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DESIGN STANDARDDS-7 WATER SUPPLY

TABLE OF CONTENTS

DS-7.1 General ..............................................................................................................1

DS-7.2 Minimum Requirements ......................................................................................1

DS-7.3 Regional Council Requirements .........................................................................1

DS-7.4 Design ................................................................................................................1

DS-7.5 Conveyance - Reticulation Layout ......................................................................4

DS-7.6 Point of Supply .................................................................................................12

DS-7.7 Further Considerations .....................................................................................15

DS-7 WATER SUPPLY

Updated 01/07/2014 Page 1

DS-7.1 General

The primary objectives of a water supply system are to convey a potable drinkable supply andto provide for firefighting purposes. The core design principals of a water supply system shallbe carefully managed in order to avoid issues relating to public health and the ability to supplywater for drinking and fire fighting purposes.

Understanding the implications of the future land use and its design elements, such as theextent of water demand, shall be taken into account.

DS-7.2 Minimum Requirements

Designs shall provide for a water supply system that:

a) Complies with the operative City Plan and Infrastructure Development Code (IDC).

b) Is designed to acceptable urban design, landscaping and engineering methods.

c) Minimises, isolates or eliminates health and safety hazard during both its construction andits use.

d) Minimises, isolates or eliminates any adverse ecological and environmental effects.

e) The water supply system shall be located in areas that are geotechnically suitable for thesystem proposed.

Note: Where confirmation of this requirement is not clear a certification statement from aCategory 1 Geo-Professional may be required.

DS-7.3 Regional Council Requirements

Consultation and approval from Bay of Plenty Regional Council shall be undertaken for anyprivate water supply source i.e. bores, stream take etc.

DS-7.4 Design

T700

Unless otherwise approved by Council, the design of the water supply system shall be inaccordance with the IDC and may be supplemented by the documents noted in DS-7Appendix A.1 General.

A computer modelling system approved by Council may also be used.

Water reticulation design shall provide capacity for future development of land beyond theproposed subdivision and the existing reticulation assessed and upgraded if necessary tocater for both the proposed and future development. This may be varied by specificoperational requirements specified by Council.

Future development shall be designed based on ring main design, shall not compromise waterquality and avoid the development of pumped reticulation systems.

DS-7 WATER SUPPLY

Page 2 Updated 01/07/2014

Detailed design shall be required at the time of Infrastructure Development Works Approval.Where no Infrastructure Development Works Approval is required, Council approval shall beobtained at a time required by Council and before construction of the system.

DS-7.4.1 Water Supply Systems

Water supply systems shall consist of 2 main types:

a) Ordinary (residential).

b) Extraordinary (commercial, industrial and fire fighting).

In areas where a high level public supply zone does not exist, as in areas within a 30melevation of a Council reservoir, the developer shall supply an elevated storage reservoirto be vested in Council.

Council reserves the right to specify the size of the principal and rider watermains where itdeems departure from any standard is required.

DS-7.4.2 Residential (Excluding High Density Urban) Supply

The following shall apply:

a) The pipe network shall be designed to provide for annual, seasonal and peak demandutilising the available pressures in the existing mains. It is the responsibility of theDesigner to verify what supply capacities are available to serve the proposeddevelopment.

b) The parameters for the residential use are:

i) Population density of 50 people/ha.

ii) 260 litres/person/per day and a design peak factor of 5 times.

iii) Peak hourly flow 0.75 L/sec/ha.c) Where a Resource Consent application or the City Plan sets a different minimum or

maximum density of lots per hectare, the design capacity shall be modified to reflectthat density per hectare.

DS-7.4.3 Commercial and Industrial Supply


a) Water Supply consumption shall be as outlined in Table 1: Water SupplyConsumption.

b) The water demand for commercial and industrial areas, high density urban areas orirrigation shall be analysed and specifically allowed for in the design but shall not beless than 0.75L/sec/ha.

c) The principal mains serving industrial and commercial areas shall be at least 150mmØlaid in front of all industrial lots of the street. (This requirement may be relaxed in shortcul-de-sacs as long as adequate fire fighting coverage is available.)

DS-7 WATER SUPPLY


d) Where exact land use is not known a density flow of 0.75 L/sec/ha shall be used.

