Tauranga / Bay of Plenty (BOP) – Technical References

DS-10 – Appendix A.1 General

Rev. 1 – 16 August 2021

(TCC -Infrastructure Development Code, IDC)


This reference list is based on the Tauranga City Council (TCC) DS10 Appendix A list for their IDC, but has been upgraded to include several other geotechnical and engineering geological references to provide a basic set of geo-professional guides and technical papers for professional practice in the TCC area and the wider BOP region.

This reference list is located at https://www.nzgs.org/tauranga-bay-of-plenty-bop-technical-references/ or can be found by searching for “Tauranga technical references” on NZGS.org.

Documents from Sections 1-3 and 5 can be downloaded from the referenced websites, i.e. TCC for section 1, Standards NZ for Section 2 and MBIE for section 5.

The purposes of this reference list include:

· A set of useful technical references for Tauranga City, adjacent District Councils and the BOP region.

· A basic resource for geotechnical professionals, civil engineers and Council personnel.

Please make sure any references used in reports or official documents are cited to meet copyright requirements, particularly any university papers, reports and maps.

The latest revision or operative version of the following legislation, standards and guidance documents shall be used in conjunction with the Tauranga City Council Infrastructure Development Code (IDC).


  1. City Plan
  2. TCC OZONE Technical Library, refs TL485, TL607 & TL2325 (see ‘Other TCC references’ below)


  1. Resource Management Act 1991 (& amendments).
  2. New Zealand Building Act 2004 (& amendments).
  3. Health and Safety at Work Act 2015 (HSWA) & any amendments.


  1. NZS1170.5 – Structural Design Actions, Part 5 Earthquake Actions
  2. NZS 4402 – Methods of Testing Soils for Civil Engineering Purposes
  3. NZS 4404 – Land Development and Subdivision Infrastructure
  4. NZS 4431 – Code of Practice for Earth Fill for Residential Development
  5. NZTA Bridge Manual 3rd Edition (‘BM3’) including current amendments. Also see ref. 4-D-a).

4. OTHER TAURANGA CITY COUNCIL REFERENCE MATERIAL: (All files in zip format – Section 4ASections 4B-4G)

A. Slope Stability

  1. Relic Slip Verification Study – Tauranga District Council Environs”, Laurie Richards, David Bell and Roydon Thompson, 31 March 2001 (TCC OZONE Technical Library ref. TL485).
  2. Tauranga Storm Event of 18 May 2005: Landslip Issues” – Final Causation Report, BD Hegan, L Wesley and L Richards, (TCC OZONE Technical Library ref. TL2325).
  3. The Design of Permanent Slopes for Residential Building Development – Full Report“, SA Crawford & PJ Millar, EQC Research Project 95/183, published in NZ Geomechanics News, June 1998, (TCC OZONE Technical Library ref. TL 607).
  4. A summary of the above Crawford & Millar report is presented in the 9th ANZ Conference on Geomechanics (1999) technical paper, “The Design of Permanent Slopes for Residential Building Development”, by Crawford & Millar.
  5. “Stability Assessment Checklist for Consent Applications”, SA Crawford & PJ Millar (1998), Extract – NZ Geomechanics News (June 1998).
  6. “Relic Slip Verification Study – Tauranga District”, DH Bell, L Richards & R Thompson (2003), NZ Geotechnical Society Symposium, Tauranga.
  7. “Stability Assessment of Coastal Land in Tauranga County”, Tonkin & Taylor (1981), ref.4879.
  8. “Omokoroa Point – Land Stability Investigation Report”, prepared by CP Gulliver, Tonkin & Taylor and BF Houghton, NZ Geological Survey, DSIR (1980), T+T ref.4487-2. (TCC OZONE Technical Library ref. TL214).
  9. “Geotechnics on the Volcanic Edge”, Proc. from NZ Geotechnical Society Symposium, Tauranga (2003), convened and edited by SA Crawford, P Baunton & Dr S Hargraves.
  10. “Geotechnical Issues in Land Development”, Proc. from NZ Geotechnical Society Symposium, Hamilton (1996).
  11. “Assessment of Slope Stability at Building Sites”, BRANZ Study SR4, Worley Consultants (1987).
  12. “Preliminary Assessment of Geological Factors Influencing Slope Stability in and around Tauranga City (1980 and 1984)”, BF Houghton & BD Hegan, NZ Geological Survey, Engineering Geology Report No. EG248, Department of Scientific and Industrial Research. (TCC OZONE Technical Library ref. TL11750).
  13. “Te Hono Street (Maungatapu, Tauranga) Slope Instability Concerns” (ref. A1964033), DH Bell, 14 August 1995. (TCC OZONE Technical Library ref. TL3143).
  14. “Geotechnical Appraisal of Minden Area – Western BOP (1992)”, by NW Rogers, Tonkin & Taylor Ltd (ref. A3417772; T+T ref. 10899). (TCC OZONE Technical Library ref. TL741).
  15. “The Nature and Causes of Coastal Landsliding on Maungatapu Peninsula, Tauranga, NZ” Bird, G. A. (1981), Master of Science (MSc) Thesis. The University of Waikato, Hamilton, NZ. Retrieved from https://hdl.handle.net/10289/14442 (TCC OZONE Technical Library ref. TL11756).
  16. “Geotechnical Characterisation of Volcanic Soils in Relation to Coastal Landsliding on Maungatapu Peninsula, Tauranga, NZ” (1997), R. Oliver, MSc thesis, University of Canterbury, Dept of Engineering Geology. (http://hdl.handle.net/10092/6667)
  17. “Slope Stability Criteria for Tauranga District Council (B1-VM4 NZBC)”, L Richards, 19Nov.2002, ref. A2706970. (TCC OZONE Technical Library ref. TL1030).

