Here is a video of the complete watershed I installed at the farm. It is taken during heavy rain while most of the swales are overflowing. I did manage to catch the entire event and had no water leave the system at the lower dam.
A swale is a ditch on contour used to harvest rainwater, stop it, and allow it to passively soak into the landscape over time. This feature, when installed properly, can control erosion by slowing and stopping rainwater at periodic distances across the landscape. They control flooding by regulating and slowing the flow of runoff water into waterways. Swales rehydrate the landscape by holding up the water and allowing it to gently soak into the ground.
The mound produced by digging the ditch can be used to plant trees and offers a way to break up grazing land into useful sizes for grazing cells or paddocks. If one chooses to plant trees on the mounds, as I have, there will be plenty of shade for better grass and a place for your animals to escape the sun, wind, and even rain and be more comfortable.
On the farm, water is a valuable resource. Shouldn't we be trying to keep it on the farm for as long as possible? The video series below demonstrates how I dig my swales with a bulldozer. Enjoy!
Here is a satellite view of the farm taken shortly after we moved here. The property line is shown in black. For scale, the cleared area is about 30 acres. The total acreage is 96.
A major part of what I want to do is to install a full farm mainframe earthworks system to control erosion, slow and direct water, hold water in the landscape as much as possible, define grazing cells, and create ponds for fish production, waterfowl, livestock watering, recreation, and to attract wildlife. Also, earthworks are just plain fascinating to me and I enjoy every aspect of them including the layout, the engineering, operating the big equipment to install them, and seeing them operate.
If you want to design, engineer and install your own earthworks, I highly recommend the work of P.A Yeomans and The Designers Manual by Bill Mollison (click the research tab). Even if you won't be doing the machine work yourself, it is imperative that you know what you want, where to put it, and how to convey this information to the operator you will be hiring on your project to bring your design into existence.
With mainframe earthworks, you don't know what your doing until you've done it. This is not meant as a discouragement but just an observation based on my own personal experience. I submitted the above design to get my Permaculture Design Certificate from the first Geoff Lawton online course which I was finishing up shortly after moving here. You can see the immovable objects such as the county road entrance, the creeks and the swampy area. This drawing was done before doing any surveying and was based on a short period of observation. It will be interesting to compare this picture with the actual satellite photo when Google gets around to updating it. So far some of it even turned out to be somewhat accurate!
Shown above is a closer view of the pasture. A farmer in my neighborhood had been making hay and taking it away for years and the soil was exposed in areas and badly compacted and just in poor condition in general. Notice the "government solution" to erosion in the form of the mounds you see stepping down the hill. These were installed in the 1940's and are actually drains going downhill against contour. They do, however, allow the fields to dry out more quickly (if you actually want that). I have since installed swales on contour which have rendered the drains inoperable and slow the water and let it soak into the landscape where is is needed.
Here is a photo taken shortly after installing 3 swales in the center field. It's hard to tell, but they are full of water from the spring rains. I will go into further detail in future posts.