By default, in the Cells/Layers tab, the water quality cell length is set to Use Defined RAS Cross Sections Spacing. To modify the default setting and adjust the cell length by reach or globally:

  1. In the Geometry Editor, go to the Cells/Layers tab.
  2. In the Cell Length panel, select the Adjust Cell Lengths radio button to enable the Edit button.
  3. Click the Edit button to open the Cell Length Editor (Geometry Editor – Cells/Layers Tab – Cell Length Editor).


Geometry Editor – Cells/Layers Tab – Cell Length Editor

In the Cell Length Editor, two options exist for modifying the cell lengths (in feet or meters, depending on the watershed units of measure and display units):

  1. Global Cell Length Limits – Sets a global minimum and maximum cell length for all reaches in the geometry dataset.
  2. Value by Reach – Sets a minimum and/or maximum cell length value for individual reaches (selected by default).

To enter a minimum and maximum cell length by ResSim reach:

  • Select the Value by Reach radio button.
  • In the Value by Reach table, enter the minimum and maximum lengths in the Minimum and Maximum columns.
  • Empty cells in the table will default to the water quality cell lengths.

To set a global minimum and maximum cell length for all reaches:

  • Select the Global Cell Length Limits radio button.
  • Enter the minimum and maximum lengths in the Minimum and Maximum fields.

Click OK to save the changes and close the Cell Length Editor. Alternatively, click Cancel to close without saving changes.

To view the changes to the HEC-ResSim water quality cells:

  • In the Geometry Editor, click Apply.
  • View the changes in the map window of the ResSim main window. Zoom to the reach of interest using the Zoom Tool  on the Toolbar, or from the Extent or Connections tabs in the Geometry Editor (refer to Geometry Editor – Extent Tab or Geometry Editor – Connections Tab, respectively), select the reach (e.g., Yoakim Bridge).