Table 1: Water Supply Consumption

Type of Development Consumption (peak hourly flow)Residential excluding high density urban 0.75 L/sec/haCommercial, industrial and high density urban 0.75 L/sec/ha

(unless specific analysis results in ahigher figure)

DS-7.4.4 Fire Fighting Supply

The water reticulation shall comply with the requirements of the New Zealand Fire Service(NZFS) Firefighting Water Supplies Code of Practice SNZ PAS 4509 and in particular shallmeet the requirements with regard to fire fighting flows, running pressure, the spacing andclose proximity rules of hydrants together with any additional requirements set out by theNZFS or Council including storage where applicable.

Unless stated otherwise in the IDC, the fire risk classification shall be as shown in SNZPAS 4509.

DS-7.4.5 Working Pressures


a) Where available Council will provide details of the pressures and flows at the point orpoints of connection to the existing reticulation and these shall be used for designpurposes. Where this information is not available the Designer shall engage a Councilapproved contractor to undertake tests at the nearest hydrant(s) to the point ofconnection.

b) The water supply shall be designed and operated to achieve the pressures as outlinedin Table 2: Operating Pressures.

c) The water supply shall be designed and operated to ensure that during fire fightingevents the operating pressure shall be maintained to achieve 100kPa of head athydrants and individual building platforms.

d) Pipe classes shall be selected to suit the working pressure in each distribution area inaccordance with Table 3: Pipe Classification / Working Pressures.

e) The Council has the right to specify the diameters to be used for the principalwatermains within a development.

DS-7 WATER SUPPLY


Table 2: Operating Pressures

Allowable operatingpressure (head)

Residential, Commercial &Industrial (measured at the

building platform)

Fire fighting(measured at the

fire hydrant)Maximum 800 kPa(80m) 800kPa(80m)Minimum 300kPa (30m) 100kPa (10m)

Table 3: Pipe Classification / Working Pressures

Class of Pipe Maximum Working PressurePN Rating Metres of Head kPa

PN 9 90 900

PN 12 120 1200PN 15 150 1500

DS-7.4.6 Non-Council Supply

In order to meet the requirements of the Building Act and Health Act, all developmentswhere Council is not obligated to supply water shall provide details of the source, capacityand quality of the existing and proposed water supply.

Where any lot is connected to Council’s water supply network and uses an alternativesupply of water, for irrigation, residential supply or any other use, those alternative sourcesof supply shall be installed with backflow devices appropriate to the hazard rating that aremaintained at all times to prohibit cross contamination of the Council’s system.

DS-7.5 Conveyance - Reticulation Layout

T701, T705, T706, T709

The layout of the primary reticulation system is to be designed to the following minimumrequirements:

a) The reticulation layout shall be located within the road berm & shall be no closer than 1.8mto any property boundary & set back a minimum of 500mm from the back of any kerb line.A reduction up to 500mm set back from a property boundary is provided for at roadintersections.

b) In the case of arterial and dual carriageway streets, principal mains shall be laid on bothsides of the street.

DS-7 WATER SUPPLY


c) The alignment of water mains at street intersections shall be as shown on the StandardDrawings.

d) Where pipelines cannot be located within the road berm they shall be located parallel toand within 1.5 metres of the lot boundaries and be no larger than 150mm in diameter.

e) Within the road berm there shall be a 500mm separation (measured horizontally) betweenthe watermain and any wastewater and stormwater services laid parallel to it.

f) 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 water main could undermine the stability of theslope over its life, then the watermain shall be located away from that zone of influence. Itmay, 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 completionand construction occurring

g) Trees, manholes and similar structures shall not be positioned in berms where they willinterfere with the standard alignment of the watermain unless approved by Council.

In all cases where these standard layouts cannot be achieved, proposed alternative layoutsshall be referred to the Council for approval before installation. This referral shall include aproposed alternative.

DS-7.5.1 Close Proximity Rules


a) Buildings or structures to be constructed close to a main or lateral/connection shallcomply with the requirements of T753 and T754. Where dispensation has beengranted for a building or structure to be built over a main or lateral/connection,foundations shall be designed by a Chartered Professional Engineer.

b) Where a deviation or bend in a main is present, specific design is required. This shalladdress issues such as the impact of pressure loadings on the pipe, on pipe fittingsand associated restraints e.g. thrust blocks, anchor blocks etc.

c) No building or concrete slab shall be constructed over a connection point to a main.

d) No buildings shall be constructed over a main if there is a connection closer than 1.0mto the building unless the connection is relocated to the satisfaction of Council.

e) Encroachment of removable, non-permanent structures e.g. carports, decks, fencesmay be approved by Council when the structure is designed and built such that it canbe dismantled easily in sections. The removal and re-erection of these structures shallbe at no cost to Council. Council approval is required in all instances. Council willassess each application on a case by case basis as the variables at each site will notalways be the same e.g. pipe size, trench details etc. Council may add a record to theproperty file of any such approval to ensure that future property owners are aware ofthe approval and Council’s right to have the structure removed at any time for thepurposes of maintenance work, emergency work or upgrade work.

