This should always be done if camp is not to be moved frequently. Do not dig the ditch V-shaped, but cut straight down, just outside the tent pegs and slope the trench inward toward this dam (Fig. 16). Cast the dirt away; never bank it against the tent, for it would quickly rot the canvas. Give the ditch a uniform slope toward the lowest ground around the tent. In the shallowest places it need not be over three inches deep. A trench that does not drain well is worse than none.