Water Quality in the Central Nebraska Basins, Nebraska, 1992-95

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Summary of Major Issues and Findings in the Central Nebraska Basins Study Unit

Location map of the study unit

What factors are important in determining water-quality conditions in the Central Nebraska Basins?

Land use in central Nebraska appears to affect water quality significantly; streams in rangelands generally had fewer occurrences and smaller concentrations of pesticides than did streams in croplands where corn and soybeans were planted extensively. Subbasins with greater proportions of rangeland, such as the Dismal River, had negligible herbicide concentrations. The largest pesticide concentrations were in storm runoff following pesticide applications. Because some pesticide concentrations may exceed the U.S. Environmental Protection Agency's (USEPA) drinking-water Maximum Contaminant Levels (MCLs) in storm runoff, the timing and intensity of rainfall has implications for drinking-water supplies. Pesticides in streams from storm runoff may enter alluvial aquifers as a consequence of ground-water withdrawals. Sites with degraded water chemistry commonly had degraded physical habitats as well. Streamflow regulation of the Platte River has affected water quality through habitat alterations that are deleterious to native species. The combination of degraded physical and chemical environments commonly resulted in structurally simple fish communities.

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Agricultural chemicals are applied to enhance crop production.

Nitrate content in water is related to agricultural land management (p. 6-7)

Agricultural activities potentially affect the management of public-water supplies withdrawn from the Platte River and the alluvial aquifer (p. 8-9)

Water quality in the Platte River alluvial aquifer may be affected by surface-water quality in areas of ground-water withdrawals (p. 10-11)

Aquatic environments potentially are altered by human activities (p. 12-13)

Aquatic and migratory species are affected directly by changes in the physical characteristics of the Platte River (p. 14-15)

1 Nitrate, as used in this report, was analyzed as nitrite plus nitrate and concentrations were reported as total nitrogen.

U.S. Geological Survey Circular 1163

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Suggested citation:
Frenzel, S.A., Swanson, R.B., Huntzinger, T.L., Stamer, J.K., Emmons, P.J., and Zelt, R.B., 1998, Water Quality in the Central Nebraska Basins, Nebraska, 1992-95: U.S. Geological Survey Circular 1163, on line at <URL:>, updated Sept 14, 1998 .

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Last modified: Fri Sep 11 14:57:40 1998