DS-7 WATER SUPPLY


DS-7.5.2 Cover over Pipelines


a) The cover over water mains shall be as outlined in Table 4: Pipe Cover.

b) 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 DevelopmentWorks Approval.

c) The sections of main adjacent to a carriageway crossing may be deepened to allowthe 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.

d) Pipe cover and depth shall be stated on the detailed design drawings.

e) Where minimum cover cannot be achieved, specific design of pipe and cover shall berequired to achieve the manufacturer's requirements and ensure adequate protectionof the pipe and fittings.

Table 4: Pipe Cover

Location Cover RequiredFootpaths and Berm 0.8m - 1.0mCarriageways 1.0m - 1.2mPrivate Property 0.8m - 1.2m

DS-7.5.3 Loads on Pipes


a) All pipelines shall be designed to withstand all the likely loads that they may be subjectto.

b) Load parameters shall be designed to support an 8.2 tonne design axle load in the firstinstance.

c) AS 2566 shall be used as a design guide as applicable.

d) During construction of the pipeline and other development works any loads relating tobackfill techniques, construction traffic, temporary storage of materials and the likeshall be incorporated into design parameters and construction methodology.

DS-7.5.4 Concrete Capping

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

DS-7 WATER SUPPLY


DS-7.5.5 Pipe Materials

Refer to AM-7 Water Supply.

DS-7.5.6 Pipe Joints

All pipelines shall be fully sealed by use of rubber joint rings, unrestrained mechanicalcouplers or welding as appropriate unless otherwise approved by Council.

DS-7.5.7 Pipe Bedding and Backfill


a) Pipe bedding and backfill shall be specifically designed, shown on the detailed designdrawings and submitted to Council for approval.

b) All watermains under carriageways shall have sand or fine granular bedding andsurround.

c) All backfill under carriageways shall be designed to allow for the required pavementlayers for the class of road it is beneath.

d) In all instances particular attention shall be shown to the compaction of these layers.

DS-7.5.8 Saline and Contaminated Areas

Where a reticulation main is to be located on or near saline or contaminated land, thefollowing is required:

a) Options to de-contaminate or de-salinate the area.

b) Selection of appropriate pipeline materials and jointing techniques to maintain waterquality.

c) Selection of pipeline materials to achieve the required life expectancy of the pipeline.

d) Safety of construction and maintenance personnel.

e) Special pipeline maintenance considerations.

All bolts, nuts and washers shall be of gun metal or stainless steel. No galvanized or mildsteel or brass fittings or bolts and nuts shall be used.

DS-7.5.9 Pipe Sizing and Classification

T700


a) Principal mains:

i) Shall be not less than 100mm internal diameter in all areas.

ii) With pipe systems greater than 200mmØ specific consultation is required.

DS-7 WATER SUPPLY


iii) In terms of reticulation sizing the parameters outlined in Table 5: Main Capacityshall be used for principal mains.

b) Rider mains:

i) Shall have a minimum internal diameter of 50mm (63mm OD for MDPE).ii) In terms of reticulation sizing the parameters outlined in Table 6: Rider Main

shall be used as guidance for rider mains.

c) All pipes for water mains shall have a minimum rating of PN9 (Class C). Specificdesign may be required where a higher pressure rating is necessary and shall beapproved by Council.

d) In determining the size of main to be used the following shall apply:i) A rider main of not less than 50mmØ shall be laid along the road frontage of all

lots not served by a principal main.

ii) A 50mmØ rider main shall be provided in conjunction with a principal mainwhere the main is 250mmØ or larger and the principal main is also defined as abulk main.

iii) Rider mains shall be supplied from both ends, except for privateways.

iv) In the case of arterial or sub arterial roads and dual carriageways streets (i.e.four lanes of traffic) principal mains shall be provided on both sides of the street.

v) The principal mains serving industrial and commercial areas shall be at least a150mmØ in the front of all industrial lots on the street.

vi) The layout of mains for cul de sacs shall be as shown on Standard Drawings.

vii) Rider mains may be located within privateways (right of ways) with separateservice connections for each lot where the privateway (right of way) servesmore than 6 residential lots. Such rider mains shall be covered by an easementin gross in favour of Council and the construction standard shall allow for aflushing point and backflow prevention at the end of the line.

