Abstract: The Carrizo Aquifer of Smith County, East Texas

Jeff Lauman

The Carrizo aquifer is the main source of groundwater for municipal and industrial withdraws in Smith County. Since the 1940s, pumping levels in many of the water wells have fallen hundreds of feet. During the mini-drought of July/August 1993, several municipal water companies recorded significant drops in water levels. The Texas Water Development Board has, at the request of the 69th Texas Legislature, identified Smith County as having critical groundwater problems or the potential for such problems within the next 20 years.

Sidewall cores recovered from the Texaco 60 Sand Flat unit, in the north-central part of the county, indicate that the Carrizo Sand has a porosity of 37% and a permeability of 702 md. Four density logs show that the Carrizo porosity ranges from 35-38%. Analysis of over 300 petroleum and 20 water well logs/records indicates that the Carrizo ranges from 30 to 110 ft thick, with the axis of deposition running from the southwest corner of the county through the Tyler area to 5 mi east of the Lindale townsite.

AAPG Search and Discovery Article #90983©1994 GCAGS and Gulf Coast SEPM 44th Annual Meeting, Austin, Texas, October 6-7, 1994