Uncertainties are a key issue for long-term capital investment planning in asset intensive organizations. Amongst the sources of uncertainty are the quality and accuracy of readily available data and the assumptions underlying the several estimations involved in capital investment plans, namely those related to renewals, replacements and expansion costs and the useful lives of the assets. This article proposes a novel methodology for efficiency-based long-term investment planning in water infrastructures and discusses the effect of uncertainties in the investment strategies. An industrial water supply system of the Industrial and Logistics Zone of Sines (ILZS), installed in the Portuguese seacoast around 40 years ago, is used as a case study to demonstrate the proposed methodology. The study includes stochastic and deterministic approaches to an asset management key-performance indicator (KPI) that is currently being tested in the Portuguese water sector—the Infrastructure Value Index (IVI).

The current paper aims at the establishment and validation of reference cost functions for different types of assets of water supply systems based on known hydraulic (e.g., flow, pump head, pump power) and physical (e.g., volume, material, nominal pressure, diameter) characteristics of the assets. A five-step methodology was followed: (1) database construction and asset characterization; (2) present cost value calculation; (3) key parameters and cost function establishment; (4) model specification; and (5) model testing and validation. A sample of cost and infrastructure data from several Portuguese water utilities has been used. Multiple linear regression analysis has been carried out to obtain cost functions. Cost modeling also includes the estimation of prediction bands to describe cost uncertainty. Developed cost functions have been tested and validated using 10% of randomly selected data.

The current study aims at economic asset valuation of water and wastewater infrastructures to prioritize rehabilitation interventions using the infrastructure value index (IVI) as a key performance indicator. The proposed methodology follows a three-step procedure: (1) identification, characterization and site inspection of existing assets; (2) estimation of the current replacement cost and the current value; and (3) establishment of the priority needs. Data from a utility in the Algarve region of Portugal are used as a case study. The specific objectives are to illustrate the methodology and highlight the inherent challenges and complexities associated with economic asset valuation. Results include the IVI calculation for different assets using scenarios of service lives. Different strategic interventions of rehabilitation in the long term were studied, allowing to assess the evolution of IVI, rehabilitation cost and increased risk assets. Asset valuation is important to establish short-term rehabilitation priorities and to analyse long-term strategies of rehabilitation.

The present paper aims at the establishment and testing of construction cost functions for wastewater treatment plants (WWTP) based on their hydraulic and physical characteristics. A five-step methodology is followed: (1) database construction and asset characterization; (2) present cost value calculation; (3) key parameters and cost functions establishment; (4) cost modelling; and (5) model testing. A large set of construction costs and infrastructure data from several Portuguese wastewater utilities is analysed including 147 WWTP. Simple linear regression analysis is carried out to obtain cost functions for five types of WWTP. The cost modelling also includes the estimation of 90% prediction bands. Each developed cost function is tested for checking their statistical significance. Results allow the estimation of capital costs of new WWTP and the assessment of the current value of existing assets at the strategical and tactical planning levels without the knowledge of the specific components of the facilities.

A novel comprehensive resilience assessment framework for drinking water systems is proposed integrating different resilience perspectives (i.e., robustness, autonomy, flexibility, reliability, preparedness and recovery), oriented by objectives, criteria and metrics, applicable at the tactical level. The resilience assessment framework is applied to a Portuguese real water distribution network, enabling the evaluation of the system’s resilience. The infrastructure dimension is the main contributor to the low resilience results, particularly in terms of infrastructural robustness, as the infrastructure has exceeded the average service life and has low rehabilitation rates. In terms of autonomy, the system highly depends on external water and energy sources. Regarding the service dimension, most of the drinking water available is used for non-potable uses (e.g., irrigation), without alternative sources. The detailed diagnosis identified network area R6 as the priority area. Assets rehabilitation, increasing storage capacity, finding alternative water and energy sources, and minimizing non-potable uses are relevant improvement measures that promote the reinforcement of the system’s resilience. The resilience assessment framework is a very useful tool for the daily and tactical management of drinking water systems.