• Prior to this release, a bug was preventing the Maximum Iterations on accounting slots from being checked. This bug is fixed for RiverWare 4.0 so models will now abort if an accounting slot is set more than the maximum number of iterations on a given timestep. It is possible that existing models have been violating this restriction all along. If this is the case, these models will now abort. The user will need to increase the Maximum Iterations on accounting slots for the model to run completely again. This is done by selecting View->Simulation Run Parameters from the Run Control dialog box.

• RiverWare is now available for the Windows 2000 platform. RiverWare will also run on NT, however, it is only supported for Windows 2000. Important information about using the Windows executable is included below in the RiverWare for Windows 2000 section.

• Rulesets saved in the new release CANNOT be used in older executables. There is no message to warn the user about this. Rulesets saved under previous executables CAN be used with the new release however.

• The Stage Table Lookup method on Reach objects was enhanced to compute the Outflow Stage when the reach is solving downstream. Prior to this change, Outflow Stage was only computed when the reach was solving upstream. Because existing models may not have data in the Outflow Stage Table, the table interpolation may fail during the execution of this method. This will prompt a warning message that will not stop the run and will not affect results. However, if the user does not wish to see the warning message, data will need to be input to the Outflow Stage Table.