A Beginner's Introduction to Rainwater Harvesting

Want to learn more about rainwater harvesting? High Plains Water District is sponsoring rainwater harvesting workshops in Canyon (April 5), Lubbock (April 12) and Levelland (April 19)! Find more information about these workshops at rsvp.hpwd.org.

The History

Inside the Basilica Cistern  by Clint Koehler 2010

Inside the Basilica Cistern by Clint Koehler 2010

Rainwater harvesting systems date back thousands of years to the first human civilizations!

In the ancient ruins of the Indus Valley, it is still possible to find huge cisterns cut into rocks that collected rainfall. During the drier seasons, these allowed for the communities to irrigate their crops and have access to drinking water. These rock cisterns are still used today in some parts of India.

In the 6th Century, the Roman Empire integrated rainwater collection into their cities. Today, some of their impressive constructions can be found in Istanbul in the Basilica Cistern, which was used to collect rainwater from the streets above.

Rainwater harvesting fell out of use largely in the 17th Century because the reservoirs rapidly spread disease. The treatment systems in large-scale modern rainwater harvesting systems help to prevent the spread and growth of any bacteria or diseases.

How it Works

Basic Rainwater Barrel System, www.lastormwater.org

Basic Rainwater Barrel System, www.lastormwater.org

Rainwater harvesting is a water supply approach that nearly anyone can use. It captures, diverts and stores rainwater for later use.

The systems can range in complexity, but all systems have four basic components: a catchment surface, conveyance system, storage and distribution. If the water is being used as a potable source, then proper disinfection using ultraviolet light or similar methods is required.

  • In most instances, roof tops are the catchment surface for rainwater harvesting systems. The rain falls on the roof, runs off, and is transported through a conveyance system of gutters and downspouts.
  • The conveyance system moves the water to the storage container, which can vary in cost, material, and size. This depends entirely upon the needs of the user. A 50-gallon barrel may work well for homeowners while 15,000 gallon tanks may be needed for large scale agricultural or industrial use.
  • The distribution system moves the harvested rainwater from final storage to point of use. Distribution systems can be as simple as filling up a watering can or they can include pumps and drip irrigation systems. Each method caters to a different need-so it is important to find one that works best for the intended end use for the harvested rainwater.

While it may seem complex at first, installing and using a rainwater harvesting system is a fairly easy way to save water for a not-so-rainy day!


How you can use it

Rainwater catchment is used today to help people offset their use of groundwater and municipal water supplies. In areas like West Texas, where water resources can be strained at times, using stored rainwater can be a great help in conserving water. Here are just a few of the ways rainwater harvesting can help out:

  • Landscaping - If you are looking to start a garden, rainwater is great for plants because it is largely free of salts and minerals that can harm root growth.

  • Fire Protection - Rainwater storage can be used for fire protection in case of an emergency. In remote areas that may be far away from the closest fire department, stored rainwater is a great means of protection from fire damage.

  • Daily Use - Some businesses use rainwater as an alternative to using potable water for toilet flushing.


How the World Uses It

Across the world, rainwater harvesting is becoming more and more popular. As water scarcity becomes an increasing challenge, global efforts to conserve and use water in creative ways is vital to solving the water problems facing the global community.

  • China - In China, most new developments include rainwater harvesting. This has been especially beneficial in regions where water access is limited.
  • Brazil - Thousands of cisterns have been installed to help supplement water resources after the record-breaking drought.
  • Israel - In Israel, rainwater harvesting systems are installed in schools to teach children the value of water conservation.
  • Australia - During the countrywide drought in 2006-2012, rainwater cisterns were used to help reduce water usage when fighting fires.