Making Swales Part 4: The A-Frame

Our Swale Making workshop/workparty occurred over the weekend and went very well, but you’ll have to wait for the full report. And there’s still a little bit more to be done – we will have another workparty next weekend on June 30th. But here we’re still catching up with sharing our preparations. These guest posts are written by Angela, along with a little of my input…

David built this A frame with a plumb line:

The ‘A’ frame is designed to help determine the most level points between the two legs. It is used to map contour lines – a level line across your property. Brian K. used the elevation map to roughly design the swales, and we will use the A-Frame to more precicely mark them out. It is important to make the swales on contour to hold and store more water and the resources that water carries. The contour line is needed because if your swale and berm is on contour you will hold the water much more effectively.

Finding a contour line with the A-Frame

1. Start at one end of your property, and set one leg of your A-Frame down and mark it with a stake.

2. Move the other leg on your ‘A’ frame to the next place it is level. Then mark the other foot with a stake.

3. Move the level over so the first leg is on the second stake.

4. Then move the second leg again until the ‘A’ frame is level. Then mark the foot with a stake.

5. Keep going until you have marked the area that you need for your swale.

Using the map of the elevation lines on the property to roughly gauge where the contours are, David used the A frame to plot the course of contour lines across the property where we plan to carve the swales.

Using this map with elevation contour lines:

2010_AP_wContourLinesFeet.pdf

Using the A-frame to find the level spots at this contour line (we cheated and added a level to the A-Frame):

Next, putting a stake in to mark that spot….