About
The Edwards Aquifer
The Edwards Aquifer is intensely faulted and fractured carbonate limestone
that
lies within the Balcones fault zone. The dynamics and size of the this
geologic anomaly make it one of the most wondrous aquifers in the nation,
through its storage capacity, flow characteristics, water producing
capabilities and efficient recharging ability.
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here for a larger example of a cross section diagram. |
The Edwards aquifer and its catchment area in the San Antonio region
is about 8,000 square miles and includes all or part of 13 counties
in south-central Texas.
The recharge and artesian areas of the Edwards aquifer underlie the
six counties south and east of the Balconces fault escarpment. The aquifer
underlies approximately 3,600 square miles, is about 180 miles long
from west to east and varies from 5 to 30 miles wide. The Edwards aquifer
receives most of its water from the drainage basins located on the Edwards
Plateau. The catchment area, about 4,400 square miles, contains the
drainage basins of the streams that recharge the Edwards aquifer.
In the San Antonio region, the Edwards limestone attains a thickness
of approximately 450 to 500 feet. The water wells supplying SAWS customers’
number a total of 92 with an average daily pumpage of 136.50 million
gallons per day or 418 acre-feet. From 1934 through 1994 the average
recharge to the Edwards aquifer was 676,600 acre-feet.