Table 5: Main Capacity

Capacity of main (single direction feed only)

NominalInternal

Diameterof main(mm)

Residential

Ruralresidential (ifa reticulated

supply isavailable)

Light Industrial/ Commercial

High useindustrial

DN Lots(dwellings)

Lots(dwellings)

Ha ofdevelopment

Ha ofdevelopment

100 40 10

150 160 125 23³200 Specific Design

DS-7 WATER SUPPLY


Table 6: Rider Main

Diameter of Rider Main Maximum number of Residential Units (Lots)

Internal Diameter (mm)(Nominal Bore)

One End Supply Two End Supply

50 7 15

65 15 30

85 20 40

100 30 60

DS-7.5.10 Flushing Points

T708

Flushing points with suitable double check backflow protection device shall be installed asshown on the Standard Drawings.

DS-7.5.11 Connection of Rider Main to Principal Main

T707


a) Where a rider main is to be extended at right angles to a principal main, it shall beconnected with a ductile iron tee with a female threaded branch (or an elongatedgibault joint, tapped) and with 50mm diameter or greater resilient seated gate valve asshown in the Standard Drawings.

b) Where a rider main is to be extended along the same alignment beyond the end of theprincipal main, it shall normally be connected with a ductile iron tee (or elongatedgibault joint) with an anchored blank end plate and with a vertical socket and rightangle gate valve, as shown on the Standard Drawings.

c) In all cases this pipe shall be well anchored by compaction along its length andterminated with a blank end gibault and an adequate concrete anchor block.

d) Taper reducers (to be long tapers only) shall be adequately anchored.

DS-7.5.12 Reticulation Fittings

This section describes the requirements for fittings that may be present in conveying aWater Supply reticulated system. These are categorised as:

a) Fire Hydrants (FH).

b) Valves (V).

c) Anchor / Thrust Blocks.

d) Other fittings as specifically designed.

DS-7 WATER SUPPLY


DS-7.5.12.1 Fire Hydrants

T713, T714, T715, T724

Unless stated in the IDC, fire hydrants shall comply with SNZ PAS 4509 andsubsequent amendments. The following shall apply:

a) The maximum spacing between hydrants is:

i) 135m for residential areas.

ii) 90m for commercial and industrial areas.

b) The maximum distance from a hydrant to the furthest serviceable point for firefighting i.e. building platform is:

i) 135m for residential areas.

ii) 90m for commercial and industrial areas.

iii) For the purposes of this requirement, a building platform means any part ofa front, corner or through site and that part of a rear site which does notinclude the access strip. This distance shall be measured along the routewhich a fire hose would normally be laid after construction of the building orstructure.

c) In a cul-de-sac or other terminal streets, the last hydrant shall be at the end of themain at the turning head.

d) If necessary a 100mm diameter principal main shall be constructed and a hydrantplaced within the private way to satisfy the above requirements. This main will beaccepted as public reticulation by Council and shall be protected by anappropriate easement to allow access for maintenance etc.

e) Hydrants shall be readily accessible to fire appliances and should generally bepositioned near street intersections and not placed within 6m of any buildingunless authorised by the Chief Fire Officer. Attention shall be given to the locationof hydrants at intersections and in cases of dispute the Council will refer thematter to the Chief Fire Officer who shall make the final decision.

f) Hydrants are not to be offset into the roadway except in commercial or industrialareas where buildings can be constructed on the boundary.

g) Hydrants shall be located wherever practicable within the berms. To avoid conflictwith driveways, hydrants shall be located in the middle third of the road frontage.

h) Additional to fire fighting requirements, hydrants shall be located:

i) At high points on reticulation mains to release air during charging, allow airto enter the main when dewatering and facilitate manual release of any buildup of air where automatic combination air valves are not installed.

ii) At localised low points on water mains to drain the water main where scourvalves are not installed.

iii) Where a scour valve is not provided at the end of any main 100mmØ orgreater.

i) Adequate drainage facilities shall be provided to receive the hydrant flows fromdewatering and flushing operations.

DS-7 WATER SUPPLY


j) Where approved by Council, hydrants installed on trunk mains will be fitted withan isolating valve. The tee will be positioned facing horizontal. All fittings shall beflanged.

k) Refer to AM-7 Water Supply for fire hydrant type.

