what the swales were slowing, spreading, & sinking from greywater & very little rainwater. Reminder: greywater that had already passed through a kitchen garden, willow grove, & swale & berm food forest! It's fair to say that at this particular point in their life, they were being pretty much completely neglected (by humans) & were feral fruit trees.

I placed the bowl full of almonds in the kitchen. When dinnertime rolled around the 20-something-year-old community members of Quail Springs, who'd not been around during the time of the swale & berm food forest installation some years earlier, asked aloud "Where did these almonds come from?!" I smiled & told them that I had gathered them from the swale & berm food forest located farthest from the yurt. They were blown away; they had no idea they even had any almond trees on site, LOL!

Having been told my whole life how water intensive almond trees are & how irresponsible they are to grow in Southern California, my paradigm had just been totally shifted on that. Yes, I agree it's irresponsible to divert massive amounts of water from other people's watersheds for industrial monoculture (almond) production. However, I have now seen with my own eyes a functioning desert swale-&-berm food forest system that passively collects rainwater & greywater & integrates them into a diverse multi-strata agroforest system & works very well, even when utterly neglected in an arid climate.

In his Permaculture Design Courses, Bill Mollison mentioned that one of the things that inspired him to design systems with swales was the mimicking a feature of a natural process: when glaciers / ice sheets recede, they often leave behind swales on the land as the changing seasons cause the ice to recede in a pulsing action. Thus, swales are in fact one of nature's patterns in many landscapes.

Human-made swales are great example of implementation of the idea Brad Lancaster got from a person successfully re-greening arid areas of Africa: "First, plant the rain."

PS- Nice meeting up with you a couple of weeks ago James; I wish you well on your project with Gerry

It seemed like a few years ago that swales were a very "in" thing to have.

Does anybody have some insights on how effective swales have been for them? Would you still recommend? Is there any new learnings with swales?

Swales have improved the ground all over the world, there is plenty of evidence of the benefits.
No doubt, having read the notes above, there are also some cases where damage was caused, but on reflection that may have been because of lack of knowledge of a 'new' concept.
Swales are very old, they were use in India over centuries, its just that 'western' people rush in without thought sometimes.
Anywhere soil conservation, water retention is being encourage swales will be there.
Maybe not giant basins, but low shallow pans quietly holding or moving water at a slow pace to enable it to sit and soak.

It's a good question. I think that holding water in place is a very good idea.

For example: In my sand/silt soil, you'd think any water that touched it would immediately sink in. Wrong! If to top dries out, it is extremely resistant to absorbing moisture (hydrophobic?). A big thundershower can shed right off a sloped garden and be lost forever. To combat this, I have had to terrace my gardens. And of course, mulch heavily so the soil is able to receive moisture.

In other places, around trees on a slope, mini-swales or dams above and below each tree accomplish the same thing -- the results are obvious to see.

So I can see how large-scale swales could make a big difference.

from Kenyan company
'Poor swales construction or maintenance can lead to erosion, which can reduce their effectiveness and cause sedimentation in other areas. Because of their expansive nature, swales may not be practical in places with little available land or densely populated regions.'

They are' Express Drainage Solutions Limited ' which is a Leading Water and Wastewater Treatment Company in Kenya and Wastewater Treatment Service Provider in Kenya

Not sure about efficiency of swales, but folks here are into contour ploughing - minimising run-off of any rain that might magically fall from the sky.  Mostly a broad acre thing for cropping.  I'm getting a bit jaded on the prospect of rain . . .
https://en.wikipedia.org/wiki/Contour_plowing

Contour ploughing and swales are quite different although the effect can look similar, its all a matter of scale.
Rivers, lakes and basins are massive forms of swales,
Historically swales are usually man made are shallow, tend to follow contours so they do not wash away and turn into a gullies,  but may be very wide and long.
In India they carried water many miles.
Today they may be a short as 5M and a few metres wide but to be effective for water retention and catchment  there is no limit.

Good link, great discussion by an Italian lady who is an expert in the science, making, designing of swales, ponds
and the like.

Before You Create Permaculture Swales, Watch this Swale Guide and Example!

I will have to say, as a person who's lived their whole life on the West Coast of the US, where most of it is one step above a desert, I have never once had a swale get even 2 inches of water in it, let alone slow water down.  

There are no monsoons here.  There may be two months where there could possibly, may be heavy enough rain where you'd think rain water might run along the ground but it just doesn't here.    We don't get any rain from the end of May through the beginning of December, so those swales sit there doing nothing for most of the year except make it hard on a wheelbarrow and a car.

If it's a drought year there's no rain in general, let alone trying to catch it and divert it.

I've almost sprained an ankle a few times stepping into one, either in the dark, backing up or losing my balance, so they add a level of danger for a person living in a rural situation who relies on having all limbs working 24/7 in order to do the physical labor needed to live in such a place.    Swales just don't do anything here.

We also have to alter other versions of Permaculture in general; hugel mounds into hugel trenches, tactics to deal with gophers and voles, it's too dry for cardboard/straw mulch, and it just makes a safe and hidden place for rodents, etc.  

So the type of rainfall is a very important factor, how many months of rainfall there are, and the type of soil, location.  

Christo, you need to understand proper swales are large and shallow, you dont go driving cars through them they are to hold water  so it can infiltrate  the ground and in India move slowly.
 large volumes of water to area where the water can soak into the ground.
The water will move very slowly.
Driving through them will compact the soil and perhaps impede infiltration.

Cristo Balete wrote:I will have to say, as a person who's lived their whole life on the West Coast of the US, where most of it is one step above a desert, I have never once had a swale get even 2 inches of water in it, let alone slow water down.

Howdy, Cristo.

You should check out what they are doing in China. The government has turned large areas
of the Gobi Desert into forest and productive farmland. I'd say that the Gobi is more problematic
to growing stuff than your land in CA vis a vis, dare I say, growing stuff.

I'll try to find some videos but try to just type in what I described and YouTube shorts and I bet ya
you'll get some hits.

Cheers, ...

Swales more or less slow the water down. They will buy you time. If you have 16 acres, you should go with passive storage via catchment and drainage ponds. Drainage systems to flow into a big pond....series and Cascades of ponds. The trees can be in neat rows or guilds and will start holding the water in the soil more and establish water table for the future.

Go with ponds for drought and by the time the trees come up you could pump water lines drip irrigation type from those ponds to the trees.

Think of swales like capillaries in your circulatory system. Cover the soil via mulch, leaves, straw etc that will keep the soil moist always for your plants. You could even do bowls ie zuni bowls for the trees instead of swales also. Probably less work for you too. Place them clay vessels in the ground for water if you want.

You could also do giant cheap sturdy roofs and collect rainwater. Or short and wide solid tarps to catch the water or funnel it into storage.

You local forest conservation ie dcnr could give you advice too. Sometimes they have incentive to come out and provide trees seeds and labor for your property. Need to do research on this.

Some ideas hope that helps