Whanganui District Council Land Development & … · Whanganui District Council Land Development & Subdivision Engineering Document 2016 Whanganui District Council Supplement document

Whanganui District Council

Land Development & Subdivision

Engineering Document 2016

Whanganui District Council

Supplement document to NZS4404:2010

January 2016

NZS 4404:2010

1 Whanganui District Plan - Appendix I (Engineering Document 2016) (Operative 15 May 2017)

1 PART 1: GENERAL REQUIREMENTS AND PROCEDURES……………………………………………………..23

1.1 Scope…………………………………………………………………………………………………………………..23

This document shall be read in conjunction with NZS4404:2010. Delete last sentence of C1.1 and replace with: For these purposes, refer to the Whanganui District Council District Plan.

1.2 Interpretation…………………………………………………………………………………………………….…….23

1.2.2 Definitions….…………………………………………………………………………………………….…24

Add to the end of first sentence: ….and plural words have the same definition of singular words:

Add the following new definitions: • AUTHORISED OFFICER – the Authorised Officer for Wanganui District Council for approving

engineering plans is the Council’s Subdivision Engineer or as delegated by Whanganui District Council.

• AUTHORISED REPRESENTATIVE - A person appointed by the Authorised Officer to oversee the Development works on his behalf.

• DESIGNER/DESIGN ENGINEER - the Designer/Design Engineer shall be a person with experience and qualified to sign off producer statements.

• DEVELOPERS SITE REPRESENTATIVE - means a professional engineer or engineering technician appointed by the Developer, and accepted by the Whanganui District Council, to supervise the development works on his behalf.

• EARTHWORKS: area greater than 100m2 and 500mm deep.

• GEOTECHNICAL ENGINEER means a Chartered Professional Engineer (CPEng), or an engineering geologist, with recognised qualifications and experience in geotechnical engineering, and experience related to the development.

• SUITABLY QUALIFIED DESIGN PROFESSIONAL - As defined in the “Guidance on Use of Producer Statements” document – See Appendix k.

• SUITABLY QUALIFIED PROFESSIONAL – See above.

1.3 Context…………………………………………………………………………………………………………………30

1.4 Low Impact Design……………………………………………………………………………………………………32

1.5 Climate Change……………………………………………………………………………………………………….32

Replace: “proposed ‘New Zealand coastal policy statement’ (policy 52)” with “New Zealand Coastal Policy Statement 2010 (policy 25)”.

1.6 Urban design protocol………………………………………………………………………………………………...32

1.7 Requirements for design and construction…………………………………………………………………………33

1.7.1 Investigation and design

Add the following new clause: (d) The developer's designer shall be confirmed and accepted in writing with Whanganui District Council prior to design commencing.

NZS 4404:2010


1.8 Approval of design and construction………………………………………………………………………………...33

1.8.2 Drawings………………………………………………………………………….………………………..34

1.8.2.4 Content of drawings……...……………………………………………………………………………….34

Add the following: See legend of line type and symbols in Appendix A.

1.8.2.5 Recording of Infrastructure – As-built information……………………………………………………..35

1.8.2.5.1 As Built drawings shall be submitted in accordance with Appendix J of this document

1.8.2.5.2 All levels to be shown on a plan shall be in terms of a recognised datum. The following hierarchical precedence is currently in effect for datums.

City datum New Zealand Vertical Datum 2009 (NZVD 2009) Note:NZVD 2009 = Moturiki 1953 + 0.24m; or NZVD 2009 = City Datum + 0.30m The recognised LINZ mean sea level datum i.e. Moturiki Datum 1953 or Wellington Level Datum 1953 or New Zealand Geodetic Datum 2000 (NZGD2000) Assumed datum with easily recognised origin (i.e. Manhole lid and invert level) A local peg is only acceptable in rural areas.

1.8.2.5.3 Level Control

On each development in excess of 7 lots, and, where a road is required to service the lots, and there is an existing Whanganui City or Land Information New Zealand level Bench Mark within 500m of the intersection of the new road with the existing road, the developer shall arrange with the surveyor to install within the new road reserve, (in a position that will remain free from disturbance and as part of the survey traverse network), a permanent Reference Mark set in a concrete block of 300mm square and 450mm deep.

The mark is to be either a Land Information New Zealand bronze plaque or a stainless steel pin complying with the Land Information New Zealand Geodetic standards. The mark so placed is to be levelled in terms of the adjacent Bench Mark to Land Information New Zealand 2nd Order Standards. The level is to be shown in Whanganui City Datum on the as built plans supplied to the Whanganui District Council at the completion of the development. Where there is no existing Bench Mark within 500m of the development, a mark as described above is to be placed for future expansion to the level network.

1.8.2.5.4 Detail plans are required for each service on a separate sheet. A general arrangement plan to

show all services without detailed information shall also be provided. The drawings shall be submitted in PDF and DXF format. The format of the DXF file must be identified when submitting.

1.8.3 Design basis for documents submitted for approval……………………………………………………35

1.8.3.3 Life cycle costing…………………………………………………………………………………………..36

Add the following clause:

Whanganui District Council require that the designer ensure that their design promotes minimum maintenance costs. This applies to all references relating to lifecycle cost throughout NZS 4404.

1.8.4 Approval of design…………………………………………………………………………………………36

1.8.4.1 Add the following clauses:………………………………………………………………………………..36

The Whanganui District Council require 3 sets of drawings for approval. One signed approved set will be

NZS 4404:2010


returned to the developer. This matches the Building Consent approval process. Rail Subdivisions adjoining or crossing a rail line will require the necessary approval from KiwiRail (New Zealand Railways Corporation).

Airports Subdivisions adjoining or crossing an airport will require the necessary approval from the Airport Authority.