DS-7.5.12.2 Valves

T716, T717, T718, T719, T720, T721, T722, T723, T724


a) Air release valves, scour valves, pressure reducing valves and pump outbranches require the specific approval of Council and shall be designed andinstalled in accordance with NZS 4404 Part 6.

b) The maximum distance between valves on mains are:

i) With service connections – 500m.

ii) Without service connections – 1000m.iii) Or as approved by Council.

c) Wherever practicable valves shall be located in berms. For new water mains,valves shall be located at junctions with existing mains. Rider mains shall havevalves at both ends of the rider main immediately adjacent to the principal main.Valves shall be located as close to the principal main as possible.

d) Valve layout for intersections shall be as shown on the Standard Drawings.

e) Valves shall be specifically located with a view to minimising disruption of supplyto consumers. Sufficient valves shall be provided to satisfy this requirement. Nomore than 40 independent dwelling units shall be isolated together. Isolatingmultiple dwelling units beyond this requires specific approval from Council.

f) Butterfly valves shall not be used unless approved by Council.

g) Pressure zone dividing valves and hydrants shall be installed as shown on theStandard Drawings.

h) Additional valves may be installed to provide a secure service connection to acustomer requiring a greater security of supply such as hospitals and largeindustrial or commercial developments. The typical arrangements to facilitatepartial isolation of the main while maintaining supply to the customer is shown onthe Standard Drawings.

i) An extension spindle shall be incorporated as necessary to ensure the top of thespindle is between 150mm and 1000mm below the finished surface level.

DS-7.5.12.3 Anchor or Thrust Blocks

T721, T722, T723

Cast insitu concrete anchor blocks shall be provided at all bends, tees, pipe reducers,valves, dead (blank) ends and hydrants points where an unbalanced thrust occurs onmains ³ 50mm internal diameter.

DS-7 WATER SUPPLY


The design of anchor or thrust blocks shall be based on the bearing value of the site’ssoil conditions, using a minimum concrete strength value of 17.5 MPa concrete.Anchor or thrust blocks shall be designed in accordance with the Standard Drawings.

A protective non compressible membrane shall be provided between the pipe(irrespective of the pipe material) and the concrete anchor and thrust blocks to preventabrasive damage to the pipe and the fitting.

DS-7.5.12.4 Other Fittings

Approval is required from Council before undertaking detailed design which shall berequired at the time of Infrastructure Development Works Approval. Where noInfrastructure Development Plan approval is required as part of a Resource Consent,then Council approval shall be obtained at a time required by Council and beforeconstruction of the system.

DS-7.6 Point of Supply


a) The point of supply is the connection between a property’s private pipework and the publicwater supply network.

b) The reticulation shall provide a point of supply no further than 300mm from any property orlot boundary.

c) For multi units or unit title type developments the point of supply shall be at the roadfrontage, internal connections and reticulation shall be designed to meet the samestandard as if the assets were to be vested in Council, albeit they shall be held inownership and or management of a body corporate or similar management structure.

DS-7.6.1 Minimum Requirements


a) Property service connections shall be designed to the following minimumrequirements:

i) All lots shall be served by one service connection to a rider or principal main.Such connection shall be a minimum internal diameter of a 20mm. Forcommercial and industrial lots or land uses the size of connection shall bedetermined once the water usage required for the lot is established.

ii) Any connections to the existing Council reticulation system shall only beundertaken by a Council Licensed Contractor.

iii) At the point of supply the connection shall include metering, toby box and backflow prevention the type of backflow prevention to be determined by theactivities on site.

iv) Any individual lot connection shall be designed and located to suit the existingand future development scenarios and where possible sized, located anddesigned to meet the service of the whole lot.

DS-7 WATER SUPPLY


b) The design shall satisfy the requirements of the Council policy on metering of supplywhich is contained in the current Water Supply System Bylaw and related regulations.Property service connections to existing water reticulation mains shall be undertakenin accordance with the Water Supply System Bylaw.

DS-7.6.2 Private Supply Pipes

T700

Generally all water supply pipes installed between a building and the point of supply areprivate assets. The Building Act requires that a building consent shall be obtained for theirinstallation or alteration and that this work shall only be carried out by a suitably qualifiedcraftsman plumber.

