Rain harvesting systems date back to the earliest civilizations, particularly those that were located in arid regions. For these early civilizations, captured rain water was extremely important as it was used for cooking, irrigation, and cleaning. Even a short rain can provide a lot of water. For example, if you had a 2000 square foot roof and your city gets approximately 12 inches of rain during a year. For every inch of rain that fell, you could collect 1200 gallons from your roof! Even if you only collected 50 gallons, that small amount of water could run a drip irrigation system between 4-14 square feet of landscape for six months! Imagine what you could do with 1200 gallons!

Modern Day DIY systems:

Plastic barrel (typically 50 gallons).

Photo: The Flying Paquets

Plastic round rain barrels are probably the most common type of rain barrel on the market. They are relatively cheap ($70-200) and are durable and weather-proof. However, they can be fairly ugly and hard to hide. If designed for rain catchment, then it will be installed with a spout at the bottom to connect a hose to. A spout at the bottom, where you can connect a hose, helps make getting the water out much easier.

Photo:  jessycat_techie

To save even more money, you could purchase and adapt a standard plastic trash can, which typically has a capacity of 32-44 gallons. However, you have to adapt a hose connection to the bottom of the trash can, if you want to connect a hose. Be careful when using trash cans if watering any edible fruits or vegetables. The plastic that trash cans are made from are not food grade, meaning that the plastic can leech into the water it is storing.

Oak Barrels

Photo: Blue Cinderella

Oak rain barrels are a more natural alternative to plastic barrels and also look cool. This company sells retrofitted oak barrels that were once used to distill bourbon in Kentucky. Oak barrels are very heavy, and could be very expensive to ship if you can’t buy them locally.

Modular

Rainwater HOG

Photo: mywaterfuture

This modular rain barrel holds 50 gallons of water and is designed to fit where other rain barrels can’t. You can install this system close to your house, beneath the ground or deck, or it can be built into the frame-rails of your walls! You can also easily connect these units together to increase your total water storage. You can buy this type of barrel here.

Setting up a rain barrel is really easy. You simply divert some or all of the water flow from your gutter downspout into the rain barrel. It is important to have a filter (wire or mesh) on the rain barrel opening to keep any large debris from entering the barrel. Every 12-18 months, you will also need to clean out the rain barrel, as dirt and silt will build up inside. You can easily do this with a high-pressure hose or sprayer.

Do you have a rain harvesting system in operation at your home? Post up links to pictures or offer your advice on what systems work best!

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Rain Harvesting Systems Around the World

The Gansu province in China and the semi-arid north east region of Brazil, have developed and rely upon some of the largest rooftop rainwater projects in the world.

In Bermuda and the U.S. Virgin Islands, all new construction is required by law to include rainwater harvesting adequate for the residents of that building.

In Colorado, water rights laws severely restrict rainwater harvesting . According to Colorado law, a property owner who captures rainwater is effectively stealing it from those who have rights to take water from the watershed. Pretty crazy, right?

El Jadida Cistern - Morocco

Additional Resources:

How much rainwater can you rescue from your roof ?

Tutorials and plans for many types of different home-made rain barrels.