Add support for stormwater inflow during scenario
Currently, the reservoir volume is fixed upon initialisation and can only drain out through the breach.
This must be extended to also allow continuous inflow into the reservoir during the breach, thus artificially slowing down the lowering of the reservoir water level. This should be implemented in a way that allows both continuous inflow as well as varying inflow defined via an external hydrograph file.
Edited by David F. Vetsch