State Highway Subdivisions adjoining or crossing a state highway will require the necessary approval from the New Zealand Transport Agency.

1.8.4.2 Approval before commencing construction……………………………………………………………36

Add the following clause: No development works are to commence until the developer has identified all potential hazards, and formulated a Health and Safety Plan to address these hazards and all other requirements of the Health and Safety in Employment Act.

1.8.5.2 .…………………………………………………………………………………………………….………..36

Add the following clause: All CCTV and Testing of pipes, trenches, fill and road formation shall be submitted and approved by Whanganui District Council prior to sealing of road.

1.8.9 Maintenance……………………………………………………………………………………………….38

Add the following clause: The Whanganui District Council will, at S224 approval stage, require a two year performance bond from the Developer, effective from the time of issue of the Section 224 Certificate. Whanganui District Council may call upon the applicant to meet the costs of any failure of the road or public services, which can be attributed to faults in the design, or construction of the development.

NZS 4404:2010


2 EARTHWORKS AND GEOTECHNICAL REQUIREMENT…………………………………………………………..45

2.5 Construction…………………………………….……………………………………………………………………..52

2.5.1 Plant Pest Management

Add the following new section: The management response to minimise the potential for weed establishment can be controlled through identification of weeds that should not be tolerated on site because of their aggressiveness or persistence. Adequate site biosecurity is required for machinery and materials brought onto the site to ensure that weed propagules do not enter the site. This involves cleaning machinery prior to bringing it on to the site and ensuring that other materials brought on to the site, including gravels, are free of seeds and vegetation. Using locally sourced gravel and soils, or other materials where possible may reduce the potential for the introduction of new weeds to the area.

2.6 Final documentation……………………………………………………………....………………………52

2.6.2 As-built drawings for earthworks and subsoil drains…………………………………………………. 53 Add the following sentences: This is required where earthworks exceed 100 square metres and the depth exceeds 500mm. For fill areas compaction results are required in terms of Appendix I, Section 2.

See drawing CM - WDC-02 –Depth Contours Cut / Fill Areas in Appendix A

WDC has the following documents: • Institute of Geological & Nuclear Sciences (IGNS) Reports. (Copies held by WDC

Emergency Manager):

Report No. Title

2A, B Active Geological Structures, Earthquake Scenarios

3A Numerical Assessment of the Earthquake Hazard in the Manawatu Whanganui Region

4A Geological Setting & Earthquake Hazards, Lifeline Vulnerability & Analysis of Possible Damage

4B Characteristics of Near Surface Geological Conditions in Urban Areas of Manawatu Whanganui Region

4C Measurement of Earthquake Ground Shaking in Palmerston North & Whanganui

4D Assessment of Liquefaction-induced Ground Failure Susceptibility in Manawatu Whanganui Region

4E Ground Shaking Hazard Assessment for Urban Centres of Manawatu Whanganui Region

• Aerial photography – current and historical vertical aerial photography of the urban area is held by WDC. WDC also has rural aerial photography. Old stereo pairs are held by WDC Planning Services. The Regional Council holds district wide aerial photography.

NZS 4404:2010


3 ROADS .............................................................................................................................................................. ……..56 3.1 Scope…………………………………………………………………………………………………………………………56

3.2 General ........................................................................................................................................................ ……..56

3.2.1 Objective ...................................................................................................................................... ……..56

3.2.2 Related Standards and guidelines ........................................................................................... ……..56

Add the following new paragraph: The developer shall comply with t WDC policy and procedures for excavation and reinstatement of works within road reserve:

• National Code of Practice for Utility Operators’ Access to Transport Corridors ex NZUAG: • New Zealand Transport Agency Code of Practice for Temporary Traffic Management (CoPTTM)

3.2.3 Road purpose ........................................................................................................................ …….56

3.2.4 Place and link context. ............................................................................................................ …….57

3.2.4.2 Add the following new paragraph: Subdividers /developers should obtain a specific determination from WDC, on a proposed/current road’s status, before proceeding with detailed designs for roads. Where local roads are cul de sac’s, they shall not exceed 300 metres in length in urban areas without specific approval from WDC. Cul de sac’s of this length shall be designed in terms of “Urban” roads in Table 3.2. This approval will only be given where the proposal has been subject to specific design attention, including an analysis of alternative layouts. WDC’s approved Long Term Road Hierarchy Network Plan is covered in the District Plan. Add the following new clause: WDC reserves the right to determine whether a road is deemed to be public or private. In most cases a road will be deemed public if it serves 7 or more dwelling units.

3.2.4.2: Add to the end of the paragraph in (c): Motorways are not included in this Standard.

3.2.5 Network connectivity ................................................................................................................... ……..60

Add the following new paragraph: Where urban roads run generally parallel at a separation of 200 metres or less, and where the topography permits, they shall be connected by lateral roads at a spacing of no less than 600 metres.

3.2.6 Design and access statement ................................................................................................. …….61

3.2.7 Road safety audit. ................................................................................................................... …….61

Add the following new paragraph: The completed roading design may be required to be subject to an independent safety audit by a qualified and approved traffic safety professional, at the developer’s expense, with the audit report made available to WDC at the time that the design plans are submitted to WDC for approval.

3.3 Design………………………........ .................................................................................................. ……..62

3.3.6 Parking, passing, and loading ................................................................................................. …….81

The requirements of Chapter 12 of the District Plan shall be met.

3.3.7 Intersection and alignment design ......................................................................................... …….81

Add to the end of the 2nd paragraph: All residential road intersections of collector/collector class and below shall have a minimum kerb radius at intersections of 9 m. Such intersections shall also have the lot corners splayed by a minimum of 6 m along both boundaries. Add to the end of the last paragraph: Two local roads intersecting a local road shall be offset at least 40 m centreline to centreline. Except for the above minimum specific requirements, intersections shall be detailed to satisfy Austroads Guide to Traffic Engineering Practice Part 5: Intersections at Grade.

