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Timothy Cowdery

Hydro Geologist

Contact Info

Short Biography

Tim Cowdery has been a hydrogeologist with the U.S. Geological Survey in Minnesota since 1991.  He graduated with a BA in Geology from Carleton College in Minnesota and with a MS in Hydrogeology from the University of Minnesota.  During his time at the USGS, Tim has managed many groundwater investigation projects focusing on groundwater quality, groundwater/surface-water interaction, quantification of groundwater flows, and numerical groundwater modeling.  Tim has extensive experience in collecting continuous groundwater hydrographs, including both instrumentation and data-acquisition and correction automation.  His interests also include graphical presention of scientific ideas and graphical design.

Tim Cowdery is a hydrogeologist with the U.S. Geological Survey in Mounds View, Minnesota. He currently serves as a chief for several projects at the Water-Science Center in Minnesota. He earned a master's degree from the University of Minnesota in groundwater geology in 1997.  His research  interests include groundwater/surface-water interactions, numerical groundwater modeling, and groundwater recharge analysis, and glacial geology.

Tim joined the USGS in 1992 as the groundwater specialist for the Red River of the North National Water-Quality Assessment, conducting groundwater-quality research at many spatial scales in that basin.  He has designed and executed to two groundwater modeling studies at local and regional scales  in southwestern Minnesota and in the southern Twin Cities Metropolitan area.  He has developed systems for automated groundwater data collection, telemetry, and processing and has used these data to estimate the spatial and temporal variability of groundwater recharge.

Since 2002, Tim has managed the Glacial Ridge Hydrologic Assessment, a groundwater/surface water interaction study that documents changes in the hydrology of a large area in northwestern Minnesota undergoing extensive wetland and prairie restorations.  This project is documenting changes in hydrologic flows and quality resulting from the restorations.  He continues to manage several other projects involving groundwater modeling, water-quality sampling, groundwater recharge, and continuous groundwater level measurement.


Cowdery, T.K. and Brigham, M.E., 2013, Mercury in wetlands at the Glacial Ridge National Wildlife Refuge, northwestern Minnesota, 2007-9, U.S. Geological Survey Scientific Investigations Report 2013–5068, 17 p. [Link]

McMahon, P. B.; Cowdery, T. K.; Chapelle, F. H.; Jurgens, B. C., 2009. Redox Conditions in Selected Principal Aquifers of the United States. U.S. Geological Survey Fact Sheet 2009-3041, 6 p. [Link]

Cowdery, Timothy K.; Lorenz, David L.; Arntson, Allan D., 2008. Hydrology Prior to Wetland and Prairie Restoration in and around the Glacial Ridge National Wildlife Refuge, Northwestern Minnesota, 2002-5. Geological Survey (U.S.) Scientific Investigations Report 2007-5200, vi, 68 p. [Link]

Cowdery, Timothy K., 2005. Hydrogeology and ground-water/surface water interactions in the Des Moines River valley, southwestern Minnesota, 1997-2001. Scientific Investigations Report 2005-5219, viii, 51 p. [Link]

Ruhl, J. F.; Cowdery, T. K., 2004. Regional ground-water-flow models of surficial sand and gravel aquifers along the Mississippi River between Brainerd and St. Cloud, central Minnesota. Scientific Investigations Report 2004-5087, 26 p. [Link]

Lorenz, D. L.; Goldstein, R. M.; Cowdery, T. K.; Stoner, J. D., 2003. Comparison of two methods for delineating land use near monitoring wells used for assessing quality of shallow ground water. Water-Resources Investigations Report 2003-4067, vi, 13 p. : ill. (some col.), maps ; 28 cm. [Link]

Puckett, Larry J., Cowdery, Timothy K., 2002. Transport and fate of nitrate in a glacial outwash aquifer in relation to ground water age, land use practices, and redox processes: Journal of Environmental Quality, 31 (3), p. 782-796, illus. incl. 6 tables. [Link]

Puckett, Larry J., Cowdery, Timothy K., McMahon, Peter B., Tornes, Lan H., Stoner, Jeffrey D., 2002. 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: Water Resources Research, 38 (8), p. 20, illus. incl. 5 tables, sketch map. [Link]

Cowdery, Timothy K., 1999. Water resources of the Prairie Island Indian Reservation, Minnesota, 1994-97. U.S. Dept. of the Interior, U.S. Geological Survey ; Branch of Information Services [distributor], Water-Resources Investigations Report 99-4069, iv, 36 p. :ill., maps ;28 cm. +1 computer disk (3 1/2 in.)

Puckett, Larry J., Cowdery, Timothy K., Lorenz, David L., Stoner, Jeffrey D., 1999. Estimation of nitrate contamination of an agro-ecosystem outwash aquifer using a nitrogen mass-balance budget: Journal of Environmental Quality, 28 (6), p. 2015-2025, illus. incl. 5 tables, sketch maps. [Link]

Trotta, L. C.; Cowdery, T. K., 1998. Ground water resources of the Mille Lacs Lake area, east-central Minnesota. U.S. Geological Survey ; Branch of Information Services [distributor], Water-Resources Investigations Report 97-4116, iv, 29 p. :ill., maps ;28 cm.

Cowdery, T. K., 1998. Ground-water quality in the Red River of the North Basin, Minnesota and North Dakota, 1991-95. U.S. Dept. of the Interior, U.S. Geological Survey ; Branch of Information Services [distributor], Water-Resources Investigations Report 98-4175, vi, 15 p. :ill., map ;28 cm.

Stoner, Jeffrey D.; Lorenz, D. L.; Goldstein, R. M.; Brigham, M. E.; Cowdery, T. K. , 1998. Water quality in the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1992-95. U.S. Geological Survey, Circular 1169, 33 p. [Link]

Stoner, J. D.; Cowdery, T. K.; Puckett, L. J., 1997. Ground-water age dating and other tools used to assess land-use effects on water quality. U.S. Geological Survey, Water-Resources Investigations Report 97-4150, 1 folded sheet (6 p.) :col. ill., col. maps ;28 cm. [PGS - 5 p.]

Cowdery, Timothy K., 1997. Shallow Ground-Water Quality Beneath Cropland in the Red River of the North Basin, Minnesota and North Dakota, 1993-95. U.S. Geological Survey Water-Resources Investigations Report 97-4001, vii, 52 p.

Cowdery, T. K., 1995. Similar agricultural areas, different ground-water quality, Red River of the North Basin, 1993-95. U.S. Geological Survey, Open-File Report 95-441, 4 p. :col. ill., col. maps ;28 cm.


My Science Topics

Science Topic
Water Resourcesaquifers
Water Resourcesground water
Water Resourcesground-water quality
Techniques and Methodsmathematical modeling
Water Resourcesmovement and recharge
Water Resourceswater budget
Water Resourceswater quality
Hydrologic Processesground-water flow
Hydrologic Processesground-water level
Hydrologic Processeshydrology
Techniques and Methodsreal-time monitoring and reporting
Hydrologic Processeswater cycle


Image of Current Focus for Hydrogeology
  • Quantification of groundwater flows
  • Groundwater/surface-water interactions
  • Numerical groundwater modeling
  • Groundwater quality
  • Collection of continuous groundwater data
  • Glacial geology
  • Graphical design


  • 1983–present:  Sigma Xi, The Scientific Research Society.
  • 1988–present:  Geological Society of America.
  • 1998–2006:     Licensed Professional Geologist, State of Minnesota.

Contact Information

Timothy Cowdery
2270 Woodale Drive
Mounds View, MN 55112
763-783-3103 - Fax
612-805-8124 - Mobile
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