Addressing uncertainty in water consumption when optimising promising water supply and disposal schemes

Abstract

The design of urban water supply and disposal systems is associated with overcoming various uncer-tainties of an economic, technical, natural and anthropogenic nature. Among them, the estimated loads for water consumption and discharge are the most significant. If water supply and disposal systems are designed and built for loads higher than the actual values, the water and runoff flow rates will cause quiescent area, pipeline silting and even plugging. If the actual load exceeds the designed load, this will lead to significant hydraulic pressure losses, overstated operating costs and considerable equip-ment wear. The risks involved with overestimating or underestimating the design loads are very high, as both would require reconstruction and immense financial investments. To minimise such risks, we propose a methodology based on a multi-stage and adaptive project implementation with minimum risks when making a decision at each step. A numerical study demonstrated the efficiency of the proposed methodology and its conformity with the domestic design process and development of water supply and disposal systems. This method allows the optimal way of system development to be chosen ac-cording to the life cycle costs.