NMT Student Awarded Research Grant to Study the Volumetric and Chemical Influence of Groundwater on the Rio Grande

By Marcus Gay, NM WRRI Senior Student Program Coordinator

Groundwater contributions to surface flows (e.g., irrigation returns, lateral basin flow paths) can provide significant base flow in the Rio Grande. As flow paths exit the basin and converge, the solute from each distinct source contributes to the chemical evolution of the riparian aquifer and the river. For example, Hogan et al. (2007) found that deep upwelling groundwater is the primary source of salinization in the Rio Grande. Quantifying the proportions of these distinct groundwater contributions to the Rio Grande hydrologic system could help evaluate the system’s resilience in the face of increased water stress.

NM WRRI has awarded New Mexico Tech graduate student, Ethan Williams, a Student Water Research Grant to study the volumetric and chemical influence of groundwater on the Rio Grande in the southern Albuquerque Basin. The project entitled, Quantifying groundwater to surface water exchanges in the Belen reach of the MRGCD, has three objectives: (1) to identify the proportion and provenance of groundwater contributions in the study area, (2) to record how these fluxes change through the 2021 water year, and (3) to integrate the results into the hydrogeologic context of the basin.

Under the guidance of his faculty advisor, Dr. Alex Rinehart, Williams will collect water samples and flow data at strategic locations in the project area and perform end-member mixing analysis (EMMA). Williams will then calculate volumetric source contributions, develop conceptual flow models for the study, and present his findings within the context of the current literature.

Williams expects the findings to clarify groundwater’s role in maintaining and supplementing flow in the Rio Grande in the southern Albuquerque Basin. According to Williams, “this work aims to provide a nuanced understanding of how, where, and when distinct groundwaters contribute to the Rio Grande. This data will have significant implications for meeting compact obligations, maintaining riparian habitat, and supporting beneficial water use. By evaluating individual groundwater sources, we will characterize how distinct groundwaters affect the chemical evolution of the river and the spatial distribution of individual inputs. These findings will help us accurately anticipate the effects of drought on issues like river salinization and inform our ability to deploy mitigation strategies.” Williams has submitted an abstract about this research to the Geological Society of America Fall Conference in Portland, Oregon. He will also present a poster on this topic at the 66th Annual New Mexico Water Conference.

Originally from Oak Park, Illinois, Williams graduated in 2018 from the University of New Mexico with a BS in Geology. After working for a consulting company on a groundwater monitoring project in northeastern New Mexico, Williams enrolled in the Department of Hydrology at New Mexico Tech where he plans to graduate with an MS in Hydrology next year. After graduation, Williams plans to pursue a career in water where he hopes to “develop and maintain safe and sustainable water sources in water-stressed regions.”