We built a permaculture swale above the vegetable garden and blueberry bush area to capture the rain to prevent runoff and conserve the water for future use. Swales have been proven to retain water by forcing the rainwater into the Earth down to the impervious layer of soil. The water then travels under the surface and provides plant roots with needed irrigation. Such water can travel great distances and be stored for extended periods of time. Swales conserve valuable rainwater that normally runs down slopes and eventually ends up in driveways and storm sewers. They also help reduce evaporation of rainwater.
We built a swale above the garden to capture water running down the hill from the north end of the property. The swale is approximately one foot deep and 16 inches wide. Swale depth can vary depending on slope of hill and soil type. For example we made the swale shallower but wider in areas with rock closer to the surface which made digging more difficult. The swale at the top of the hill provides water for the peach trees, blueberry bushes and concord grapes. Decomposed leaves are placed in the swale to help retain water. Wheat straw covers the leaves and swale berm to prohibit erosion.
Another smaller swale was dug at the bottom of the hill using the same technique. This swale catches additional water for the vegetable garden. We are considering the addition of strawberries on the berm portion of this swale since they have deep roots and will help stabilize the berm. Not to mention fresh strawberries in the future.
Additional swales will be built on the property in the future.
To see a video of our swales visit video.
Geoff Lawton is a renowned permaculturist and did a great video on how swales work. Visit his video by clicking how swales work.