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Timothy K Cowdery (Former Employee)

Science and Products

Filter Total Items: 20

Hydrologic change in the St. Louis River Basin from iron mining on the Mesabi Iron Range, northeastern Minnesota

This study compares the results of two regional steady-state U.S. Geological Survey Modular Three-Dimensional Finite-Difference Ground-Water Flow (MODFLOW) models constructed to quantify the hydrologic changes in the St. Louis River Basin from iron mining on the Mesabi Iron Range in northeastern Minnesota. The U.S. Geological Survey collaborated in this study with bands of the Minnesota Chippewa T
Authors
Timothy K. Cowdery, Anna C. Baker, Megan J. Haserodt, Daniel T. Feinstein, Randall J. Hunt
By
Upper Midwest Water Science Center

Long-term hydrologic sustainability of calcareous fens along the Glacial Lake Agassiz beach ridges, northwestern Minnesota, USA

Calcareous fens are peat-accumulating wetlands fed by calcium-rich groundwater that support several threatened species of plants that thrive in these geochemical conditions. This investigation characterized the hydrology of two calcareous fens in the Glacial Lake Agassiz beach ridge complex in northwestern Minnesota, USA. Sandy surficial beach ridge aquifers and underlying buried glacial aquifers
Authors
Nicholas R. Budde, Howard D. Mooers, Timothy K. Cowdery, Nigel J. Wattrus
By
Upper Midwest Water Science Center

The hydrologic benefits of wetland and prairie restoration in western Minnesota—Lessons learned at the Glacial Ridge National Wildlife Refuge, 2002–15

Conversion of agricultural lands to wetlands and native prairie is widely viewed as beneficial because it can restore natural ecological and hydrologic functions. Some of these functions, such as reduced peak flows and improved water quality, are often attributed to restoration; however, such benefits have not been quantified at a small scale. To inform future restoration efforts, especially in no
Authors
Timothy K. Cowdery, Catherine A. Christenson, Jeffrey R. Ziegeweid
By
Upper Midwest Water Science Center

Simulation of the regional groundwater-flow system in the St. Louis River basin, Minnesota

The St. Louis River Basin (SLRB) covers 3,600 square miles in northeastern Minnesota, with headwaters in the Mesabi Range and extensive wetlands and lakes throughout the basin. To better understand the regional groundwater system in the SLRB, a two-dimensional, steady-state groundwater-flow model of the SLRB was developed by the U.S. Geological Survey, in cooperation with the Minnesota Ojibwe Band
Authors
Megan J. Haserodt, Randall J. Hunt, Timothy K. Cowdery, Andrew T. Leaf, Anna C. Baker
By
Upper Midwest Water Science Center

Mercury in wetlands at the Glacial Ridge National Wildlife Refuge, northwestern Minnesota, 2007-9

The Glacial Ridge National Wildlife Refuge was established in 2004 on land in northwestern Minnesota that had previously undergone extensive wetland and prairie restorations. About 7,000 acres of drained wetlands were restored to their original hydrologic function and aquatic ecosystem. During 2007–9, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service and the Red La
Authors
Timothy K. Cowdery, Mark E. Brigham
By
Water Resources Mission Area, Central Midwest Water Science Center

Redox Conditions in Selected Principal Aquifers of the United States

Reduction/oxidation (redox) processes affect the quality of groundwater in all aquifer systems. Redox processes can alternately mobilize or immobilize potentially toxic metals associated with naturally occurring aquifer materials, contribute to the degradation or preservation of anthropogenic contami-nants, and generate undesirable byproducts, such as dissolved manganese (Mn2+), ferrous iron (Fe2+
Authors
P. B. McMahon, T.K. Cowdery, F. H. Chapelle, B.C. Jurgens
By
Water Resources Mission Area, Colorado Water Science Center

Hydrology Prior to Wetland and Prairie Restoration in and around the Glacial Ridge National Wildlife Refuge, Northwestern Minnesota, 2002-5

The Nature Conservancy (TNC) owned and managed 24,795 acres of mixed wetland, native prairie, farmland and woods east of Crookston, in northwestern Minnesota. The original wetlands and prairies that once occupied this land are being restored by TNC in cooperation with many partners and are becoming part of the Glacial Ridge National Wildlife Refuge. Results of this study indicate that these restor
Authors
Timothy K. Cowdery, David L. Lorenz, Allan D. Arntson
By
Water Resources Mission Area, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Hydrogeology and ground-water/surface water interactions in the Des Moines River valley, southwestern Minnesota, 1997-2001

Increased water demand in and around Windom led the U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources, local water suppliers, and Cottonwood County, to study the hydrology of aquifers in the Des Moines River Valley near Windom. The study area is the watershed of a 30-kilometer (19-mile) reach of the Des Moines River upstream from Windom. Based on stratigraph
Authors
Timothy K. Cowdery
By
Water Resources Mission Area, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Regional ground-water-flow models of surficial sand and gravel aquifers along the Mississippi River between Brainerd and St. Cloud, central Minnesota

This report documents regional ground-waterflow models constructed by the U.S. Geological Survey in cooperation with the Minnesota Department of Health (MDH) to satisfy the requirements of their Source Water Protection Plan (SWPP). Steady-state single-layer ground-water-flow models were constructed with the computer program MODFLOW to simulate flow in surficial sand and gravel aquifers along the M
Authors
J. F. Ruhl, T.K. Cowdery
By
Water Resources Mission Area, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Comparison of two methods for delineating land use near monitoring wells used for assessing quality of shallow ground water

