24 August 2021
Aline
OIA-159
Via email
: [FYI request #16209 email]
Dear Aline,
Thank you for your request for information made under the Local Government Official
Information and Meetings Act 1987, partially transferred from Hutt City Council to
Wellington Water on 29 July 2021. You asked for the following information:
What does the most recent report by Wellington Water on the condition of each of
the three water systems in Lower Hutt say about their condition - what does this
report say about how much of each system is in very bad, bad, average, good, or
very good condition, or however they categories the condition of each system?
The two documents attached were provided to Hutt City Council’s Auditors during the
March 2021 audit of the Long-Term Plan consultation document. They set out the condition
assessment information for the Hutt City’s water supply, wastewater and stormwater pipe
networks. The numbering of the documents reflects the packaging and order they were
provided to the Auditor in.
The condition assessment uses the International Infrastructure Management Manual (IIMM)
published by the Institute of Public Works Engineering Australasia (IPWEA). The IPWEA is an
association for the professionals who deliver public works and engineering services to
communities in Australia and New Zealand.
The document
“3.11 Condition Assessment Information-V1” provides the explanation to the
approach to establishing when pipes need to be replaced based on their age and how this is
used to assess condition. The concept being that the older the pipe the poorer the condition
with the risk of failure and service interruptions increasing as they reach or exceed their
expected useful life.
The second document
“3.12 HCC Renewals Profiling – Pipe Condition Grading by Length“ provides the results of this condition assessment and lengths of pipe in each condition grade
for each of the three water networks. As explained in
“3.11 Condition Assessment
Information-V1” condition grade 1 is Very Good through to condition grade 5 being Very
poor and unserviceable.
Please find the attached:
• 3.11 Condition Assessment Information-V1
• 3.12 HCC Renewals Profiling – Pipe Condition Grading by Length
If you have any concerns with this response, you have the right to request an investigation
and review by the Ombudsman under section 27(3) of the Local Government Official
Information and Meeting Act 1987.
Information about how to make a complaint is available at
www.ombudsman.parliament.nz
or freephone 0800 802 602.
Your sincerely
Ian Dennis
Manager Customer Experience
Wellington Water