Determination of Baseline Water-Quality Conditions Using Continuous Specific Conductance and Discrete Measurements of Total Dissolved Solids and Selected Major Ions, Arkansas River Basin, Colorado
Links
- Document: Report (9.60 MB pdf) , HTML , XML
- Companion Files:
- Table 1.1 (5.15 KB csv) Distribution of significant trends in monthly mean streamflow using the Mann-Kendall test at selected sites on the Arkansas River and Fountain Creek, water years 1995–2022
- Table 1.2 (12.0 KB csv) Distribution of significant trends in monthly median specific conductance values using the Mann-Kendall test at selected sites on the Arkansas River and Fountain Creek, water years 1995–2022
- Data Release: USGS data release - Surrogate Models for Total Dissolved Solids and Major Ion Concentrations at Real-Time Water-Quality Sites, Arkansas River Basin, Colorado, October 1989 - December 2023
- Database: USGS water data for the Nation U.S. Geological Survey National Water Information System database
- Download citation as: RIS | Dublin Core
Abstract
From 2022 through 2024, the U.S. Geological Survey (USGS) in cooperation with the Regional Resources Planning Group (Southeastern Colorado Water Conservancy District, Colorado Springs Utilities, Pueblo Water, Lower Arkansas Valley Water Conservancy District, Aurora Water, and Upper Arkansas Water Conservancy District) established a basinwide water-quality monitoring network in the Arkansas River Basin in Colorado. The study leveraged ongoing continuous measurements of streamflow and specific conductance (SC) at 13 sites along the main stem Arkansas River and Fountain Creek from the USGS 07108600 Arkansas River at Granite, Colo., (Ark Granite) site to the USGS 07137500 Arkansas River near Coolidge, Kansas, (Ark Coolidge) site. Baseline water-quality conditions were established using data from October 1989 through September 2022 to help identify changes in water quality that could result from changes in land and water use.
Total dissolved solids (TDS) concentration was the main indicator of general water quality in this study because it can be accurately estimated from SC and is sensitive to changes in streamflow, water operations, and source contributions. Median TDS concentrations in Arkansas River samples (October 1989 through December 2023) ranged from 75 milligrams per liter (mg/L) at Ark Granite near the headwaters to 3,660 mg/L at Ark Coolidge near the Colorado–Kansas State line. Distinct seasonal differences in median streamflow and TDS were apparent during the winter and summer months.
Seasonal Kendall tests showed no significant trends in monthly mean streamflow (October 1995 through September 2022) at Arkansas River sites upstream from Pueblo Reservoir. Upward trends in TDS concentrations and loads occurred only at Ark Granite. Downward trends in streamflow, TDS concentrations, and TDS loads occurred at Arkansas River sites from USGS 07109500 Arkansas River near Avondale, Colo., to Ark Coolidge. Downward trends in streamflow and SC (surrogate for TDS) were more prevalent during winter base flow months and may indicate changes in groundwater quantity, and possibly groundwater quality, potentially affecting the river water-quality condition.
Plain Language Summary
The Arkansas River Basin in Colorado is an important water source for southeastern Colorado. This report discusses continuous water-quality monitoring data across the Arkansas River Basin from 13 sites and evaluates 2 major indicators of general water quality: total dissolved solids and specific conductance. These data were used to establish baseline water-quality conditions that could help identify water-quality changes from potential changes in land and water use or water management.
Suggested Citation
Miller, L.D., Eng, L.E., and Sharp, J.B., 2026, Determination of baseline water-quality conditions using continuous specific conductance and discrete measurements of total dissolved solids and selected major ions, Arkansas River Basin, Colorado: U.S. Geological Survey Scientific Investigations Report 2026–5013, 33 p., https://doi.org/10.3133/sir20265013.
ISSN: 2328-0328 (online)
Table of Contents
- Abstract
- Plain Language Summary
- Introduction
- Methods for Collection and Evaluation of Water-Quality Data
- Comparison of Specific Conductance at Arkansas River Sites Near Moffat Street
- Determination of Baseline Water-Quality Conditions
- Summary
- References Cited
- Appendix 1. Trends in Monthly Mean Streamflow and Specific Conductance Values at Selected Sites on the Arkansas River and Fountain Creek
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Determination of baseline water-quality conditions using continuous specific conductance and discrete measurements of total dissolved solids and selected major ions, Arkansas River Basin, Colorado |
| Series title | Scientific Investigations Report |
| Series number | 2026-5013 |
| DOI | 10.3133/sir20265013 |
| Publication Date | July 01, 2026 |
| Year Published | 2026 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston VA |
| Contributing office(s) | Colorado Water Science Center |
| Online Only (Y/N) | Y |