Harvesting rainwater is an inventive method of altering your dependence on other water sources. Rainwater harvesting is simply the process of capturing and storing rainwater for later use. Individuals may choose to harvest rainwater because that is their only water source, they recognize the purity of rainwater, they are interested in self-sufficiency, they want to conserve water, or they want to reduce their water bill. Rainwater harvesting is beneficial because it reduces demand on existing water supply, and reduces run-off, erosion, and contamination of surface water. Homeowners are encouraged to start small with a rain barrel.

Last spring the City of Corpus Christi’s rain barrel distribution event for a called “Catch a drop!” to encourage the adoption of rainwater harvesting among homeowners. During the event 430 households purchased and installed 741 rain barrels. As a result of the interest in last year’s program the city currently conducting a rain barrel sale through April 29th. They can be purchased at a discounted rate and picked up during a distribution event on May 7th. All barrels must be ordered online through www.upcycle-products.com. Once at the website, you will need to select the order form for Corpus Christi.

Once involved in water harvesting, interest can grow to larger more elaborate collection systems. Last November, participants in the “Catch a drop!” program were surveyed and 47% of the respondents indicated that they would likely purchase a larger rain water collection system as a result of their rain barrel adoption experience. Depending on how elaborate the cistern of these larger systems, cost can range from $0.50 to over $2.25 per gallon. As a general guide, 0.6 gallons of water per square foot of roof can be captured per inch of rainfall. So a 2000 square foot of roof can produce 1,200 gallons of water per inch of rain. Assuming 32 inches of rainfall for Corpus Christi, annual collection on the above roof would be just over 38 thousand gallons.

However, a cistern of that size would not only be unpractical for most homeowners, it would be unnecessary as well. Homeowners must also take into account distribution of annual rainfall and monthly household and landscape demand. A cistern less than half that size would be needed even if we received 100% of annual rainfall for a 3 year period. Assuming 80% of annual rainfall over that 3 year period, and you could probably get by with a 4500 gallon tank or less. A calculator to help estimate cistern size and water demand can be found at: http://rainwaterharvesting.tamu.edu/.

Freshwater is only 2.5% of the world’s water. Of that 68.9% is locked in glaciers and 30.8% is groundwater. The remaining portion (0.3%) is found in rivers and lakes. Rainwater can be used for nearly any purpose that requires water; how will you use yours?

Individuals with disabilities, who require an auxiliary aid, service or accommodation in order to participate in any of the mentioned activities, are encouraged to contact the County Extension Office eight days before all programs for assistance. Extension programs serve people of all ages regardless of socioeconomic level, race, color, sex, religion disability or national origin.