The Reservoir Boundary for Incrementals category on the computational subbasin is instantiated when one of the Incremental Local Inflows category methods are selected. The selected Reservoir Boundary for Incrementals method establishes whether the computation of incremental local inflows should stop at reservoirs or continue through reservoirs.

This method is the default for the Reservoir Boundary for Incrementals category and should be selected when cumulative local inflow data is cumulative only until a reservoir is reached in a river system. When this method is selected the computation of incremental local inflows will stop at a reservoir and begin again below the reservoir. Between a reservoir and a downstream control point there will be no subtraction of cumulative local inflows to determine the incremental flow at the downstream control point. It is assumed that the cumulative local inflow data is also the incremental local inflow data for the first control point downstream of a reservoir in a subbasin.

This method should be selected when cumulative local inflow data is cumulative throughout the entire river system including reservoirs. When this method is selected the computation of incremental local inflows will continue through reservoirs. Between a reservoir and a downstream control point the reservoir’s routed cumulative local inflow will be subtracted from the control point’s cumulative local inflow to determine the incremental local inflow at the downstream control point.

This method should be selected when cumulative local inflow data is cumulative throughout the entire subbasin but reservoir are not included; that is, the reservoirs do not have any cumulative or incremental hydrologic inflows. When this method is selected, reservoirs do not need to be included in the subbasin and should not have an incremental flow method selected. If the reservoir is in the subbasin and has an incremental flow method selected, an error will be issued that method selection is inconsistent. When the incremental flow calculation is processing pairs of objects, it will skip the reservoir and find the next downstream object (either a control point or confluence).

This method, available only when the Compute Forecast Period Incremental Local Inflows method is selected, should be selected when the user wants to input local inflow data into the Cumulative Hydrologic Inflow slot on the reservoirs but the reservoirs do not have any upstream objects for which there are cumulative local inflows. This usually happens on headwater reservoirs but can also occur when a reservoir is directly downstream of another reservoir and inflows do not accumulate between the two reservoirs. This method allows users to input cumulative inflows consistently throughout the model in the Cumulative Hydrologic Inflow slot. Typically, the user would set up one subbasin containing all of the headwater reservoirs and other reservoir for which this applies. When the subbasin executes the Compute Forecast Period Incremental Local Inflows method, the Cumulative Hydrologic Inflow is forecasted into the Forecasted Cumulative Hydrologic Inflow and then copied to the Hydrologic Inflow Forecast slot.