From the get-go, our blank canvas was screaming for swales. Even with just a preliminary study of permaculture, you realize what resources you have and how to take advantage of them. We had a sunny, open space on a slope.
It was easy to see that heavy rains would wash down the slope, flooding the lowest corner. Our rich clay soil had been tilled for several years prior, causing a hard crust to form by mid-summer, causing water to run off rather that penetrate the soil. We had plans for the improving the soil, but that would take time.
To make the most of our rainfall, we opted to dig swales on contour across our garden. Swales are essentially trenches that are dug to hold water. The soil removed from the trench is mounded immediately downhill like a speed bump that stops the flow of water down a slope. Swales can be designed to hold water in one trench dug across an area of equal elevation, also called on contour, or angled gradually down a slope to move water to a lower spot.
Jen rigged up a tool called an A-frame from scrap lumber.
We used this tool to find the areas of equal elevation and marked them with flags to get a general sense of where our swales would go. Although we intended to hang dig them (presumably by volunteers who would likely not return ;)), the township park department graciously offered to dig them with their excavator. Phew!
Our swales also double as walking paths – we filled the trenches with lose organic matter like leaves and mulch. There is plenty of free space to hold water, but no obnoxious trenches to trip over.
Crimson clover, a legume that adds nitrogen to the soil, was interplanted with currants on our largest swale. Crimson clover also attracts pollinators,