can hogs create swales?

Have an idea about using appropriately fenced, appropriately timed pig activity on a hillside to create large swales - a long, on contour shallow ditch designed to slow and sink water. 

I think an on-contour pen as long and as wide as the desired swale could be constructed out of the usual one or two hot wire pig fence, like a bowling alley (preferably under/downhill from some mast trees for foraging).  The downhill side would also have some sort of check dam construction (made out of brush and sticks probably gathered on site), acting as a bit of a lip a few feet high to catch the dirt the pigs erode towards it. 

I imagine the pigs' rooting behavior would leave a shallow but effective depression in the middle of the fenced area while flattening it generally towards the downhill side, and upon removal they leave a fertilized and perfectly disturbed area that begs for planting!   Might take a couple of seasonal pulses to get pig food out of it and move enough dirt to make it last, but the fence could be left in place until the work is done...although they might eventually undermine the uphill fence.... 

This might be one of those "great" ideas that sounds simple and is a nightmare in practice. 

We intend to find out, want to try it sometime in the future, anyone think it could work?  On not- too steep of a hill I think it could work (I have a hill in mind on our place). 

The only problem I see and it is a relatively small one; is that swales generally need to be dead level. It would be difficult to achieve that with hogs alone. I think your ideas of how to try sound reasonable though and if the hogs do the majority of the hard work you should be left with only some small adjustments to get to level.

A couple of other ideas on how to use the hogs:
Faster more intense more cost to you: you can buy or produce some additional feed for the hogs so you can distribute it where you want them to root to work over specific areas. Use your idea but make smaller paddocks of the entire area. Run the hogs in one area, move them, then spread the feed in the area they just left and scratch or rake it into the now turned up soil (I am thinking corn here). When they are done in the next paddock either move them forward to a new area or back to the area you spread feed in to go back to work. You will need to make these adjustments based on your observations and keep them shifting around as necessary.

A slower method would be to plant sunchokes (Jerusalem artichokes) where you want the hogs to root up let them grow and then let the hogs self harvest the tubers. The sunchokes should help break up the ground some on their own and the hogs should do the rest harvesting the tubers. You could also harvest the stock of the sunchokes before hand for use in you check dam construction.

Good Luck and please update later on with what you did and how it is going. I believe you are on the right track though with looking to use the natural tendencies of the hogs to work for you.

Jeff

If you put up fencing on the contour, animals are a good way to terrace. Even without fencing, many animals tend to graze on the contour and will build up terraces.

The only problem I see and it is a relatively small one; is that swales generally need to be dead level. It would be difficult to achieve that with hogs alone. I think your ideas of how to try sound reasonable though and if the hogs do the majority of the hard work you should be left with only some small adjustments to get to level.

Right, I was thinking the planting stage post-disturbance would be when you do the final adjustments to the swale making and the pigs just get the bulk of the dirt moved. 

I was also thinking that the pigs would mostly disturb the soil, but rain would move the disturbed dirt down hill, and the dam would prevent it from washing away entirely.  Water is an excellent leveler. 

A slower method would be to plant sunchokes (Jerusalem artichokes) where you want the hogs to root up let them grow and then let the hogs self harvest the tubers.

Our pigs don't eat sunchokes, even cooked ones put in their slop, they ate around them!  :/  We have a breed that doesn't do a lot of rooting, maybe we'd have to find a different one for this application.  They do rustle around in the dirt looking for grubs and nuts, which is why I thought multiple years of looking for acorns could move enough soil.  Plus, on my particular site, we'd be doing this in the woods, and I'm not sure I want to introduce such a persistent species to my local forest ecology.  I like the idea of spreading out annual seeds for them to find, though. 

Might work with other pigs in other locations though, I like the idea! 

Even without fencing, many animals tend to graze on the contour and will build up terraces.

I was thinking you could capitalize on this natural tendency and control it with fencing. 

I've tried this a bit with our pastured hogs.  It takes a bit of tweaking, but you can make it work.

We have a lot of western juniper here, so first I go in with the chain saw and cut the lower limbs to open up the understory for the hogs.  We chop up the limbs, and lay them on contour as a checkdam.

The hogs come in, make huge nests/wallows along the checkdams, and push the dirt downhill.  If left long enough, they would get everything almost level just naturally, but I usually take them out once things are turned up a bit.

I also use them for drainage trenches.  We just dug a new pond downhill from the hog barn, and I made a strip of pasture straight to the new pond.  It goes down hill at an angle, and as they walk and move things around, they create a trench to the pond.