Provides a disaggregated estimate of the current and future municipal and industrial demand for water for a given study area. Water demands are estimated by sectors such as single-family residential, multifamily residential, commercial, manufacturing, and government. The water demands of each sector are expressed as a product of the number of users (housing units, employees) and the average rate of water use per household or per employee as determined by a set of explanatory variables for each sector.

The conservation component of IWR-MAIN provides estimates of water savings from passive, active, and emergency conservation programs. Conservation savings estimates are generated by sector and by twenty different end uses of water. The water savings are incorporated into long-term forecasts of water demand for the study area. The benefit-cost component of IWR-MAIN uses a number of economic feasibility tests to evaluate the economic merits of conservation programs. The results of the benefit-cost analysis can be used in comparing supply augmentation and demand management alternatives. Once the water planner has conducted the initial analysis of water use, conservation, or benefits and cost, IWR-MAIN provides the ability to conduct numerous sensitivity analyses to examine the impact of changes in socioeconomic conditions, weather, water pricing, or conservation programs upon long-term water demands.


water demand analysis, municipal and industrial water demand, water conservation, water resource planning



Expertise Required

Documentation is provided in the User's Manual, training and technical assistance are available.


50 water authorities, utilities, state water resource offices, USGS offices, and Army Corps of Engineers District offices.


Water resource planners working for water utilities, state or federal agencies.


Socioeconomic data, weather data, and water and wastewater pricing for the user defined study area may be required depending upon the type of model the user selects for each sector. To verify and calibrate water use models, additional data regarding local water use patterns are required. Context-sensitive help provided.


Monthly, annual, and maximum-day water use forecasts by sector with and without conservation savings. Conservation savings by sector, end use, and conservation program. Net present value, benefit-cost ratio, discounted payback period, levelized cost, and life-cycle revenue impact of conservation programs from five different perspectives. Standard report formats, state-of-the-art graphing capabilities exporting to a variety of other software formats.

Computer Platform

Pentium PC with Windows 95, 98, NT 4.0, or higher. Requires at least 16 MB RAM, 40 MB disk space, 640x480 VGA, CD-ROM.

Programming Language



IWR-MAIN provides water demand forecasts disaggregated by sector and time periods. Forecasting models may be simple or complex depending upon data availability. Many factors affecting water demand, such as household income, persons per household, weather, water and wastewater rates, housing and employment projections, and conservation programs, can be changed to assess the impacts of alternative scenarios upon future water demands.


The level of forecast model verification is dependent upon the detail of water use data available in the given study area.



Planning and Management Consultants, Ltd.


6352 South U.S. Highway 51
P.O. Box 1316
Carbondale, Illinois 62903
United States


(618) 549-2832


(618) 529-3188






Software Suite with User's Manual is $1,995. Specialized on-site training available.