× Search
  1. Home
  2. General
  3. Infrastructure Development Processes
  4. Quality Assurance Information Requirements
    1. QA-1 Resource Consent Application Requirements
    2. QA-2 Works Undertaken By or For a Council
    3. QA-3 Development Works Approval
    4. QA-4 Survey Plan (s223) Approval
    5. QA-5 Final Sign Off (s224c) Application Requirements
    6. QA-6 As-Built Information
    7. QA-7 Bonds and Maintenance Fee
    8. QA-8 Building Consent Considerations
  5. Design Standards
    1. DS-1 General Provisions
    2. DS-2 Streetscape
    3. DS-3 Reserves
    4. DS-4 Transportation Network
    5. DS-5 Stormwater
    6. DS-6 Wastewater
    7. DS-7 Water Supply
    8. DS-8 Public Lighting
    9. DS-9 Network Utilities
    10. DS-10 Natural Hazards & Earthworks
    11. DS-11 Road Zone/Road Reserve Occupancy
    12. DS-12 Building Consent Considerations
  6. Standard Drawings
    1. SD-1 General Provisions
    2. Street design diagrams
    3. T100 Perspective Drawings
    4. T200 Streetscape
    5. T300 Reserves
    6. T400 Transport Network
    7. T500 Stormwater
    8. T600 Wastewater
      1. T601-Manhole - Standard
      2. T602-Manhole - Shallow
      3. T603-Manhole - Ladder and Steps
      4. T604-Manhole - Precast 1050mmØ Lid
      5. T605-Manhole - Entry Fixing
      6. T606-Manhole - Standard and Raised Access Detail
      7. T607-Manhole - Inclined Access Detail
      8. T608-Manhole - Internal Drop
      9. T609-Manhole - External Drop
      10. TT610-Manhole - PE Pipe Connections - Wall Adapter and Pre-Cast Manhole
      11. T611-Manhole - PE Pipe Connections - Stub Flange and In-Situ Base
      12. T612-Manhole - PE Pipe Connections - Electrofusion Coupler and In-Situ Base
      13. T613 Manhole - PE Pipe Connections - Puddle Flange and Pre-Cast Manhole
      14. T614-Manhole - Access Detail in Carriageway
      15. T620-Rodding Eye - Shallow < 2.5m
      16. T621-Rodding Eye - Deep > 2.5m
      17. T630-Property Connection - Standard
      18. T631-Property Connection - Depth > 2.5m
      19. T632-Property Connection - Within Property
      20. T633-Property Connection - Outside Property
      21. T634-Property Connection - Entry to Wastewater Main/Manhole
      22. T637-Lateral Connection - Single Connection to Manhole
      23. T638-Lateral Connection - Two or More Connections to Manhole
      24. T639-Lateral Connection - Single Connection to Main
      25. T640-Lateral Connection - Two Connections to Main
      26. T641-Lateral Connection - Two Adjacent Connections to Main
      27. T642-Lateral Connection - Rear Lot Connection
      28. T643-Mains Connection - Saddle Connection
      29. T651-Bedding and Backfill Details
      30. T652-Anti-Scour Block and Trenchstop
      31. T653-Buildings Near Public Mains
      32. T654-Close Proximity - Retaining Wall Restrictions
      33. T660-Pump Station - Typical Site Layout
      34. T661-Pump Station - Elevation Section
      35. T662-Pump Station - Plan Section
      36. T663-Pump Station - Pedestal Base Plate, Pedestal Mounting, Valve Chamber and Riser Connection
      37. T664-Pump Station - Deflector Plate, Ladder and Plinth
      38. T665-Pump Station - Valve Extension Spindle, Spindle Guide and Handwheel
      39. T666-Pump Station - Cover Slab
      40. T667-Pump Station - Frame
      41. T668-Pump Station - Chamber Lid
      42. T669-Pump Station - Chamber Lid Padlock and Handle
      43. T670-Pump Station - Rising Main Entry to Receiving Manhole
      44. T671-Pump Station - 25mm Water Service Connection
      45. T672-Pump Station - Electrical - Standard 2 Pump Stn Without Soft Starters (1 of 2)
      46. T673-Pump Station - Electrical - Standard 2 Pump Stn Without Soft Starters (2 of 2)
      47. T674-Pump Station - Electrical - Standard 2 Pump Stn SMC - 3 Soft Starters (1 of 2)
      48. T675-Pump Station - Electrical - Standard 2 Pump Stn SMC - 3 Soft Starters (2 of 2)
