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:

AnAqSim In Depth Webinar Series April and May 2019

We’ve had a good running of the series in spring 2019 with 61 attendees – thank you!  Follow the link below and go to the bottom of the page if you want to be notified of future training opportunities.

The webinar series covers all key aspects of AnAqSim and helps you become a power user.  There is one one-hour session per week for 6 weeks.  Each session has segments of  presentation, software demonstration, and Q&A, plus optional home exercises.  Learn AnAqSim, which is quick, easy to use, and far more capable than other analytic element programs.  Details, registration.

Use PEST with AnAqSim

Several AnAqSim users are using PEST (parameter estimation software) to automate calibration and optimization of AnAqSim models.  AnAqSim’s command line mode and text outputs allow you to solve a wide range of parameter optimzation problems such as

  • find aquifer parameters and recharge rates that best fit observed heads and discharges,
  • find optimal well locations and discharges that will capture contaminant plumes with a minimum of discharge, and
  • find optimal well discharges through time to meet dewatering criteria.

Read more and explore two example PEST runs created by AnAqSim users.

Release 2019-1 posted 4 February 2019

Release 2019-1 includes the following new features plus other enhancements and fixes.

  • Add ability to output Excel file with all model inputs
  • Popup labels for curves in chart plots
  • Changed color palette on charts so adjacent curves are easier to distinguish
  • Add Head Above – Head to cursor data displayed to left of plot
  • Streamline plot-making, with one MakePlot menu item with current layer, time step settings, another allows you to choose layer, time
  • Add calibration points where simulated velocity and direction are compared to observed. Add these results to calibration plot and text output
  • Use parallel processing to speed up creating of contours and pathlines in plots
  • Add analysis feature that writes the number of captured pathlines to run log, and include this in automated run outputs

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

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
Barr Engineering
Calif. Dept. of Toxic Subst. Control
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
So. Florida Water Mgmt. District
Telesto Solutions
Tetra Tech
University of New South Wales
University of Western Australia
Woodard and Curran
WSP Group
WSP Parsons Brinckerhoff


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.