B. Geology

  1. “Geology of the Tauranga Area, incl. Sheet U14 1:50,000”, RM Briggs, GJ Hall, GJ Harmsworth, AG Hollis, BF Houghton, GR Hughes, MD Morgan & AR Whitbread-Edwards, (1996), Occasional Report No. 22, University of Waikato, Dept of Earth Sciences, collaborating with BOP Regional Council and Institute of Geological & Nuclear Sciences.
  2. “Geology of the Maketu Area, Bay of Plenty, North Island, New Zealand, incl. Sheet V14 1:50,000”, RM Briggs, DJ Lowe, WR Esler, RT Smith, MAC Henry, H Wehrmann & DA Manning, (2006), Occasional Report No. 26, Department of Earth and Ocean Sciences, University of Waikato in collaboration with Bay of Plenty Regional Council. Report excl. geology map V14 can be retrieved from https://hdl.handle.net/10289/14488
  4. “Quaternary Surfaces and Sediments at Waihi Beach” (1961), Kear & Waterhouse, NZ Journal of Geology & Geophysics 4:4 434-451.
  5. “Age of Quaternary Surfaces at Waihi Beach” (1971), MJ Selby WA Pullar & JD McCraw, Earth Sciences Journal, Vol.5 No.2.
  6. “Landform Development in Central Coastal BOP Region” (2003), JH Rae, NZGS Symposium, Tauranga.

C. Maps from TCC & Retrolens

  1. “Mapi” – Tauranga City GIS Map resource for “Natural Hazards, Man-made hazards and Land Features” including:
    • Slopes (2:1, 3:1 & 4:1) and Relic Slips
    • Sloping areas requiring a TCC Category 1 Geotechnical Stability Assessment
    • Liquefaction vulnerability areas
    • Ground motion hazards for liquefaction & landslides
    • Areas especially prone to settlement – peat deposits, estuarine/alluvial soils & compressible soils
    • Geomorphology
    • Building Restriction lines
    • Soakhole decommissioning
    • Uncertified fills
  2. “Retrolens” – resource for historical aerial photography

D. Seismic Loading & Site Classification

  1. “Re-Evaluation of NZ Seismic Hazard for Geotechnical Assessment & Design”, M Cubrinovski, B Bradley F Wentz & A Balachandra, NZ Society for Earthquake Engineering Bulletin Vol. 54 (May 2021 – early release).
  2. “Site Subsoil Class Determinations in Tauranga, NZ”, E Pearse-Danker & L Wotherspoon, Geomechanics News (June 2016).
  3. Refer to NZS 1170, Part 5 and NZTA Bridge Manual (3rd Edition)

E. Liquefaction & Ground Improvement

  1. “Liquefaction Hazard Assessment – Tauranga Eastern Zone, TC52/19” (2020), J Russel & ME Jacka, Tonkin & Taylor, ref 1009973.v1.
  2. “Liquefaction Hazard Assessment – Tauranga Western Zone, TC51/19” (2020), D Mahoney, K Martelli & R Griffiths, Aurecon NZ Ltd, ref 506454, Rev. 1
  3. “Microzoning for Earthquake Hazards for the Western Bay of Plenty” (2003), Report by Opus International Consultants Ltd.
  4. “LQ Hazards in the Western BOP” (2003), P Brabhaharan & J Thrush, NZGS Symposium Tauranga.

F. Soakage Assessment

  1. “Decommissioning of Soakholes in Otumoetai Area” (2006), D Milner, C Bauld & L Wesley, Tonkin & Taylor report to TCC (ref. A4258724; T+T ref. 23064).(TCC OZONE Technical Library ref. TL1030).
  2. “Soakhole Decommissioning Extension Study for the Matua and Avenues Areas” (2008), SJ Karlson, D Milner & C Bauld, Tonkin & Taylor report to TCC (TL6140; T+T ref. 850913).
  3. “Soakage and the Building Code” (2017), MD Trigger, NZGS Symposium, Napier.

