Tie a big rock to the bottom of the string so it hangs below the cross piece, but doesn’t hit the ground.You can barely see the rock!
Look for level ground. Mark each footvery carefully with small sticks. Draw a markwhere the string crosses the crossbar.
Then turn the A Frame around and place each foot in the otherfoot’s place. Mark the spot again.
Rarely do the two marks match. Find the mid-point of the two marks.Make a large mark there.THAT is your LEVEL MARK
Now you can move across thelandscape moving the A-Frame corner to corner. That is: one foot stays in its placewhile the other is rotated out to where you believe level ground is.When the rock stops moving, the stringshould be at the Level Mark IF the land is level. If not, move that foot over a bit!
If you want the water to move ever so slowly down slope, you can give it a 1% - 2% slope.Who’s math smart???How many quarter inches would that be on the yard stick?
As the line meets the Level Mark,put a stick in the place where the foot of the A-Frame was. When you finish, you will have your contour measured.Advantages: you can do it alone.Disadvantages: it takes a long time towait for the rock to balance.