NZS 4404:2010


Add the following new clauses: Design of roundabouts shall comply with the TNZ Manual of Traffic Signs and Markings Part 2 and Austroads Guide to Traffic Engineering Practice Part 6: Roundabouts as amended for New Zealand conditions.

3.3.8 No-exit roads……………………………………………………………………………………………….82

Add to the start of the 2nd paragraph, & add to the end of the paragraph: Subject to design……. Where the head of a cul-de-sac is also a low point it shall be provided with a double sump with individual leads from each sump.

3.3.11 Footpaths, accessways, cycle paths and berms .......................................................................... ……..82

Add the following new clause: The requirements of Chapter 12 of the District Plan shall be met.

Add the following new sentences: The berm shall incorporate not less than 100 mm compacted thickness of loam topsoil placed over a base material capable of allowing root penetration and sustaining growth. Stormwater disposal and lighting shall be provided to all pedestrian accessways.

3.3.11.2 Cycle paths………………………………………………………………………………………..……83

Add the following new paragraph: Cycleways shall conform to AustRoads, NZ Cycle Network and Route Planning Guide and WDC’s Shared Pathways Strategy.

3.3.11.3 Footpaths and cycle path surfacing………………………………………………………………….83

Add the following new sentence: In residential areas the acceptable surfacing for footpaths shall be concrete. Coloured concrete and stamped concrete shall not be used. Add to the end: Typical details are shown in Subdivision Supplement to NZS4404:2010, WDC drawing RD-WDC-019 AA.

3.3.11.4 Berms………………………………………………………………………………….………………..84

Add the following new paragraphs at the end: In rural areas, the combination of carriageways and shoulders shall be of adequate width to allow safe passage and stopping of bicycles, pedestrians and motorized traffic. In no case shall berms provide less than 2 m width between the road side channel and road reserve boundary. Rural berms shall be topsoiled to the same standards as urban berms unless they make use of already grassed undisturbed ground.

3.3.12 Traffic signs, marking, and road furniture………………………………………………………………..84

Add the following new clause: All road markings and traffic signs shall comply with the TNZ Manual of Traffic Signs and Markings Add to the 1st sentence last paragraph: ……..requirements and shall comply with NZS4121:2001 Design for Access and Mobility. Add the following new clause: Road and Street Name Signs Road and street name blades shall comply with Table 3.7. Posts shall be either: 100mm by 100mm rough-sawn H4 treated timber posts painted white or, 60mm diameter round fluted aluminium posts powder-coated white.

PTO for diagram

NZS 4404:2010


Table 3.7: Road and Street Name Signs

3.3.13 Trees and landscaping….…………….……………………………………………………………….….84

Add the following new sentence: No building, fence or vegetation on any property shall be erected or permitted to grow in a manner which adversely affects visibility at any road intersection, including access to lots.

3.3.14 Road lighting….…………………………………………………………………………………………....84

Add the following new clause: All new lighting should be LED lighting and agreed to by Council with regards to the appropriate lighting category as per AS/NZS 1158.3.1:2005 – Part 3.1. Lighting poles options shall be as follows: a) A 7.3m CSP suburban type with a 1m curved outreach, or equivalent alternative, and ground planted b) A 10.0m CSP pole with a 3.0m curved outreach, or equivalent alternative, and ground planted c) A 10.0m CSP pole with 3.0m curved outreach, or equivalent alternative, with a shear base. d) Poles shall retain a stainless steel finish, ie. not painted any colour.

Add the following new clauses: 3.3.14.1 Urban Street Lighting……………………………………………………………………………85

In addition to recognising the relative requirements of the roading hierarchy, the lighting design shall focus on potential hazard areas, such as intersections, pedestrian crossings, public transport waiting areas and other points of community gathering. Street lighting shall be provided on all public roads as well as pedestrian and cycle accessways. If developers wish to light private rights of way, then the costs of installing, operating and maintaining such lights shall be at the expense of the developer and/or the subsequent owners.

NZS 4404:2010


3.3.14.2 Rural Street Lighting

Developers in rural areas, where new development creates a hazard, shall provide street lighting. Such areas may include (but are not necessarily limited to) new road junctions, additional traffic loading on existing junctions, or areas of substandard geometry or width. Each case is to be judged on its merits, but it is important that the lighting system provides an unambiguous message to rural drivers. To this end, single lanterns are not considered adequate warning of a rural intersection.

3.3.14.3 Other Utilities For urban and peri -urban areas, underground cabling is the method of installation. Refer also to the WDC’s District Plan requirements.

3.3.15 Bridges and culverts...................................................................................................................... ..85

3.3.16 Private ways, private roads, and other private accesses ............................................................. ..85

Add to the start of the clause: The requirements of Chapter 12 of the District Plan shall be met. Add to the end of the first paragraph: For rear lots or multi-unit or comprehensive developments the provisions of 3.3.18 (Fencing) apply. For individual lots, whether urban, rural, or rural residential, the designer shall show that it is possible to form an access to each lot, that can be safely traversed by normal road going vehicles. Add to the end of the first line of the first sentence, 2nd paragraph: as part of the buildings and on all commercial/industrial accessways, this shall be noted…..

3.3.17 Crossings………………………………………………………………………………………...89

3.3.17.1: Urban………………………………………………….………………………………………....89

Add the following new clause: The width of the vehicle crossing shall be defined as the width at the property boundary.

Replace the 2nd to last sentence of the 3rd paragraph with: All crossings shall be surfaced with concrete.

