Spiral pump

The spiral pump works by having a coil of pipe or hose turn around a center. The center uses a mechanical seal to allow the spiral portion to spin and take a gulp with each revolution. The other end of the mechanical seal is connected to a discharge hose or pipe. A spiral pumps can be coupled to a paddle wheel and placed in a stream to supply water to some location on shore.

Ram Pump

A Ram pump uses gravity to get the water flowing down hill through the open swing check valve on the top of the pump. As the water speeds up it eventually causes the swing check valve to slam shut converting the waters momentum to pressure. This opens the spring check valve and makes the water flow uphill. The water that bleeds through the swing check valve will flow back into the stream. It may not be the most efficient pump be the energy (gravity) is free. Again another low cost, inexpensive, easy to build pump.

Rope Pump

A rope pump uses “washers” made from ¾” caps sanded down to fit inside a 1” pipe. The rope is threaded through holes in the “washers” and a knot is tied to keep the rope from sliding. The down pipe and up pipe and lashed together and support a pulley at each end. The pulleys are notched to grip the “washers”. The upper pulley has a crank, used to turn the rope. Its simple construction and inexpensive parts list make this a good option for places where a relatively low volume of water is needed and no power(other than human) is available.

Airlift Pump

Got some water to pump, but no pump? If you have an air compressor, and a few hoses, you're in business. One of the simplest pumps you can build is an airlift pump. This kind of pump is made using a large hose, with a smaller hose supplying air to the submersed end of the larger hose.You can use some brake line tubing clamped to the larger hose to make the bend at the submersed end.

An airlift pump works because the water with the air bubbles is less dense than the water on the outside of the pipe. This difference in density pushes the aerated water up the larger pipe.

An airlift pump works best when it's about 6" off the bottom of the tank and the bubbles are diffused as small as possible. One big advantage of an airlift pump is the ability to pump water with chunks of debris in it. Might be an inexpensive way to drain a swimming pool or circulate water in a fish pond or water effect.