Accounting for local water storages in assessing WDN supply capacity

In many real WDNs, as in the Mediterranean area, customers are traditionally supplied by local water storages (i.e. roof or basement tanks) fed from the top by service pipes of the urban WDN through volume-controlled orifices. The present contribution shows that the prediction of WDN water supply capacity achieved by a model accounting for the filling/emptying of local tanks, is different from both classical demand-driven analysis and the pressure-driven analysis based on Wagner's demand-pressure relationship at each node. The WDNetXL system (www.hydroinformatics.it) is used to perform multiple simulation runs to assess WDN capacity under increasing demand scenarios.