      49. T676-Pump Station - Electrical - Standard 2 Pump Stn IMS2 Soft Starters (1 of 2)
      50. T677-Pump Station - Electrical - Standard 2 Pump Stn IMS2 Soft Starters (2 of 2)
      51. T678-Pump Station - Electrical - Standard 2 Pump Stn ISMC - 3 Soft Starters (1 of 3)
      52. T679 Pump Station - Electrical - Standard 2 Pump Stn ISMC - 3 Soft Starters (2 of 3)
      53. T680-Pump Station - Electrical - Standard 2 Pump Stn ISMC - 3 Soft Starters (3 of 3)
      54. T681-Electrical - 2 Pump Stn Mincas SMC-3 Soft Starters (1 of 2)
      55. T682-Electrical - 2 Pump Stn Mincas SMC-3 Soft Starters (2 of 2)
      56. T683-Pump Station - Electrical Cabinet
    9. T700 Water Supply
      1. T700-Water Supply Pipe Hierarchy
      2. T701-Water Supply - Looped and Linked Principal Mains
      3. T705-Water Main - Location at Intersections
      4. T706-Watermain - Location at Cul de Sac
      5. T707-Water Main - Rider Main to Main Connection
      6. T708-Water Main - Flushing Point
      7. T709-Water Main - Branch Valves and Hydrant Combinations
      8. T710-Water Main - Support for Asbestos Cement Main
      9. T713-Hydrant Surround
      10. T714-Hydrant Box
      11. T715-Hydrant Surround Blocks
      12. T716-Valve Surround
      13. T717-Valve Box
      14. T718-Valve Surround 75mm Concrete
      15. T719-Valve Surround 100mm Concrete
      16. T720 Valve Surround Heavy Duty Concrete
      17. T721-Anchor block for Sluice Valves on Mains
      18. T722-Anchor Block for Flanged Fittings on Mains
      19. T723-Thrust Blocks
      20. T724-Hydrant and Valve Marker Post
      21. T727-Water Meter - Type 1 and 2 Point of Supply Location Installation
      22. T728-Water Meter - Type 3 and 4 Point of Supply Location Installation
      23. T729-Water Meter - Fire System Connection With Potable Supply Installation
      24. T730-Standard 20mm Manifold Connection
      25. T731-Standard 20mm Manifold Connections - Plan View
      26. T732-Multiple 20mm Installations
      27. T733-20mm Connection Requiring Double Check Valve
      28. T734-20mm Connection Requiring RPZ Installation
      29. T735-25mm, 40mm or 50mm Meter Installation With Double Check Valve
      30. T736-<50mm Meter Installation with RPZ
      31. T737-Property Connection - 50mm Combination Meter Installation with Double Check Valve
      32. T738-Combination Meter Installation with RPZ
      33. T739 >50mm Combination Meter Installation with RPZ & Bypass Option
      34. T740-Property Connection - Secure Connection
      35. T741-Manhole - Class A Loading
      36. T742-Chamber - Class A Loading
      37. T743-Manhole - Class B Loading
      38. T744-Chamber - Class B Loading
      39. T751-Bedding and Backfill Details
      40. T753-Buildings Near Public Mains
    10. T800 Public Lighting
    11. AB As-Built Drawings
  7. Approved Materials
  8. Construction Standards
    1. CS-1 General
    2. CS-2 Site Clearance
    3. CS-3 Earthworks
    4. CS-4 Excavation
    5. CS-5 Excavation in Trench
    6. CS-6 Fill
    7. CS-7 Bedding & Backfill
    8. CS-8 Subsoil Drainage for Earthworks & Roads
    9. CS-9 Pipework
    10. CS-10 Pipe Fittings
    11. CS-11 Manholes & Rodding Eyes
    12. CS-12 Sumps
    13. CS-13 Trenchless Technology
    14. CS-14 Road Ripping
    15. CS-15 Road Pavement Layers
    16. CS-16 Kerb & Channel
    17. CS-17 Concrete Work
    18. CS-18 Carriageway Surfacing
    19. CS-19 Roadmarking
    20. CS-20 Berm Features
    21. CS-21 Street Structures
    22. CS-22 Road Maintenance
    23. CS-23 Grassing & Turfing
    24. CS-24 Vegetation Planting & Gardens
    25. CS-25 Reinstatement
  9. Inspection & Testing Requirements
    1. IT-1 General Provision
    2. IT-2 Streetscape
    3. IT-3 Reserves
    4. IT-4 Transportation Network
    5. IT-5 Stormwater
    6. IT-6 Wastewater
    7. IT-7 Water Supply
    8. IT-8 Public Lighting
    9. IT-9 Network Utilities
Infrastructure Development Code

