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Andrew T Leaf

Andrew Leaf is a Hydrologist at the Upper Midwest Water Science Center.


  • groundwater flow modeling
  • simulation of groundwater-surface water interactions
  • model calibration / parameter estimation
  • application of GIS and the python programming language to hydrologic modeling and data analysis
  • distributed temperature sensing



  • Mississippi Alluvial Plain (MAP) Regional Water Availability Study

  • FloPy

  • Central Sands Lake Study

  • Coastal Lowlands Aquifer System Regional Groundwater Availability Study

  • rOpen - Open landscape nitrate retention mapping

  • Groundwater-surface water interactions in the Bad River Watershed, Wisconsin.
  • Field investigation of Haskell Lake water balance and subsurface lithology, Lac du Flambeau Reservation, WI.
  • Other project and science support, teaching, and outreach as requested



Reviewer for Groundwater, Water Resources Research, Geophysical Research Letters, Environmental Modeling and Software and various USGS publications.

2016 to present - Member, State of Wisconsin Groundwater Coordinating Council Research and Monitoring Subcommittee

2015 to present - American Water Resources Association Wisconsin Section Board (President Elect)



GW1774-Introduction to Python for Hydrologic Modeling - USGS course given to government and academic professionals, Feb 26-Mar 2, 2018, Lakewood, CO, Co-instructors: M.N. Fienen, J. D. Hughes, and C.D Langevin; April 4-8, 2016 Madison, WI. Co-instructors: M.N. Fienen and J. D. Hughes

General Python course given to DOI scientists at the California Volcano Observatory, Menlo Park, CA, July 25-28, 2017. Co-instructor: M.N. Fienen

Geospatial Python course given to DOI scientists at the Upper Midwest Environmental Science Center in La Crosse, WI, Nov. 15-17, 2017. Co-instructor: M.N. Fienen

Understanding and Evaluating Groundwater Flow Models course given to EPA and tribal environmental staff, March 8-9, 2015, Fond du Lac, MN and April 6-8, Chicago, IL. Co-instructors: D.T. Feinstein and R.J. Hunt.



Contributor to FloPy, SFRmaker and other open-source software projects for improving the quality, reproducibility and efficiency of hydrologic models (


Professional Experience

  • 2012 - present  Hydrologist, USGS Upper Midwest Water Science Center

  • 2010 - 2012  Hydrogeologist, SoundEarth Strategies, Inc., Seattle, WA

  • 2007 - 2010  Research/Teaching Assistant, University of Wisconsin-Madison, Dept. of Geoscience

Education and Certifications

  • M.S., Hydrogeology - University of Wisconsin-Madison, 2010

  • M.S., Water Resources Management - University of Wisconsin-Madison, 2010

  • B.A., Geology and History - Gustavus Adolphus College, 2005

Abstracts and Presentations

  • Leaf, A.; Breaker, B.; Adams, R.; Dietsch, B., 2018. Improving Numerical Simulation of Streams and Shallow Groundwater in the Mississippi Alluvial Plain, Mississippi Water Resources Conference, Jackson, MS, April 3-4.

  • Leaf, A.T., 2018. A Field Investigation of a Small Drainage Lake and Contamination Plume in Northern Wisconsin, AWRA – Wisconsin Section Annual Meeting, Appleton, WI, March 8-9.

  • Leaf, Andrew T., Hunt, R.J., Christiansen, D.E., and Haj, A.E., 2017, Promise and peril of calibrating a high resolution gridded regional watershed model, MODFLOW and More conference, Golden, CO, May 21-24, 2017.

  • Leaf, Andrew T., Fienen, M.N, White, J.T. and Hunt, R.J., 2017, Data worth analysis for optimizing data collection for groundwater models, Minnesota Groundwater Association Spring Conference, Minneapolis, MN, April 26.

  • Leaf, A.T., 2017, A Distributed Temperature Sensing Investigation to Inform Lakebed Pore-Water Sampling. AWRA – Wisconsin Section Annual Meeting, Elkhart Lake, WI, March 9-10.

  • Leaf, A.T., 2015, A program for rapidly building groundwater flow models. AWRA – Wisconsin Section Annual Meeting, Oconomowoc, WI, March 5-6.

  • Leaf, A.T., Gotkowitz, M.B. and Dunning, C.P., A groundwater flow model for Columbia County, Wisconsin. AWRA – Wisconsin Section Annual Meeting, Brookfield, WI, March 7-8, 2014.

  • Leaf, A.T., Hunt, R.J. and Fienen, M.N., Teaching concepts of non-uniqueness and uncertainty in groundwater. GSA Annual Meeting, Denver, CO. October 27-30, 2013.

  • Leaf, A.T., Fienen, M.N. and Hunt, R.J., Prediction uncertainty analysis to inform additional data collection. MODFLOW and More conference, Golden, CO, June 3-5, 2013.

  • Leaf, A.T., M.N. Fienen, and R.J. Hunt, Simulation of groundwater flow and groundwater/surface water interactions in the Bad River Watershed, Wisconsin, AWRA – Wisconsin Section Annual Meeting, Brookfield, WI, March 7-8, 2013.

  • Leaf, A.T., Hart, D.J. and Bahr, J.M., Single-well thermal tracer tests using distributed temperature sensing, GSA Annual Meeting, Denver, CO, October 31-November 3, 2010.

  • Leaf, A.T. and J.M. Bahr, Water quality changes during aquifer storage recovery in the Cambrian-Ordovician Aquifer, Oak Creek, WI, GSA Annual Meeting, Houston, TX, October 5-9, 2008. (Co-winner, Best Student Paper)

Science and Products