Wadiso 6 User Guide > Tank Cost Optimization to be included in future Wadiso version

In a next major Wadiso version, it is envisaged that the program will permit the user to optimally size the storage facilities (tanks) in a water distribution system, simultaneously with the pipe sizing. This is important because of the trade-off which exists between pipe cost and storage cost. In general a smaller, less expensive pipe size combination will require larger, more expensive tanks to balance the peaks in the water demand. The least expensive pipe size combination which does not violate the pressure constraints may therefore have large and expensive storage tanks associated with it, and may indeed not result in the optimal total system cost.

Apart from calculating the required balancing capacity of the tanks in the system for each pipe size combination, Wadiso also allows the user to consider other factors, such as emergency storage and existing tank volumes, in the optimization. For the most part, the input for the tank sizing optimization is exactly the same as for the regular optimization, but some additional information is required. This includes:

•Tank cost function(s).

•For each tank in the system: the average water level for the balancing volume of the tank; emergency volume requirement (if any); and existing volume (if any).

•Consumption information, viz.: the annual average water demand rate in the system; a peak day factor; a peak week factor (if available); and a 24-hour demand pattern.