DS-10 - Appendix G - Geotechnical Considerations for Building Consents


DS-10 - Appendix G.1   General

The following issues are recommended for consideration when designing geotechnical features at the time of subdivision and for Building Consent purposes.

DS-10 - Appendix G.2   Stability and Retaining Walls

Prior to issuing a code compliance certificate (CCC), all site works and retaining walls shown on building consent plans or present at the time of CCC inspection shall comply with New Zealand Building Code clauses: 

  1. B1 Structure.
  2. B2 Durability.
  3. D1 Access Routes.
  4. E1 Surface Water.
  5. F4 Safety From Falling

Council may apply discretion when existing works were undertaken for previously consented buildings and the new building works do not rely on the stability of those works.

Walls that are low risk and do not require a PS1 Design Producer Statement shall have the construction details shown on plans. Council may ask for more information regarding compliance with the building code during consenting or following construction. 

Construction contractors shall keep construction records and issue a PS3 Construction Producer Statement (refer Schedule 6 NZS3910 or Schedules E1/E2 NZIA SCC 2011) for these walls.

Retaining walls shall be set back from boundaries the distances shown in the MBIE Schedule 1 guidance document or designed for the surcharges in DS-10 - Appendix G.2 Table 1: Retaining Wall Surcharge Requirements, unless an assessment by a chartered engineer demonstrates to the satisfaction of Council that the wall is sufficiently setback from the boundary that loads beyond the boundary will not add a surcharge and failure of the wall will not affect other property.The surcharges in DS-10 - Appendix G.2 Table 1: Retaining Wall Surcharge Requirements are to be taken as dead loads due to uncertainty regarding load and load duration unless otherwise indicated in DS-10 - Appendix G.2 Table 1: Retaining Wall Surcharge Requirements.

