Swales without excavation?

Tell me if this is not going to work, because I'd MUCH rather not have to dig anything out.

This spring I'm going to get started on my veg garden area. It's got a south facing slope and what I was thinking was to make swales for the garden beds but I am thinking... what if I just built up hugels along the contour the way I'd do a swale, just without excavating. I may have gaps in the hugel here and there, leading to the next "row" of swales for accessibility (which will actually end up looking much more like an RSS symbol) but if I do, I'll stagger them to continue to save water runoff.

Would it make a significant difference? It would sure be a lot easier, especially since it's the veg garden, and that way I don't have to worry about using excavating equipment around my mushroom-inoculate stumps. My orchard I'll definitely be doing the excavating, since I'm doing fruit and nut trees with deep root systems, but for the veg that's what I'm thinking. Are there gaps in my plan?

If the slope is modest, I would not worry about any of the possible downsides, but I would not expect the same benefits in water retention that you get with swales. The excavated part of the swale holds water and gives it time to infiltrate. With what you are describing, the water will flow along the surface, run into the hugel, some will be absorbed into the hugel with capilkary action drawing it upward, while much of the water will keep flowing along the surface, under the hugel. Some will be captured by the hugel, but little will actually infiltrate downward into the ground.

I guess what I am saying is I do not see a problem putting in hugels as you describe, but I would not expect them to be equivalent to swales.

Peter Ellis wrote:If the slope is modest, I would not worry about any of the possible downsides, but I would not expect the same benefits in water retention that you get with swales. The excavated part of the swale holds water and gives it time to infiltrate. With what you are describing, the water will flow along the surface, run into the hugel, some will be absorbed into the hugel with capilkary action drawing it upward, while much of the water will keep flowing along the surface, under the hugel. Some will be captured by the hugel, but little will actually infiltrate downward into the ground.

I guess what I am saying is I do not see a problem putting in hugels as you describe, but I would not expect them to be equivalent to swales.

Gotcha. So it will run underneath? Didn't think of that. I do want to make sure to retain as much water as possible so I have to add as little supplemental water as possible, so maybe it will be necessary.

I'm just wondering where you'll get all the dirt to cover the hugels without digging. Seems if you're going to be covering hugels you might as well dig a swale so you have some dirt.

I've been doing pretty much the same thing in my forest. There just isn't really any soil too put over the hugelbeds - most places have 90% rocks with the trees just starting to create a layer of humus that is no more than 2-3" thick before you get into large rocks and boulders.

It's going to be slower going than if there was the option of covering it with good dirt right away but I do think that there's the possibility of creating good water capturing swales this way. Initially the piled brush is going to act like a spongy gabbion, it'll let a lot of the water through while soaking up a small amount and filtering out what debris is washed down during good rain events. That filtered debris along with the fallen leaves/needles and any herbaceous plants that happen to grow through the piles will start to fill in and close up what gaps there are, slowly making the swale retain more water vs. letting it pass through. This will start to create ideal fungal habitat which will in turn support greater and greater soil biological diversity maximizing the hugelbed's water absorbing potential as well as maximizing the swale's infiltration potential.

One key thing that I'm working on with my forest swales is establishing a broad mix of chop and drop worthy plants close to my swales so that I can maximize the organic matter that I can pile upon the swales. Once these are established and woody perennials are growing in the hugels there should be plenty of material growing in or being added to the swales to compensate for the settling/consumption of the initial material used to build the swales.

Unfortunately, I'm only one year in on my oldest forest swales and I'm operating on a shoestring budget with a one man labor force so the going is a little slow. I try to ease the pain of lack of progress by telling myself that it's better to go slow and observe than to work faster than nature can.

Danielle Venegas wrote:I'm just wondering where you'll get all the dirt to cover the hugels without digging. Seems if you're going to be covering hugels you might as well dig a swale so you have some dirt.

i wondered the same thing

i would suggest a shallow - wide ditch just uphill of the swale as a way to get material to cover the down hill hugel/swale

Danielle Venegas wrote:I'm just wondering where you'll get all the dirt to cover the hugels without digging. Seems if you're going to be covering hugels you might as well dig a swale so you have some dirt.

Oh - I have huge piles of topsoil from the excavation from our home, can borrow my dad's tractor to put those on my hugels but to properly do an excavated swale, I'd need to pay someone with a small backhoe. Unless it can be done with a regular small tractor? Which I thought it couldn't.

You can make swales with a tractor pretty effectively with a one or two bottom moldboard plow. You would still have some shovel work to do to make sure the final grade was perfectly on contour, but it works really well.

You could even build some terraces with hugels to help with water retention, it just kinda depends on what your soil is like and what kind of slope you are dealing with.

I think that Peter Ellis is right on with his description of what you would be accomplishing with on contour hugel mounds. I've noticed similar results on some of mine as to what he describes. Water will flow underneath the mound unless you have dug a trench or something to slow it down. Something as simple and digging out a spade's width and depth then dropping some of your woody material in there (you could even orient the logs vertically to help wick moisture up directly towards the crown of the mound) would go a long way. At that point you are still excavating swales, you're just building a hugel over the top. You could even do a nice wide swale at the very top of your garden area, start your first hugel mound in the bottom third (down slope side) of the swale then go on from there with your contour hugels. That might be a nice compromise of not doing a lot of excavation and still gaining the water harvesting benefits you are looking for.

Bethany Dutch wrote:

Danielle Venegas wrote:I'm just wondering where you'll get all the dirt to cover the hugels without digging. Seems if you're going to be covering hugels you might as well dig a swale so you have some dirt.

Oh - I have huge piles of topsoil from the excavation from our home, can borrow my dad's tractor to put those on my hugels but to properly do an excavated swale, I'd need to pay someone with a small backhoe. Unless it can be done with a regular small tractor? Which I thought it couldn't.

I have dug a 14x30x31/2' deep duck pond as well as several swales with berms with the bucket of our Kubota tractor. It's not even a terribly large tractor.

Oh, I thought lack of soil was the issue. If you have a loader bucket and enough room for access then you can dig your swales with your dads tractor.

I can dig them with the tractor...well that makes things a lot easier! I guess I should head over to youtube