• The water wheel is one of humankind's oldest power-generating inventions.NA/Photos.com/Getty Images
  
  As long as you have access to running water, you have a free source of power. Running water has momentum -- it carries the energy of movement with it. You can capture this energy with a variety of devices that you can build yourself to use the power of water to perform a variety of jobs. Many of these home hydropower projects require no special training or tools.
  
  

Hydroelectric Generator

• Make a small-scale hydroelectric generator to run tools and appliances or to charge batteries to run them later. A generator produces electricity when its axle is rotated. Make a small water wheel to turn the axle of a small generator by cutting slots in small squares of wood and fitting them onto the rim of a wooden wheel or disc. Place the wheel in a stream or river, or even under a waterfall, and the water will push against the fins, turning the wheel. The wheel is connected to the generator by a pulley or adapter bearings. These water turbines can generate up to half a kilowatt of electrical power, and cost as little as $50 to build. Save money on construction costs by adapting an old DC motor to serve as your generator.
  
  

Irrigation

• Harvest the rainwater to irrigate your garden or crops. All you need for this simple project is a barrel for catching rain, some pipes and fittings, and a mesh filter. Place the barrel on a roof or a stand, leaving its top open to the sky. Cut a hole in it near the bottom, and fit pipe into the hole. Fix the mesh filter over the pipe to keep out leaves and other contaminants. Gravity will cause the water to flow out of the storage barrel and into the pipe. Fix a spigot to the other end of the pipe to turn the water on or off at will.
  
  

Hydro-Powered Mill

• If you enjoy making your own food from scratch, whether for its taste or health benefits, then make your own hydro-powered mill. You need a water wheel set horizontally. A pipe carrying water from a stream sprays its water onto the wheel, rotating it. The axle of the wheel rises straight up through a stand and into a mill wheel sitting on top of the stand. As the water turns the wheel, the mill wheel is also turned, grinding grain that is placed beneath it.