Integrating desalination to reservoir operation to increase redundancy for more secure water supply

Abstract

We investigate the potential of integrating desalination to existing reservoir systems to mitigate supply uncertainty. Desalinated seawater and wastewater are relatively reliable but expensive. Water from natural resources like reservoirs is generally cheaper but climate sensitive. We propose combining the operation of a reservoir and seawater and wastewater desalination plants for an overall system that is less vulnerable to scarcity and uncertainty, while constraining total cost. The joint system is modeled as a multiobjective optimization problem with the double objectives of minimizing risk and vulnerability, subject to a minimum limit on resilience. The joint model is applied to two cases, one based on the climate and demands of a location in India and the other of a location in California. The results for the Indian case indicate that it is possible for the joint system to reduce risk and vulnerability to zero given a budget increase of 20-120% under current climate conditions and 30-150% under projected future conditions. For the Californian case, this would require budget increases of 20-80% and 30-140% under current and future conditions, respectively. Further, our analysis shows a two-way interaction between the reservoir and desalination plants where the optimal operation of the former is just as much affected by the latter as the latter by the former. This highlights the importance of an integrated management approach. This study contributes to a greater quantitative understanding of desalination as a redundancy measure for adapting water supply infrastructures for a future of greater scarcity and uncertainty.Of the different alternatives, we focus on the last two, namely desalinated seawater and desalinated wastewater

Optimal Model of Desalination Planning Under Uncertainties in a Water Supply System

“…In terms of quantitative methods, other research has aimed to determine the plant capacity and position of desalination plants using mathematical optimization methods considering cost and energy consumption (Atilhan et al, 2011;Liu et al, 2011;Herrera-León et al, 2018;Herrera-León et al, 2019;Shahabi et al, 2017). The appearance of intelligence algorithms has brought considerable research attention to the problem of water source planning and water allocation schemes in urban multisource water supply systems (Bhushan and Ng, 2016;Matrosov et al, 2015). However, the uncertainties of input data are seldom considered in the literature mentioned above (Paton et al, 2014;Triantafyllidis et al, 2018).…”