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This Week at Milberger's

To Water or Not to Water
By Calvin Finch, Ph.D.

Last weekend a listener of my radio show on KLUP called to mildly chastise me about the one-day-per-week watering regime.

Her point was that if you had a Wednesday or Thursday watering day based on the last digit of your address you were faced with a tough decision. "If I gamble that it is going to rain this weekend and am wrong, my lawn has to survive another whole week without watering. Under the two-day a week watering regime, you only gambled for 3 or 4 days." She chose not to gamble and watered.

I am also a Thursday water and I decided not to water. My lawn looked lush, there was rain forecast for Saturday, and the grass could easily survive until the next Thursday. Another reason why it is good to postpone watering is if we use too much water in Stage 1 we will move into Stage II of restrictions. There is reason to believe that lots of SAWS ratepayers made the same decision as I did because pumping was low and the aquifer level did not fall much on Thursday before the rains. Our gamble was rewarded with 1-2 inches of rain in most neighborhoods.

The decision to adopt the one-day-per-week watering regime was made by the elected representatives on the Edwards Aquifer Authority Board. They represent Bexar County and the other counties that rely on the Edwards Aquifer and are charged with the responsibility of protecting the aquifer and its related communities.

I believe they selected one-day per week for some pretty good reasons.

1. Turfgrass survives well on once per week watering. The ET (evapotranspiration) experiment conducted over three years with 64 households proved the lawns prospered under the regime.
2. People like one day per week watering. The experimenters in the ET trials selected a one-day-per-week regime over an irrigation regime when the ET determined it was time to water.
3. People like one day per week watering. The experimenters in the ET trials selected a one-day-per-week regime over an irrigation regime when the ET determined it was time to water.
4. It is relatively easy to enforce one-day-per-week watering by last digit of the address.
5. For emergency backup you have the flexibility in Stage I of the restrictions to water problem areas by hand or drip irrigation.

In summary, when you are deciding whether to water even if your lawn still looks good, remember:

1. St. Augustine can easily survive 2-3 weeks without any water.
2. If we pump extravagantly in Stage I, we will move into Stage II where the restrictions are more limiting.