Infrastructure Development Code

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Drawing Ref: T630, T631, T632, T633, T634 

This section describes the requirements for collection of wastewater. These are categorised as: 

  1. Property service connections.
  2. Alternative collection methods.

DS-6.6.1   Property Service Connections

A connection is the point of union between a property’s private drain and the public wastewater network. Private drainage generally extends to the property boundary at which point Council accepts responsibility for the downstream pipelines.

DS-6.6.2   Minimum Requirements

Property service connections shall be designed to the following minimum requirements:

  1. Each lot shall be served by one service connection.
  2. Any individual lot/property connection shall be designed and located to suit the existing and future development scenarios and where possible sized, located and designed to meet the service of the whole property (land parcel), but as a minimum the building platform.
  3. Any connections shall be located to service the lowest practical building platform on the property.
  4. The design shall specify the requirements for the property connections including plan location, lot contours and invert level at property boundary or junction with the main as applicable.

DS-6.6.3   Private Drainage

City Plan Performance Standard: Appendix 12C
  1. Any individual lot connection shall be designed and located to:
    1. Provide for the existing or proposed development for the site;
    2. Be at a depth that will drain the serviced area;
    3. Be sized to convey the design flow for the property, designated building platform or area being serviced;
    4. Be within the property boundary;
    5. Be free of obstruction and accessible for future maintenance.

Generally all wastewater pipes installed between a building and the connection point to Council’s wastewater network are private assets. The Building Act requires that a Building Consent shall be obtained for their installation or alteration and that this work must only be carried out only by a registered drainlayer. 

The following shall apply:

  1. Further approval must also be obtained from Council before these drains may be connected to the wastewater network. Application for this shall be on Council's Water Supply / Drainage / Vehicle Crossing Connection Application Form.
  2. All connections to Council infrastructure shall be carried out only by a Council Licensed Contractor.

DS-6.6.4   Connection Locations

City Plan Performance Standard: Appendix 12C
  1. Any individual lot connection shall be designed and located to:
    1. Provide for the existing or proposed development for the site;
    2. Be at a depth that will drain the serviced area;
    3. Be sized to convey the design flow for the property, designated building platform or area being serviced;
    4. Be within the property boundary;
    5. Be free of obstruction and accessible for future maintenance.

Connections shall be:

  1. Clear of obstructions, e.g. trees, tree roots, paved areas.
  2. Easily accessible for future maintenance.
  3. Clear of any known future developments, e.g. swimming pools or driveways.
  4. For infill subdivisions, particularly where upgrading of existing 100mmØ connections in sound condition and at reasonable grades would be impractical, up to four dwelling units may be connected subject to Council approval.

DS-6.6.5   Connection Depth

Drawing Ref: T630, T631

The following shall apply:

  1. Connection depths shall be set to drain the whole serviced area recognising the following factors:
    1. Any connection points shall have a minimum cover of 600mm and be no deeper than 1.5m. (Deeper connections may be installed in some circumstances but only with the prior approval of Council).
    2. Surface level at plumbing fixtures of buildings (existing or proposed).
    3. Depth to invert of pipe at plumbing fixture or intermediate points.
    4. Invert of public main at junction point.
    5. Allowance for crossing other services.
    6. Allowance for minimum gradients of laterals and private drainage.
    7. Lateral junctions installed at minimum of 45° (vertical) to main.
  2. The designed invert level at the connection shall be no higher than the lowest calculated level consistent with these factors.

DS-6.6.6   Installation of Connections

Drawing Ref: T630, T631, T632, T633, T634 

The following shall apply:

  1. The end of each connection pipe shall be sealed with a solvent-welded cap painted red if the connection does not occur immediately.
  2. Where the inspection is servicing a property containing multiple residential units then a surface-accessible inspection chamber such as a manhole, rodding eye or other Council approved structure shall be installed.
  3. Each connection point shall be marked with a 50mm x 50mm timber stake painted white which shall extend from the invert to a minimum of 300mm above finished ground level. A red marker tape labelled "sewer" shall be attached to the connection pipe, brought up and tied to the top of the stake.

DS-6.6.7   Connection Destinations

Each service connection shall connect to one of the following points of discharge. The mechanisms are listed in order of preference.
Where the main is within the property boundary a separate connection shall be provided to each lot.

  1. Connections to wastewater mains greater than 5.0m deep will not be approved. In these cases a high-level wastewater main will need to be constructed.
  2. Connections to trunk mains will generally not be approved by Council.

