http://swissbaync5d7ykaz7dh7v4qjrb4gmen5aj3bogxrcgbb43ij34bjuyd.onion/pdf/Books/Survival/Survival/shltrall.html
A channel several inches wide and as
deep may be made with a sharp stick instead of a handier tool. If this furrow is in the way of foot traffic as it may be at the front, or if
the ground is such that it will crumble easily, the drain usefulness may be
maintained by filling it loosely with small stones.