Replace last sentence, 3rd paragraph with: Drawing series RD-WDC-001AA to RD-WDC-013AA shows acceptable details of vehicle crossings

Insert at end of the 5th paragraph: ……..,, NZS 4121 for disabled persons access and shall incorporate tactile tiles.

3.3.17.2: Rural…………………………….………………………………………………………………89

Add the following new clause: The width of the vehicle crossing shall be defined as the width at the property boundary. Refer RD-WDC-010AA Maximum breakover angles for vehicular access to property

3.3.17 Fencing……………………………………………...……………………………..……..…………………89

3.3.19 Road run-off ................................................................................................................................... ..90

3.3.19.4……………………………………………………………………………………………………..90

For more information on drainage in urban streets refer to Part 4 of this Standard

3.3.19.7.1: Sump location…………………………………………………………………………….….95

Add the following to the end of (a): Unless the specific capacity of a sump intake is known or derived from first principles, the design capacity of a single back entry sump with standard grating shall be limited to about 28 L/s;

Add the following to the end of (c): At all low points double sumps shall be used as a minimum.

NZS 4404:2010


3.3.19.7.2 Sump design………………………………………………………………………………103

Add the following to the end of 3.3.19.7.2: Side-entry systems associated with traditional grated sumps significantly improve sump intake as they are less prone to blockage from debris. They are the preferred type of sumps for normal use. They should generally be detailed to provide a trap to limit the ability of solid or floatable debris entering the stormwater systems. They shall not be used without debris control in commercial or industrial areas or in areas where long lengths of set down kerb may compromise the side entry.

3.3.19.7.5: Add the following new sentence: Secondary flow paths shall be shown on subdivision drawings.

3.4 Construction……………………………………………………........................................................104 3.4.1 Introduction..................................................................................................................................104

Add the following new sentence: Construction work in the public road reserve shall comply with the ‘National Code of Practice for Utility Operators’ Access to Transport Corridors’.

Add the following new paragraph: Plant Pest Control To minimize the potential for establishment, control of weeds that should not be tolerated on site because of their aggressiveness or persistence, identification and controls are required. WDC working with Horizons Regional Council will identify plant pests requiring specific control measures. Adequate site biosecurity is required for machinery and materials brought onto the site to ensure that weed propagules do not enter the site. This involves cleaning machinery prior to bringing it on to the site and ensuring that other materials brought onto the site, including gravels, are free of seeds and vegetation. Using locally sourced gravel and soils, or other materials where possible may reduce the potential for the introduction of new weeds to the area.

3.4.2 Materials for flexible pavements ……………………………………………………………………….104

3.4.3 Road surfacing…………………………………………………………………………………………...105

Add the following new sentence: Clause ( d ) and ( e ) subject to specific approval.

3.4.4 Road surfacing materials………………………………………………………………………………..106

3.4.4.1 First and second coat chip seals……………………………………………………………106

Replace first sentence with: The first coat seal shall consist of a grade 4 and 6 two coat seal. Two seal coats shall be applied by the developer. The second seal coat shall be applied between 12 and 18 months after the first coat. The type of each seal coat shall be agreed with Council’s Infrastructure Group prior to the work commencing. 3.4.4.4 Other ashphaltic mixes………………………………………………………………………..107

Replace middle of 1st sentence (was): ….such as open graded porous asphalt or macadam wearing mix.

3.4.5 Subgrade checking………………………………………………………………………………………108

Insert the following clause as 1st paragraph: The subgrade shall be inspected by the designer to assess the suitability of the exposed subgrade for the proposed design. Where necessary the design shall be modified and soft spots removed before sub-base placement is commenced.

3.4.16 Footpaths and cycle paths…………………………………………………………………………………… 110

3.4.14.1 Concrete………………………………………………………………………………………110 Penultimate paragraph. Delete second sentence.

NZS 4404:2010


3.4.14.3 Concrete pavers………………………………………………………………………………111

Add the following new sentence: Block paving shall not be used.

3.4.14.4 Surface finish, tolerances…………………………………………………………………….111

Add the following new sentence: Coloured concrete and stamped concrete shall not be used.

3.4.15 Kerb and channel………………………………………………………………………………………...111

Replace the first paragraph with the following: Where kerbs and channels are to be provided on carriageways they should comply with RD-WDC-021AA. Footpaths may need strengthening if mountable kerb is used. See Drawing RD-WDC-021 Add the following new sentence: Coloured concrete and stamped concrete shall not be used.

3.4.15 Berms and landscaping…………………………………………………………………………………111 3.4.16 Surface finish and tolerances on kerbs, paths, and accessways…………………………………..112

Add the following new sentence: Coloured concrete and stamped concrete shall not be used.

3.4.17.2 Paths and accessways………………………………………………………………………112 Add the following sentence as sentence 1, paragraph 1: Concrete paths and accessways shall be laid with construction joints at not more than 3 m centres.

Add the following % to sentence 2, paragraph 3: Crossfalls of 3% shall be provided.

3.4.17 As-built and completion documentation ...................................................................................... .112

Add the following new paragraphs: On completion of the physical works, and before acceptance of the works by WDC, the developer shall submit a full set of As-Built drawings of the works to Council in accordance with 1.8.10. The As-Built drawings shall include the full detail required to enable WDC to update its inventory, locate and maintain the works, along with the manuals necessary to operate plant, signals or other devices. As-Built drawings may take the form of construction drawings modified to account for amendments or refinements in the field, but shall be clearly labelled as “As-Built” and certified as an accurate post-construction record. See WDC Land Development and Subdivision Engineering Document 2012 Appendix J: Schedule 1D As-Built Plans and Documents for WDC requirements.

