Collecting rainwater allows you to water your garden without increasing your water bill. You can collect over half a gallon of water for every inch of rainfall per square foot of your home's roof. A rain barrel allows you to collect and store the rain water until you are ready to use it. Nearly any waterproof container makes a suitable rain barrel, though the container may need modification before you can put it to use.
Both metal and plastic drums work well for rain barrels, though plastic drums are less prone to rust and dents. Use 55- to 75-gallon drums that are either new or have only held food-grade items. Avoid drums that held chemicals, such as fuel or pesticides. Recycled drums must have a hole for the gutter downspout and an overflow valve installed before you begin rain collection. There also are manufactured drum-style rain barrels that already have these installed, as well as a spigot for hooking up a garden hose.
Wood provides a more aesthetically pleasing choice than plastic, especially if the barrel must be placed in a visible area of the yard. Often, wood is not watertight enough to store the rain water for a long period of time. Wet wood also is more prone to rot. Many wood barrels come with plastic or metal inserts that prevent the water from leaking through the wood, while also protecting the wood from water damage.
Plastic and metal dustbins are an inexpensive alternative to other rain barrel options, but they are not as sturdy as drums and wood barrels. Collected water should be used as soon as possible to prevent stress on the dustbin. Use only sturdy, well-made dustbins, otherwise they may split under the pressure from the water inside. Durable plastic and metal is preferable over thin-walled cans.
Large plastic buckets work well for collecting small amounts of rainwater, such as from the top of a potting shed or other small structure. Use 5- to 10-gallon buckets with lids for rain water collection. Always drill and overflow hole in the side of the bucket, as these smaller container quickly fill up, even in short rain storms. Buckets are inexpensive and easy to transport, allowing you to store the water until you need it. You can replace the buckets with a new one as they fill.