Optimization computations are carried out in the same RiverWare standard units used for Simulation computations with one difference. As with Simulation, values are converted automatically from display units to internal units for computations, but for Optimization, that internal conversion might also include scaling. For example, storage volumes in standard units are often on the order of 109 m3, whereas elevation changes might be on the order of 10-1 m. Introducing variables with such a wide range of magnitudes can lead to instability in an Optimization solution. Storage and elevation values are therefore scaled when added to the Optimization problem so that they will tend to be of similar orders of magnitude.

RiverWare determines how to scale values automatically based on their unit types, and all conversions are carried out internally. The user, therefore, does not typically need to be concerned with scaling. The only case in which it might be necessary to be aware of this scaling is if viewing the full LP problem generated for debugging purposes.Values in the LP text file will be the scaled values. Contact CADSWES (riverware‑support@colorado.edu) with further questions about scaling.