Integrated Urban Water Modeling Platform

At a Glance

Researchers at Colorado State University have developed and demonstrated The Integrated Urban Water Model (IUWM) web tool for forecasting urban water demand with options to assess effects of water conservation and reuse, climate change, population growth, and land use change.

The IUWM is available online here on the eRAMS platform as an example.
Greater and customized capabilities of the IUWM system for developers are available for license.


The state-of-the-art modeling and analysis tool, The Integrated Urban Water Model (IUWM), enables the forecasting of urban water demand and assessment of demand management scenarios under varying scenarios of population growth, land use change and climate change in addition to water conservation and reuse strategies.

IUWM is a mass balance model (Figure 1) that simulates water demand and waste water production associated with urban water demand management strategies (

Demands are projected for residential indoor, commercial, industrial, and intuitional (CII) indoor and outdoor uses separately. Strategies included in IUWM include wastewater reuse, graywater reuse, indoor conservation, urban irrigation conservation and storm water capture and use.

The user selects an area, identifies water management scenarios to evaluate and then is provided with outputs such as demand for municipal potable water and wastewater production. The model is geographical information system (GIS) interfaced and simulates water demands and savings through use of demographic, land cover, and climate data via either nationally available databases or user uploaded data. The model works on a daily timestep and is readily applied from the block to municipal scale.


Water Conservation and Reuse Scenarios: A key element to assess vulnerability of water systems is to evaluate the impact that water conservation and reuse strategies have on water demand projections.  IUWM includes explicit options for evaluate of indoor conservation fixtures, irrigation conservation and use of alternative water sources (i.e. wastewater, graywater, and storm water).  Indoor water conservation can be modeled on a fixture basis based on performance of high efficiency fixtures.  Outdoor irrigation conservation is estimated based on several parameters that represent irrigation behaviors, e.g. percentage of evapotranspiration met during irrigation, efficiency of irrigation system and type of landscape (e.g. turfgrass, xeriscape, etc.).  A unique feature of IUWM is its ability to simulate various source water (wastewater, graywater, and stormwater) and end use (irrigation, toilet flushing and potable) combinations.  Each water source modeled can be used for any potable or non-potable end use to estimate demand reduction potential associated with multiple source water end use combinations.

Urban Growth and Development Scenarios: IUWM has two options for running scenarios of population and land use change.  The first option is the ability to select projections within the interface for changes as a percentage increase or decrease in population, number of household, and land use (i.e. percentage change in area that is open space, low density, medium density, and high density).  This enables a user to apply a change that occurs evenly throughout their service area and evaluate impact to water use.  Another option that enables running of scenarios of population growth and land use change specific to subunits (e.g. blocks, block groups, or tract) is to upload projected values for population, number of households and land use type into the subunit table.  This enables data associated with any specific subunit to be uploaded into a table based on the geographical identification for that subunit so that scenarios of population and land use changes in each subunit can be run.

Climate Scenarios: IUWM includes options to evaluate alternate climate scenarios.  The user can specify both a temperature and precipitation offset to be applied to the historical climate dataset or can upload a file of projected climate.  These features enable ready analysis of multiple scenarios of climate change and impacts to water demand.


  • Demonstrated successfully to various water utility companies, consultants, and water managers (e.g. Denver Water)
  • Includes explicit options for projections of water demand under varying scenarios
  • Model is deployed as an accessible, platform independent, online tool with GIS capabilities
  • Developed to be readily applied across spatial and temporal scales, enabling specification of model parameters, dependent on the user’s goals
  • Allows for alternative water sources (graywater, storm water, and treated wastewater)


  • Water Utility Companies
  • Water Resource Managers
  • Consulting firms in the area of water resource management

IUWM supports decisions on water conservation and reuse practices to promote in a particular area and enables users to project multiple scenarios of future water use, thus guiding decisions for water supply planning.

Last Updated: October 2020

Available for Non-Exclusive License (Research and Business Models Available)
Open to Collaboration

IP Status

Copyright / Software


Sybil Sharvelle
Larry Roesner
Mazdak Arabi
Brad Reichel
Andre Dozier

Reference Number
Licensing Manager

Jillian Lang