Hydraulic modeling approach for evaluating the performance of flow-starved water transmission networks

Abstract

The planning and design of water networks in water supply systems are primarily based on demand-driven modeling. The prevailing design provisions, such as minimum diameter, lead to oversizing of the water network, affecting operation. In upstream balancing reservoirs, outflow due to the water transmission network's excessive withdrawal capacity surpasses the available inflow causing flow starvation under intermittent water supply. This flow starvation causes partial flow in the downstream vicinity and forms a standing water column in the balancing reservoir's immediate downstream pipe. Traditional modeling approaches cannot simulate the piped network performance under this phenomenon due to their inability to model partial flow. Hence, a novel modeling approach is developed using a tank with an irregular cross-section, which integrates the hydraulic performance of the tank and the downstream pipe. Additionally, a reservoir and control valve represent the water withdrawal mechanism at the downstream reservoir. The proposed modeling approach simulates performance of a flow-starved water transmission network. A case study based on a real network is used to illustrate the robustness of the proposed approach. The developed modeling approach can serve as a management tool to devise operation schedules, helping better manage the operations of the water networks.