The City of San Angelo will begin blending water from the Hickory Aquifer with surface water on May 1 at a rate of approximately 10 parts lake water to one part Hickory water.
That ratio, which is half of the ratio approved by the Texas Commission on Environmental Quality, ensures the blended water will meet the Environmental Protection Agency’s public drinking water standards.

The blending operation will last approximately two weeks, during which the City will monitor the process to ensure there are no operational or treatment issues.

Water Utilities Director Ricky Dickson said he wants to limit withdrawal of water from the aquifer so the City can continue to “bank” water for future use should San Angelo’s surface water supplies continue to dwindle because of the drought.

A 1997 court decision establishes how much water San Angelo can draw from the McCulloch County aquifer. Currently, the City can draw 2,750 acre-feet of water per year from the aquifer. The less water San Angelo uses now, the more it will have available in the future if San Angelo’s four reservoirs are not replenished by significant rainfall.

San Angelo’s allocation of Hickory water increases to 5,000 acre-feet per year in 2021 and 10,000 acre-feet in 2026. San Angelo uses about 15,000 acre-feet per year.

San Angelo’s available surface water supply is less than 14 months, assuming no rainfall or runoff during that span. If the water supply dips below 12 months, outside watering would be prohibited under the City’s drought contingency ordinance.

Without rainfall, Ivie Reservoir, San Angelo’s primary water source, is projected to be depleted in November, when construction is scheduled to be complete on a groundwater treatment facility to remove radium and iron from the Hickory water.