Swales for Water Harvesting and Food Production
A swale is not a complicated technique, nor is it something new. Swales are nothing more than water harvesting ditches on contour. On contour simply means level. The contour lines of a topographical map are level, at least on a large scale. Another way of putting it is to think of the jagged shoreline of a lake. Wherever water meets land is level and on contour.
The benefit of using swales, even on a small scale, are: 1. Collects water, slows it down and spreads it out. 2. Soaks water into the ground hydrating the surrounding area and recharging the water table. 3. Prevents erosion or reduces erosion from the landscape. 4. Reduces the need for irrigation if used in conjunction with food and fuel growing systems.
Our land is sloped and even though we get adequate rainfall each year (average of 30 inches) most of it quickly runs off and is wasted.
On our homestead we just completed nearly 200 yards of swales. This is not a large project by any means but it will add our homestead greatly in the coming years. We combined the addition of growing systems with the swale in order to gain the maximum benefit. We have planted a combination of fuel wood: black locust and honey locust which are also nitrogen fixing trees and forage trees and food producing trees: fruit and nut.
For constructing the swales we used very simple tools like an A-frame level. This is a simple device for determining an accurate contour line. In this case we used two means of verification: a simple bubble level fixed to the A-frame and a plumb bob with markings. Having both of these are redundant but I like redundancy! A neighbor of ours also helped us out with providing a tractor with a bucket loader. This is not the ideal tool for making swales (excavators and bull dozers would of worked much better) but it is what we had available to us and we appreciated our neighbor lending us a had immensely. The tractor combined with shovels and, of course, sweat equity made for a successful venture. We cut swales on contour and made very simple spillways in order to shed excess water should we get a large rain event.