DS-10 - Appendix G.2 Table 1: Retaining Wall Surcharge Requirements

Situation Surcharge Requirement Reason
Sloping ground < 4 degrees above or below the wall None required Nominal slope unlikely to have significant effect
Sloping ground > 4 degrees above or below the wall Increase coeffcient of active earth pressure using soil mechanics equations if slope above the wall.  Decrease coefficient of passive earth pressure using soil mechanics equations. Will increase horizontal load on the wall or reduce the soil resistance respectively.
Boundary of other residential property (undeveloped) 5 kPa dead load. Does not restrict single level dwellings or driveways
Boundary of other residential property (developed) 2.5kPa dead load if no parking or building area present.
5kPa minimum deadload if surcharged from building or vehicle areas.
Site conditions are known
Road carriageway 12 kPa (normal) 
24kPa (overload) 
in accordance with the NZTA Bridge Manual unless otherwise agreed with the Asset Manager.
Consistency with NZTA Bridge Manual 3rd edition 
Boundary supporting council road reserve 10 kPa dead load. Large vehicles may be parked above wall
Boundary supporting all other council land 5 kpa dead load.  
Boundary supporting private right of way 7.5 kPa dead load. More frequent traffic than a private driveway
Residential parking / manoeuvring 5 kPa dead load. Modern SUV's / boats and campers can exceed the maximum weight for light vehicles given NZS1170.
Residential building (NZS3604 type construction) including freestanding garages 5 kPa dead load. Specific assessment for buildings higher than 1 storey
Commercial parking / manoeuvring 12 kPa dead load. Allows for truck and goods deliveries
Boundary of other commercial property (undeveloped) 12 kPa dead load. Does not restrict the development of adjacent property


All retaining wall designs that require a PS1 Design Producer Statement shall have a site specific geotechnical assessment by the appropriate category of Geo-Professional and have investigations to sufficient depth to characterise soil and groundwater conditions within the depth range providing support to the foundations. The geotechnical design report shall summarise GIS information, site observations, the proposed works and geotechnical design parameters. The structural design report shall provide the basis for the design and address all load cases. 

The design engineer shall provide a letter confirming that they have been engaged to inspect the retaining wall construction and a schedule of inspections.  If the design relies on a geo-professional and structural engineer from separate companies, then two letters will be required.

The certification shall cover: foundations conditions, structure, drainage, backfill and finished landform with respect to B1 and B2.

Following the completion of works, the engineer(s) shall provide Council a summary of the inspections undertaken, as-built information records, any calculations to support minor design changes and a PS4 Construction Review.

Explanatory Note:
The NZ Building Code requires that retaining walls are designed for the combination of loads that may occur throughout their life. Walls adjacent to existing or proposed boundaries need to consider potential surcharges that may occur but are not under the control of the owner. Please refer to the Ministry of Business, Innovation and Employment (MBIE) Schedule 1 guidance document for surcharge zones.


DS-10 - Appendix G.3   Foundation Design

Foundation design shall be accompanied by sufficient geotechnical information from the appropriate Category of Geo-Professional to provide council reasonable grounds to issue the building consent.  This will vary depending on the structure type, bulk, location and site conditions. 

In some cases the information in the original Geotechnical Completion Report may be sufficient, however where a site is reworked the Geotechnical Completion Report may no longer be sufficient.   Where no information is available, a site specific assessment will be required.

Explanatory Note:
It is intended that the Geo-Professional will include limits on the applicability with consideration to future works, building types, foundation types etc.


DS-10 - Appendix G.4   Site Works

Where further site earthworks are required as part of the building works the applicant shall provide council an assessment from the appropriate Category of Geo-Professional with regards to fill induced settlements, batter stability and any drainage requirements.  A specification for the proposed works shall be provided that addresses fill materials, compaction and testing requirements, and inspection requirements.  The specification shall be in accordance with the IDC and NZS4431.

Prior to the Council’s foundation inspection the Geo-Professional shall confirm in writing that they have undertaken the works as per the specification and also tested the cut platform. A letter outlining the works, inspections and testing records along with a statement of suitability shall be provided prior to a code compliance certificate being issued. It is important that the statement of suitability applies to the whole building platform i.e. both cut and fill areas. It would also include the geotechnical suitability of any retaining walls within the zone of influence of the building platform.  Where relevant, this shall also include the stability of the accessway, stormwater and wastewater provisions.

Definitions in this section

As-built information

Asset manager


Geotechnical completion report








Tauranga City Council, Private Bag 12022, Tauranga, 3143, New Zealand  |  Terms of use

Back To Top