NZS 4404:2010


4 STORMWATER DRAINAGE

4.1 Scope…………………………………………………………………………………………………………………113

4.2 General……………………………………………………………………………………………………………….113

4.3 Design………………………………………………………………………………………………………………...116

4.3.9 Pipelines and culverts……………………………………………………………………………………127

4.3.9.3 Minimum pipe sizes………………………………………………………………………………………127

Replace: Single sump outlets – 200mm to become 225mm Public mains – 200mm to become 300mm

4.3.9.9 Subsoil drains…………………………………………………………………………………………….128

Add the following paragraph to the end of the clause: The developer needs to check with Whanganui District Council’s approved Product List or apply for a new product to be added at the developer’s expense.

See drawing CM-WDC-024 & CM-WDC-025 in Appendix B for subsoil details

Note: Wanganui is prone to iron ochre effecting subsoil drains. Where the water table is high and subsoil drains are necessary Council advice should be sought. Whanganui District Council have specific requirements for subsoil drains to minimise difficulties associated with the presence of the iron ochre. These requirements may include the use of special vitrified clay subsoil pipes. Whanganui District Council has a supply of these pipes and will sell them to developers for use in the iron ochre prone areas.

NZS 4404:2010


5 WASTEWATER…………………………………………………………………………………………………………134

5.3 Design………………………………………………………………………………………………………………...135

5.3.7 System layout……………………………………………………………………………………………..141

5.3.7.4 Pipes in private property…………………………………………………………………………………142

Add the following new paragraph Building over pipelines is not recommended practice. Approval to build over pipelines shall be obtained from the TA which may set special conditions. Alternative options such as relocating the building or diverting the pipeline around the building should always be considered.

5.3.8 Maintenance structures………………………………………………………………………………….144

5.3.8.2 Location of maintenance structures…………………………………………………………………….144

Table 5.7 Acceptable MH, MS and TMS options for wastewater reticulation

Add the following note: (4) The Developer is to refer to WDC if MS or TMS is used.

5.3.8.4 Manholes………………………………………………………………………………………………….145

Add the following note to the beginning of the clause: Refer to Wanganui District Council Supplement Drawings in Appendix B for manhole details.

Note: WDC drawings take precedence over NZS 4404 drawings.

5.3.8.4.4 Internal falls through manholes…………………………………………………………………………146

Add the following paragraph: The invert level of a property connection to a terminal manhole shall be a minimum of 150mm above the outlet pipe invert level

5.3.10 Connections………………………………………………………………………………………………150

Add the following note at the end of paragraph: See drawings CM-WDC-018 to CM-WDC-022 in Appendix B, which show Council and private owners’ responsibility for drains.

5.3.10.4 Location of connection…………………………………………………………………………………...151

Add the following new clause: (e) See example drawing CM-WDC-017 in Appendix B.

5.3.10.5 Connection Depth………………………………………………………………………………………..151

Add the following new clause: All connections to have a rodding point constructed in the road reserve within 300mm of boundary. See Drawing CM-WDC-017.

5.4 Approval of Proposed Infrastructure………………………………………………………………………………152

5.5 Construction………………………………………………………………………………………………………….152

Add the following new section and clauses:

5.6 On-Site Wastewater Disposal System

5.6.1 Process

If on-site treatment and disposal of sewage is necessary in areas where there is no available connection to the WDC sewerage system, then design shall be undertaken as follows, based on an actual assessment of conditions on the site.

The design of an on-site wastewater treatment and disposal system shall be carried out by a suitably qualified and experienced professional, based on a specific assessment of the site conditions and the number of bedrooms in the dwelling (office, rumpus and media rooms count as a bedroom). An assessment report and design must be submitted to the format set out in the accompanying guideline (to be developed). The guide sets out the following:

• factors to be addressed in the site assessment. • information to be provided in support of any building consent application.

NZS 4404:2010


• example site plan showing proposed building location, levels, and location of treatment and disposal system including any reserve area.

• high level information on soils and other site specific constraints for on-site wastewater treatment and disposal in the Whanganui District.

For any subdivision for which on-site disposal is proposed, proof of the ability to provide a suitable wastewater system compatible with building consent requirements for each lot shall be submitted. This will be a preliminary design based on field assessment and design to the standards outlined in clause 5.6.2. The preliminary design shall provide the following information as part of an overall subdivision plan: • preliminary design based on household occupancy of at least 5 persons. • location and extent of the wastewater treatment system and disposal area. • location and extent of the required reserve area. • location of any water or drainage courses, water bodies, water sources, high groundwater level and

fixtures.

Prior to approval under section 224 of the Resource Management Act 1991 the Developer shall submit to, and have approved by WDC, a report by a suitably qualified person acceptable to WDC. If this assessment determines that secondary treatment of effluent is required for any lots, a Consent Notice shall be placed on the title for that Lot which provides the following: ‘The owner of the Lot, prior to the occupation of any dwelling on the Lot, shall install an on-site secondary treated wastewater system approved by the Council and certified by a suitably qualified professional person engaged by the owner’. Note: Horizons One Plan rules require secondary treatment plants with a disposal field comprising subsurface drip line and a wastewater loading rate of no more than 3mm/day. A final on-site system design must be carried out for the Building Consent once the house and site development is known. This will be the responsibility of the Building Consent applicant, and is to be noted in the design documentation submitted to the WDC.

5.6.2 Requirements for Design Compliance

The design must comply with the following:

• All systems shall comply with the requirements of Horizons Regional Council One Plan and the rules contained there-in.

• AS/NZS 1546 On-site domestic wastewater treatment units. • AS/NZS 1547 On-site domestic wastewater management.

