An official website of the United States government.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Capture Zone Analytic Element Model (CZAEM)

CZAEM, or Capture Zone Analytic Element Model, is a single-layer model for simulating steady flow in homogeneous aquifers using the Analytic Element Method. It serves as a tool in the wellhead protection decision making process by delineating groundwater capture zones and isochrones of residence times. CZAEM supports a limited number of analytic elements that can accommodate fairly realistic boundary conditions, such as streams, lakes, and aquifer recharge due to precipitation. CZAEM generates output on groundwater capture zones and residence times. The model accurately defines capture zone boundaries by first determining all stagnation points and dividing streamlines in the flow domain.

Version 1.1
Release Date August 1996
Development Status General Release
Operating System Dos

Minimum System Requirements


  • IBM PC/AT or compatible
  • Microsoft PS/2 or compatible mouse device
  • At least 1.5 MB of available extended memory
  • At least 2 MB of available hard-disk space


  • MS/PC DOS version 5.0 (or higher)
  • DOS extender bound with CZAEM.EXE (provided)
  • ANSI.SYS driver (supplied with DOS)


Program and Installation Files (ZIP)(422 K)

US EPA. (1994) "CZAEM User's Guide, Modeling Capture Zones of Ground Water Wells Using Analytic Elements." Publication No. EPA/600/R-94/174.

US EPA. (1995) "Demonstration of the Analytic Element for Wellhead Protection - Project Summary." Publication No. EPA/600/SR-94/210.

Installation Instructions

To download and install CZAEM, the following procedures must be followed:

  1. Refer to the user's manual for further instructions.
  2. Download the program and installation files.
  3. After the download is complete, unzip the program and installation files into a new directory called CZAEM on your hard drive.
  4. CZAEM.EXE will start the program in a DOS window.