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At least 883 records · Page 49Linked to original sources

USGS1999

Ground-water resources of Tooele Valley, Utah

Ground water provides much of the water supply for residents of Tooele Valley (fig. 1). The protection, development, and wise management of ground-water resources are important to support community growth and to ensure the continued availability of ground water for all users. The U.S. Geological Survey, in cooperation with Tooele County, Tooele City, Grantsville City, the U.S. Army, and the State of Utah, has been studying the water resources of Tooele Valley since 1913 to define the quality and amount of water in the principal ground-water aquifers. The most recent studies in the 1990s have provided new insights into the hydrology of the valley. This fact sheet presents a synopsis of the recent studies and describes ground-water occurrence and movement, water quality, and a water budget for the principal basin-fill aquifer in Tooele Valley.

Utah↗

USGS2015

National Field Manual for the Collection of Water-Quality Data. U.S. Geological Survey Techniques of Water-Resources Investigations, Book 9

The mission of the Water Resources Discipline of the U.S. Geological Survey (USGS) is to provide the information and understanding needed for wise management of the Nation's water resources. Inherent in this mission is the responsibility to collect data that accurately describe the physical, chemical, and biological attributes of water systems. These data are used for environmental and resource assessments by the USGS, other government agenices and scientific organizations, and the general public. Reliable and quality-assured data are essential to the credibility and impartiality of the water-resources appraisals carried out by the USGS. The development and use of a National Field Manual is necessary to achieve consistency in the scientific methods and procedures used, to document those methods and procedures, and to maintain technical expertise. USGS field personnel use this manual to ensure that the data collected are of the quality required to fulfill our mission.

Techniques of Water-Resources Investigations↗

USGS2009

Hydrogeology of the Lake Tahoe Basin, California and Nevada

Ground water in the Lake Tahoe basin is the primary source of domestic and municipal water supply and an important source of inflow to Lake Tahoe. Over the past 30-40 years, Federal, State, and local agencies, and research institutions have collected hydrologic data to quantify the ground-water resources in the Lake Tahoe basin. These data are dispersed among the various agencies and institutions that collected the data and generally are not available in a format suitable for basin-wide assessments. To successfully and efficiently manage the ground-water resources throughout the Lake Tahoe basin, the U.S. Geological Survey (USGS) in cooperation with the U.S. Forest Service (USFS) compiled and evaluated the pertinent geologic, geophysical, and hydrologic data, and built a geodatabase incorporating the consolidated and standardized data for the Lake Tahoe basin that is relevant for examining the extent and characteristics of the hydrogeologic units that comprise the aquifers.

California, Nevada↗

USGS2013

Analysis of changes in water-level dynamics at selected sites in the Florida Everglades

The historical modification and regulation of the hydrologic patterns in the Florida Everglades have resulted in changes in the ecosystem of South Florida and the Florida Everglades. Since the 1970s, substantial focus has been given to the restoration of the Everglades ecosystem. The U.S. Geological Survey through its Greater Everglades Priority Ecosystem Science and National Water-Quality Assessment Programs has been providing scientific information to resource managers to assist in the Everglades restoration efforts. The current investigation included development of a simple method to identify and quantify changes in historical hydrologic behavior within the Everglades that could be used by researchers to identify responses of ecological communities to those changes. Such information then could be used by resource managers to develop appropriate water-management practices within the Everglades to promote restoration. The identification of changes in historical hydrologic behavior within the Everglades was accomplished by analyzing historical time-series water-level data from selected gages in the Everglades using (1) break-point analysis of cumulative Z-scores to identify hydrologic changes and (2) cumulative water-level frequency distribution curves to evaluate the magnitude of those changes. This analytical technique was applied to six long-term water-level gages in the Florida Everglades. The break-point analysis for the concurrent period of record (1978–2011) identified 10 common periods of changes in hydrologic behavior at the selected gages. The water-level responses at each gage for the 10 periods displayed similarity in fluctuation patterns, highlighting the interconnectedness of the Florida Everglades hydrologic system. While the patterns were similar, the analysis also showed that larger fluctuations in water levels between periods occurred in Water Conservation Areas 2 and 3 in contrast to those in Water Conservation Area 1 and the Everglades National Park. Results from the analysis indicate that the cumulative Z-score curve, in conjunction with cumulative water-level frequency distribution curves, can be a useful tool in identifying and quantifying changes in historical hydrologic behavior within the Everglades. In addition to the analysis, a spreadsheet application was developed to assist in applying these techniques to time-series water-level data at gages within the Everglades and is included with this report.

