Hydrogeology and Stratigraphy of Michigan Flat, Culberson County, Texas

David T. Sites, III

The purpose of this study was to collect data from the field and from published reports that will identify and describe wells that produce from the Michigan Flat area in order to identify existing aquifers within Michigan Flat.  This study also determined if there is a unique chemical signature for each aquifer, thus breaking the reservoirs into four units.  This study will attempt to break the reservoirs of Michigan Flat into four units.

Michigan Flat is located just east of Van Horn, Texas, in far West Texas.  Michigan Flat is a finger-like projection of the southern part of a larger area known as the Salt Flat.  This area stretches from the Texas – New Mexico border south through Hudspeth and Culberson Counties.  Michigan Flat is bordered on the northeast by the Apache Mountains and on the west by the Beach Mountains and the Baylor Mountains. 

Investigation of the water quality in wells located in and around Michigan Flat strongly suggests that the quality of the subsurface water is dependant upon which aquifer is being pumped.  There are four aquifers available underneath Michigan Flat.  These include the Salt Bolson Aquifer System, Salt Bolson and Cretaceous Rock Aquifer System, Cretaceous Rock Aquifer System, and the Permian Aquifer System.  These aquifers are separated by aquatards or aquacludes.  Therefore, there is probably limited inter-connectivity between the aquifers vertically as well as horizontally in some areas.  Well logs and driller’s reports show a number of wells were drilled to a depth adequate to penetrate and produce water from two or more aquifers.  This leads to differences in the water chemistry between wells in close proximity that are pumping from the same depth.

With low annual rainfall, high evaporation rates, low recharge rates, and an ever growing demand for groundwater resources, the need for wells pumping an adequate amount of fresh water is at an all time high.