CRAM is a water resources model used to support decisions for short, medium and long-range planning of a system’s raw water supply. CRAM simulates all components of a system including reservoirs, water rights, wells, diversions, exchanges and more, through an intuitive drag and drop user interface. Whether your role is decision-maker, water resources manager, planner, engineer or accountant, CRAM will provide you with a more complete understanding of your water supply and demand, as well as how to optimize the use of this limited resource. CRAM is currently used by many cities, states and agencies throughout the United States for their water resources modeling and decision-making.

How it Works

CRAM uses priority-based assignments applied to the physical constraints of a system to properly allocate water according to past, present or future operations. CRAM operates within the familiar environment of Excel, so its easy to learn and use. CRAM’s interface allows users to build networks that represent real systems. The network is forced by hydrologic time series (flow) at a consistent time step.


  • Simulate municipal water supply
  • Evaluate changes in water demand
  • Evaluate the effects of capital improvement projects
  • Water allocation by water rights (prior appropriation)
  • Evaluate climate change scenarios
  • Manage water use within a watershed
  • Evaluate water rights
  • Simulate water resources facilities and their operations


  • Interactive user interface
  • Reservoir operations
  • Trans-basin diversions
  • Minimum flow requirements
  • Return flows
  • Groundwater
  • “What-If” scenario analysis

Model Benefits

  • Highly customizable
  • Cost effective
  • Reliability analysis

CRAM Projects

  • City of Aurora: Raw Water Supply Model
  • Oklahoma Water Resources Board: Basin Water Resources Planning
  • City of Boulder: Water Supply
  • Colorado River Basin Simulation
  • Bureau of Reclamation, Colorado Water Conservation Board and others : Gunnison Basin Planning Model

How to Get Started

Visit the Interactive CRAM Tool or our Water Congress 2020 Version to see how it works and find CRAM model documentation at Read the Docs ( For more information on CRAM, a white paper discussing the model and its applications can be found here:

Example CRAM Schematic