Florida↗

USGS1985

Reconnaissance of ground-water resources in the lower Gunnison River basin, southwestern Colorado

Information about ground-water quantity and quality in the lower Gunnison River basin assists in developing, appropriating, and managing the basin 's water resources. Hydrogeologic data are presented for 51 wells and 61 springs. Chemical analyses are given for 34 wells and 17 springs. Drillers ' reports for 71 wells are included. Springs normally discharge from short alluvial flow systems and commonly are less saline than well water. These springs are a calcium magnesium bicarbonate water type. Spring discharges of as much as 200 gallons per minute were measured. The most productive wells in the study area are completed in alluvium, with reported yields of as much as 750 gallons per minute for an irrigation well. Alluvial gravels are most productive. Specific-conductance values of water samples from alluvial deposits ranged from 80 to 32,200 micromhos per centimeter at 25 Celsius. The Mancos Shale and Mesaverde Formation include aquifers with large areal extents. Reported yields of wells completed in the Mesaverde Formation range from 0.7 to 24 gallons per minute. The Dakota Sandstone, Morrison Formation, and Entrada Sandstone include potential aquifers of lesser extent. Reported yields of wells completed in the Dakota Sandstone range 5 to 14 gallons per minute in the study area. Specific-conductance values of water samples from the Mesaverde Formation ranged from 325 to 5,390 micromhos per centimeter at 25 Celsius. Insufficient data prevented water-quality analysis of other rock units. (USGS)

Water-Resources Investigations Report↗

USGS2012

USGS advances in integrated, high-resolution sea-floor mapping: inner continental shelf to estuaries

The U.S. Geological Survey (USGS) has been involved in geological mapping of the sea floor for the past thirty years. Early geophysical and acoustic mapping efforts using GLORIA (Geologic LOng Range Inclined ASDIC) a long-range sidescan-sonar system, provided broad-scale imagery of deep waters within the U.S. Exclusive Economic Zone (EEZ). In the early 1990's, research emphasis shifted from deep- to shallow-water environments to address pertinent coastal research and resource management issues. Use of shallow-water, high-resolution geophysical systems has enhanced our understanding of the processes shaping shallow marine environments. However, research within these shallow-water environments continues to present technological challenges.

Conference Paper↗

USGS2025

The 3D Elevation Program—Supporting New Mexico’s Economy

Introduction Federal, State, Tribal, and local entities managing lands in New Mexico have concerns about wildfire risk, wildlife habitat, and flood risk. Land managers in urban areas along the Rio Grande corridor and in the State’s rural northwest and southeast also have concerns about existing and developing roads, buildings, and other infrastructure. Federal, State, Tribal, and local organizations actively manage and monitor New Mexico’s water resources. Critical applications that meet the State’s management needs depend on light detection and ranging (lidar) data that provide a highly detailed three-dimensional (3D) model of the Earth’s surface and aboveground features. The 3D Elevation Program (3DEP) is managed by the U.S. Geological Survey in partnership with Federal, State, Tribal, U.S. territorial, and local agencies to acquire consistent lidar coverage at quality level 2 or better to meet the many needs of the Nation and New Mexico. The status of available and in-progress 3DEP baseline lidar data in New Mexico is shown. 3DEP baseline lidar data include quality level 2 or better, 1-meter or better digital elevation models, and lidar point clouds, and must meet the Lidar Base Specification version 1.2 or newer requirements. The National Enhanced Elevation Assessment identified user requirements and conservatively estimated that availability of lidar data would result in at least $9.32 million in new benefits annually to the State.

