How to Dig a Water Well Using Water Pressure
To dig a water well using water pressure, called a jetted well, a narrow pipe is threaded to the bottom of the existing hole. A wide drill bit at the end is used to loosen soil. Water is jetted down the narrow pipe to carry the loosened soil back up through the annulus between the wall of the well and outside of the jet-stream pipe.
Erect a tripod above the hole. The tripod should be firmly planted into the ground and stand at least the height of two men. The tripod should be tall enough to accommodate the drill pipes and casing.
Centering under the tripod with a plum bob, dig a starter hole 1 meter deep.
Dig a trench several meters from the tripod to fill with water for jetting. A trench can be too close, causing seepage into the well before the well wall casing is in place. A trench measuring 1 meter wide and deep should be an adequate size.
Dig a track a few inches deep from the well hole to the trench that slopes downward from the well, so that water overflowing the well will flow toward the trench.
Set the water pump next to the trench, with the water hose for intake dropping into the filled trench. The water pump will be pumping water from the trench into the well. Overflow from the well will flow back into the trench.
Add the hose to the pump outlet, which should be attached to a swivel hose connection hung from a pulley hanging from the tripod. The rope to support the swivel hose connection will be lowered by a pulley as the drill pipe digs down.
Attach the jetting bit to the bottom end of the drill pipe and lower it into the hole.
Attach the top section of drill pipe to the swivel hose connection. The swivel hose connection will allow the hose to turn as the water jet propels a turning, drilling motion that pulls the pipe downward.
When the swivel hose connection has dropped down to ground level, disconnect the swivel hose connection, attach another section of pipe and connect the swivel hose connection to the new section of pipe, which is then inserted into the pipe already in the ground. Repeat the process. Finishing the well, including the insertion of the wall casing and well screen, is similar to normal well drilling (see References).
- A variation of the jetted well is to use a percussion bit to loosen the dirt, while pouring in water. When the resulting paste is too thick to allow the bit to hit earth solidly, the percussion bit is lifted out, water is added to thin the paste and a bailer is lowered in to remove the paste (see References).
Paul Dohrman's academic background is in physics and economics. He has professional experience as an educator, mortgage consultant, and casualty actuary. His interests include development economics, technology-based charities, and angel investing.