The final type of navigation dam operations is combining hinge point control with both a minimum and maximum limit on the water surface at the dam. This editor has a third button as shown in the figures below.

The minimum and maximum pool controls are treated as separate control points even though they are both located immediately upstream of the dam. They each have a full set of target water surfaces and Flow Factors. The program will compute a desired flow for each control point. Therefore, there will be a flow based on the hinge point targets, a flow based on the minimum pool elevation, and a flow based on the maximum pool elevation. During normal operations, the flow will be based on the hinge point target. However, the desired flow will not be allowed to go below the minimum pool control flow and it will not be allowed to go above the maximum pool control flow.
Having separate control points for the minimum and maximum control allows a smooth transition between pool control (either high or low) and hinge control for a full range of flows. It also provides the greatest control and sensitivity for allowing the water surface at the pool to be maintained within the tightest tolerances.

The optional steady profile limits table may still be used. As before, it only applies to hinge control.

Figure 14 34. Navigation Editor with Hinge and Maximum and Minimum Control (Min Pool Control Shown)



Figure 14 35. Navigation Editor with Hinge and Minimum and Maximum Control (Max Pool Control Shown)