New Mexico↗

USGS2023

The value of scientific information — An overview

Introduction The U.S. Geological Survey (USGS) provides reliable science, data, information, and models (hereafter collectively referred to as “information”) to describe and understand the Earth. This information is used to minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect quality of life. USGS science informs public and private decisions, operations, and risk management in all major United States economic sectors, as defined by the Bureau of Economic Analysis, and provides critical information for natural resource and natural hazard management and stewardship decisions. Understanding the value of scientific information supports applications of USGS science in land- and water-management decisions, and better informs the public about the return on investment of USGS programs. USGS economists, social scientists, and physical scientists are engaged in collaborative efforts to advance methods to estimate the value of information (VOI) produced by the USGS. These efforts involve collaborating with an international community to develop and refine estimation methods, establish best practices to determine VOI, develop a study repository, and conduct projects to assess the VOI of specific information products and their application. This report focuses on economic valuation conducted by USGS specifically, although the methodology has much broader applicability within the U.S. government, academia, and beyond. Noneconomic valuation techniques for assessing the VOI also exist but are not addressed in this report.

Open-File Report↗

USGS2011

Fluctuations in groundwater levels related to regional and local withdrawals in the fractured-bedrock groundwater system in northern Wake County, North Carolina, March 2008-February 2009

A study of dewatering of the fractured-bedrock aquifer in a localized area of east-central North Carolina was conducted from March 2008 through February 2009 to gain an understanding of why some privately owned wells and monitoring wells were intermittently dry. Although the study itself was localized in nature, the resulting water-resources data and information produced from the study will help enable resource managers to make sound water-supply and water-use decisions in similar crystalline-rock aquifer setting in parts of the Piedmont and Blue Ridge Physiographic Provinces. In June 2005, homeowners in a subdivision of approximately 11 homes on lots approximately 1 to 2 acres in size in an unincorporated area of Wake County, North Carolina, reported extremely low water pressure and temporarily dry wells during a brief period. This area of the State, which is in the Piedmont Physiographic Province, is undergoing rapid growth and development. Similar well conditions were reported again in July 2007. In an effort to evaluate aquifer conditions in the area of intermittent water loss, a study was begun in March 2008 to measure and monitor water levels and groundwater use. During the study period from March 2008 through February 2009, regular dewatering of the fractured-bedrock aquifer was documented with water levels in many wells ranging between 100 and 200 feet below land surface. Prior to this period, water levels from the 1980s through the late 1990s were reported to range from 15 to 50 feet below land surface. The study area includes three community wells and more than 30 private wells within a 2,000-foot radius of the dewatered private wells. Although groundwater levels were low, recovery was observed during periods of heavy rainfall, most likely a result of decreased withdrawals owing to less demand for irrigation purposes. Similar areal patterns of low groundwater levels were delineated during nine water-level measurement periods from March 2008 through February 2009. Correlation of groundwater-level distribution patterns with orientations of geologic structures obtained from surficial mapping, borehole geophysical measurements, and interpretation of fracture traces suggests two dominant trends striking north-south and N. 65 degrees W. A variation in overall response to groundwater withdrawals was noted in the continuous groundwater-level records for the monitored observation wells and dewatered private wells. The largest overall declines during the study period were observed in an observation well in which the water-level declined as much as 247 feet from mid-July through early August 2008, during a period of heavy usage. A private well had a water-level decline of about 94 feet during the same monitoring period. The large declines recorded in the observation well and the private well indicated a substantial temporary loss of storage in the fractured-bedrock aquifer near the wells, thus reducing the amount of water available to shallow wells in the area (those wells with total depths of about 300 feet), and resulting in temporary well failures until such time as the aquifer recovered.

North Carolina↗

USGS2013

Evaluating changes to reservoir rule curves using historical water-level data

Flood control reservoirs are typically managed through rule curves (i.e. target water levels) which control the storage and release timing of flood waters. Changes to rule curves are often contemplated and requested by various user groups and management agencies with no information available about the actual flood risk of such requests. Methods of estimating flood risk in reservoirs are not easily available to those unfamiliar with hydrological models that track water movement through a river basin. We developed a quantile regression model that uses readily available daily water-level data to estimate risk of spilling. Our model provided a relatively simple process for estimating the maximum applicable water level under a specific flood risk for any day of the year. This water level represents an upper-limit umbrella under which water levels can be operated in a variety of ways. Our model allows the visualization of water-level management under a user-specified flood risk and provides a framework for incorporating the effect of a changing environment on water-level management in reservoirs, but is not designed to replace existing hydrological models. The model can improve communication and collaboration among agencies responsible for managing natural resources dependent on reservoir water levels.

International Journal of River Basin Management↗

USGS1978

Water resources of south-central Iowa

The objective of this report is to present information on the water resources of south-central Iowa that will help solve the supply problems of the water users in the region and that will aid planners and water managers who must consider water resources on a regional basis. The information presented includes the availability, quality, and utilization of water from all known sources and the future demands upon the water resources.

