They are used by smaller farmers for crop irrigation, drainage and fisheries. Impeller designs have improved as well bringing even more efficiency and reducing energy costs to farming there. Earlier designs were less than two meters long but nowadays they can be up to 6 meters or more to enable them to more safely "reach out" to the water source while allowing the power source (many times two-wheel tractors are used) to be kept in safer, more stable positions, as shown in the adjacent picture.