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Top Elevation of Glacial Till and Thickness of the Big Sioux Aquifer Delineated From Electrical Resistivity Tomography Surveys Near Sioux Falls, South Dakota, 2022 and 2025

Scientific Investigations Report 2026-5023
Prepared in cooperation with City of Sioux Falls, South Dakota
By:  and 
https://doi.org/10.3133/sir20265023

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Abstract

The City of Sioux Falls, South Dakota, requested the U.S. Geological Survey perform electrical resistivity surveys on three parcels of land north of the city. Electrical resistivity data were collected along a total of 22 transects during March 14–18, 2022, and November 17–21, 2025. Results from electrical resistivity surveys were used to delineate the top of glacial till deposits for the purpose of characterizing the Big Sioux aquifer near the city. Delineating geologic contacts provides important information on groundwater storage, flow dynamics, well design and placement, contaminant transport, groundwater–surface-water interactions, and regional water modeling. The top elevation of glacial till and the thickness of the Big Sioux aquifer varied among the three survey areas. The interpreted top elevation of glacial till in the North survey area decreases from east to west toward a slough, with elevations ranging from 1,403 to 1,418 feet (ft). The estimated thickness of the Big Sioux aquifer in the North survey area increased from east to west, with thicknesses ranging from 23 to 38 ft. The top elevation of glacial till in the Well 72 survey area generally decreases from northwest to southeast. Top elevations of the glacial till in the Well 72 survey area ranged from 1,400 to 1,409 ft along the southern end of transect W72_2. The estimated thickness of the Big Sioux aquifer in the Well 72 survey area was greatest along a southeast to northwest trending channel, with thicknesses ranging from 28 to 40 ft. The top elevation of glacial till in the Nose survey area generally decreases west toward the Big Sioux River. Top elevations of the glacial till in the Nose survey area ranged from 1,362 to 1,395 ft. The estimated thickness of the Big Sioux aquifer in the Nose survey area ranged from 33 to 70 ft.

Suggested Citation

Medler, C.J., and Anderson, T.M., 2026, Top elevation of glacial till and thickness of the Big Sioux aquifer delineated from electrical resistivity tomography surveys near Sioux Falls, South Dakota, 2022 and 2025: U.S. Geological Survey Scientific Investigations Report 2026–5023, 29 p., https://doi.org/10.3133/sir20265023.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Purpose and Scope
  • Electrical Resistivity and Real-Time Kinematic Surveying
  • Top Elevation of Glacial Till and Thickness of the Big Sioux Aquifer
  • Summary
  • References Cited
  • Appendix 1.
  • Appendix 2.
  • Appendix 3.
Publication type Report
Publication Subtype USGS Numbered Series
Title Top Elevation of Glacial Till and Thickness of the Big Sioux Aquifer Delineated From Electrical Resistivity Tomography Surveys Near Sioux Falls, South Dakota, 2022 and 2025
Series title Scientific Investigations Report
Series number 2026-5023
DOI 10.3133/sir20265023
Publication Date May 12, 2026
Year Published 2026
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Dakota Water Science Center
Description Report: vi, 29 p.; Data Release
Country United States
State South Dakota
Other Geospatial Big Sioux Aquifer
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Additional publication details