In addition WDC require the following and these requirements shall have precedence over NZS provisions (for septic tanks):

• all dwellings shall install a minimum 4500 l capacity septic tank. • all septic tanks shall be fitted with a proprietary outlet filter to prevent solids carryover to the disposal

system. • all sites assessed to have category 1 soils (AS/NZS 1547:2000 - Table 4.2A1 - gravels and sands - free

draining) shall be required to provide a pumped dosing system to distribute effluent evenly over the entire disposal system. Traditional gravity trench and beds systems shall not be acceptable.

• all sites assessed as having category 5 or 6 low permeability soils, shall be required to provide an alternative design ((secondary treatment plan with land application via subsurface pressure compensating drip line) ) for disposal of wastewater, as traditional gravity trench or bed disposal systems shall not be acceptable.

• all sites with high or fluctuating water tables, or where there is potential for environmental contamination and/or the sites do not meet the conditions set out in Rule DL 2, shall be required to install an advanced on-site wastewater treatment and disposal system.

• A passive reserve area shall be provided on the lot, either adjacent to the disposal area or located downstream of it. Reserve area requirements shall be as follows1: − 100% of the disposal area for septic tank and trenches.

1 Reference : On-site Wastewater System Guidelines for Manawatu – Wanganui Region; Horizons Regional Council November 2000 : AS/NZS1547:2000 On Site Domestic Wastewater Management.

NZS 4404:2010


− 50% of the disposal area for septic tank and pumped dosed systems. − 33% of the disposal area for advanced wastewater treatment systems.

5.6.3 Maintenance and Ownership

On-site systems shall be designated on the plan. Systems are to remain the maintenance responsibility of, and in the ownership of, the property owner/developer.

Note: See wording in HRC One Plan regarding ongoing Council compliance certification for onsite

wastewater disposal systems.

NZS 4404:2010


6 WATER SUPPLY……………………………………………………………………………………………………….154

6.1 Scope…………………………………………………………………………………………………………………154

6.2 General requirements……………………………………………………………………………………………….154

Add the following new clause 6.2.3 System review The designer shall undertake a system review to ensure compliance with the requirements of the TA and this Standard and a report to this effect shall be provided. Compliance shall cover at least the following issues: (a) Minimum allowable operating (working) pressure can be maintained at all property connections. This may require zoning; (b) Maximum allowable operating (working) pressure will not be exceeded anywhere in the system; (c) Pipe class is suitable for the pipeline application (including operating temperature, surge and fatigue); (d) Maximum and minimum flow velocities meet TA requirements; (e) Pipe and fittings materials are suitable for the particular application and environment; (f) Minimal likelihood of water quality problems or water stagnation; (g) Valve spacing and positioning allow isolation of required areas; (h) Mains layout and alignment meet TA requirements; (i) Minimum fire fighting demands. Control valves and scour systems where required are positioned to give required control of the system.

6.3 Design………………………………………………………………………………………………………………..155

6.3.5.2 Network analysis…………………………………………………………………………………………156

Add the following new paragraph: Within the area of Whanganui the developer will provide key design information to allow the Whanganui network model to be analysed, if necessary, at the developer’s expense.

Add the following new paragraph: 6.3.5.2.1 Impact of consequential change

An assessment and risk analysis shall be conducted to evaluate and address the impact of environmental and property damage in the event of a major water main failure.

AS/NZS 4360 can be used as a guide for this process.

The following aspects should be considered:

(a) Failure mode of the selected pipeline material;

(b) Failure mode of the selected pipeline jointing system;

(c) The topography of the area adjacent to the water main and how it affects the natural flow of surface water;

(d) The capacity of the local drainage system to cater for a water main failure;

(e) The type of property development adjacent to the water main and the impact of a water main failure on below ground developments such as basements, below ground car parks or terraced development;

(f) Impact on community infrastructure;

(g) Clearance from other services and structures to reduce the likelihood of consequential damage; and

(h) The provision for future access for operational purposes.

NZS 4404:2010


6.3.5.2.2 System test pressure

Add the following paragraph: The system test pressure is the pressure of hydrostatic testing (static), applied to test the integrity of a pipeline system. The system test pressure generally exceeds the actual design pressure of the system. The excess pressure is accommodated by the inherent design safety factor.

6.3.5.3 Peak flows………………………………………………………………………………………………...156

Add the following sentence to the end of the clause: Cross check the results from 6.3.5.3 with 6.5.5 (as modified).

6.3.5.5 Minimum flows……………………………………………………………………………………………157

Replace clause (a) with the following new clause: (a)15L/min for normal residential sites;

6.3.5.7 Sizing of mains……………………………………………………………………………………………157

Table 6.2 Empirical guide for principal main sizing

Add the following Note to the table: Note: The “Rural Residential” column does not apply to Wanganui.

6.3.8 System layout……………………………………………………………………………………………..160

6.3.8.8 Rider mains and duplicate mains………………………………………………………………………162

Delete clause 6.3.8.8 (g).

6.3.12 Structural Design……………………………………………………………………………………………166

6.3.12.10 Embedment………………………………………………………………………………………..…….168

6.3.12.10.1 Minimum pipe cover………………………………………………………………………168

Add the following paragraph: Pipe laying depths:

• 900mm min cover for service mains • 600mm min cover for rider mains in technical specs • 900mm min cover for road crossings

6.3.12.10.2 Minimum trench width…………………………………………………………………………………168

Replace clause with the following: Pipe trench width design considerations shall be based on the minimum side clearances detailed in Appendix

A Drawing CM-WDC-017.

6.3.14 Valves……………………………………………………………………………………………………169

6.3.14.2 Siting of valves….……………………………………………………………………………………...170

Add a new paragraph: Typical valve installation and chamber details are shown in the standard drawings in Appendix A.

