For The Answer
Saturday, March 2, 2002
Submitted by Calvin Finch, Ph.D., Manager, Conservation Division, Water Resources & Conservation Department, SAWS, and Horticulturist
HINTS TO HELP YOU MINIMIZE YOUR LANDSCAPE WATER USE
Only about 50% of the homeowners in San Antonio provide supplemental irrigation to their landscapes; most people rely on rainfall to water their lawn. If you do water your lawn, you have a special responsibility to do it efficiently. Here are some hints that will help you minimize the amount of water you use on the landscape. Use one of the watering strategies listed below:
· Only irrigate the grass when it needs it. Turfgrass shows a slight color change when it is time to water. Another test is to walk across the lawn and if the footfalls spring back it indicates that the lawn does not need water.
· Water the lawn according to the average ET (evapo-transpiration) requirements. During the summer it takes .75 inch water per week for St. Augustine and zoysia in the sun. St. Augustine and zoysia in the shade require .50 inch per week, as does Bermuda grass in the sun. Buffalo grass in the sun requires about .38inch per week or .75 inch every two weeks.
· Water according to actual ET recommendations. In San Antonio they are published in the Express-News San Antonio Life section every Saturday. In the fall, spring, and winter very little water is required.
· Apply only enough water to keep the grass alive. For St. Augustine grass that means about half an inch of water every two weeks in the summer. Zoysia, Bermuda, and buffalo grass can go dormant until the rains green the lawn up.
If you have a sprinkler system, it is easier to irrigate than it is if you must drag a hose. This is reflected in the fact that almost all homeowners with irrigation systems use more water than hose draggers. If you have an irrigation system consider these ideas:
· Inspect your irrigation system every two weeks when you are using it regularly. Look for leaks and misaligned or broken heads. Have your irrigation contractor inspect the system twice per year.
· Install a wafer-type rain sensor if you use your timer. The rain sensor prevents the sprinkler from running in a rainstorm. The cost is inexpensive and SAWS customers will receive a 50 percent rebate of up to $50 (whichever is cheaper) for a rain sensor installed in systems installed before 2000.
· Only use your timer between June 1 and October 31, if you use it at all. Water when the lawn needs it, rather than on a regular schedule.
· Have the back-flow preventers inspected every two years. The law requires the inspection and it is necessary to protect your drinking water.
If you are considering a new irrigation system consider these recommendations:
· The law requires that a certified irrigator oversee the installation. Make sure the irrigation company you select has a certified irrigator. Irrigation systems that are poorly designed can be a nightmare because they waste water, do not do the job, and can be unsafe.
· Insist that your irrigator give you a schematic (map as built) of the system, an operators manual, and instructions on how to use the system. Even the best systems malfunction and you need to know how to turn it off at times.
· Select a contractor that is familiar with conservation techniques and can install drip irrigation in vegetable gardens and flower gardens.
· Utilize zoning that allows high-water-use areas of the yard (lawn) to be watered separately from low-water-use areas. Add a rain sensor and do not irrigate thin, narrow areas like the area between the sidewalk and road.
· Use a contractor who has a good reputation. Ask around the neighborhood for the name of a contractor who has satisfied people you know.