Groundwater Model Workshop
Introduction to Building and Running Groundwater Models
Workshop Description
This course will give students knowledge necessary for setting up, executing and using groundwater models. The half-day workshop will focus on using the use of groundwater models to model groundwater flow and transport. The groundwater model MODFLOW will be used as the primary modeling tool, but other surface water and groundwater models will be discussed. Students will be guided through example models using accessible files. Discussion of calibration of groundwater models and other more advanced topics will be included.
Who should attend:
- Practicing hydrologists
- Civil and water resources engineers
- Students interested in expanding their modeling toolkit beyond traditional approaches.
Instructor:
Nathan Miller & Justin Clark
Time / Date:
September 9, 2026, 12:30 PM to 4:30 PM
Location:
City of Flagstaff Water Services, 2323 Walgreens Street, Suite 100 Flagstaff, AZ 86004
Free parking, park on south side of building and enter through double doors
Limit:
20 people (first-come, first-served)
Cost:
See below; Early Bird pricing ends August 12th
PDHs:
4
Course Outline
Modeling Overview – modeling terminology, model types, groundwater model usage and justification, MODFLOW versions, and examples of Arizona groundwater flow models
MODFLOW Examples – hands-on use of seven test different test models
MODFLOW Data Extraction and Visualization – extracting data from list, heads, and budget files; introduction to FloPy; connecting model output to maps
Advanced Topics – particle tracking (MODPATH) and contaminant transport (MT3D), 3D visualization techniques, integrated surface water–groundwater modeling, and model calibration using PEST
Course Requirements:
Participants must bring:
- Laptop (Windows recommended; macOS or Linux supported upon request)
- Your favorite text editor installed (TextPad preferred)
- Microsoft Excel (preferred) or Google Sheets
Provided by Instructors:
- Example model files, input data, and exercise materials – no prior modeling experience required • GitHub repository: https://github.com/JustinClarkHydrologist/AHS-Intro-to-Modeling-Course
- Command Line usage tutorial, provided in GitHub repository. To be completed before course
Instructor Nathan Miller
Nathan Miller is a graduate of the University of Arizona and serves as the Corporate Board President of the Arizona Hydrological Society. Nathan has worked in the consulting business in Arizona since 1999. In his current role as Vice President – Groundwater Modeling Services for Matrix New World Engineering he leads the Arizona team and directs groundwater modeling services for the company. Mr. Miller combines his technical proficiency in hydrogeology and groundwater modeling with an understanding of Arizona’s key regulatory policies affecting the use of groundwater to serve municipalities, water utilities, developers, and regulatory agencies. Mr. Miller serves as technical lead and primary interface for several high-profile groundwater resources investigations
Contact: [email protected]
Instructor Justin Clark
Justin Clark is a groundwater hydrogeologist with 13 years of experience specializing in groundwater modeling, geochemistry, and environmental data analysis. His expertise includes model calibration, sensitivity and uncertainty analyses, and developing tools for processing large environmental datasets. He earned a bachelor’s degree from the University of Arizona and a master’s degree from the University of Waterloo. In his current role as Senior Hydrogeologist at Luhdorff & Scalmanini he applies advanced modeling and data analysis to provide actionable insights for groundwater resource management.
Contact: [email protected]