G. Other

  1. “The Role of Peer Review”; edited summary by SA Crawford, presentations by D Cook, GA Pickens &G MacDonald, Pp 49-62, NZ Geomechanics News (Dec 1995).
  2. “Accreditation of Geotechnical Engineers and Engineering Geologists” (1996), Bruno Petrenas, NZGS Symposium, Hamilton-Geotechnical Issues in Land Development, Pp152-161.
  3. “A Ground Investigation Specification for NZ” (2017), R Roberts, T Fairclough, S Hargraves, G Cassidy, H Wahab & M Stannard, NZGS Symposium, Napier.
  4. “Chartered Professional Engineer (Geotechnical) – Body of Knowledge and Skills”, NZ Geotechnical Society (March 2019).
  5. “Professional Engineering Geologist – Body of Knowledge and Skills”, NZ Geotechnical Society (July 2020).


A. NZGS/MBIE Geotechnical Earthquake Engineering Guidance, Modules 1-6 (2016-17)

  • Module 1: Overview of the Guidelines – provides regulatory context, and guidance for estimating ground motion parameters for geotechnical design. Also see ref. 4-D-a).
  • Module 2: Geotechnical Investigations for Earthquake Engineering.
  • Module 3: Liquefaction Hazards – identification, evaluation and mitigation.
  • Module 4: Earthquake Resistant Foundation Design to address lateral spreading, settlement, foundation failures, subsidence of areas close to waterways, and large volumes of sediment ejecta on the ground surface.
  • Module 5: Ground Improvement of Soils Prone to Liquefaction.
  • Module 6: Earthquake Resistant Retaining Wall Design.

B. Canterbury Residential Technical Guidance documents, MBIE (2012, updated 2018)

“Repairing and Rebuilding Houses Affected by the Canterbury Earthquakes”:

  • Introduction: Objectives, regulatory context & scope; Summary of technical categories (TCs), land criteria and repair & rebuild approaches
  • Part A: Technical guidance (TC1 and TC2)
  • Part B: Technical information: insurance & regulatory requirements; observed land and building performance; future liquefaction expectations.
  • Part C: TC3 (including updates)
  • Part D: Subdivisons
  • Part E: Repairing and rebuilding multi-unit residential buildings


A. Soil Properties & Performance

  1. “Geotechnical Properties of Two Volcanic Soils” (2003), LD Wesley, NZGS Symposium Tauranga.
  2. “Compaction Properties of BOP Volcanic Soils” (1980), IM Parton & AJ Olsen, 3rd ANZ Conf. on Geomechanics, Wellington.
  3. “Engineering Geology of the Ruahihi Power Scheme”(2003), DA Burns & AJ Cowbourne, NZGS Symposium, Tauranga.
  4. “Is There a Potassium-based Solution to Sensitive Soil Slipping in the BOP?” (2017), T Robertson, VG Moon & DJ Lowe, NZGS Symposium, Napier.
  5. “Sensitive Pyroclastic Soils in the BOP – Microstructure to Failure Mechanisms” (2017), VG Moon, PR Mills, MO Kluger, DJ Lowe, CJ Churchman, WP de Lange, DA Hepp, S Kreiter & T Morz, NZGS Symposium, Napier.
  6. “Landslides in Sensitive Soils, Tauranga, NZ” (2013), VG Moon, MJ Cunningham, MJ Wyatt, DJ Lowe, T Morz & ME Jorat, NZGS Symposium, Queenstown.

B. Projects & Experience

  1. “Canal Failure, Ruahihi Hydro-Electric Power Scheme, Bay of Plenty, NZ” (1988), LE Oborn, 5th ANZ Conference on Geomechanics, Sydney.
  2. “Design & Construction of a Large Cut in Sensitive Volcanic Ash Soils” (2003), DL Dennison & NJ Edger, NZGS Symposium, Tauranga.
  3. “Design of a Pile Reinforced Embankment, PJK Expressways Project, Tauranga” (2003), AJ Cowbourne. NZGS Symposium, Tauranga.
  4. “Liquefaction Assessment for an Urban Road Project in BOP” (2017), H Wahab &PJ Clayton, 20th NZGS Symposium, Napier.
  5. “Determination of Age of Tauranga/Maketu Basin Peats Based on Apparent Pre-consolidation Pressure Due to Soil Creep” (2015), IC Manley, L Cho & KC Cheung, 12th ANZ Conference on Geomechanics-Wellington.
  6. “Tauranga Harbour Link foundation pile construction & testing” (2008), N Wharmby, M Zame, R Hillier &P Burton, 18th NZGS Symposium
  7. “South British House – A collaborative approach for the seismic upgrade of a building” (2017), H Wahab & K de Graaf, 20th NZGS Symposium, Napier.

