Maximum order constraints are operated to share the available channel capacity defined for a constraint at a point in a river system. In the ordering phase, when the amount of ordered water expected (ie. forecast) to flow down the river past a maximum order constraint is more than the constraint, then the specified orders are reduced. If orders are less than the value specified by the constraint, no adjustment is made. In the flow phase, orders cannot be adjusted, so where the actual amount of water flowing down the river past a maximum order constraint is greater than forecasted, the constraint may be exceeded.
Figure 1. Maximum Order Constraint node
The maximum order constraint can be specified as a single value, or via a function using the Function Editor. When ownership is enabled, you can define a sharing hierarchy to control how the constraint is apportioned between downstream owners (Ownership).