Iowa↗

USGS1977

Ground-water data for the Drewsey Resource Area, Harney and Malheur counties, Oregon

Appraisals of the resources of selected management areas in eastern Oregon are being made by the U.S. Bureau of Land Management. To provide needed hydrologic information the Bureau of Land Management requested the U.S. Geological Survey Water Resources Division to inventory ground-water data for the Drewsey Resource Area. Included in this report are well data, drillers ' lithologic logs, hydrographs, a summary of observation-well data, and chemical analyses of ground water. (Woodard-USGS)

Open-File Report↗

USGS2021

Hydrologic and water-quality conditions in the Cedar River alluvial aquifer, Linn County, Iowa, 1990–2019

Alluvial aquifers in Iowa have more wells with nitrate exceeding drinking-water standards than other aquifers; are susceptible to contamination by organic contaminants; and have high concentrations of naturally occurring iron and manganese in depositional areas that contain abundant organic matter. The U.S. Geological Survey, in cooperation with the City of Cedar Rapids, Iowa, studied the Cedar River alluvial aquifer in Linn County, Iowa, from 1990 to 2019 to understand the effect of municipal pumping on spatial and temporal hydrologic and water-quality variability. The Cedar River alluvial aquifer is the source of water for the city of Cedar Rapids, Iowa. Withdrawal of large quantities of water for municipal and industrial supply has altered the normal flow of water in the alluvial aquifer. Pumping induces flow from the Cedar River and the underlying bedrock aquifer into the alluvial aquifer. Water quality in the alluvial aquifer varies along the Cedar River. Changes in nitrate, ammonia, manganese, and iron in the alluvial aquifer are seen as the upstream free-flowing reach of the Cedar River transitions to a partially regulated downstream reach, likely because of differences in reduction-oxidation conditions in the aquifer, which are controlled by infiltration from the Cedar River under normal conditions and when wells are being pumped. Nitrate, normally found in oxygenated environments, had the highest concentrations in the most upstream wells in the Seminole well field and the lowest concentrations in the most downstream wells in the East well field. In contrast, ammonia, manganese, and iron, normally found in greatest abundance in anoxic (reducing) conditions, had the greatest concentrations in the most downstream wells. Additionally, dissolved nitrate plus nitrite nitrogen concentrations in wells were substantially less and manganese concentrations were greater in production wells near backwater wetlands in contrast to wells near the Cedar River. Temporal variability in water quality in the alluvial aquifer was driven by pumping that increased flow from the Cedar River into the alluvial aquifer and ultimately led to changes in reduction-oxidation conditions of the aquifer. Increasing dissolved nitrate plus nitrite nitrogen concentrations in the Cedar River from 1990 to 2019 were mirrored in the alluvial aquifer. Anoxic conditions are prevalent in the alluvial aquifer next to the Cedar River when the aquifer is not under pumping stress. However, production well pumping caused induced infiltration of oxygenated river water into the aquifer resulting in increased dissolved nitrate plus nitrite nitrogen concentrations and pesticides and decreased naturally occurring dissolved iron and manganese. Hydrologic and water-quality conditions in the Cedar River alluvial aquifer from 1990 to 2019 provide baseline conditions needed to evaluate the effects of current and future nutrient reduction efforts and land-use changes in the Cedar River Basin on water quality of the Cedar River alluvial aquifer and its source water, the Cedar River. This summary and analysis provide information that can assist the City of Cedar Rapids Utilities Water Department in managing groundwater resources, and provides information that could be used develop a groundwater-quality model to characterize variability over larger areas of the alluvial aquifer, allowing water providers to plan for future water needs of their users.