C. Earth Science (from University of Waikato, NZ)

  1. “Tephrochronology in Aotearoa New Zealand” (2021), JL Hopkins, DJ Lowe & JL Horrocks, NZ Journal of Geology and Geophysics, 64:2-3, 153-200, DOI: 10.1080/00288306.2021.1908368
  2. “Tephrochronology in NZ – Supplemental Tables SM1 and SM2″, Hopkins et al. 2021.
  3. “Inception of the Modern North Island NZ Volcanic Setting between 3.0 and 0.9 Ma” (2021), A Pittari, ML Prentice, OE McLeod, EY Zadeh, PJJ Kamp, M Danisik & KA Vincent, New Zealand Journal of Geology and Geophysics, 64:2-3, 250-272, DOI: 10.1080/00288306.2021.1915343
  4. “The Taupo Eruption Sequence of AD232 in Aotearoa NZ: A Retrospection” (2021), DJ Lowe & A Pittari, Journal of Geography (Chigaku Zasshi), Vol. 131 (1), 117-141, doi:10.5026/jgeography.130.117.
  5. “Sub-millennial eruptive recurrence in the silicic Mangaone Subgroup tephra sequence, New Zealand, from Bayesian modelling of zircon double-dating and radiocarbon ages” (2020), M Danišík, DJ Lowe, AK Schmitt, B Friedrichs, AG Hogg, & NJ Evans, Quaternary Science Reviews, Vol. 246, 15 Oct. 2020, 106517, ISSN 0277-3791, https://doi.org/10.1016/j.quascirev.2020.106517
  6. “Wiggle-match Radiocarbon Dating of the Taupo Eruption (2019) _with supplemental docs”, AG Hogg, CJN Wilson, DJ Lowe, CSM Turney, P White, AM Lorrey, SW Manning, JG Palmer, S Bury, J Brown, J Southon & F Petchey, Nature Communications 10, 4669, https://doi.org/10.1038/s41467-019-12532-8
  7. “Rainfall Threshold for Initiating Effective Stress Decrease and Failure in Weathered Tephra Slopes” (2020), MO Kluger, M Ehsan Jorat, VG Moon, S Kreiter, WP de Lange, T Morz, T Robertson & DJ Lowe, Landslides Journal Vol. 17, 267-281, doi:10.1007/s10346-019-01289-2.
  8. “A New Attraction-Detachment Model for Explaining Flow Sliding in Clay-Rich Tephras” (2017), MO Kluger, VG Moon, S Kreiter, DJ Lowe, GJ Churchman, DA Hepp, D Seibel, M Ehsan Jorat & T Morz, Geological Society of America, Publication Vol. 45, No. 2, 131-134, www.gsapubs.org
  9. “Tales of the Unexpected: Halloysite Delivers Surprises and a Paradox” (2016), DJ Lowe and GJ Churchman.
  10. “Unique but Diverse: Observations on the Formation, Structure and Morphology of Halloysite” (2016), JG Churchman, P Pasbakhsh, DJ Lowe & BKG Theng, Clay Minerals, Vol.51 395-416, doi:10.1180/claymin.2016.051.3.14
  11. “Halloysite Behaving Badly: Geomechanics and Slope Behaviour of Halloysite-rich Soils” (2016), VG Moon, Clay Minerals, Vol.51 517-528, doi:10.1180/claymin.2016.051.3.09
  12. “Discovery of Halloysite Books in Altered Silicis Quaternary Tephras, Northern NZ” (2016), MJ Cunningham, DJ Lowe, JB Wyatt, VG Moon & GJ Churchman, Clay Minerals, Vol51, 351-372, doi:10.1180/claymin.2016.051.3.16.
  13. “Static Failure Mechanisms in Sensitive Volcanic Soils in Tauranga, NZ” (2016), P R Mills & VG Moon, 11th ANZ Young Geotechnical Professionals (YGP) Conference, Queenstown.

This reference list has been compiled by SA Crawford with assistance from Dr S Hargraves, Dr M O’Halloran, N Rooseboom (TCC) and K Brown (TCC).

We also wish to acknowledge the significant contributions from Professor DJ Lowe (University of Waikato), and assistance provided by TJ Cowbourne, J Scott, P Tudor & L Horvath (Tonkin & Taylor Library), A Munro and A Rodgers (University of Waikato) and T Yates (BOPRC) in helping to source suitable pdf files.

We also wish to thank the NZ Geotechnical Society for their willingness to host the referenced documents in pdf form on the BOP webpage on their website, and for maintaining this website to keep this list current.

We welcome any feedback and further contributions from the geo-professional community and the respective councils within the BOP region. Please forward all feedback to:

Mr SA Crawford can be contacted at email: steve@crawfordgeotechnical.co.nz or mobile (021) 978 913.