About IWR-MAIN

The Institute for Water Resources – Municipal And Industrial Needs (IWR-MAIN) model was developed by the Corps of Engineers Institute for Water Resources based upon models of residential water demand developed by Howe & Linaweaver (1967) and Howe (1984), commercial water use coefficients developed by Boland (1985), and industrial water use coefficients developed by Planning and Management Consultants, Ltd. (PMCL, now a subsidiary of CDM).

PMCL (now CDM) developed the PC version of IWR-MAIN and added the conservation routine to the software in 1987 (Versions 4.0, 5.0 and 5.1). In 1994, PMCL released a new version of IWR-MAIN under copyright that included new residential water demand models based on Dziegielewski (1993), new commercial and industrial water use coefficients, a new end-use conservation model, and a benefit-cost analysis module for conservation measures (Versions 6.0 and 6.1). These versions continued to operate on the DOS platform.

In 1999, PMCL released the IWR-MAIN Water Demand Management Suite for Windows which eliminated the static water demand models and coefficients. Users of the IWR-MAIN software were required to provide user-specified model parameters, thus giving the software the maximum flexibility as a planning tool.

PMCL developed numerous custom applications of the IWR-MAIN software. CDM maintains this experience in custom applications through the staff in its Carbondale office.