We recently completed our newest rainwater cistern. It cost about $1,600 to make, and took us about a week. It holds 6,000 gallons of potable water, and can be made by just about anyone. We start by leveling a site and making a ring of bricks. The bricks serve as a foundation for the metal walls of the cistern. Then, we lay out the metal in a cylinder, bolting it together. Once the walls are in place, we cut out holes for inlets and overflows. The roof sits on a ledge of angle iron inside the walls. It consists of a PVC frame, covered by billboard vinyl, and then that is covered with a thin cap of acrylic concrete. It is pretty easy to do, and gives you a cheap storage space for a lot of water. If you conserve water, this storage tank could last your family a very long time. For more detailed instructions, please visit: Cistern Howto - VelaCreations More photos: 2nd Cistern - a set on Flickr