Monitors keeping close tabs on levels in aquifer

On the northeast side of San Antonio, in a conserved area of Bexar County, Chuck Crawford lowers a massive measuring tape into a deep well. The tape plunges down for several moments, zipping past 50 feet, 100 feet, 200 feet. When an alarm buzzes, indicating that a pressure sensor at the end of the measuring tape has reached the water in the Trinity Aquifer, Crawford stops.

He leans forward to note the measurement — 245.86 feet from the ground to the top of the water.

“Looks about right,” he said, though he checks a second and a third time. “You just have to be certain.”

Crawford is the data collection supervisor for the Edwards Aquifer Authority, the water management agency that regulates the Edwards Aquifer. Every month, he and three other data collectors check the aquifer levels at 70 wells across the Edwards and Trinity aquifers, a region that spans Bexar, Medina, Comal, Uvalde and Hays counties. On Wednesday, Crawford analyzed a well by the Aquifer Authority’s field office.

For decades, wells tapping the Edwards Aquifer have been monitored for depth. Frequent measuring enables officials to act promptly when conditions such as drought and rain cause the aquifer’s level to change significantly. Besides taking field measurements, the Edwards Aquifer Authority receives water level data remotely every 15 minutes from 22 of the most important wells via wireless pressure sensors installed at the aquifer’s surface. And to ensure such readings are correct, the team takes its measuring tape to the wells monthly.

San Antonio implemented Stage 1 water restrictions last month, which provide designated watering days and times for residents. The Edwards Aquifer Authority was alerted to the condition triggering those restrictions by the J-17 index well, which is in a tiny building on Fort Sam Houston and is the most impor