For The Answer
By Calvin Finch, PhD, SAWS Conservation Director, and Horticulturist
Week of June 21, 2004
KEEPING YOUR WATER BILL LOW THIS SUMMER
Our lawns are in good shape this spring. The weather has been mild and there has been plenty of rain. Most of us have not had to water our lawns yet. If you are content to let the lawn go dormant this summer, you will not have to water at all. Native grasses, Bermuda grass, zoysia, and buffalo grass all have the capability to go dormant when the rains stop and the temperatures increase. Going dormant is not the same as dying. The grasses quit growing and turn brown for a period until the rains start again. St. Augustine does not have the capability of going dormant but it can go a long time without irrigation, especially if it is in the shade. Allowing your lawn to go dormant is the easiest way to keep your water bill low.
A second strategy to keep the bill relatively low is to keep your water use below 17,205 gallons per month. At 17,205 gallons for a month the water rate increases from about $.10 per 100 gallons to about $.40 per 100 gallons. The trick is to stay below 17,205 gallons. That is easy if you limit lawn watering to twice per month. The average household uses about 8,000 gallons in the house and the average lawn watering uses 3,000 to 4,000 gallons per application. Water the lawn every two weeks and you end up using 15,000 to 16,000 gallons per month. None of your water use is billed at the fourth tier (highest rate) and your water bill is relatively low. St. Augustine will stay alive with watering every two weeks and most summers the other grasses will not go dormant if they get some water every two weeks.
There is another option that will keep the water bill reasonable and will also keep your grass green, water according to the SIP recommendations. SIP stands for Seasonal irrigation Program. It is a lawn watering program that applies weather data every day to a formula that calculates the amount of water that the grass used that day. If you add up the water use for the week and then apply 60 percent of it to the lawn, the lawn stays green. SIP works. We experimented with 60 lawns for four years and last year had over 5,000 people using the information. Receiving the information for your lawn every week is easy. The easiest way is to visit the SAWS website at saws.org and sign up to receive a weekly email or telephone message on your watering day. You can also listen to the “Gardening South Texas” radio show at noon on Saturday or 1 p.m. on Sunday on KLUP 930 AM.
SIP recommendations are based on the type of grass you have and the amount of sunlight the lawn receives (sun or shade). You do need to know how long your irrigation system or sprinkler takes to apply 1/2 inch of water. Call SAWS at 704-7354 to receive a free SIP kit that has the instructions and catch basins necessary to make the calculations. Another way to learn how much water the system applies is to call your irrigation contractor out to do a maintenance check of the system. They will adjust heads and repair leaks. Also ask them to tell you how much water your system is applying every 15 minutes and how to set the controller at 1/2 inch and 3/4 inch. That way, when the SIP recommendation is 1/2 inch, you just flip the switch to apply 1/2 inch. Some weeks the recommendation will be 3/4 inch and you can use that setting. Other weeks no water will be required and you will not have to run the irrigation.
There is a third way to prepare yourself to take advantage of SIP recommendations. Call SAWS at 704-7354 for a free irrigation audit. The Conservation technicians will prepare a report that tells you how much water your system is applying to the lawn. They can also show you how to reset the irrigation controller and how to run the system manually.
Keep your water bill low this summer. Select from the watering options of letting your lawn go dormant, water every two weeks, or use SIP.