Part of a series of articles titled Water Resources Monitoring in the Snake River at Flagg Ranch, Wyoming.
Article
Snake River Water Quality at Flagg Ranch, Wyoming
Water quality in the Snake River is considered very high quality and the river is valued for its natural, cultural, and recreational contributions to the region. We sampled the Snake River at Flagg Ranch, WY, for water chemistry and core water quality parameters monthly from May to November in 2021. Core water quality parameters include temperature, specific conductance, dissolved oxygen, pH, and turbidity.
Results in 2021 were comparable to previous years and indicative of high-quality waters; samples contained low levels of dissolved and total nutrients. Trace metals such as arsenic, copper, and iron have been detected in the watershed and are naturally present in measurable concentrations. Fluctuations in these trace metals are driven by elevated discharge during runoff. Total iron levels were greatest during times of peak flow in the month of May and exceeded the Wyoming Chronic Aquatic Life Criterion for total recoverable iron (1 mg/L). Levels of sulfate, sodium, and arsenic were lower during months characterized by higher flows.
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2021 Water Quality Lab Results
The following two tables contain water quality lab results for the Snake River at Flagg Ranch, WY, from May through July and August through November, respectively. Download tabular data here for these tables.
Table 1. May through July 2021 monthly water chemistry lab results (in mg/L) for the Snake River above Jackson Lake at Flagg Ranch, WY. All samples were processed at Energy Laboratories in Billings, MT. Reporting limit (in mg/L) is the threshold value that many analytical labs consider to be the lowest reportable value for an individual analyte; this value may be higher than the maximum detection limit. ND = non-detectable result. Naturally occurring exceedances of the Wyoming Chronic Aquatic Life Criterion are labeled with "EX" after the value. Values followed by an "H" indicate the analysis was performed after holding time for this analyte (e.g., ortho-phosphate has a 48-hour holding time) but within 24 hours of method holding times. Some sampling events included a replicate or blank sample where indicated; blank samples are processed using certified inorganic free deionized water.
| Water Chemistry Lab Parameters (Madison River near West Yellowstone, MT) | Reporting Limit | 13-Apr | 2-May | 26-Jul | 26-Jul Blank Sample | 31-Aug |
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Table 2. August through November 2021 monthly water chemistry lab results (in mg/L) for the Snake River above Jackson Lake at Flagg Ranch, WY. All samples were processed at Energy Laboratories in Billings, MT. Reporting limit (in mg/L) is the threshold value that many analytical labs consider to be the lowest reportable value for an individual analyte; this value may be higher than the maximum detection limit. ND = non-detectable result. Values followed by an "H" indicate the analysis was performed after holding time for this analyte (e.g., ortho-phosphate has a 48-hour holding time) but within 24 hours of method holding times. Some sampling events included a replicate or blank sample where indicated; blank samples are processed using certified inorganic free deionized water.
| Water Chemistry Lab Parameters (Madison River near West Yellowstone, MT) | Reporting Limit | 21-Sep | 21-Sep Replicate Sample | 20-Oct | 10-Nov | 12-Dec | 12-Dec Blank Sample |
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Table 3. Monthly water quality field parameter results for the Snake River above Jackson Lake at Flagg Ranch, WY.
| Water Quality Field Parameters (Madison River near West Yellowstone, MT) | 13-Apr | 2-May | 26-Jul | 31-Aug | 21-Sep | 20-Oct | 10-Nov | 12-Dec |
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More Data
Data prior to 2016 are available at the Water Quality Portal using GRTEWQ01 for the project and WQX-GRTE_SNR01 as the site identifier for the Snake River at Flagg Ranch, WY.
Last updated: June 28, 2022