6.3.14.3.2 Branch Mains………………………………………………………………………………171

Replace first paragraph 1 with the following new paragraph: Stop valves shall be located on branch mains adjacent to the through water main. The type of joint to be used (Soc-Soc, FI-Soc or FI-FI) shall be based on the required security of the water mains. For supply mains or reticulation mains <DN250, a tee with a flanged branch and flanged valve shall be used (see Appendix A Drawings WS-WDC-001 and WS-WDC-002).

6.3.14.6 Air valves…………………………………………………………………………………………………173

6.3.14.6.1 Installation design criteria……………………………………………………………………..………..173

Replace paragraph 4 with the following: The normal size of the large orifice of air valves shall be DN50 for installation on mains.

6.3.14.8 Flushing points………………………………………………………………………………………..178

Replace paragraph with the following new paragraph: Flushing points should be installed at dead ends on any main or ridermain (see Appendix A drawing WS-WDC-002). Flushing point can be a fire hydrant.

NZS 4404:2010


6.3.16 Connections………………………………………………………………………………………………176

6.3.16.1 Toby……………………………………………………………………………………………………….176

Add the following new clause: Tobies to be positioned outside the vehicle crossing, in order to facilitate maintenance.

6.3.16.2 Property service connections……………………………………………………………………………176

Add the following clause: See Appendix H for property connection sizes. Where there is a water supply in a Right of Way, WDC ownership is to the boundary of the Right of Way

Add the following clause: 6.3.16.2.1 High risk connection

Specify RPZ Backflow Preventer at road reserve boundary in accordance with Council’s Standard detail. See drawing WS-WDC-011 in Appendix A.

6.4 Approval of proposed infrastructure……………………………………………………………………………….178

6.5 Construction………………………………………………………………………………………………………….179

Add the following new paragraphs before 6.5.1. Construction shall be in accordance with WDC’s specifications. Water mains shall only be installed by persons who have had the requisite inoculations.

6.5.3.2 Berms……………………………………………………………………………………………………..179

Replace paragraph with the following new paragraph: Pipe trenches under grass berms and footpaths shall be backfilled in accordance with the requirements of Appendix A Drawing CM-WDC-017.

6.5.3.3 Detector tape…………………………………………………………………………………………………..179

Delete clause: Detector tape is not used by WDC.

6.5.3.4 Tracer wire……………………………………………………………………………………………………..180

Add the following new paragraph: Tracer wire shall be used for all pipe installations.

6.5.4 Pressure testing of water mains…………………………………………………………………………180

Add the following new sentence to the end of the paragraph: Pressure test shall be carried out in the presence of an authorised representative of Council.

Add the following correct equation and criteria at the end of the paragraph: Appendix C Clause 3.7.4 (c) Field Testing of Pipelines

C3.7.4 Air Volume Assessment Replace the equation in (c ) with the following:

∆𝑉𝑉𝑚𝑚𝑚𝑚𝑚𝑚 𝑚𝑚𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑚𝑚𝑎𝑎𝑎𝑎𝑎𝑎 = 1.2 𝑚𝑚 𝑉𝑉 𝑚𝑚 ∆𝑃𝑃 (1𝐸𝐸𝑎𝑎� +

𝐷𝐷𝑎𝑎 𝑚𝑚 𝐸𝐸𝑅𝑅

)

Add e to the equation criteria: ∆𝑉𝑉𝑚𝑚𝑚𝑚𝑚𝑚 𝑚𝑚𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑚𝑚𝑎𝑎𝑎𝑎𝑎𝑎 is the allowable water loss in litres; V is the volume of the tested pipeline section in litres;; ∆𝑃𝑃 is the measured pressure loss in kilopascals; 𝐸𝐸𝑎𝑎 is the bulk modulus of water in kilolpascals; 𝐷𝐷 is the internal pipe diameter in metres; e is the wall thickness of the pipe in metres: 𝐸𝐸𝑅𝑅 is the modulus of elasticity of the pipe wall in the circumferential direction in kilopascals; 1.2 is an allowance factor (e.g. for air content) during the main test phase

NZS 4404:2010


Add the following new clause 6.6 Rural settlements and areas on restricted water supply

All of the above users are advised to have 24 hours on-site storage.

These supplies generally do not have fire-fighting capability. The flows to the properties are restricted based on land area and land use. Testable double check backflow preventors are to be installed on each connection and generally supplies are metered.

Each Scheme has its own Rules, Capital Contributions and connection costs.

Connection manifolds and fittings inside the manifolds are the property of Council.

Note: Rules 16-1 and 16-2 of Horizons One Plan set out the permitted activity limits and conditions that relate to the take and use of surface water and groundwater. If you have any questions regarding water takes please contact Horizons duty consents planner on Freephone 0508 800 800.

Add the following new clause 6.7 Storage

Where storage is required for domestic purposes, a day’s storage based on 500 litres/head/day shall be provided.

For industry it is recommended that a day’s water usage be provided as storage.

Add the following new clause 6.8 Pump stations Requires specific approval with regard to design, operation, maintenance, safety and compatibility

Pumps shall be Variable Speed Drive controlled.

Each pump station shall have a standby pump in addition to the duty pump/s.

Pumps, control and telemetry system shall be compatible with other pump stations operated by WDC.

NZS 4404:2010


7 LANDSCAPE……………………………………………………………………………………………………………..181 7.1 Scope………………………………………………………………………………………………………………….181

Add the following paragraph at the end of the clause: WDC has the following policy documents and guidelines:

The Tree Strategy Solar Protection Policy Guidelines for carriageway clearances (refer Tree Strategy)

7.2 General…………………………………………………………………………………………………………………181 7.2.1 Concept stage………………………………………………………………………………………………181

Replace the first sentence last word to read: Consultation with the TA on landscape design and construction at an early stage of the design development is required.

