This post is all about one rock dam and zeedyk structures and how they can help your homestead, especially in the desert.
A few years ago on a whim I put in a one rock dam on a small drainage in our south pasture. I had heard of them and the wonderful things they did and wanted to see it for myself. I snapped a few photos and left. A year later I was surprised when I went back to look at what had happened. The drain was shallower than it had been and the area (which had been barren before) was flush with grass. It was amazing! Thus began my journey with one rock dams and zeedyk structures. Why put these structures in? What are they? And what do they do?
On our desert homestead everything is influenced by how much water we have. When it rains it is in two or three big rain storms, and then nothing. In those big storms, the ground gets saturated very quickly and all the excess water just washes away and ends up in some holding pond, where it quickly evaporates. Five days later the dirt is dry again and you would never know it had rained.
So given the nature of how we get water in the desert, how can we best manage it so that it gets stored and used effective on our properties? Over the years as we have studied how best to manage water on our property, several principles keep getting brought to our attention. And it all starts with the soil.
Good Soil, The Largest Water Tank?
Good soil can hold a TON of water. Roughly good soil can hold up to 100,000 gallons of water per acre. That is almost the amount that an average water happy family in the United States uses in a year. I hear that and I get excited! But notice that is GOOD soil. Good soil has to have organic matter, which is workhorse for holding all that water. For an acre of land to hold 100,000 gallons of water, it has to have about 5% organic matter content (for every 1% increase in organic matter your soil can hold 20,000 gallons more water.) Erosion can be the enemy of organic matter. The problem with big storms is that they almost always create runoff, and runoff creates erosion which makes if virtually impossible to keep organic matter in your soils. How do you mitigate erosion?
SLow and spread
Something you hear a lot that can help mitigate erosion is slow and spread the water. This means that when you have a big rainstorm you want to slow down and spread out your water, stopping it from stealing your soil, letting it soak in longer and *BONUS* dropping organic matter and silt it has carried away from your neighbors properties. One of the ways this can be accomplished with one rock dams.
One Rock Dam (ORD)
One rock dams are just what they sound like, they are dams that are one rock high. They are super easy to make, it took me 2 hours to make one for a small drainage. What they do is help disrupt the flow of the water, making it slow down, spread out, sink in and drop it’s silt. Because they are relatively low profile, they don’t create these churning pools that cause further erosion.
Typically they are placed across drainages perpendicular to the flow of water. I put mine across a drainage that was starting to erode and still had gradually sloping sides. I have a wash with much steeper sides where it would be interesting to build a one rock dam and see how it performs.
Context, Context, Context
While a one rock dam is amazing, where you put them and the size of rock you use will depend greatly on your individual context. For us they are perfect because we are trying to prevent erosion from our relatively flat pastures and fields.
When you are building yours consider your context. What size of rock would work best, how wide should you make the dam? What are you trying to accomplish with the ORD? Don’t be afraid to experiment and see what happens, try different sizes of rocks and placements.
A guide that I rely heavily on for water management on our homestead is Rainwater Harvesting for Drylands and Beyond Vol 1 and 2, by Brad Lancaster. They are well worth the read and his methods are adaptable to a variety of homesteads and situations. These books will also help you asses you context and what you need.
How to Build a ONe rock dam
Gather rocks, I used rocks between the size of a baseball and a basketball, and line them up where you want them. I put ours perpendicular across our drainage. Only put them one or two rocks tall and as wide as you want/need/ or your rocks will allow. You can make it a foot wide, 10 feet wide or wider. Here you can see that I made ours roughly two feet wide. Make your dam wider than the drainage or place you are trying to mitigate erosion in.
And that’s it! Leave and let it work it’s magic!
Here are the before and after photos of ours.
Zeedyk Structures
If you are looking into one rock dams, zeedyk structures are worth thinking about too.
The technical definition of Zeedyk structures according to the USDA are “…low profile, hand-built treatments made of rock or wood intended to restore hydrologic and ecological function of wet meadows and small streams impacted by head-cutting, gully erosion, and channel incision.” They are primarily used to restore wetlands and other riparian climates. But I things they would work in other contexts as well, helping to slow and spread your water.
Zeedyk structures were developed by Bill Zeedyk, (visit his website here.) He has written a couple of books covering his methods that you can check out here if you are interested.
In Colorado they used them to help restore a wetland/marsh area and the before and after pictures are AMAZING and inspiring. I highly recommend looking into the report for that project. It has amazing pictures and includes instructions for the different kinds of zeedyk structures. You can find it here.
conclusion
A one rock dam can be a great solution for many properties and are well worth looking into, especially if you live in a desert where every drop of water counts. By building your soil and preventing erosion you can maximize the water that comes onto your homestead.
Check out the homesteading resource page for more awesome books and resources on homesteading!