Criticality Analysis of a Water Distribution System Considering Both Economic Consequences and Hydraulic Loss Using Modern Portfolio Theory

Abstract

This study introduces an approach using Modern Portfolio Theory (MPT) to consider hydraulic resilience and economic consequence resilience of a water distribution system (WDS) to identify critical assets. ECLIPS (Economic Consequence Linked to Interruption in Providing Service), a way to represent loss of water provision as economic loss, is used to measure economic consequence following a reduction of WDS functionality. The approach is demonstrated using a hypothetical WDS and tested for pipe breakage and replacement scenarios using EPANET hydraulic simulations. First, the correlation between hydraulic resilience and economic consequence resilience was investigated to assess differences between two resilience measures for identifying pipe’s criticality for replacement. The results confirmed the two resilience measures exhibited differing responses (covariance = 0.2), suggesting that use of both would provide complementary insight. Results of the MPT analysis identified the benefits of balancing hydraulic and economic consequence resilience measures to yield lower risk. This study provides a practical approach to incorporate economic consequence into planning, design, and research applications identifying critical WDS assets.

Emerging Issues and Methodologies for Resilient and Robust Water Distribution Systems

“…Two contributions by Lee et al [7,10] in this Special Issue were made in the context of WDS criticality analysis. Lee et al [7] introduced a criticality analysis approach based on the modern portfolio theory (MPT), considering two different resilience measures, i.e., hydraulic and economic consequence resiliencies (HR and ER, respectively), to demonstrate the requirement of the economic measure in identifying critical pipes. Economic consequence resilience is defined as the ratio of delivered water to the required water weighted by economic consequences and output per unit of water under service interruptions.…”

“…The papers are sorted in the order of publication date (Jun and Kwon [1], Yoo et al [2], Choi and Kim [3], Diao et al [4], Lee at al. [5], Jung et al [6], Lee et al [7], Kim et al [8], Balut et al [9], Lee et al [10], Li et al [11]). Among the 11 papers, Yoo et al [2] received the largest number of full-text views, whereas the abstract of Kim et al [8] was viewed the most often.…”

Quantitative Measure of Sustainability for Water Distribution Systems: A Comprehensive Review

“…Thus, a higher Eco Eco will be achieved by lower O&M costs or increasing revenues by adjusting the price of water. Furthermore, Eco Soc is related to Eco Eco , but considers the affordability of the water price to customers, which is calculated using the ECLIPS factor introduced by Lee et al [47] and Lee et al [48], with consideration of the burdensome index (BI). Unlike Eco Eco , Eco Soc increases when the water price is low and the economic status of customers rises; Eco Env considers the efficiency of the WDS and evaluates the ratio between the total water delivered and supplies (or billing if data is sufficient).…”

Development of Failure Cause–Impact–Duration (CID) Plots for Water Supply and Distribution System Management

“…A water supply and distribution system (WSDS) consists of various components (e.g., water treatment plant (WTP), pump station (PS), reservoir, pipes) to deliver the required quantity of water from source to customers with acceptable pressure and water quality [1]. WSDS component failures can result in water service outages, while the impact area and duration differ for each failure event [2][3][4]. For example, the segment (i.e., a subsection of the system) delineated by the surrounding valves should be closed (segment isolation) during replacement of a broken pipe [5].…”

“…For example, it is difficult that a local distribution pipe failure causes a service interruption for more than two weeks. Because the ultimate goal of water utilities is to minimize such service interruptions, understanding the impact and duration of different types of failure events is a critical task for developing effective preparation and response action plans [3,[9][10][11].…”