Posted by: Chris
The project list around the Horticulture Unit has grown from legal pad size to novelty scroll that keeps unraveling. One project in particular has consistently remained in the background – our swale. The swale follows the lower fence from the southwest to southeast corner of the unit. Its design and installation have taken weeks, and while the end result may look just like rocks in a ditch, it’s unfortunately not that simple.
The project began by marking out the length and general shape the swale would take; this was accomplished with spray paint (to mark the swale’s center) and wooden stakes (every 20ft to help gauge an even finished grade). The swale begins at the southwest corner of the Unit, meandering along the fence line until its conclusion near the base of the orchards. Stakes were placed every 20ft and using our surveying equipment, marked to ensure a 2% drop. This gradual slope is steep enough to move water without it becoming stagnant, and shallow enough to avoid erosion problems. Using the bobcat’s bucket attachment, the swale was graded and cut to the approximate shape it would take.
The next big step was to install a French drain running through the center of the swale. Using a variety of machinery, a trench was excavated through the middle of the swale, which subsequently required some handy shovel work to ensure the bottom of the trench was deep enough and at the 2% incline needed to move water through it.
Before we laid pipe, we filled the trench with a layer of gravel to prevent the perforation on the bottom from clogging. We then laid in the hundreds of feet of 3” perforated pipe into its new home, which we then buried with another layer of gravel.
With the French drain successfully buried, we then went to work beautifying the swale. Using 2-4” rock, we littered the swale to mimic a natural, flowing stream. We scattered bigger boulders along the edges for the swale to bounce off and flow around, giving it a natural feel, along with medium sized rocks all throughout.
The process of dumping 2-4” in between medium sized, and maneuvering around the behemoth boulders, continued repetitiously for days.
Finally, after everyone had successfully broken their backs moving rock for days and days, we finished. Awesome.