DS-7.6.3 Connection Locations

T727, T728, T729


a) Front lots (or dwelling units with individual street frontage):

The service connection shall be at the street boundary. The service pipe shall beterminated 300mm on the street side of the front boundary and next to the electricityand telephone connections with a manifold incorporating a toby valve, a dual checkvalve (backflow preventer), a Class C meter and a toby box.

b) Back lots (or dwelling units without individual street frontage) of up to two dwellingunits shall have separate service connections at the street frontage, as in (a) above.The terminal ends shall be clearly pegged.

c) In private ways serving more than 3 rural residential lots or more than 6 residentiallots/units:

i) A 50mm internal diameter service main shall be laid in the private way withseparate service connections off that service line for each lot or dwelling.

ii) A 25mm scour valve and backflow prevention shall be installed at the end of themain.

iii) Special circumstances may apply for privateways and may be discussed at thepre-approval meeting.

iv) The connection toby shall be within the privateway adjacent to the lot served.The service line (up to the point of supply) shall have easements in favour ofCouncil over them.

d) Body corporate and multi unit developments shall either:

i) Construct internal water mains and individual connections to the standardsrequired within the IDC and vest these with easements in Council

ii) Install a bulk supply meter and backflow at the road frontage plus individualmeters on the internal connections and retain supply in Body Corporateownership.

DS-7 WATER SUPPLY


Refer to Council's Water Supply Bylaw for further details.

e) Commercial/industrial lots shall have the point of metered supply service connectionlocated as per (a) and (b) above except that for connections larger than 20mmdiameter the backflow prevention system shall be located as near as practical to theproperty side of the boundary / R.O.W. (as applicable) and as close as practicable tothe metered supply.

DS-7.6.4 Connection Depth

The service connection is to have 500mm cover (± 50mm) from the main to within 500mmof the edge of the meter box and rise to 350mm cover through the meter box. Connectiondepth shall be noted on the detailed design drawings.

DS-7.6.5 Connection Pipes


a) Every separable dwelling or tenancy shall have its own manifold incorporating anisolating valve (toby) at the point of supply. - All lots shall be provided with a 20mminternal diameter water supply connection. If a larger supply is proposed, the applicantshall apply to Council for approval.

b) Refer to AM-7 Water Supply.c) The Designer shall take into account head losses for service connections in serving

building sites over long distances especially in rural or rural residential areas.

d) Service pipes located in private easements are not permitted.

DS-7.6.6 Connection Fittings

T730, T731, T732, T733, T734, T735, T736, T738, T739, T740


a) Water Meters

i) Meter type and specifications shall be in accordance with AM-7 Water Supply.

ii) For meters 50mm Nominal Diameter or larger, design information shall beprovided via a Water Supply / Drainage / Vehicle Crossing ConnectionApplication form for approval and shall include the design flow rates (minimum,average, maximum), proposed meter make/model and manufacturersspecification.

iii) Where automated meter reading is to be used, please refer to Council's SmartMetering Guide for Developers (available on request from Council).

iv) Meters within gated communities will be subject to a separate service levelagreement. Council may vest ownership of the meters beyond the point ofsupply and agree to read these meters on behalf of the body corporate.

v) Meter manifolds shall be located where customers can easily locate theproperty isolating valve in the meter box in case of emergency.

DS-7 WATER SUPPLY


b) Backflow Protection

i) Backflow protection is required at the Point of Supply and as near as practical tothe boundary. Any above ground device (Reduced Pressure Zone) is to beinstalled parallel to the front boundary.

ii) The level of protection is determined after surveying the occupancy of theproperty and referring to clause 3.3 Cross Connection Hazards in The ApprovedDocument for New Zealand Building Code clause G12, Water Supply, SecondEdition.

c) Tapping Bands

iii) Each service connection to a principal main or rider main shall be by means of atapping band. The tapping band for each service connection shall be sitedadjacent to the electricity and telephone connections, close to a side boundary,but not perpendicular to the toby. It shall be located within the boundaryalignment.

DS-7.6.7 Connection to Existing Council Reticulation

Approval shall be obtained from Council before connection can be made to the watersupply network. Application for this shall be on Council's Water Supply / Drainage / VehicleCrossing Connection Application Form.

All connections to Council infrastructure shall be carried out only by a Council LicensedContractor.

DS-7.7 Further Considerations

The following shall also be considered as part of the design process:

a) DS-7.7.1 Manholes and Chambers for Control Valves and Bulk Flow Meters.

b) DS-7.7.2 Special Measures for Pumping and Storage.

c) DS-7.7.3 Easements.

d) DS-7.7.4 Trenchless Pipe Installation.

e) DS-7.7.5 Rural.

