The Edwards Aquifer Authority (EAA) is saying that slow rainfall in the region could compel the declaration of Stage I drought restrictions within weeks.
EAA officials base their concern on the declining rate of springflow at the San Marcos Springs, where the 10-day average as of Jan. 15 was 97.8 cubic feet per second (cfs). The reading for triggering Stage I restrictions is 96 cfs, less than two feet slower than the present reading.
Due to amounts well below the historical norm across the region for 2008, EAA officials estimate that springflow at San Marcos Springs could drop below the 96 cfs trigger by the first week of February.
Under Stage I, municipal, industrial and agricultural users must cut their pumping from the aquifer by 20 percent. Stage I for the San Antonio Pool applies to all Edwards Aquifer groundwater permit holders within Atascosa, Bexar, Caldwell, Comal, Guadalupe, and Medina counties.
However, the EAA said, voluntary conservation now could help delay the mandatory cutbacks.
The San Marcos Springs is one of three indicators identified in the Edwards Aquifer Authority Act to gauge aquifer conditions and to trigger various stages of the critical period management plan for the San Antonio Pool of the Edwards Aquifer region.
The other two indicators – water level as measured at the J-17 Index Well in Bexar County and the rate of spring discharge at the Comal Springs – have not yet dropped to critical period trigger levels.
The Edwards Aquifer Authority manages the Edwards Aquifer, one of the major groundwater systems in Texas serving approximately 1.7 million people.