In Optimization, the Impulse Response method can now be selected for the Routing category on Reach objects. The formulation is the same as for simulation:

Outflow(t) = C0 Inflow(t) + C1 Inflow(t-1) + C2 Inflow(t-2) + ... + Total Gain Loss

Refer Impulse Response in Optimization for details about the slots associated with this method.

Previously a sloped power reservoir using the backwater lambda approximation technique was unnecessarily writing input constraints when the reservoir had already dispatched successfully in the pre-optimization simulation run. In some cases, this caused an infeasibility. To resolve this problem, input constraints are no longer written for the Pool Elevation slot at timesteps for which prior dispatching was successful. In addition, the automatic setting of approximation points was improved to make use of known values when the object already dispatched successfully for some timesteps.