DS-7.7.1 Manholes and Chambers for Control Valves and Bulk Flow Meters

T722, T741 T742, T743, T744

Chambers are required for control valves (generally pressure reducing valves and bulkwater meters) and shall be specifically designed. Designers are encouraged to discusstheir design with Council prior to completing the detailed design of a chamber. Designsshall consider the following parameters:

a) Fittings

DS-7 WATER SUPPLY


i) Spacing between valves, fittings, upstream and downstream faces of bulkmeters shall be allowed for in accordance with the manufacturers’recommendations. As a minimum, 5 diameters upstream and 2 diametersdownstream of bulk meter flange faces shall be straight pipe lengths.

ii) Sufficient clearance and appropriate fittings shall be allowed for to facilitateinstallation, access to bolts and dismantling and removal of equipment,including sufficient clearance from the face of the chamber to flanges.

iii) Space for practical access and maintenance between the fittings and thechamber sides/floor shall be allowed for.

iv) Reducers and isolating valves shall be installed outside of the chamber.Anchors for thrust and/or movement prevention shall also be constructedoutside the chamber in accordance with T722.

v) All flush joints shall to be sealed to ensure water tightness.

b) Chamber

i) Chambers housing control valves (with or without bulk meters) shall have a fullopening access.

ii) Chambers housing bulk meters may have a standard cast iron 600mm Ømanhole lid where the chamber will be infrequently accessed. Should theoperation of this chamber require frequent access, Council shall be contactedfor advice.

iii) Galvanised mild steel supports shall be designed to provide vertical support forthe infrastructure. Please refer to T741.

iv) Access steps shall be per AM-5.4.4.

v) Where chambers are situated in free draining soils and not at risk of high watertables, drainage of the chamber shall be provided for.

vi) The chamber pipe interfaces shall be sealed to prevent water/moisture ingress.Chamber joints are to be sealed.

vii) Chambers situated where there is risk of surface inflow of water shall have adouble sealed cast iron lid installed to prevent water ingress. A localised sumpmay also be necessary and requires discussion with Council on a case by casebasis.

viii) The following table can be used as a guideline for selection of the appropriatechamber size.

DS-7 WATER SUPPLY


Type ofInfrastructure

Nominal Diameterof Infrastructure

ChamberDiameter

LidDiameter

Bulk Meter (BM) Less than 200mm 1050mm Ø 600mm ØBulk Meter (BM) Equal to or

greater than 200mm1200mm Ø 600mm Ø

Pressure ReducingValve (PRV)

Less than or equalto 200mm

1200mm Ø 1200mm x 1200mm

Pressure ReducingValve (PRV)

Greater than 200mm 1500mm Ø 1200mm x 1200mm

Combo(BM + PRV)

80mm / 80mm 1200mm Ø 1200mm x 1200mm

Combo(BM + PRV)

100mm / 100mm 1200mm Ø 1200mm x 1200mm

Combo(BM + PRV)

150mm / 150mm 1500mm Ø 1200mm x 1200mm

Combo(BM + PRV)

200mm / 200mm 1650mm Ø 1200mm x 1200mm

Combo(BM + PRV)

Greater than200mm / 200mm

Specific Design Specific Design

ix) For further guidance regarding the sizing of chambers, refer to T741.

c) Operation

i) Operation and maintenance shall be considered including confined spaceaccess and mitigation of risk to maintenance personnel.

d) Telemetry

ii) Bulk meters and control valves that are required to be linked to telemetry, shallinclude ducting and support for cables entering (and being fastened to) thechamber without compromising the chambers requirement to be watertight orthe ability to access it.

DS-7.7.2 Special Measures for Pumping and Storage

Approval is required from Council before undertaking detailed design. Detailed designshall be required at the time of Infrastructure Development Works Approval. Where noInfrastructure Development Works Approval is required as part of a Resource Consent,then Council approval shall be obtained at a time required by Council before constructionof the system.

DS-7.7.3 Easements

Discussion with Council regarding easements is recommended early in the design phase.

DS-7 WATER SUPPLY


An easement in gross will be required where a structure, pipe or other asset that forms partof the wastewater / stormwater / water supply system is to be vested in or maintained byCouncil and is located within land not vested in Council or a Reserve.

All easements shall allow for right of access for practical maintenance.

DS-7.7.4 Trenchless Technology

Trenchless technology may be preferred or required for alignments passing through orunder:

a) Environmentally sensitive areas.

b) Built-up or congested areas to minimise disruption and reinstatement.

c) Railway and major road crossings.

d) Significant vegetation.

e) Vehicular crossings.

