The CE-QUAL-W2 Model has been developed by the Water Quality Resources Group linked to Portland State University. DSI developed the pre- and post-processor for CE-QUAL-W2, called W2_Tool. W2_Tool comprises of W2_Control, for setting up the model and W2_Post, for post-processing of the model. Details of these components are outlined below and the package may be downloaded from Portland State after registering.

Capabilities of the CE-QUAL-W2 Model include:

  • Longitudinal-vertical hydrodynamics and water quality in stratified and non-stratified systems
  • Multiple algae, epiphyton/periphyton, zooplankton, macrophyte, CBOD, and generic water quality groups
  • Internal dynamic pipe/culvert model
  • Hydraulic structures (weirs, spillways)
  • Algorithms including for submerged and 2-way flow over submerged hydraulic structure
  • Dynamic shading algorithm based on topographic and vegetative cover.

Capabilities of W2_Control

The W2_Control GUI is able to aid the model user in setting up the Control File and in evaluating and changing the bathymetry of the system. This preprocessor does not automatically set-up the bathymetry of the system, nor does it provide post-processing support. A lot of effort is required to properly set-up the model bathymetry prior to using the Bathymetry editor within W2_Control.


Some of the post-processing capabilities in W2_Post include:

  1. Plan View Longitudinal Profiles by Branch
    • Normal View (i.e. using model input angles and widths)
    • Simple View (simplified block view of grid)
    • Line View
  2. Longitudinal Profiles by Branch
  3. Segment Profiles
  4. Cells colored by connection and type
  5. Google Earth KML, metafile and bitmap outputs


  1. Animations time interpolate model stored results (in the W2L file) to user specified interval to speed up/slow down animations.
  2. Compare up to four separate model runs within a single animation. Mix and match parameters.
  3. Up to four parameters from a single run can be animated.
  4. User control of min/max color ranges.
  5. User control of axis formats and types (i.e. segment/layer labels or distance/elevation units)


  1. View profile of any segment at any time (@ W2L intervals) for any parameter.
  2. Automatic comparison of model and measured data with various statistics.
  3. Various output formats.
  1. View any branch longitudinal profile for any constituent.
  2. Rapidly scroll through time.
  3. Color filled and/or line contours.
  4. Branch/Longitudinal Profile calibration statistics.
  5. Various output formats.


  1. Point and click interface to select cells to plot.
  2. Get a time series of any cell (if inundated) for any parameters for all or some of the modeled times.
  3. Wide range of graph formatting options.
  4. Various output options.
  1. View 2D velocity patters for any branch/longitudinal profile.
  2. Rapidly scroll through time.
  3. Various arrows formatting options.
  4. Various output formats.


  1. View 2D plan view concentrations at: Rapidly scroll through time
    • A specified layer
    • Top active layer for each segment
    • Volume weighted average for each segment
  2. Rapidly scroll through time.
  3. Use real world coordinates
  4. If the model is using UTM, then Google Earth KML export option is available