A rainwater storage tank is not unusual for farms; the rainwater can be used to water crops or livestock, so there is less fresh water used. You can also have a rainwater tank on your property, farm or not, in order to water your lawn, wash your car and pets, or to have in case of a fire or sudden drought. Note a few things to look for when you're ready to choose a rainwater storage tank for your property.
Above or below ground
Note that you need to choose a tank that is meant for either above or below ground storage in particular when making your selection. Tanks stored above ground may need a special outside coating to keep the material from breaking down in direct sunlight. Tanks stored underground may need to be especially strong to withstand shifting soil and excess moisture that is underground. Trying to bury an above ground tank can mean seeing the tank bend and collapse. An underground tank may become too hot or have the plastic of the tank literally start to melt and soften if you stored it above ground.
You can put a rainwater tank in the middle of your lawn and it will collect water when it rains; however, this is not the best way to actually collect rainwater. A tank is often put next to your home or garage; this allows the tank to collect water that runs off the roof of the building. You can also shorten a downspout and put it over the tank, so that it directs water into the tank itself.
Consider this location carefully as you need a tank that will easily fit next to your home without overlapping your patio, looking too large for the space, or being so tall that it covers the home's windows. You may also want to plant shrubbery around the tank to hide it from view, and you'll need to consider the size of shrubbery you would need according to the size and location of the tank.
Don't assume that a larger tank is always a better option; your area may not get enough rainfall to actually fill that tank, and a larger tank may get so heavy with hundreds of gallons or liters of water in it that the tank starts to sink into the ground. Consider your area's average rainfall and also note if a full rain water tank would need a cement slab to sit on; if you don't want to add that piece of concrete, opt for a smaller tank.