Rehabilitation Planning of Water Distribution Network through a Reliability—Based Risk Assessment

Marianna D’Ercole,Maurizio Righetti,Rita Maria Ugarelli,Gema Raspati,Paolo Bertola

doi:10.3390/w10030277

Abstract

The efficient and effective management of existing water distribution systems (WDSs) faces challenges related to aging of infrastructure, population growth, extended urbanization, climate change impacts and environmental pollution. Therefore, there is a need for integrated solutions that support decision makers to plan today potential interventions, considering the possible consequences and variations in mid- and long-term perspectives. This study is a part of a more comprehensive project, where advanced hydraulic analysis of WDS is coupled with a dynamic resources input-output analysis model. The proposed modeling solution provides a robust tool to support planning of intervention actions and can be applied to optimize the performance of a water supply system considering energy consumption and environmental impacts. This paper presents an application of the proposed method in pipe rehabilitation/replacement planning, maximizing the network mechanical reliability and minimizing the risk of unsupplied water demand and pressure deficit evaluated at nodal level, under given economic constraints.

Highlights

According to an Environmental Protection Agency (EPA) report [1]: “System rehabilitation is the application of infrastructure repair, renewal, and replacement technologies to return functionality to a drinking water distribution system or a wastewater collection system”
The present study describes a replacement planning approach based on mechanical reliability to minimize unsupplied water demand and pressure deficit
Cumulative risk reduction evaluated based and on the target replacement percentage of pipe in in the masterplan calculated for the first year in thethe management of the water distribution systems (WDSs)

Summary

Introduction

According to an Environmental Protection Agency (EPA) report [1]: “System rehabilitation is the application of infrastructure repair, renewal, and replacement technologies to return functionality to a drinking water distribution system or a wastewater collection system”. The process of intervention planning and prioritization is a function of a network’s current condition assessment, the extent of critical repair needs, the availability of funding for rehabilitation work options, and the ability to inspect and assess the condition and deterioration rate of each element [2]. A well-managed water loss program should always include a budget for selective replacement of mains and/or service pipes to reduce leakage if ALC, or PM is no longer a feasible option to mend the situation [3]

Methods

Results

Conclusion