New Zealand Gravity Pipe Inspection Manual

The 4 edition of the New Zealand Gravity Pipe Inspection Manual incorporates the evolution of pipeline inspection and the changing requirements of the water industry since the publication of the 3 Edition in 2006. The scope of the revision was identified in the report prepared for the ‘Evidence Based Investment Decision Making for 3 Waters Pipe Network Programme’ a joint initiative between Water New Zealand, IPWEA, University of Canterbury Quake Centre titled “Recommendations for the Revision of the New Zealand Pipe Inspection Manual, December 2016” by ProjectMax. This included consideration of:

  • Development of technology
  • Increased sophistication of data analysis
  • Increased emphasis on asset management as a key driver of service and efficiency
  • The creation of other guidelines such as the “Meta-data Standards”
  • Benchmarking and desire to align more closely with other international standards and practices
  • A desire for more, and better, guidelines

This edition observes a change in title of the manual with the addition of ‘Gravity’ to differentiate this manual from pressure pipelines which are intended to be covered in separate publications such as “National Asbestos Cement Pressure Pipe Manual, February 2017”.

The 4 edition makes comprehensive changes intended to improve the ability of the industry to scope the works required, undertake inspections to a consistent and high-quality standard and then interpret the outcomes in relation to the maintenance and/or renewal of the asset in accordance with best asset management practices. The manual has been completely revised and substantially extended to align with the industry’s desire to incorporate more guidance and specific requirements. For the first-time this edition includes a process for the inspection of manholes, laterals and acceptance of new and lined pipes.

Some of the most significant changes have been made to the defect/feature classifications and pipe grading systems that improve the description of defects and more closely align the New Zealand classification system to other international classification standards such as the Australian WSA05: Conduit Inspection Manual and the European EN 13508-2:2003: Conditions of drain and sewer systems outside buildings Part 2: Visual inspection coding and Classification Systems. Care has been taken to ensure that any changes that have been made to the classification system maintain compatibility with the codes in the previous versions of the manual, ensuring that existing condition data captured under the previous editions can continue to be used. The upgraded defect scores provide condition grading that better aligns with assessed condition and enables more meaningful benchmarking.

The overarching intent of the manual remains, as it has since the first edition, to provide asset owners and contractors with a consistent and reliable basis for undertaking inspections of gravity pipeline and for assessing the condition of the pipe for good asset management and renewal planning purposes.

This edition has been produced with the input and collaboration of the New Zealand Water industry, through industry surveys, nationwide workshops, review and feedback from steering committees and feedback from individual councils and industry groups.

This updated manual will provide a powerful tool for the systematic and effective inspection and management of gravity pipelines.

On behalf of the industry ProjectMax and Water New Zealand have already approached and provided known asset management software providers with the revised list of condition assessment codes with the intent that software updates should be available to allow for immediate use of this manual.

The decision was made not split this manual into several documents, as such this is a large download at 47 Mb.

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Note: As of 23 June 2021 Table E1.3 - Defect Scores (Pages 244-248) has been corrected. 

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