Two methods were compared for delineating land use near shallow monitoring wells. These wells were used to assess the effects of agricultural cropland on the quality of recently recharged ground water in two sand and gravel aquifers located near land surface. The two methods for delineating land use near wells were (1) the sector method, which used potentiometric-surface maps to estimate average f
Authors
D. L. Lorenz, R. M. Goldstein, T.K. Cowdery, J. D. Stoner
By
Water Resources Mission Area, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Transport and fate of nitrate in a glacial outwash aquifer in relation to ground water age, land use practices, and redox processes

A combination of ground water modeling, chemical and dissolved gas analyses, and chlorofluorocarbon age dating of water was used to determine the relation between changes in agricultural practices, and NO−3 concentrations in ground water of a glacial outwash aquifer in west-central Minnesota. The results revealed a redox zonation throughout the saturated zone with oxygen reduction occurring near t
Authors
Larry J. Puckett, Timothy K. Cowdery
By
Water Resources Mission Area

Using chemical, hydrologic, and age dating analysis to delineate redox processes and flow paths in the riparian zone of a glacial outwash aquifer‐stream system

A combination of chemical and dissolved gas analyses, chlorofluorocarbon age dating, and hydrologic measurements were used to determine the degree to which biogeochemical processes in a riparian wetland were responsible for removing NO3−from groundwaters discharging to the Otter Tail River in west central Minnesota. An analysis of river chemistry and flow data revealed that NO3− concentrations in
Authors
Larry J. Puckett, Timothy K. Cowdery, Peter B. McMahon, Lan H. Tornes, Jeffrey D. Stoner
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Lake Superior from Bare Bluff

Monitoring and Analysis of Water Resources with Fond du Lac Band of Lake Superior Chippewa

The USGS has partnered with the Fond du Lac Band in monitoring and investigations since 2006 to collect, interpret and publish information needed to manage water levels and restore wetlands for wild rice production. Initial work included a streamgage and a report describing aquifer properties. New investigations include groundwater and surface-water modelling of the St Louis River Basin.
By
Upper Midwest Water Science Center
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Monitoring and Analysis of Water Resources with Fond du Lac Band of Lake Superior Chippewa

The USGS has partnered with the Fond du Lac Band in monitoring and investigations since 2006 to collect, interpret and publish information needed to manage water levels and restore wetlands for wild rice production. Initial work included a streamgage and a report describing aquifer properties. New investigations include groundwater and surface-water modelling of the St Louis River Basin.
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Photo of the discharge from an aquifer pumping test

Groundwater monitoring and research

Groundwater is an important water resource. The USGS collects information on the quality and quantity of groundwater and conducts advanced modeling of groundwater flow and groundwater/surface-water systems. The USGS also evaluates the effects of water-use, land-use, and climate change on groundwater, surface-water, and the ecosystems that rely on them.
By
Upper Midwest Water Science Center
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Groundwater monitoring and research

Groundwater is an important water resource. The USGS collects information on the quality and quantity of groundwater and conducts advanced modeling of groundwater flow and groundwater/surface-water systems. The USGS also evaluates the effects of water-use, land-use, and climate change on groundwater, surface-water, and the ecosystems that rely on them.
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St. Louis River, looking downstream from County Highway 52 bridge crossing.

Assessing Hydrologic Changes in the St. Louis River Basin from Past Land Uses

Resource managers can use assessments of past and future land use to make science-based decisions. This project characterizes how changes in land use can change groundwater and surface-water flows in the St. Louis River Basin, MN. The USGS is constructing a set of groundwater models to simulate groundwater/surface-water interactions and evaluate how water flows have changed.
By
Upper Midwest Water Science Center
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Assessing Hydrologic Changes in the St. Louis River Basin from Past Land Uses

Resource managers can use assessments of past and future land use to make science-based decisions. This project characterizes how changes in land use can change groundwater and surface-water flows in the St. Louis River Basin, MN. The USGS is constructing a set of groundwater models to simulate groundwater/surface-water interactions and evaluate how water flows have changed.
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USGS Monitoring Well - Wetland and Prairie Restoration Hydrology Study Glacial Ridge National Wildlife Refuge, Mentor, MN

Continuous Groundwater Monitoring Network - Minnesota

This project monitors groundwater level, groundwater temperature and precipitation at hourly intervals at a long-term network of sites throughout Minnesota. These data are collected from surficial and buried aquifers and can be used to estimate groundwater recharge and assist water-availability assessments. Data are corrected to manual measurements at least twice per year and are available through...
By
Upper Midwest Water Science Center
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Continuous Groundwater Monitoring Network - Minnesota

This project monitors groundwater level, groundwater temperature and precipitation at hourly intervals at a long-term network of sites throughout Minnesota. These data are collected from surficial and buried aquifers and can be used to estimate groundwater recharge and assist water-availability assessments. Data are corrected to manual measurements at least twice per year and are available through...
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A Soil-Water-Balance model and precipitation data used for HEC/HMS modelling at the Glacial Ridge National Wildlife Refuge area, northwestern Minnesota, 2002-15.

A soil-water balance model (SWB) was developed to estimate evapotranspiration in six ditch basins of the Glacial Ridge National Wildlife Refuge area, northwestern Minnesota, during 2002-2015. The model was used to estimate evapotranspiration in water balances in six ditch basins as part of the associated report, U.S. Geological Survey Scientific Investigations Report 2019-5041 (http://dx.doi.org/1
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Science and Products

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government