Publications

No abstract available.

No abstract available.

Water-resources activities of the U.S. Geological Survey in Iowa consist of collecting hydrologic data and conducting interpretive studies. Hydrologic investigations in Iowa are made through three basic types of projects: (1) hydrologic data-collection programs; (2) local or areal studies; and (3) statewide or regional investigations. These projects are funded through cooperative joint-funding agr

Preemergent herbicides and their metabolites, particularly atrazine, deethylatrazine, and metolachlor, persisted from 1989 to 1990 in the majority of rivers and streams in the midwestern United States. In spring, after the application of herbicides, the concentrations of atrazine, alachlor, and simazine were frequently 3-10 times greater than the U.S. Environmental Protection Agency maximum contam

Hydrologic data were collected in the Big Spring basin located in Clayton County, Iowa, during the 1990 water year. The data were collected by the U.S. Geological Survey in cooperation with the Iowa Department of Natural Resources, Geological Survey Bureau, to provide information on variation and movement of agricultural chemicals in the hydrologic cycle in the basin. Precipitation, surface-water,

Seventeen methods for estimating ice-affected streamflow are evaluated for potential use with the U.S. Geological Survey streamflow-gaging station network. The methods evaluated were identified by written responses from U.S. Geological Survey field offices and by a comprehensive literature search. The methods selected and techniques used for applying the methods are described in this report. The m

Alachlor, atrazine, cyanazine, metolachlor, and metribuzin were measured at six sites during 1984 and 1985 in large subbasins within the Cedar River, IA. A computer model separated the Cedar River discharge hydrograph into groundwater and overland-flow components. The concentration of herbicides in the river when groundwater was the major flow component was less than 1.0 μg/L and averaged 0.2 μg/L

No abstract available.

An approach was developed to obtain a consistent, regional distribution of herbicide and nitrate data from near-surface aquifers in the corn and soybean producing region of the mid-continent. Near-surface aquifers are defined as those with the top of aquifer material within 50 feet of land surface, regardless of whether the material is saturated or unsaturated. Three hundred wells will be selected

Hydrologic data were collected in the Big Spring Basin located in Clayton County, Iowa, during the 1989 water year. The data were collected in cooperation with the Iowa Department of Natural Resources, Geological Survey Bureau, to provide information on variation and movement of agricultural chemicals in the hydrologic cycle in the Big Spring Basin. Precipitation, stream, and ground-water data wer

The U.S. Army Corps of Engineers operates the Red Rock Dam on the Des Moines River in Marion County, Iowa. The dam consists of a gravity concrete control structure between two earthen embankments and has an impoundment storage capacity of 1,700,000 acre-feet. Since the impoundment of Lake Red Rock commenced during 1969, water seepage beneath the dam has been significant enough to cause continuing

Flood-elevation profiles and flood-peak discharges for floods during 1972, 1982, and 1987 in the Nishnabotna River basin are given in this report. The profiles are for the 1972 flood on the West and East Nishnabotna Rivers, the 1982 flood on Indian Creek, and the 1987 flood on the lower West Nishnabotna River. A flood history describes rainfall conditions and reported damages for floods occurring