DS-6.6.8   Lateral Configurations

Drawing Ref: T637, T638, T639, T640, T641, T642

To provide a service connection to each lot, a minimum 100mmØ line shall be extended from the main reticulation system to terminate within the property boundary at a minimum distance of 1.0m from the front and side boundaries whether created by cross-lease, unit title or fee-simple subdivision.  
These connections shall also form part of the public system to the site boundary and be brought up to within 1.2m of the final ground surface level.
In addition the following shall apply:

  1. For a lateral providing a service connection for 1 lot connecting to a manhole refer to T637.
  2. For a lateral providing a service connection for 2-6 lots connecting to a manhole refer to T638.
  3. For a lateral providing a service connection for 1 lot connecting to a main refer to T639.
  4. For a lateral providing a service connection for 2 lots connecting to a main refer to T640.
  5. Where lateral is over 50m long or the number of connections exceeds 6 lots, normal wastewater reticulation conditions apply. 
  6. Where practicable and where the connection is within 5m of a manhole the connection shall be to the manhole.
  7. Where the main is within the property boundary a separate connection shall be provided to each lot.
  8. All connections directly to the main shall be made using factory made fittings.
  9. For major land use development where significant privately owned reticulation works (i.e. not being vested with Council) are being constructed and are connecting into Council infrastructure, all works shall be designed and constructed in accordance with the IDC requirements, however the reticulation will remain private.

DS-6.6.9   Infill Subdivision – 3 Lots or Less (Excludes Existing Lot)

It is recognised that infill subdivisions require flexibility in their reticulation layout. However, normal trade practices and standards are needed to ensure that the desired service life is achieved.

  1. Reticulation of infill subdivisions shall comply with the following criteria:
    1. Drainage within the parent lot shall remain private and be protected by an appropriate easement.
    2. Drainage lines shall be separated at the point of connection to the Council’s reticulation system and remain separate for each lot unless specific approval is gained from Council.
    3. Infill subdivisions shall be reticulated on a site-by-site basis.
    4. For minor infill subdivision type works, all private drainage works shall be constructed in accordance with the NZ Building Code regulations.
  2. Infill subdivisions shall be reticulated on a site by site basis to the approval of Council.
  3. Lateral connections shall be constructed or upgraded in accordance with the IDC. This lateral can be vested in Council and provide each lot with the same standard of individual connection as new ‘greenfields’ lots.
  4. Where this is considered impractical or unnecessary, the Consent Holder may make application to Council for the lateral to remain private within an appropriate easement. However common private drains are not encouraged so as to alleviate the friction that sometimes occurs between neighbours when shared services are involved.
  5. Drainage lines shall be separated at the point of connection to Council’s reticulation system and remain separate for each lot unless specific approval is granted by Council. Where the main is within a neighbour's property, the new junction may be installed immediately within the property being subdivided.

DS-6.6.10   Multi-Unit Properties (Such as Apartment Buildings and Body Corporate Developments)

For multiple occupancies (unit title, cross lease or company lease) service of the whole property shall be achieved by providing a single point of connection to the wastewater system. Connection of the individual units is by joint service pipes owned and maintained by the body corporate, tenants in common or the company as the case may require. In this instance the whole of the multiple occupancy shall be regarded as a single lot. All drainage within the development boundary would be private. 

Where multi-unit developments are proposed, a single 150mmØ lateral/connection will be required.  Multi-unit developments will generally be required to upgrade existing laterals if less than 150mmØ. The connection shall include a surface-accessible inspection chamber or manhole immediately inside the boundary. 

DS-6.6.11   Commercial and Industrial Connections

The following shall apply:

  1. All commercial and industrial lots shall be provided with a wastewater connection.
  2. Pollutants and contamination issues shall be identified and managed to the satisfaction of Council though the Building Consent Process.

DS-6.6.12   Connection to Existing Council Reticulation

Approval shall be obtained from Council before connection can be made to the wastewater network. Application for this shall be on Council's Water Supply / Drainage / Vehicle Crossing Connection Application Form.
All connections to Council infrastructure shall be carried out only by a Council Licensed Contractor.


Definitions in this section

Asset

Building act

Building platform

Consent holder

Council

Design

Ground

Infill subdivision

Infrastructure

Licensed contractor

Lot

Water supply

Wastewater