Posted: Wed, 5 Aug 2009 10:28 AM - 7,090 Readers

By: Lower Colorado River Authority

Lake Travis is now at its third-lowest all-time elevation, the result of an almost two-year severe drought that has produced record hot temperatures and restricted rain and inflows into the Highland Lakes.

Even so, LCRA officials say the Highland Lakes chain still has enough water to meet the critical needs of its municipal, power generation, and industrial customers if there is a repeat of the Drought of Record of the 1940s and 1950s. But LCRA added that its customers need to fully implement their water conservation and drought contingency plans.

As of 8 a.m. Aug. 5, Lake Travis was at 636.49 feet above mean sea level (msl). That places the lake below its previous third-lowest all-time elevation, 636.58 feet (msl), which was set in October 1984 at the end of a severe drought. The lake is almost 30 feet below its average elevation for August.

Barring significant rainfall, the lake will continue to drop at the rate of about a foot or more a week during the next several weeks, falling to as low as 630 feet msl by Sept. 1. That would still be higher than Travis’ second-lowest elevation of 615.02 feet msl set in November 1963 and its all-time low of 614.18 set in August 1951. Lake Buchanan, LCRA’s other water-supply reservoir, was at 996.04 feet msl, significantly below its average elevation for August. The combined capacity of both lakes is at 46 percent.

While hot summer weather typically increases demand for water, the main factor affecting both lakes is the lack of significant rain, resulting in record low inflows into the lakes, according to Mark Jordan, manager of LCRA’s River Management department.

The Pedernales River, which feeds into Lake Travis, is dry, as is Sandy Creek, which feeds into Lake LBJ and on down into Travis, Jordan said. Other lake tributaries are flowing but at a fraction of their average rates.

If dry conditions continue, 2009 will see a new record for lowest inflows into the Highland Lakes since Lake Travis was completed in 1942, surpassing the current record low set last year,” he said.

The lower elevations at Travis and Buchanan may be unusual to newer area residents, but the levels of these water supply reservoirs historically have fluctuated over time, according to Jordan.

The lakes are doing their intended job of capturing flood waters when it rains in order to provide the lower Colorado River basin with a reliable water supply during drought,” Jordan said. If these two lakes did not exist, the City of Austin and other communities, businesses and individuals would be without a reliable water supply that we otherwise take for granted.

“LCRA continues to provide Austin and other water customers, as provided for by state law and contractual obligations,” Jordan said, noting that demands for some uses, such as agricultural irrigation, peaked in early July and have dropped to more than half of that peak due to a reduction of acreage for the second crop of rice.

However, if dry conditions continue, water for next year’s irrigation season may need to be significantly curtailed so that water will continue to be available to meet the critical needs of LCRA’s municipal, power generation, and industrial customers, Jordan said.

“LCRA is following its state-approved Water Management Plan that includes the implementation of water conservation and drought contingency measures by all our customers as drought conditions worsen,” Jordan said. “It is important that we all use water as wisely and as efficiently as possible, given that we do not yet know when this drought will end.”

Jordan said that LCRA municipal and industrial customers will be asked to implement mandatory water-use restrictions under their drought contingency plans later this month. He noted that many have already done so.

*  Story Contributed by: Lower Colorado River Authority