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:
Using a level and a plumb line to find the level spots at this contour line:
Back in the previous post there were some videos showing how this is done...see:
And it always helps to have a nice kitty doing rollie-zollies in the grass nearby.