To view the river water quality cells placed between the cross-sections, by default, these cells are drawn in the map window schematic of the ResSim main window when the geometry is created. The riverine water quality cell length is set by the spacing of the HEC-RAS cross-sections (as shown in the HEC-ResSim Main Window – Geometry Dataset Displayed – Default Water Quality Cell Length – set by HEC-RAS Cross-Sections).
Figure 4.30 – HEC-ResSim Main Window – Geometry Dataset Displayed – Default Water Quality Cell Length – set by HEC-RAS Cross-Sections
By default, the WQ Reach Cells layer is displayed with alternating gray and blue shading to help distinguish individual cells. The HEC-RAS cross-sections are drawn below the reach water quality cells map layer by default (refer to Water Quality Layers and Layer Properties for more information on map layer properties).
To view the water quality cell length values set by the HEC-RAS cross-sections, go to the Geometry Editor and select the Cells/Layers tab. Click the Show Table of WQ Cells button. This will open the WQ Cell Length Table window (Geometry Editor – Cells/Layers Tab – WQ Cell Length Table – Example).
The WQ Cell Length Table features a navigation bar that allows you to view the table for "All Reaches" or for a specific reach name. The table lists the cell length for each associated ResSim reach and the corresponding HEC-RAS upstream and downstream cross-sections, as set in the Connections tab (refer to Geometry Editor – Connections Tab).
Geometry Editor – Cells/Layers Tab – WQ Cell Length Table – Example
Although the WQ Cell Length Table window does not allow for direct editing of cell lengths, it can remain open while you edit the water quality cell lengths in the Geometry Editor. To view any modifications to cell lengths, you must close and reopen the WQ Cell Length Table window.
Note: An asterisk 
next to a cross-section in the table indicates that the cross-section (identified by its river mile value) was interpolated either in HEC-RAS before being imported into the ResSim geometry dataset, or in ResSim by modifying the water quality cell length within the tool. For more details on cross-sections, refer to the HEC-RAS User's Manual.
The following sections will provide instructions for editing the default water quality cell lengths or reservoir layer heights.