Rio Grande River Basin Horizontal Groundwater Characterization

COLOG was hired to characterize the horizontal movement of groundwater through the Rio Grande River Basin .
This project proved challenging due to the complex hydrogeology and lack of historical geologic data from past drilling programs. In the Rio Grande Basin, many wells flow artesian at hundreds, to sometimes thousands of gallons per minute. Other wells show no artesian flow –  while yet others exhibit downflow within the wellbore. The nature of the hydrogeologic setting and the deteriorated condition of the wells meant multiple flow-logging techniques needed to be utilized and integrated for accurate characterization. The Corehole Dynamic Flowmeter (CDFM) was used in Low to Moderate flow conditions where water level was significantly deeper than elsewhere on the project, while Hydrophysics (HpL) was used where borehole diameter varied significantly and  spinner flowmeter or packer testing could not be employed. The spinner flowmeter was used extensively in the high-flowing wells and collected well-specific data that when compared side-by-side, showed the true heterogeneity of the site. The Colloidal Borescope Flowmeter (CBFM) was used to measure the horizontal groundwater flow velocity passing through a short screened intervals. This data was converted into a Specific Discharge in the aquifer and was used to compare to a state model of the groundwater flow direction and velocity in the basin and help the local community better manage their planned discharges into the river.