New Mexico Geological Society Annual Spring Meeting — Abstracts

The vertical component of specific discharge was estimated across several depth zones in the aquifer system at Canutillo, Texas. The specific discharge was estimated with temperature and thermal conductivity data from four observation wells bottoming near the base of the aquifer system.

Specific discharge was first calculated (using a steady-state model) from slopes of conductive heat flow versus temperature plots. The heat flow plots for all four wells suggested a zone of downward ground-water flow from ~70 to ~210 depth, and one or two zones of upward flow from ~800 to ~210 feet depth. Head data from the observation wells did support the conclusion of an upper zone of downflow indicated by the temperature data; however, the head data suggested that ground-water should presently be moving downward from ~210 to ~800 feet depth.

We developed a computer model to determine if the temperatures may be remanent and therefore reflect prepumping ground-water flow, particularly in the deep flow zone. Estimates were made of both maximum original and during-pumping ground-water flow, and maximum original and during-pumping flow. The computer model estimates and the steady-state heat flow estimates of vertical specific discharge were similar for the upper zone having downward flow. In the deep flow zone specific discharge estimates modeled on the computer for minimum (prepumping) upflow agreed with steady-state heat flow specific discharge estimates. Hence present temperature data may demonstrate a significant remanent ground-water flow component.