Rain barrels are a great way to conserve water and to save money. If you live in city limits, your sewage bill is based on your water bill, so you are saving on two utility bills at the same time. Not to mention, the added perk of less water in your basement if drainage is an issue for you, like it is in many urban neighborhoods.
Gravity creates pressure comparable to any city water system if you get your rain barrels high enough. The formula is basic: 1 foot of height equals .43 PSI of pressure, so if you place your rain barrels 12 feet off the ground, you have approximately 5 PSI of pressure. A neighbor and friend who has been using rainwater for much longer than we have helped us build this structure on which on our rain barrels are secured (I used the term “us” loosely; I had little to do with the project beyond instigating it).
On the right side, you can see a pipe running down the side of the structure with a spigot attached to the bottom. We attach a hose to a spigot and use the water for a variety of purposes from there. During the dry summer months, we use most of the water on plants and do not have much left over. During most of the rest of the year, we have enough water to use for flushing toilets and doing laundry. Eventually, I’d like to have the system plumbed into the house, but for now, I just turn off the water to the downstairs toilets and run the hose into the fill tank on the back of the toilet. Similarly, I fill my laundry tank with the hose for the wash cycle and then let it cycle automatically from there. It is a fabulous system for the time being (aside from the occasional flooding mishaps when I forget the hose is running – oops!).