More water restrictions now in effect

Aquifer agency forecasts additional limits if dry spell lasts into summer

Water usage in San Antonio is now further restricted as drought conditions worsen in the area and across the state.

The San Antonio Water System moved to Stage 2 of its drought management plan Monday, and the Edwards Aquifer Authority predicted the area could be in Stage 3 by midsummer.

Stage 2 restrictions are triggered when the 10-day rolling average level of the Bexar County aquifer index well falls below 650 feet above sea level. Monday, it measured 649.9 feet. Paul Bertetti, the Edwards Aquifer Authority’s

director of aquifer science, said a lack of rainfall that has plagued the area for more than two years leaves a “bottom 10 percentile forecast” likely in store this summer.

In an average year, San Antonio’s rainfall total is about 32 inches. But the city recorded about 22 inches in 2019 and 20.7 inches last year. Near the end of the first four months of 2021, the city has seen just 3.15 inches.

“We’re not at absolutely no rain, but it looks like it’s at the bottom 10 percent in terms of water levels for this summer, and that’s what we should anticipate,” Bertetti said. “Obviously, that could change if we just got some modest amounts of rainfall or even a couple of unexpected storm events. But without those, it looks like we’re in for an extended Stage 2 or Stage 3 period this summer.”

Bertetti said it is unlikely, based on statistics dating to the 1930s, that the index well would dip below 630 feet, triggering Stage 4 restrictions, before temperatures begin to moderate in September.

Record lows for the San Antonio index well are 612.5 feet in August 1956 and 622.7 feet in June 1990.

“The numbers that we have suggest that it probably won’t get as low as Stage 4, but it could be as low as we’ve had in the last

four or five years,” Bertetti said. “Right now, according to our forecasts, which are based on historical data, the uncertainty of rainfall suggests that we might have an extended period in the summer where we might be below 635 feet. So we would be in Stage 3, but still above Stage 4.”

Under a local ordinance, City Manager Erik Walsh, in consultation with SAWS President and CEO Robert Puente, declared Stage 2 on Monday. Since June, the city has received less than 40 percent of its normal rainfall, according to the utility.

SAWS and other permitted users are required to reduce pumping by 20 percent under Stage 1 of the Edwards Aquifer Authority’s rules, 30 percent under Stage 2, and 35 percent under Stage 3.

To help carry the region through droughts, SAWS has sought to develop alternative water supply sources.

“Although SAWS has plenty of water to meet customer demand coming from water projects such as the Vista Ridge pipeline project, our desalination plant and various others, city ordinance requires SAWS to enter Stage 2 watering rules when the Edwards Aquifer level is triggered,” Puente said. “We have worked hard to diversify our water sources to ensure that San Antonio is water secure for generations. As a reminder, Stage 2 watering rules are primarily focused on moderating business and residential landscape watering.”

Watering days stay the same in SAWS Stage 2 as in Stage 1. However, the hours during which watering is allowed are shortened. Watering with a sprinkler, irrigation system or soaker hose is allowed only between 7 and 11 a.m. and 7 and 11 p.m. on a designated weekday, based on street address. Watering with a hand-held hose is still allowed anytime on any day.

Stage 3 watering rules, if implemented this summer by the city, would limit SAWS customers to wetting their lawns with sprinklers, irrigation systems or soaker hoses no more than once every two weeks.

The next hope for rain is a couple of days away. The National Weather Service has predicted a chance of showers later in the week that could elevate the aquifer level. A 30 percent chance of rain Thursday increases to 40 percent Thursday night and 60 percent Friday.

The Edwards Aquifer Authority’s forecast is based on historical well data and doesn’t consider other trends affecting water use, such as urban growth and supply projects. The Vista Ridge pipeline came online about a year ago, carrying water more than 140 miles from the Carrizowilcox Aquifer in Central Texas. Bertetti said it could provide a “buffer” for the environmentally sensitive Edwards Aquifer, which provides for endangered species at Comal and San Marcos springs.

“We don’t know how that’s going to affect water levels currently,” Bertetti said. “It may be that as SAWS is able to bring more of that online and put alternative water sources in play, they’re able to stem the water level … because they’re pumping less and less (from the Edwards). And so that way, we stay in Stage 2 for a longer period of time and really don’t enter into Stage 3. But we don’t have enough data.”