In preparation for a 277-lot subdivision of an 860-acre property near Red River, New Mexico, a geohydrologic study including drilling four test wells and three pumping tests was conducted.
The property is underlain by highly fractured Precambrian metamorphic, Tertiary volcanic and intrusive rock. The groundwater in the area occurs in alluvium along creek and drainage bottoms, and within bedrock fractures. The extensive fracturing created an extensive aquifer which was hypothesized to be in hydrologic connection with Moreno Creek in the southern portion of the property.
The pumping test aquifer transmissivity data from the four test wells and Theis-estimated storage values were used to construct a MODFLOW model of the aquifer. The effects on groundwater levels and the nearby streams, Moreno Creek, Bitter Creek, Red River, and North Moreno Creek, were calculated.
The conclusions from the model and pumping test results indicate that the wells are capable of producing the required water for the proposed subdivision. After 40 years the predicted drawdown in the water table extended approximately one mile from test sites and created a change in head of two feet or less.
The model predicted that the groundwater diversions will effectively dry up the majority of the springs on the property and would have a significant effect on the Moreno Creek.
Model grid of predicted drawdown from wells completed into fractured crystalline rocks. The model was also used to predict depletion effects on Moreno Creek.
Hodgins, M., Lazarus, J., Chudnoff, M., 2002, Groundwater Surface Water Communication in Fractured Crystalline Bedrock Aquifer Near Red River Pass, Colfax County, New Mexico, Fractured-Rock Aquifers 2002, March 13-15, 2002 National Ground Water Association, Denver, Colorado.