7.2.4 Ecological, functional, and aesthetic opportunities……………………………………………………182

Replace the first paragraph: Landscaping and Planting are considered integral to sub-division design. Planting provides a range of ecological, functional, and aesthetic opportunities for environmental enhancement. The landscape design shall allow for sufficient planting to ensure that these opportunities are maximised.

7.2.5 Landscaping and planting opportunities……………………………………………………………….182

Add the following to the end of the first paragraph: The Landscaping opportunities can allow for innovative and site specific planting plans that do not necessarily conform to a more traditional avenue approach of planting. Add the following new clause: 7.2.6 Street landscaping Layout and density of planting shall be considered and approved by the TA at the planning stage as per Clause 7.2.1. Accepting that there will be a range of sub-division layout designs, where there are specimen trees to be planted, there shall be no fewer than at least one tree per two properties.

7.3 Design………………………………………………………………………………………………………………...183

7.3.1 Location…………………………………………………………………………………………………….183

Replace the second sentence with the following: Planting may include specimen trees, rain gardens, swales, and other amenity garden features.

7.3.4 New trees and road geometry…………………………………………………………………………..184

Add the following paragraph to the end of the clause: Design shall allow for a minimum berm width of 1.5m to allow sufficient space for root development. Most importantly, the width allows for greater mitigation against interference to infrastructure, and allows for a greater species selection.

7.3.5 Planted grass areas, berms, swales, or rain gardens………………………………………………..184

Add the following paragraph to the end of the clause: Where swales are used in conjunction with tree planting, the berm shall be of sufficient width to allow for trees roots to reach maturity without compromising the water drainage capabilities of the swale. Alternative planting techniques may be required to ensure the integrity of swales is maintained eg use of planting pits.

7.3.6 Species selection…………………………………………………………………………………………184

Delete the following sub clauses:

(a) and (h)

7.4 Construction and maintenance…………………………………………………………………………………….186 7.4.1 Introduction……………………………………………………………………………………………….186

Replace second paragraph, second sentence with the following amended paragraph The developer is responsible (and maybe bonded) for the routine maintenance and replacement of the planting including dead wooding, weed control, mulching, replacing dead trees, shrubs and plants, formative

NZS 4404:2010


pruning and watering for a defined period from the time of acceptance of as-built landscape plans by the TA or issue of a s.224 completion certificate under the Resource Management Act 1991.

7.4.4 Planting grass areas……………………………………………………………………………………..186

7.4.4.2 ……………………………………………………………………………………………………………..187

Replace first paragraph, first sentence with the following amended sentence: Heavily compacted soils shall be ripped to a depth of 300mm with rip lines 0.5m apart, and rolled, before any laying of topsoil.

7.4.4.4………………………………………………………………………………………………………………...187 Replace first paragraph, third sentence with the following amended sentence: Other special purpose grass seed and plant species may be used in special areas such as swales and rain gardens according to the soil profile.

7.4.6 Specimen tree planting………………………………………………………………………………….188

7.4.6.1 ……………………………………………………………………………………………………………..188

Replace first paragraph, first sentence with the following amended sentence: Specimen trees are defined as trees with a trunk diameter of 25mm to 100mm appropriate to species, when measured at 1400mm above ground level.

Add to the end of the first paragraph: Refer to the Tree Strategy – Tree Planting specification.

7.4.6.2………………………………………………………………………………………………………………..188

Replace the paragraph with the following paragraph: Specimen trees shall be sound, healthy, vigorous, and free of any defects. Juvenile trees shall be of uniform size when planted out, and be a minimum grade of PB40 up to PB95, depending on the berm width. Trees shall be established in planter bags at the time of planting. Open ground and bare rooted trees shall not be used. A recommended height for specimen trees is 2.5m at the time of planting to aid early establishment unless the local conditions of a site require consideration of alternatives, for example, and exposed site may require small, well-hardened trees. Specimen trees between 1.5 – 2.5 m may be allowed with the approval of the TA.

7.4.6.3………………………………………………………………………………………………………………...188

Add the following sentence after the first sentence: Refer to the tree planting specification. Replace (b) with the following sentence: (b) Ground cultivated to a depth of 1m and a width of 0.5m to break up any compaction, fracture subsoil, and afford drainage to hard rock areas.

NZS 4404:2010


8: NETWORK UTILITY SERVICES……………………………………………………………………………………...191

8.1 Scope…………………………………………………………………………………………………………………191 8.2 General………………………………………………………………………………………………………………..191

8.2.3 Context………………………………………………………………………………………………………...191

Add the following to the end of paragraph (c) Fibre cabling shall be installed.

8.3 Design………………………………………………………………………………………………………………...192

8.3.1.1 Plans

Add the following to the end of apha-numeric list: (e) The requirements of NZS5258:2003, Gas Distribution Networks. (f) The requirements of the National Code of Practice for Utility Operators’ Access to Transport Corridors. (g) The minimum separation distances between overhead power lines and buildings, structures and earthworks outlined in the New Zealand Code of Practice for Electrical Safe Distances NZECP 34:2001

8.4 Construction………………………………………………………………………………………………………….193 8.4.1 Underground cabling…………………………………………………………………………………….193

Add the following to the end of the paragraph: Fibre cabling shall be installed.

8.4.5 Location of services………………………………………………………………………………………193

8.4.5.2 Recording of underground services…………………………………………………………………….194

Add the following: WDC requires the utility provider to certify that the developer has installed the service to the utility’s satisfaction. A completion certificate shall be supplied prior to applying for the Section 224 certificate. This is required where telecommunications are required as part of the resource consent conditions.