Answering the Demand Versus Supply Question

Abstract

This chapter presents a design methodology to enable the designer to establish the hydraulic efficiency of a rwh system and to select the optimum rwh storage tank size. The design methodology consists of two stages. Stage 1 involves the designer establishing the hydraulic efficiency for a site. This involves calculating both the demand profile and rwh supply profile for this location. The rwh supply coefficient is then established. This is defined as the percentage of demand that the rwh system can supply for a selected time period. Stage 2 then involves selecting the optimum rwh storage tank size. This can be established according to three methods, basic method, intermediate tabular method and/or a detailed daily storage model. A number of worked examples are shown to explain the design methodology.