By Brett Briant
LCRA Water Conservation Coordinator

It’s easy to overwater your landscape during the hot Central Texas summer. This can waste water and money and actually harm your lawn and landscaping by making them more susceptible to disease.

Even during the heat of summer, a typical landscape needs only about an inch of water a week to stay healthy. Because of the thinner soils found in Central Texas, many experts suggest watering about one-half inch twice a week, but only if your local water provider allows twice-a-week watering. During  the ongoing drought, some water providers, such as the City of Austin, allow watering a maximum of once a week.

Figuring out exactly how much a half-inch is may sound difficult, but it can be accomplished with a few simple tools that most people have around the house. All you need are empty cans with a straight side (cat food or tuna cans work well), a permanent marker, a ruler and a timer. Then, follow these simple steps:

• Using the ruler, mark the inside of the cans at one-quarter inch, one-half inch and one inch;
• Place one can near your irrigation system’s spray head and the other near the end of the spray zone;
• Turn that irrigation zone on and start the timer for 15 minutes;
• When the 15 minutes is up, turn the irrigation system off and check how much water has been collected in the cans;
• Add the two amounts together and divide by two to find the average amount of water for that area.

Once you’ve figured out how much water your sprinkler applies in 15 minutes, you can determine how long it takes to water one-half inch. For instance, if your cans hold one-eighth of an inch after 15 minutes, you need to water for an hour. If they hold one-quarter of an inch, you need to water for 30 minutes. If they hold one-half inch, you need to water for 15 minutes.

In general, spray heads take about 20 minutes to apply one-half inch of water. Rotary heads have a much lower watering rate and can take up to an hour or more. The time needed for hose end sprinklers to apply one-half inch of water can vary greatly, but the same catch-can method works for them too.

Remember to follow your water provider’s approved watering schedule and always water before 10 a.m. or after 7 p.m. to minimize the amount of water lost to evaporation and wind. NEVER water in the heat of the day.  As much as 60 percent of water applied in the heat of the day is lost to evaporation.

For those who want to become even more water efficient, there have been great advances in technology in the past decade that can significantly reduce water waste and decrease the amount of water applied to your landscape by as much as 50 percent. For instance, a soil moisture sensor wired directly to your system’s controller can prompt your system to skip a scheduled watering if the soil is moist enough that your lawn or landscaping does not need it.

If you are a domestic use contract holder through LCRA and have an automatic irrigation system, you are eligible for a Free Landscape Irrigation Checkup and could be eligible for up to $350 in rebates for soil moisture sensors, rain sensors and pressure regulating spray heads.

For more information on water conservation, landscape watering requirements or how to properly apply one inch of water, please contact me at 1-800-776-5272, Ext. 4775. Also, check out www.watersmart.org for more conservation tips and information.

Brett Briant is a water conservation coordinator at LCRA.