Storage Compensation
The options for applying storage compensation in the network are as follows:
- Compensation for Unmodelled Pipes - to ensure that surcharging and flooding is not over predicted due to some smaller pipes and household connections not being included in the model. These pipes provide a volume of storage that is compensated for in the model by increasing the size of manholes.
- Storage Compensation during Merging and Pruning - storage will be lost from conduits and nodes that are removed as part of the process. This loss of storage may cause unexpected results.
- Preissmann Slot and Baseflow Correction - the Preissmann Slot increases storage in pipes by a small amount while baseflow reduces storage in pipes by a small amount
- User defined compensation - you can define your own storage compensation values in the Shaft Additional Storage: User and Chamber Additional Storage: User fields for each manhole.
The additional storage from each of these methods is summed before being applied to the manhole. The resulting value will be used to adjust the plan area of the manhole to compensate for lost storage elsewhere in the system.
Because the Preissmann Slot correction involves reducing the plan area of the manhole, it is possible for the sum of all storage compensation parameters to be negative. The Minimum Plan Area at Nodes values in the Simulation Parameters ensure that the effective plan area of a node can never fall to zero.
