From purpose and objectives: The purpose of this report is to summarize the hydrologic investigation. The study objective was to provide data and a limited interpretation of surface- and ground-water flow systems.

Report and geological survey. This report examines the ground water within the Wet Mountain Valley, Colorado. It includes maps of the area.

Purpose of study and report: This study is the result of an agreement between the Denver Water Department and the U.S. Geological Survey to investigate the evaporative losses from reservoirs which are a part of the Denver water-supply system. Interim results of the study were presented by Ficke and others (1977). The subject report is a continuation of results given by Ficke and others (1977).

Purposes of study and report: This report presents the results of a continuing study conducted by the U.S. Geological Survey in cooperation with the Denver Board of Water Commissioners. Purposes of the study are: (l) To define the amounts of net evaporation losses from the Denver storage reservoirs; and (2) to conduct experiments for improving methods for measuring evaporation, particularly at reservoirs at high elevations.

This is a sheet showing 3 maps of 3 different aquifers as well as stratigraphic sections and hydrographs of selected wells.

From introduction: The purpose of this study was to define the altitude and configuration of the water table for use by water planners and users in future development of water resources.

Abstract: The Lake Minnequa area, located immediately south of the Arkansas River, is mantled with as much as 46 feet (14 meters) of alluvium covering bedrock of Pierre Shale and Niobrara Formation. Surface water enters the area by the Minnequa Canal and the St. Charles Flood Ditch. The water is stored in Lake Minnequa and other reservoirs. Seepage from St. Charles Reservoirs No. 2 and No. 3 is the major source of water to the alluvial aquifer. The depth of the water table ranges from 0 to 40 feet (0 to 12.2 meters). A 0.5-square-mile (1.3-square-kilometers) area immediately south of Lake Minnequa has a water table less than 6 feet (1.8 meters) below land surface. Lake Minnequa is the principal cause of the shallow water table and resulting waterlogged soil. The bedrock hill east of Lake Minnequa and ground-water flow also contribute to the problem. To eliminate the waterlogging problem, the water table would have to be at least 6 feet (1.8 meters) below land surface. Possible alternatives for eliminating the problem include lowering the water, level in Lake Minnequa, placing a network of dewaterinq wells, or constructing a drainage system in the waterlogged area.

From abstract: From parts of the area, water for domestic use obtained from the fractured crystalline-rock aquifer contained excessive concentration of dissolved fluoride, dissolved nitrite plus nitrate, dissolved solids, dissolved iron, dissolved manganese, dissolved zinc, coliform bacteria, gross alpha radiation, and gross beta radiation. Based on water-quality analyses from 26 wells located in small urbanized areas, water from 21 of the wells contained excessive concentrations of one of more constituents.

From abstract: because of the increased demands for water in eastern Colorado, principally in the urbanizing Denver metropolitan area, increased diversions of water from Dillon Reservoir are planned. Estimates of end-of-month storage in Dillon Reservoir, assuming the reservoir was in place and 131,000 acre-feet of water were diverted from the reservoir each year, were reconstructed by mass balance for the 1931-77 water years. Based on the analysis, the annual maximum end-of-month drawdown below the elevation at full storage would have been 171 feet.

From introduction: The overall objective of this report is to determine the cumulative effects of mining on dissolved solids in the Yampa River basin. more specifically the approach is (1) to develop a model of streamflow and dissolved solids focused on the Trout Creek drainage and a reach of the Yampa River main stem; (2) to calibrate this model with existing data; (3) to insert into the model future mine plans as given by the Mined Land Reclamation Division to determine cumulative effects of mining on dissolved solids in the streamflow.

From abstract: The High Plains Regional Aquifer System Analysis study has developed a regional water-resources (and related) data storage and retrieval system to organize and preserve areal interpretive data. The system is general and can easily be adapted for other studies. This report documents the High Plains data base as well as the general system that is independent of the High Plains area.

From introduction: Ground water is a source of municipal, domestic, stock, and irrigation water supply for most of northeastern Larimer County, Colorado. This report presents the results of a study made to determine the quantity, availability, and quality of the ground water. This information should be useful particularly for land-use planning and the utilization and protection of the ground-water resources.

This report presents changes in water quality in an alluvial aquifer near Greeley, Colorado. It contains maps, graphs, and tables.

Purpose and scope: This report describes a preliminary reconnaissance of the water-bearing properties of the Mississippian Leadville Limestone in the western part of the White River Uplift (synonymous with the White River Plateau). The purpose of this preliminary investigation is to determine areas of the Leadville Limestone suitable for exploratory drilling and testing at relatively shallow depths to confirm the quality of water in storage.

This report analyses the water quality of Lake George in Colorado and the four aquifers that feed into it. It includes maps and tables.

This report presents the findings of the analyses made for a fifty-eight mile stretch along the Yampa River in Colorado. It contains maps, graphs, and tables.

This report examines the region of the Piceance Creek basin in Colorado so that the United States Bureau of Mines may develop plans for an underground oil-shale research facility in the center of the basin. It includes maps, charts, and graphs.

From abstract: This report uses "an analysis of variance technique to determine variations in climatic characteristics in South Park," Colorado to analyze three years worth of collected data. It includes a map, graphs, and tables.

From introduction: This report presents the results of an investigation of the ground-water resources of the central part of La Plata County, Colorado. The purpose of the investigation is to describe the geologic units and the availability and quality of ground water in the central part of the county.

From introduction: This report presents the results of an investigation of the ground-water resources of the Crystal River and Cattle Creek drainage basins...The purpose of the investigation was to describe the geologic units, the aquifers and their characteristics, and the availability and chemical quality of ground water in the study area.

This report investigates the effects of the sewage-sludge recycling site and a landfill site on the ground-water system of Denver. It includes several maps.

From introduction: "The U.S. Geological Survey began a 5-year study of the High Plains regional aquifer during the 1978 to provide the hydrologic information needed for the development of computer models to evaluate the aquifer's response to ground-water management alternatives." It contains maps, graphs, and tables.

Report and geological survey. This report uses maps that depict climatic factors to make a flood-frequency model. It includes numerous maps, tables, and other figures.

From introduction: This report presents the data collected from six watersheds in northwestern Colorado and describes an initial step in the regionalization of water-quality characteristics and identification of transferability of data from individual, studied watersheds to unstudied watersheds in northwestern Colorado.