volume 1 - Halifax Regional Municipality

Halifax Water Integrated Resource Plan
Appendices
Table 2.2 presents the results of this analysis for the water system.
The table also includes the current system average life and fraction above design life
statistics based on best available asset age data. The data of Table 2.2 indicate the
following:
• At present a significant fraction of the distribution and transmission mains as well as
the water meters are beyond design asset life. The M&E and ICA components of the
treatment facilities and pumping stations are all presently within design life.
• Modelling results for asset renewal levels A level through C level all maintain a
zero % fraction above design life for the pump stations and WSPs at the end-ofperiod.
• There is some differentiation by level of renewal in the large WSPs. C level shows a
larger increase in average age than A level. The small WSP present approximately
the same end-of-period average age in all cases. The increase in average age should
not necessarily be alarming. It is dependent on a number of factors including the
backlog of renewal requirements at the beginning and end of the period. The asset
renewal process should be viewed in a dynamic light as not necessarily reaching
equilibrium for all assets during the 30-year planning period. Indeed, longer-term
analysis spanning 100 to 200 years can be employed to minimize the impact of the
current relatively short planning period.
• The asset renewal modelling results for distribution mains show an increase in
fraction above design life for all levels of asset renewal. The A level nearly maintains
the status quo at 14%.
• The fraction above design life for the transmission mains shows improvement at the
A and B levels of asset renewal while the fraction increases at the C level. The
average results increase in all cases with smaller increases associated with the A and
B levels versus the C level.
Table 2.2
Water System Asset Average Age and Fraction Above Design Life
Asset
Design
Asset
Life
(Years)
Variation
Average
Asset Life
(Weighted
Age)
(Years)*
Fraction
Above
Design Life
(Proportion
Greater than
Expected
Life)*
End-of-Period
Asset Age
(Weighted Age)
(Years)*
End-of-Period
Fraction Above
Design Life
(Proportion
Greater than
Expected Life)*
Distribution
Mains
75
A 44.80 14.00%
B 42.29 12% 49.24 20.00%
C 56.02 28.00%
Revision: 2012-10-29 Integrated Resource Plan –Appendices F-11
October 31 2012 Page 190 of 272