Canyon Lake, a water source for the city of San Marcos, has dropped to its lowest water level in over 60 years, according to Adeline Fox, executive manager of communications and outreach for the Guadalupe-Blanco River Authority (GBRA).
As of April 18, Canyon Lake’s elevation has dropped to 878.19 feet mean sea level, with the reservoir just over 46% full, according to Water Data for Texas.
Under the city’s current water supply portfolio, a combination of sources and strategies a city uses to meet its water needs, San Marcos receives up to 8.9 million gallons per day from the Canyon Lake source, making it the largest source of water for city utilities.
Paul Kite, assistant director of Water/Wastewater and Utilities for the city of San Marcos, said in a written interview with The Star while the city has not received any reductions in water flow from Canyon Lake, officials are monitoring the situation.
“At this time, the city’s infrastructure is operating within capacity,” Kite wrote. “Staff are closely monitoring system performance and planning ahead to ensure equipment, pumping capacity and storage remain sufficient, even under drought strain.”
Kite wrote if Canyon Lake’s water levels continue to decrease, water rates for city utility users could be affected. For now, however, the lake’s low levels are not impacting residents’ monthly bills.
“The city has not [currently] implemented drought-related rate increases,” Kite wrote. “Long-term drought conditions, increased treatment costs or capital improvements required for drought resilience could potentially impact future rates. Any changes would follow a formal review by [the] Citizens Utility Advisory Board and the City Council process.”
The GBRA manages water releases from the lake and typically oversees those releases when the elevation drops below 909 feet mean sea level, according to Fox.
Fox said the ongoing drought is the primary cause of the water level drop at Canyon Lake, though it’s unclear when enough rain might fall to improve the situation
“So we are just seeing the drought conditions that are beyond extremes that we have seen in the past [over 60 years],” Fox said. “But [the reservoir] is still at 47% capacity, which is a testament to how it is performing in such a severe drought.”
Canyon Lake is not the only area facing severe drought. San Marcos has been under Stage 3 drought restrictions since Oct. 27, 2024, both of which are part of a broader Hill Country drought, according to Robert Mace, director of The Meadows Center for Water and the Environment.
“There’s a big bad drought in the Hill Country, which includes San Marcos [and] Lake Medina on the western side of San Antonio,” Mace said. “At the same time, we’re seeing these systematically dropping levels in the Canyon Lake, Los Moras Springs and Brackettville.”
Fox said GBRA, which partners with the U.S. Army Corps of Engineers to operate Canyon Lake, is expanding additional water sources, including the Carrizo-Wilcox Aquifer, which San Marcos began using in December 2024, with the Carrizo Groundwater Supply Project.
“The short answer is we’re already working on additional water supplies to help fill that potential gap [from Canyon Lake],” Fox said. “The [Carrizo-Wilcox] project is a project that was partnered between us and Alliance Regional Water Authority to bring additional groundwater supplies to the city of San Marcos, Kyle, Buda and these other I-35 corridor customers… which will help.”
The current water portfolio for San Marcos Utilities includes continued water conservation, expanded recycling of non-potable water and the addition of a new water reclamation facility as methods for the city to continue meeting demand into 2075.
Mace said it is highly likely that the city will need to receive more water from the Carrizo-Wilcox source to continue meeting demand. San Marcos currently receives 2,460 acre-feet of water a year from the Carrizo Water Treatment Plan.
“The city has direct potable reuse in the water [portfolio], but they might want to implement it sooner rather than later,” Mace said. “More supply from the Carrizo will probably be needed as well, especially with revised growth numbers that nearly double earlier population projections.”
Students and residents can help reduce water use by following current Stage 3 drought restrictions measures, such as fixing household leaks, using water-efficient appliances and fixtures and turning off taps when not in use, according to Kite.
