WaterSim 5.0

WaterSim 5.0 represents an adaptation and upgrade of WaterSim 4.0 for stakeholders, researchers and educators.

The current version incorporates the water portfolios for 33 water providers that vary in size from small municipalities to major metropolitan communities. WaterSim 5.0 runs on an annual time-step where simulations can be interrupted annually by the interface enabling runtime changes to policy levers or input specifications. Model downloads and documentation can be found in related sub-directions on this site.

Coming Soon: New WaterSim Accessibility

DCDC created the WaterSim model to estimate water supply and water demand to examine water sustainability as influenced by water policy, water use, and population growth. WaterSim is a systems dynamics model for the Phoenix Metropolitan Area. This water policy and planning model permits evaluation of policy and governance on water supply, water demand, and water use as influenced by population, per capita water consumption, and climate change and drought for the Phoenix Metropolitan Area. Learn more about the new WaterSim user interface.


The Phoenix Metropolitan Area receives its water from many sources including surface water from the Colorado river, Salt-Verde Rivers, groundwater, and water reuse. Arizona’s share of Colorado River water is managed by the Central Arizona Project (CAP), which is conveyed along a 336 mile aqueduct that originates at Lake Havasu on the Arizona-California border and terminates in Tucson.

Other local rivers supply the Phoenix area with surface water. These rivers are the Salt, Tonto, and Verde which together are managed by the Salt River Project (SRP).

Groundwater found in aquifers is also an important source of water for the Phoenix area. Not every city and community receives the same mixtures of these water supplies, so the amount of groundwater versus CAP water versus SRP water depends on where you live.

The supply of Salt-Verde River’s are dependent on the demands on the collective use by individuals, population, industry, and agriculture. Learn more about the new WaterSim user interface.

Development Background

WaterSim 3.0, implemented in Powersim is the version used for WaterSim on the Web. This version was developed to analyze the potential effects of future climatic conditions, population growth, land-use change, and policy options on water supply and water demand for Maricopa County, Arizona. Gober et al. (2011) used the model to examine potential climate change impacts on residential consumptive use under various climate change and policy-driven scenarios. Annual outputs from the model generally focus on the total amount of groundwater drawdown over a simulation period and gallons per capita per day (GPCD) forecast for residential users at the metro-wide scale.

The Decision Theater and the Web Version of WaterSim were developed in PowerSim. This allowed development in a visual model building tool, but this limited use of the model and to some extent its complexity. Version 4.0 of the model was rebuilt in a Fortran model.

Version 5.0

Version 5.0 includes modifications to the Fortran to expand the number of urban water system components with a C# application interface that makes the model usable by anyone using a Windows .Net platform. This version of the model includes spatially explicit system urban system models for 33 of the water providers within the region that allows systems and policy modeling of each water provider. Working with local water resource manager the model was developed with a number of system and water resource management options not implemented in the PowerSim version. The provider urban models include groundwater, surface water, wastewater, reclaimed water, banked water, and aquifer recharge.

There is currently no visual interface to this model. An application programming interface (API) that can be used with Visual Basic or C# in a .Net managed framework is provided. This API provides access to read and set model parameters, run the model in year increments, and output model results into a database. Assemblies for the interface and a DLL for the model are provided. Source code for an application that implements a simplified visual interface to the model is provided as an example of using the API.


Would you like to be informed of updates? Contact us! Questions and comments are welcome.

WaterSim: Dr. David A. Sampson
API: Dr. Ray Quay