Built a high round tower. Place a ring gate at the top of the tower, and one at the bottom of the tower. The tower should be as high as possible, ideally it would be 100 miles high, but this might be a little outside of your building skills. Then poor in water untill you have reached the saturation of the ring gates and excess water will go out below.
Then, you'll place waterwheels inside this tower at 300 feet intervals, these will all drive different axles and will each receive 16.66 pounds of water falling at 50ft/second, every second. Having a tower as high as 1200 ft, would thus give you pretty much force.
Having Zombie bears power a Threadmill is cheaper and yields more force though.