A summary of selected chemical-quality conditions in 66 California streams 1950-72

Open-File Report
Prepared in cooperation with the California Department of Water Resources
By:  and 



Water from California streams has been analyzed for concentrations of selected chemical constituents since the early 1950's. This summary includes about 1,200 water years of data from 88 sampling sites on 66 streams.

Results of this summary show that about 80 percent of the sites had a mean dissolved-solids concentration of 400 milligrams per litre or less. All the sites that had mean concentrations ranging from 601 to 800 milligrams per litre were in either the South Coastal or Central Coastal subregions.

Results of regression analysis between specific conductance and calcium, magnesium, sodium, bicarbonate, dissolved solids, and hardness usually indicated a high percentage of explained variance. Other constituents, such as potassium, sulfate, chloride, and particularly nitrate, were not as frequently highly associated with specific conductance.

At sites where the water discharge was highly regulated, the variation in specific conductance that was explained as a function of discharge ranged from 0 to more than 90 percent. Whereas at the unregulated sites, the explained variance ranged from 50 to more than 90 percent.

Study Area

Additional publication details

Publication type Report
Publication Subtype USGS Unnumbered Series
Title A summary of selected chemical-quality conditions in 66 California streams 1950-72
Series title Open-File Report
DOI 10.3133/70184370
Year Published 1975
Language English
Publisher U.S. Geological Survey
Description vii, 104 p.
Country United States
State California
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