Iowa↗

USGS2001

Vertical gradients in water chemistry in the central High Plains aquifer, southwestern Kansas and Oklahoma panhandle, 1999

The central High Plains aquifer is the primary source of water for domestic, industrial, and irrigation uses in parts of Colorado, Kansas, New Mexico, Oklahoma, and Texas. Water-level declines of more than 100 feet in some areas of the aquifer have increased the demand for water deeper in the aquifer. The maximum saturated thickness of the aquifer ranged from 500 to 600 feet in 1999. As the demand for deeper water increases, it becomes increasingly important for resource managers to understand how the quality of water in the aquifer changes with depth. In 1998?99, 18 monitoring wells at nine sites in southwestern Kansas and the Oklahoma Panhandle were completed at various depths in the central High Plains aquifer, and one monitoring well was completed in sediments of Permian age underlying the aquifer. Water samples were collected once from each well in 1999 to measure vertical gradients in water chemistry in the aquifer. Tritium concentrations measured in ground water indicate that water samples collected in the upper 30 feet of the aquifer were generally recharged within the last 50 years, whereas all of the water samples collected at depths more than 30 feet below the water table were recharged more than 50 years ago. Dissolved oxygen was present throughout the aquifer, with concentrations ranging from 1.7 to 8.4 mg/L. Water in the central High Plains aquifer was predominantly a calcium-bicarbonate type that exhibited little variability in concentrations of dissolved solids with depth (290 to 642 mg/L). Exceptions occurred in some areas where there had been upward movement of mineralized water from underlying sediments of Permian age and areas where there had been downward movement of mineralized Arkansas River water to the aquifer. Calcium-sulfate and sodium-chloride waters dominated and concentrations of dissolved solids were elevated (862 to 4,030 mg/L) near the base of the aquifer in the areas of upward leakage. Dissolution of gypsum or anhydrite and halite in sediments of Permian age by ground water was the likely source of calcium, sulfate, sodium, and chloride in those waters. Calcium-sodium-sulfate waters dominated, and concentrations of dissolved solids were as large as 4,916 mg/L near the water table in the area of downward leakage. Dissolution of minerals in sedimentary deposits of marine origin in upstream areas of the Arkansas River drainage were the likely sources of calcium, sodium, and sulfate in those waters. Nitrate was detected throughout the aquifer and the background concentration was estimated to be 2.45 mg/L as N. The largest nitrate concentrations (8.28, 22, and 54.4 mg/L as N) occurred in recently recharged water collected adjacent to irrigated fields. Three pesticides (atrazine, metolachlor, simazine) and five pesticide degradation products (alachlor ethanesulfonic acid, alachlor oxanilic acid, deethylatrazine, metolachlor ethanesulfonic acid, metolachlor oxanilic acid) were detected in recently recharged water from six water-table wells. Five of the six wells were adjacent to irrigated fields. These data indicate that concentrations of nitrate and pesticides increased over time in some areas of the aquifer as a result of agricultural activities. Results from this study indicate that vertical gradients in water chemistry existed in the central High Plains aquifer. The chemical gradients resulted from chemical inputs to the aquifer from underlying sediments of Permian age, from the Arkansas River, and from agricultural activities. In areas where those chemical inputs occurred, water quality in the aquifer was impaired and may not have been suitable for some intended uses.

Water-Resources Investigations Report↗

USGS2016

Using large-scale flow experiments to rehabilitate Colorado River ecosystem function in Grand Canyon: Basis for an adaptive climate-resilient strategy

Adaptive management of Glen Canyon Dam is improving downstream resources of the Colorado River in Glen Canyon National Recreation Area and Grand Canyon National Park. The Glen Canyon Dam Adaptive Management Program (AMP), a federal advisory committee of 25 members with diverse special interests tasked to advise the U.S. Department of the Interior), was established in 1997 in response to the 1992 Grand Canyon Protection Act. Adaptive management assumes that ecosystem responses to management policies are inherently complex and unpredictable, but that understanding and management can be improved through monitoring. Best known for its high-flow experiments intended to benefit physical and biological resources by simulating one aspect of pre-dam conditions—floods, the AMP promotes collaboration among tribal, recreation, hydropower, environmental, water and other natural resource management interests. Monitoring has shown that high flow experiments move limited new tributary sand inputs below the dam from the bottom of the Colorado River to shorelines; rebuilding eroded sandbars that support camping areas and other natural and cultural resources. Spring-timed high flows have also been shown to stimulate aquatic productivity by disturbing the river bed below the dam in Glen Canyon. Understanding about how nonnative tailwater rainbow trout ( Oncorhynchus mykiss ), and downstream endangered humpback chub ( Gila cypha ) respond to dam operations has also increased, but this learning has mostly posed “surprise” adaptation opportunities to managers. Since reoperation of the dam to Modified Low Fluctuating Flows in 1996, rainbow trout now benefit from more stable daily flows and high spring releases, but possibly at a risk to humpback chub and other native fishes downstream. In contrast, humpback chub have so far proven robust to all flows, and native fish have increased under the combination of warmer river temperatures associated with reduced storage in Lake Powell, and a system-wide reduction in trout from 2000-06, possibly due to several years of natural reproduction under limited food supply. Uncertainties about dam operations and ecosystem responses remain, including how native and nonnative fish will interact and respond to possible increased river temperatures under drier basin conditions. Ongoing assessment of operating policies by the AMP’s diverse stakeholders represents a major commitment to the river’s valued resources, while surprise learning opportunities can also help identify a resilient climate-change strategy for co-managing nonnative and endangered native fish, sandbar habitats and other river resources in a region with already complex and ever-increasing water demands.

