DS-7.6 Conveyance Reticulation Layout

Drawing Ref: T701, T705, T706, T709

City Plan Performance Standard: Appendix 12D

Principal and rider mains shall, excluding road crossings, be located within the road zone berm and be separated from any other infrastructure or services laid parallel to it.
1. Safe, reasonable and practical access shall be provided to the water supply system for its maintenance.

The layout of the primary reticulation system shall be designed to the following minimum requirements:

The reticulation layout shall be:
1. Provided on both sides of the street for principal mains on arterial and dual carriageway streets.
2. Located within the road berm, laid parallel to the property boundary.
3. No closer than 1.8m to any property boundary.
4. Set back a minimum of 500mm from the kerb line. A reduction up to 500mm set back from a property boundary shall be provided for at road intersections.
5. Provided as shown on the Standard Drawings for the alignment of water mains at street intersections.
6. Inclusive of a 500mm horizontal separation between the watermain and any other utility service main or similar obstruction.
Where reticulation cannot be located within the road berm, it shall be located parallel to and within 1.5 metres of the lot boundaries and be no larger than 150mmØ.
Where the area of the berm between the back of the kerb and the boundary is steep (>2H:1V) and the standard position of the reticulation could undermine the stability of the slope over its life, the reticulation shall be located away from that zone of influence. It may, as a result, need to be laid under the footpath or possibly under the carriageway. These alternative locations are subject to approval by Council prior to design completion and construction commencing.

In all cases where these standard layouts cannot be achieved, proposed alternative layouts shall be referred to the Council for approval before installation

DS-7.6.1 Close Proximity Rules

The following shall apply:

Buildings or structures to be constructed close to a main or lateral/connection shall comply with the requirements of standard drawing T753.
Where a deviation or bend in a main is present, specific design is required. This shall address issues such as the impact of pressure loadings on the pipe, fittings and associated restraints e.g. thrust blocks, anchor blocks etc.
Buildings shall not be constructed over a main or over a connection point to a main.
Encroachment of removable, non-permanent structures e.g. carports, decks, fences may be approved by Council when the structure is designed and built such that it can be dismantled easily in sections. The removal and re-erection of these structures shall be at no cost to Council. Council will assess each application on a case by case basis as the variables at each site will not always be the same e.g. pipe size, trench details etc. Council may add a record to the property file of any such approval to ensure that future property owners are aware of the approval and Council’s right to have the structure removed at any time for the purposes of maintenance work, emergency work or upgrade work.

DS-7.6.2 Cover over Pipelines

City Plan Performance Standard: Appendix 12D

All pipelines are bedded, backfilled and covered to ensure that their structural integrity will not be compromised through existing ground conditions and anticipated service loads.

The following shall apply:

The cover over water mains shall be as outlined in Table 7.5: Pipe Cover.
Under State Highways and rural roads a water main may traverse a water table etc. Approval of the minimum cover shall form part of the Infrastructure Development Works Approval.
The sections of main adjacent to a carriageway crossing may be deepened to allow the required cover under the carriageway without the provision of vertical bends. Similar provisions shall be made to give the necessary cover over valve spindles i.e. 350mm cover.
Pipe cover and depth shall be stated on the detailed design drawings.
Where minimum or maximum cover cannot be achieved, specific design of pipe and cover shall be required to achieve the manufacturer's requirements and ensure adequate protection of the pipe and fittings.

Table 7.5: Pipe Cover

Location	Minimum Cover	Maximum Cover
Footpaths and Berm	0.8m	1.4m ( to the bottom of the pipe)
Carriageways	1.0m
Private Property	0.8m

DS-7.6.3 Loads on Pipes

City Plan Performance Standard: Appendix 12D

All pipelines are bedded, backfilled and covered to ensure that their structural integrity will not be compromised through existing ground conditions and anticipated service loads.

The following shall apply:

All pipelines shall be designed to withstand all the likely loads that they may be subject to.
Load parameters shall be designed to support an 8.2 tonne design axle load in the first instance.
AS/NZS2566 Buried Flexible Pipelines shall be used as a design guide as applicable.
During construction of the pipeline and other development works any loads relating to backfill techniques, construction traffic, temporary storage of materials and the like shall be incorporated into design parameters and construction methodology.

DS-7.6.4 Pipe Jointing

The following shall apply:

PVC:
1. The general pipe to pipe connection method shall be via the use of rubber ring jointed pipes.
2. Connections to fittings shall be as detailed on the standard drawings.
3. Connections for repair may utilise unrestrained mechanical couplers or any other method approved by Council or as specified in a Council maintenance contract.
PE:
1. The general pipe to pipe connection method for 125mmØ and larger shall be via Butt Welding of pipe strings.
2. The general pipe to pipe connection method for 63mmØ - 110mmØ and larger shall be via Butt Welding or Electrofusion of pipe strings.
3. The length of pipe strings shall be selected considering advice from the pipe manufacturer, health & safety of installers and shall introduce no damage to the pipe or joints.
4. Connections to fittings shall be as detailed on the standard drawings.
5. Connections for repair may utilise electrofusion couplers or any other method approved by Council or as specified in a Council maintenance contract.

DS-7.6.5 Concrete Capping

Concrete capping shall not be used except in exceptional circumstances. Approval from Council is required prior to construction.

DS-7.6.6 Pipe Bedding and Backfill

City Plan Performance Standard: Appendix 12D

All pipelines are bedded, backfilled and covered to ensure that their structural integrity will not be compromised through existing ground conditions and anticipated service loads.

The following shall apply:

Pipe bedding and backfill shall be specifically designed, shown on the detailed design drawings and submitted to Council for approval.
All watermains under carriageways shall have sand or fine granular bedding and surround.
All backfill under carriageways shall be designed to allow for the required pavement layers for the class of road it is beneath.
In all instances particular attention shall be shown to the compaction of these layers.

DS-7.6.7 Saline and Contaminated Areas

Where a reticulation main is to be located on or near saline or contaminated land, the following shall be provided to Council for approval:

Options to de-contaminate or de-salinate the area.
Selection of appropriate pipeline materials and jointing techniques to maintain water quality.
Selection of pipeline materials to achieve the required life expectancy of the pipeline.
Safety of construction and maintenance personnel.
Special pipeline maintenance considerations.

All bolts, nuts and washers shall be gunmetal or stainless steel only.

DS-7.6.8 Flushing Points

Drawing Ref: T708

Flushing points shall be installed as shown on the Standard Drawings.

DS-7.6.9 Connection of Rider Main to Principal Main

Drawing Ref: T707

The following shall apply:

Where a Rider main is to be extended at right angles to a principal main, it shall be connected with a ductile iron tee with a female threaded branch (or an elongated gibault joint, tapped) and with 50mm diameter or greater resilient seated gate valve as shown in the Standard Drawings.
Where a rider main is to be extended along the same alignment beyond the end of the principal main, it shall normally be connected with a ductile iron tee (or elongated gibault joint) with an anchored blank end plate and with a vertical socket and right angle gate valve, as shown on the Standard Drawings.
In all cases this pipe shall be well anchored by compaction along its length and terminated with a blank end gibault and an adequate concrete anchor block.
Taper reducers (to be long tapers only) shall be adequately anchored.