Hydrogeologic framework and groundwater characterization in selected alluvial basins in the upper Rio Grande basin, Colorado, New Mexico, and Texas, United States, and Chihuahua, Mexico, 1980 to 2015

Abstract

Increasing demand for the limited water resources of the United States continues to put pressure on resource management agencies to balance the competing needs of ecosystem health with municipal, agricultural, and other uses. To meet these needs, the U.S. Geological Survey conducted a multiyear study to evaluate water resources in the upper Rio Grande Basin in the southwestern United States. The upper Rio Grande Basin extends from south-central Colorado, through New Mexico, into west Texas near Fort Quitman, including parts of Chihuahua, Mexico. The upper Rio Grande Basin consists of a sequence of alluvial basins that formed in the Rio Grande rift approximately 30 million years ago.This report describes the hydrogeology of the upper Rio Grande Basin and how the groundwater resources in the basin have changed from 1980 to 2015. The hydrogeologic framework includes the horizontal delineation of the alluvial basins within the upper Rio Grande Basin from the headwaters in Colorado to Fort Quitman, Texas, including part of Mexico. Groundwater-level measurements from existing State and Federal data were used to construct groundwater-level altitude and groundwater-level change maps.Of the 2,699 wells with groundwater-level data used in this study, 1,055 wells had data for only a single 5-year period, 703 wells had data for 50 percent or more of the 35 years of the study, and only 57 wells have 5-year groundwater-level data for the entire study period. The median decline in water levels in the upper Rio Grande Basin was 0.13 foot (ft) per 5-year period, and declines were measured in 53 percent of the 703 wells that contained data for 50 percent or more of the study period. Rates of groundwater-level decline greater than 1 ft per 5-year period were measured in 17 percent of the wells, greater than 2 ft per 5-year period, in 3 percent of the wells, and greater than 3 ft per 5-year period, in 1 percent of the wells. Overall, groundwater levels rose in 6 percent of the 703 wells that contained data for 50 percent or more of the study period, and in 4 percent of the wells, groundwater levels rose by 1 ft or more per 5-year period.

Analysis of legacy gravity data reveals sediment‐filled troughs buried under Flathead Valley, Montana, USA

“…Moreover, they typically exhibit complexities in their sedimentary architecture and hydrostratigraphy as well as in their relationships with the bedrock that confines them and with any adjacent aquifers. Basin-or valley-fill aquifers are particularly important in the western one-third of the contiguous USA, including the present study area (Planert & Williams, 1995;Robson & Banta, 1995;;Houston et al, 2015). Geophysical methods, especially electromagnetic (EM) surveys, have greatly enhanced the understanding of some basin-or valley-fill aquifers in North America and Europe (e.g., Gabriel et al, 2003;Huuse et al, 2003;Pugin et al, 2014, Høyer et al, 2015Korus et al, 2017).…”

Assessment of per- and polyfluoroalkyl substances in water resources of New Mexico, 2020–21

“…16A), which are characterized by relatively high concentrations of trace elements and REEs (water group 2). Samples collected from Animas Farmington on certain dates plotted with the high conductivity waters (water group 1: sampling dates October 29, 2020, September 23, 2020, and August 6, 2021) and samples collected on other dates plotted much closer to the waters with relatively high trace-element and REE concentrations (water group 2: sampling dates November 19, 2020, andMay 26, 2021). San Juan Archuleta differed from other study sites along the second principal component axis (fig.…”

“…A Gd anomaly related to wastewater will tend toward greater peak height, in contrast to other nearby REEs. A positive Gd anomaly is observed in figure 17H for Animas Farmington on September 23, 2020, and October 29, 2020, whereas Gd enrichment is not observed for the later sampling dates of November 19, 2020, May 26, 2021, and August 6, 2021. This anomaly at Animas Farmington may suggest a wastewater signature because of the presence of three wastewater treatment facilities nearby.…”