Elevation Target overrides act as an override to the reservoir's guide curve. But, more than that, they short-circuit the reservoir's release decision logic—for each timestep that has an elevation target override, all reservoir operation rules and IF_Blocks are ignored and the reservoir decision logic follows only guide curve operation using the elevation target override as the guide curve objective and constrained only by physical capacity. Elevation Target overrides can be useful for lock & dam operation, hinge pool operation, or to assist in modeling unusual real-time situations where the operation of the pool is more important than the releases.

Configuring an Elevation Target Override Variable

To configure an OSI variable as an Elevation Target override:

  • Select Add Variable from the Edit menu to create a new OSI variable.

  • Give the variable a name and click OK in the New Variable dialog. The OSI Variable Editor will open ("Figure: OSI Variable Editor—Configured for an Elevation Target Override").

    Figure: OSI Variable Editor—Configured for an Elevation Target Override


  • Select Reservoir as the Element Type.
  • Select the reservoir from the Element list.

  • Select Elevation Target as the variable Type.

  • If your reservoir has constant minimum and/or maximum pool limits and you would like to see those limits in the plot, enter those limits in the Min Target and Max Target fields.
  • Consider adding key reservoir output time series to the plot with your pool elevation; we decided to add pool inflow and outflow as well as one or more key zone elevations. To do so, use the Add button to open the Independent Variable Definition dialog. Use it to select each time series you want to include in the plot with your release.
  • When finished, click the OK button to close the OSI Variable Editor.