Collecting and storing rainwater can allow you to water your lawn and garden very cheaply and can also mean an emergency water supply in case of fire on your property, or if your city's water supply is cut off for some reason. Before you shop for any type of rainwater storage tank, you want to ensure you know your options and have done your homework. Note a few important questions to ask about such a tank and keeping it near your home.
1. First note if it's legal
Some areas may actually restrict the collection of rainwater in order to avoid soil erosion; it is preferred in these areas that the ground collect the water and absorb it rather than collecting it in barrels or tanks. Your area may also restrict the size and material of a rainwater tank, especially one that you keep above ground. Your neighbors may not want an unsightly, oversize plastic tank in someone else's backyard, and a very large tank may obstruct their view. Whatever the restrictions, you want to start with your city or other area and ask about zoning restrictions, property laws, and the like before you start shopping.
2. Can you use any tank for storing water you will drink?
Even if you plan on putting your water through a filter or other treatment system, you may still be restricted as to the rainwater tank you use for collecting drinking water. Very often you're not legally allowed to use a tank that was once used to store toxic materials of any sort. You also want to ensure you choose a tank that will keep out the most algae and other harmful organisms; this would be steel or plastic versus wood or concrete, as wood and concrete are soft and porous and may allow in contaminants.
3. Why do storage tanks need footing under them?
Remember that even if a tank is very lightweight, water is very heavy and if you're holding hundreds of gallons or liters in your tank, it then also becomes very heavy. For storing a tank above ground, you may be recommended to have a cement pad poured first, or to otherwise brace up the soil so that the tank doesn't sink or start to shift. This can be good even for plastic or lightweight metal tanks. Your contractor or salesperson where you buy the tanks will be able to give you guidance on whether or not they need footing under them.
