Rainwater helps but not enough falls to lift restrictions

Rains this past week, as expected, have not only brought welcome relief to the landscape but dramatic reductions in water use by Austin Water Utility customers. However, the utility has no plans at this time to lift the Stage 2 water-use restrictions that were imposed in August as a result of dropping lake levels.

“The rain was welcome but not enough to break the drought,” said Daryl Slusher, the water utility’s assistant director for environmental affairs and conservation. “If we get a lot more rain, we would consider lifting the Stage 2 restrictions, but the recent rains have not had much impact on lake levels.”

Customer water use for the rainy week ending Sept. 13 totaled 885 million gallons, compared to an average of nearly 1.4 billion gallons per week for the first three weeks of August when it was hot and dry, according to Slusher. During the week of Aug. 24, the first week that the Stage 2 restrictions were in effect, customer water use totaled 1.1 billion gallons, although Slusher pointed out that the area received some rain that week.

The city imposed its Stage 2 restrictions after the combined volumes of lakes Buchanan and Travis – the two water supply reservoirs in the Highland Lakes chain – dropped below a combined volume of 900,000 acre-feet, a trigger point used by water managers to call for tighter water-use restrictions. (An acre-foot is roughly 326,000 gallons.)  Under Stage 2 restrictions, residents and commercial customers are limited to watering outdoors once a week; residential vehicle washing is limited; and operation of outdoor water fountains is banned, as is washing driveways, sidewalks and parking lots.

While the water utility handed out a total of 39 tickets when the Stage 2 restrictions were first imposed, the rain and cooler temperatures brought a hiatus to outdoor watering – and to outdoor watering violations, according to Slusher.

Rainfall this past week totaled about 2 to 5 inches in the Hill Country, with isolated accumulations of 6 to 8 inches, said Bob Rose, chief meteorologist for the Lower Colorado River Authority, which manages the Highland Lakes.

While the rains soaked the ground, they did not produce the large amounts of runoff needed in the upstream watersheds to begin refilling lakes Buchanan and Travis, he said. The level of Lake Buchanan was hardly affected by the rains, while Lake Travis has risen only about a foot and is expected to gain another half a foot as the fallen rainwater makes its way through the system, Rose said.

“The rain really helped everyone’s yards, so it has been good from that standpoint,” Rose said. “Also, the ground has gotten a good soaking, so that additional rains should produce more runoff. But it would take another two or three of these types of rain events to get the lakes back to above 900,000 acre-feet.”

As of Sept. 14, the combined volume of lakes Buchanan and Travis was just below 800,000 acre-feet, or 40 percent full. Lake Buchanan was about 21 feet below its historic average for September and Lake Travis was about 34 feet below its historic average.