Arizona↗

USGS1971

The water resources of southeast Iowa

Water is vital in the lives of the people and the economy of any area. In order to utilize this natural resource in the most efficient and beneficial manner, a basic knowledge and understanding of its sources and the occurrence and potential of each source must be gained. To provide this knowledge, the Water Resources Division of the U.S. Geological Survey in cooperation with the Iowa Geological Survey compiled this atlas describing the water resources available for development in an 11-county area in southeast Iowa. The report contains information on the availability, quality, and utilization of water from all known sources and the future demands upon the water resources in southeast Iowa. The information is presented to aid water users and other persons searching for and evaluating sources of water in a particular place, and planners and water managers who must consider water resources on a regional basis.

Iowa↗

USGS1999

Evaluating data worth for ground-water management under uncertainty

A decision framework is presented for assessing the value of ground-water sampling within the context of ground-water management under uncertainty. The framework couples two optimization models-a chance-constrained ground-water management model and an integer-programing sampling network design model-to identify optimal pumping and sampling strategies. The methodology consists of four steps: (1) The optimal ground-water management strategy for the present level of model uncertainty is determined using the chance-constrained management model; (2) for a specified data collection budget, the monitoring network design model identifies, prior to data collection, the sampling strategy that will minimize model uncertainty; (3) the optimal ground-water management strategy is recalculated on the basis of the projected model uncertainty after sampling; and (4) the worth of the monitoring strategy is assessed by comparing the value of the sample information-i.e., the projected reduction in management costs-with the cost of data collection. Steps 2-4 are repeated for a series of data collection budgets, producing a suite of management/monitoring alternatives, from which the best alternative can be selected. A hypothetical example demonstrates the methodology's ability to identify the ground-water sampling strategy with greatest net economic benefit for ground-water management.A decision framework is presented for assessing the value of ground-water sampling within the context of ground-water management under uncertainty. The framework couples two optimization models - a chance-constrained ground-water management model and an integer-programming sampling network design model - to identify optimal pumping and sampling strategies. The methodology consists of four steps: (1) The optimal ground-water management strategy for the present level of model uncertainty is determined using the chance-constrained management model; (2) for a specified data collection budget, the monitoring network design model identifies, prior to data collection, the sampling strategy that will minimize model uncertainty; (3) the optimal ground-water management strategy is recalculated on the basis of the projected model uncertainty after sampling; and (4) the worth of the monitoring strategy is assessed by comparing the value of the sample information - i.e., the projected reduction in management costs - with the cost of data collection. Steps 2-4 are repeated for a series of data collection budgets, producing a suite of management/monitoring alternatives, from which the best alternative can be selected. A hypothetical example demonstrates the methodology's ability to identify the ground-water sampling strategy with greatest net economic benefit for ground-water management.

Journal of Water Resources Planning and Management↗

USGS1978

Water resources of east-central Iowa

Water is vital in the lives of the people and the economy of any area. To utilize this natural resource in the most efficient and beneficial manner, a basic knowledge and understanding of its sources and the occurrence and potential of each source must be gained. To provide this knowledge, the Water Resources Division of the U.S. Geological Survey in cooperation with the Iowa Geological Survey compiled this atlas describing the water resources available for development in an 12-county area in east-central Iowa. The report contains information on the availability, quality, and utilization of water from all known sources and the future demands upon the water resources in east-central Iowa. The information is presented to aid water users and other persons searching for and evaluating sources of water in a particular place, and planners and water managers who must consider water resources on a regional basis.

Iowa↗