Garden View: Options for rainwater harvesting

My plants sure have been enjoying these recent light rain showers, which got me thinking about different ways that we can capture that water.

Let’s start by discussing why we would even want to capture rain water when we have water readily available from our faucets? First, in many urban settings, up to 30 to 50 percent of home water use can go to irrigating the landscape. Water conservation aside, you will be saving money on your water bill and making efficient use of a valuable resource.

Rainwater not only benefits you, but your plants as well; they prefer rainwater as it is free of salts and other minerals that can have negative impacts on the roots. Rainwater harvesting can also reduce flooding and erosion in your landscape and prevent surface water from becoming contaminated with sediments and chemicals.

There are many options when it comes to collecting rainwater and systems can be designed for both large-scale and residential landscapes. Rainwater harvesting can even be implemented on ranches and used to capture water for livestock and wildlife.

The basics of a system include supply (rainfall), demand (plants/animals), and a system for collecting and moving the water. This can be as simple as one section of gutter with a down spout to a water holding tank with a water hose attached. Or it can be very complex with gutters around the whole building and multiple large tanks storing hundreds of gallons connected to an irrigation system with pumps that can move the water around the property.

There are many options and varieties when it comes to rain tanks; Fifty-gallon barrels are often a good place to start. Just keep in mind that with only 1 inch of rain you will collect roughly 0.6 gallons of water per square foot of surface area. So a roof with a surface area of 1,000 square feet could collect up to 600 gallons of water with only 1 inch of rainfall. That 50 gallon barrel will fill up quickly and you’ll want to expand. Good news is you can connect multiple barrels together if you aren’t ready to invest in a larger tank.

If you are interested in capturing rainwater but don’t want to purchase equipment and install a system, rain gardens are a great alternative. Rain gardens are one method that can be employed to better utilize rainwater without actually having to hold that water in a tank. A rain garden is a strategically placed flower bed that has either been dug into the ground or has added berms to hold water in place allowing it to percolate down into the soil profile.

This is not a pond and is not intended to hold water, only to slow it down. This gives the water time to slowly move down into the soil encouraging deep roots and preventing the rainwater from running off your property. These gardens are usually planted with natives that are well adapted to the local climate. This is important because the plants need to be able to tolerate both dry and wet conditions.

Rainwater harvesting is a simple concept, but it’s still important to do your research and have a well-planned out design to ensure a functional and efficient system. Check out the AgriLife Bookstore ( for some detailed publications on rainwater harvesting.

Ashley Gregory is the Horticulturalist for Hidalgo County with Texas A&M AgriLife Extension Service. She can be reached at the Hidalgo County Extension Office at (956) 383-1026 or by email at