IWR-MAIN was initially public-domain software distributed by the Corps, up through verison 5.1 in 1987. With the release of version 6.0 in 1994, the copyright was transferred to Planning and Management Consultants, Ltd. (PMCL, now CDM Smith). Versions 5.1, 6.0 and 6.1 all operated on DOS operating systems. In 1999, PMCL released the Windows Version of IWR-MAIN, which remains the most recent version of the software. In the 1990s and 2000s, the IWR-MAIN software was used extensively and often reported in water resources citations. Thus, literature and internet searches for water demand forecasting software result in citations of IWR-MAIN.
In 2003, PMCL was acquired by CDM Smith. We continue to utilize the basic concepts of IWR-MAIN, but typically develop customized Microsoft Excel spreadsheet models for individual clients that address the unique attributes of each client water service area. The advances in Microsoft Excel allow us to develop water forecast models that easily link to input data, can be customized to multiple geographic areas, provides good quality graphics and exportable output, and can include Visual Basic user interfaces if requested by the clients. These customized models can be developed more efficiently than formatting data for manual input into IWR-MAIN, configuring models to work within the IWR-MAIN structure, and exporting output to more up-to-date graphing and reporting formats. Typically, we work with clients to review: (1) their project objectives and goals, (2) the available data, and (3) the resources for the project. Given these three criteria, we develop a water demand forecast approach, and model, that utilizes the available data to meet the objectives within the resources constraint.
The most recent (1999) version of IWR-MAIN is designed for both Windows95, Windows98, and WindowsNT platforms for use in developing water demand forecasts and evaluating water conservation programs. The Water Demand Management Suite includes two stand-alone software programs, Forecast Manager and Conservation Manager.