Asset Management

Useful Lives - Stormwater RCP

  • 1.  Useful Lives - Stormwater RCP

    Posted 26 June 2018 21:30

    Hi All

    Currently reviewing our unit rates for stormwater assets and we have had some robust discussion with finance regarding UL of SW pipe.
    Stormwater Services for strategic modelling purposes have placed 100years on UL and in some cases we have placed 80 years on pipes in coastal areas - Finance have determined UL at 135 years.

    I would like to ascertain what age other council's are currently placing on their UL??


    Andrew Priest
    Asset Engineer
    Sunshine Coast Council


  • 2.  RE: Useful Lives - Stormwater RCP

    Posted 26 June 2018 22:07
    Hi Andrew, I have documented the useful lives for stormwater pipes adopted by a range of Councils here:


    The range is from 80 years to 120 years for the Councils that I have information for.



    Wayne Eddy
    Strategic Asset Planning Coordinator
    City of Whittlesea


  • 3.  RE: Useful Lives - Stormwater RCP

    Posted 27 June 2018 20:34
    Hi Andrew,

    We assessed our stormwater RCPs to have a useful life of 120 years, we do not have any coastal areas within our LGA. This is the type of evidence we provided to justify our useful lifes.

    Sample spreadsheet


    Charlette Newall
    Acting Asset Engineer
    Cessnock City Council


  • 4.  RE: Useful Lives - Stormwater RCP

    Posted 27 June 2018 22:16

    Hi Andrew and mates,

    Some comments for consideration.

    1. AASB 116 requires a review of useful life at the end of each annual reporting period (Source: AASB 116.51, p.22).
    2. Confidence in Age Data appears to be a challenge for most local governments in Australia.
    3. I'm sure the Auditor would like to see where and what the evidence is to support the Age and Remaining Life to calculate the adopted Useful Life at Category and/or Sub-Category level in your organisation.
    4. Useful life estimates can be improved by reviewing those assets planned for renewal/disposal in the AM Plans, forward works programs and financed in the LTFP.
    5. This approach will result in more reliable asset register data to improve asset management and financial planning and reporting.


    Hope this helps.  Good luck.


    Stephen Verity
    NAMS Council Support | IPWEA Australasia


  • 5.  RE: Useful Lives - Stormwater RCP

    Posted 27 June 2018 22:16
    ​Pipes to my knowledge last between 2 years to over 2000 years
    2 years being a baddy laid wrongly specified pipe
    2000 years being a roman viaduct
    It depends on materials, grade, construction method, size, flowrate, ground conditions, vegetation, design. climate, distance from the coast, loading, catchment size, cleaning frequency, cleaning methods, urban usage and other  unpredictable incidents.

  • 6.  RE: Useful Lives - Stormwater RCP

    Posted 27 June 2018 22:16
    ​Thanks for all the information provided on this topic so far.

    Can I add another question to this discussion.   Would the full cost of replacing the pipes be assumed, or only partial cost ?   In other words is there part of the infrastructure which is not depreciated?

  • 7.  RE: Useful Lives - Stormwater RCP

    Posted 28 June 2018 08:52
    ​At Glenorchy we use 135 years for RCP pipes.

    Few years ago, I was working for another local Council in Tas which have massive old SW pipes (e.g. brick, EW, RCP) assets dated back to 1900s, and extensive CCTV footages collected since mid 1990s.

    After reviewed and score these footages using 1-5 score based on WSAA code and IPWEA Practice Notes, I was able to create a consistence condition database, and use cumulate frequency analysis on DN225-600 (EW, CP, RCP) to build the relationship between age and condition scores.

    The analysis indicated that 95% of pipes in the range of 0 – 70 years old were found to be condition 1, and 70% of pipes between 80-110 years old were found to be condition 2. This was used as the key evidence supporting 135 Years Standard Life assign for our reticulation assets. Using the data above, an age-based stormwater condition degradation curve was also produced.

  • 8.  RE: Useful Lives - Stormwater RCP

    Posted 28 June 2018 08:52
    ​You build a pipe line for $300 a meter and over the years other expensive services get built around it
    the Greenfields replacement cost would be say $400 a meter but the real cost of full replacement in its current location might be
    say $2000 a metre.
    So you reline the asset which costs say $1000 a metre yet in the system the replacement cost is $400  a metre.
    Current Asset systems make little sense to me and in my experience lead to massive under valuing of the drainage system.
    Which in turn leads to under expenditure and asset mining. Which all leads to increasing risk.