Groundwater Modeling Software

AnAqSim (analytic aquifer simulator) is a groundwater modeling tool that can cover a range of needs from the simplest 2D capture zone simulation to moderately complex 3D and transient simulations.  It employs the analytic element method (AEM) in a unique way that allows fully transient modeling, multi-level aquifer systems, and anisotropy.


Dr. Charlie Fitts, author of AnAqSim and the textbook Groundwater Science, 2nd ed.,  has over 35 years experience with groundwater and geotechnical consulting, and is available for consulting on groundwater modeling projects.

AnAqSim Webinars in Spring 2018

Thank you to all who attended from all around the world!

Introduction to AnAqSim

One one-hour session, March 13

Read more.



AnAqSim in Depth

6 one-hour sessions, one per week, March 26-May 1

Read more.



Release 2018-1 posted 23 Feb 2018

Release 2018-1 is now available with these and other new features:

  • Plots can now display Analysis Inputs: hydrograph points, transient lines, graph conditions on line on plots
  • Reduced the occurrence of error messages when pressing Edit or Coordinates button in a new row of an input table
  • Starting radius for well pathlines is now always just 1.2x the well radius
  • Updated the CAD drawing component, which supports DWG 2018 format
  • Made it so if there are left/right errors with line boundaries, plots can still be drawn
  • Re-coded digitize ellipse algorithm so it is more accurate and spreads points more efficiently

Please see the release notes for a full list of new features.

AnAqSim (analytic aquifer simulator)


Gain more insight in less time

A quick alternative to MODFLOW and other numerical methods for modeling cases that range from simple to moderately complex.

Comprehensive capabilities

AnAqSim is the most versatile and capable analytic element method software:  multi-layer 3D systems, full transient capabilities, heterogeneity, anisotropy, fresh-salt interface aquifers, and a full suite of line boundary types.

Many uses

AnAqSim has been used to simulate groundwater remediation designs, mine and construction dewatering, infiltration mounding, regional aquifer flow, capture zones, well field impacts, fresh/salt interface flow in coastal aquifers, pathlines, advective transport, and embankment seepage.

Learn More

Featuresspecificationstutorials and videosUser Guide.


 Video overview of AnAqSim:

3-D Dewatering Example Model

Many users are solving transient construction and mining dewatering problems with AnAqSim, so we have created an example model to show how to create such models.  This model is of a construction dewatering system that includes a partially-penetrating sheet pile barrier, three partially-penetrating wells within the barrier, and a recharge trench outside the barrier where well discharge is injected back into the aquifer.  The model has 7 layers in the system area and is transient with two phases of pumping. See the model and its results and download the model files.

Join the Ranks of AnAqSim Users (below is a small sample of them)

Aurora Water
CDM Smith
Clifton Associates
Dartmouth College
Dresdner Robin

Drumlin Environmental
Geowater Consulting
Golder Associates

Jacobs Engineering
Knight Piesold
Louis Berger
McLane Environmental
Pando Australia
Pontificia Universidad Javeriana
RDR Consultants

Rio Tinto
Telesto Solutions
Tetra Tech
University of New South Wales
University of Western Australia
Woodard and Curran
WSP Group
WSP Parsons Brinckerhoff