Refer to CS-13 Trenchless Technology for information on trenchless technologyinstallation.

DS-7.7.5 Rural


a) Where Council has not provided supply to meet either fire fighting or residential supplyneeds, a suitable supply of potable water shall be provided.

b) Storage shall also be provided to meet the fire fighting capacity requirements for therelative activity as per PAS4509:2008. For a residential dwelling this means aminimum on site storage requirement of a minimum of 40,000 litres storage,installation of a toby connection and all weather access.

c) Where principal or trunk watermains are laid "across country" or not parallel toboundary lines, the location of the watermain is to be marked by H4 treated timber orconcrete valve/hydrant posts, painted white, without the H or V mark.

Note: Council is not required to provide potable water to meet residential supply or fire fightingrequirements outside the urban water supply catchment. In these locations, should reticulationbe available, the activity may connect but no guarantee is provided about the adequacy ofsupply.

DS-7 WATER SUPPLY


DS-7 - Appendix AAssociated Standards

DS-7 - Appendix A.1 General

The latest revision or operative version of the following standards shall be used inconjunction with the IDC:

a) Council documentation:

i) City Plan

ii) TCC Water Supply Bylaw

iii) TCC / WBoPDC Hygiene Code of Practice for Water Supply Systems

iv) TCC Smart Metering Guide for Developers

b) New Zealand/Australian/British standards:i) NZS/BS 750:1984 Specification for Underground Fire Hydrants and Surface

Box Frames and Covers

ii) AS/NZS 1252:1996 High-strength Steel Bolts with Associated Nuts andWashers for Structural Engineering

iii) AS/NZS 1477:2006 PVC Pipes and Fittings for Pressure Applications

iv) AS/NZS 1567:1997 Copper and Copper Alloys – Wrought Rods, Bars andSections

v) AS 1628 Copper Alloy gate, Globe and Non-return Valves

vi) AS 1646.1:2000 Seal Rings

vii) AS/NZS 2280:2004 Ductile Iron Pipes and Fittings

viii) AS/NZS 2544:1995 Grey Iron Pressure Fittings

ix) NZS 2638.2:2003 Gate Valves for Waterworks Purposes – Resilient Seated

x) AS/NZS 2544:1995 Grey Iron Pressure Fittings

xi) AS/NZS 2845.1:1995 Water Supply – Backflow Prevention Devices – Materials,Design and Performance Requirements

xii) NZS 3501:1976 Specification for Copper Tubes for Water, Gas and Sanitation

xiii) AS/NZS 4130:2009 Polyethylene (PE) Pipes for Pressure Applications

xiv) AS/NZS 4158:2003 Thermal-bonded Polymeric Coatings on Valves and Fittingsfor Water Industry Purposes

xv) NZS 4404:2010 Land Development and Subdivision Infrastructure

xvi) NZS 4442:1988 Welded Steel Pipes and Fittings for water, sewage and mediumpressure gas

xvii) SNZ PAS 4509:2008 New Zealand Fire Service Firefighting Water SuppliesCode of Practice

xviii) AS/NZS 4765:2007 Modified PVC (PVC-M) Pipes for Pressure Applications

DS-7 WATER SUPPLY


xix) AS/NZS 4793:2009 Mechanical Tapping Bands for Waterworks Purposes

xx) NZS/BS 5163:1986 Specification for Predominantly Key-Operated Cast IronGate Valves for Waterworks Purposes

xxi) NZS/BS 5163:1986 Specification for Predominantly Key-Operated Cast IronGate Valves for Waterworks Purposes

xxii) BS 5728:1997 Measurement of flow of Cold Potable Water in Closed Conduits.Specification for Single Mechanical Type Meters.

xxiii) NZTA M/7 Roadmarking Paints

xxiv) ASTM – B21 485000 Brass Fittings

xxv) Standards Australia MP52:2001 Tapping Bands and Saddles

c) Other reference material:

i) Resource Management Act 1991

ii) New Zealand Building Act

iii) New Zealand Health and Safety in Employment Act 1992

DS-7 WATER SUPPLY


DS-7 - Appendix BConceptual Hydraulic Operation Of a Gravity Main

The following shows the conceptual hydraulic operation of a Gravity Main:

DS-7 - Appendix B.1 General

design standard - taurangaecontent.tauranga.govt.nz/data/idc/04_design_standards/ds_7_water... ·...

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