Rainwater Harvesting

By Ted Tragus, Bexar County Master Gardener Intern

September 2023

In our San Antonio climate, rainwater harvesting is a great way to have extra water available for your garden, especially at times such as these when rain is so scarce.  There are lots of systems available ranging from very simple to very complicated, depending on how much water you want to collect and store and how much time and money you are willing to invest.

The following is a series of photos (together with captions), documenting our experiences in harvesting rainwater.

Rain barrels collecting rainwater from the garden shed

Our first foray was in using rain barrels purchased from Home Depot that we hooked into the downspout of the gutters.

We now use them to collect the rainwater from the garden shed.

 We liked having extra water but found that, because we went through two barrels of water quickly, we decided we needed something bigger. We researched the various collection systems, including large round tanks designed specifically for water collection, as well as several systems that we found online.

Examples of larger water collection systems

 Some of the factors that need to be considered when deciding which collection system to use are the availability of guttering, space and materials, the cost of the materials, the topography of the area, and your own personal skills. Once you figure out what kind of container you want to use, you will need to decide the method of getting the rainwater into the tank. There are lots of options for that as well.

Five IBC’s connected together

We decided to use Intermediate Bulk Containers (IBCs). We chose IBCs because they were readily available and easy to work with. IBCs hold a lot of water relative to the space (or footprint) that they require. We were able to purchase used Food Grade IBCs (also called Caged Totes) and had them delivered at a reasonable price. We started with two 330-gallon tanks at the back of the house, behind a privacy fence.


Back yard system

We installed a “first flush system” which helps to filter the debris coming off the roof from the water going into the tank.

Hose connection

We learned lots of lessons with the first tanks.  To reduce the amount of algae, the tanks need to be wrapped or painted black. We wrapped ours like a Christmas package with heavy tarps and duct tape.  Of course, once you have the water in the system, you have to figure out how you are going to get it out!  After some trial and error, we purchased adapters that allow us to connect garden bibs. We hooked up a hose and are now able to use it to water our backyard plants.

Since then, we have installed two more tanks at the front of our house, covered them with picket fencing, and painted all the collection pipes to match the house, creating a large system daisy- chained together that provides water for our vegetable garden.

Additional Resources:

Texas A&M AgriLife Extension: Rainwater Harvesting

San Antonio Water System: Rainwater Harvesting

All photos by author