**9. Concluding remarks**

dential area),and to having assumed negligible growth of O&M costs. In this case, the com‐

Pmin(-) Pmin \*

A0 0 0.47 2.88 0.00 37.2 116 36 A1 274 0.73 2.88 0.00 1.5 52 22 A4 350 0.70 2.99 2.99 8.5 54 18

(a) All 3 alternatives (b) Alternative

(c) Alternative A1 (d) Alternative A2

Experience shows that it is often less costly simply to repair pipes and pay for the water lost in leakage than to invest in the rehabilitation of the system. This was confirmed here by looking at alternative A0 at year 5. However, for the remainder of the analysis period (yrs. 6-20) the problems identified in the diagnosis become increasingly evident, through poorer network reliability and moderate water losses that tend to intensify due to normal wear.

**Figure 5.** Metric results expressed as a 3D *cube*; left axis: time; right axis: metrics; vertical axis: alternatives.

A0

(-)

AC (%)

RL (l conn.-1 day-1)

UnmetQ (m3/year)

parison and selection of alternatives can be based on the assessment for Year 5.

Assessment metrics

IVI (-)

**Table 5.** Case study: results obtained from the evaluation of three alternatives at year 5

(c.u.)

68 Water Supply System Analysis - Selected Topics

Alternatives Inv

Infrastructure asset management of urban water infrastructures will be increasingly critical in the coming decades. In industrialized countries, particularly those affected by World War II, the heavy investments in new systems carried out in the 1950's, 1960's and 1970's are ag‐ ing fast, partly due to inadequate or deferred capital maintenance. This places an additional demand for efficiency in planning for the future. In developing regions, the shortage of fi‐ nancial and technical resources further add to the need for their well-judged, efficient use in a long-term perspective.

With the current lack of planning and capital maintenance, the services that are taken for granted in many societies are placed into an increased risk of failure, at least from the view‐ point of the levels of service currently provided.

Regardless of their size, complexity and level of maturity or development, water utilities need to implement structured IAM approaches that may ensure the sustainable manage‐ ment of their systems. There are some key recommendations to be taken into account when implementing an IAM program:

[3] Alegre, H., Covas, D. (2010). Infrastructure asset management of water services (in Portuguese). Technical Guide n.16. ERSAR, LNEC, IST, Lisboa, 472 pp. (ISBN:

Infrastructure Asset Management of Urban Water Systems

http://dx.doi.org/10.5772/52377

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[4] Alegre, H., Covas, D.I.C., Coelho, S.T., Almeida, M.C., Cardoso, M.A. (2012). An inte‐ grated approach for infrastructure asset management of urban water systems. Water

[5] Alegre, H.; Baptista, J.M.; Cabrera JR., E., Cubillo, F.; Duarte, P.; Hirner, W.; Merkel, W.; Parena, R. (2006). Performance indicators for water supply services, second edi‐ tion, Manual of Best Practice Series, IWA Publishing, London, ISBN: 1843390515 (305

[6] Alegre, H.; Hirner, W.; Baptista, J.M.; Parena, R. (2000). Performance indicators for water supply services, 1st edition, Manual of Best Practice Series, IWA Publishing,

[7] Almeida, M. C., Cardoso, M. A. (2010). Infrastructure asset management of wastewa‐ ter and stormwater services (in Portuguese). Technical Guide n.17. ERSAR, LNEC,

[8] Almeida, M.C., Leitão, J.P.; Borba, R. (2010). AWARE-P Development reports: Risk Assessment Module. Internal report of the AWARE-P project (classified document,

[9] Almeida, M.C., Leitão, J.P., Coelho, S.T. (2011). Risk management in urban water in‐ frastructures: application to water and wastewater systems. In Almeida, B., Gestão da Água, Incertezas e Riscos: Conceptualização operacional (Water management, un‐ certainty and risks: operational conceptualisation). Esfera do Caos, Lisbon, Portugal

[10] ASCE (2009). 2009 Report Card for America's Infrastructure Advisory Council,

[11] Brown, R. E., Humphrey, B. G. (2005). Asset management for transmission and distri‐

[12] Burns, P., Hope, D., Roorda, J. (1999). Managing infrastructure for the next genera‐

[13] Cabrera, E.; Pardo, M.A. (eds.)(2008). Performance Assessment of Urban Infrastruc‐ ture Services: drinking water, wastewater and solid waste, IWA Publishing , ISBN:

[14] Cardoso, M. A.; Silva; M. S.; Coelho, S. T.; Almeida, M. C.; Covas D. (2012). Urban water infrastructure asset management – a structured approach in four water utilit‐

ies, Water Science & Technology (2012), IWA Publishing (in press).

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9781843391913, IWA Publishing.

Asset Management International 8.2 (2012) 10-14.

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