Groundworks
Drainage and underground services
Install stormwater, wastewater, water, power, gas, data, and service sleeves before they are buried or covered by slabs and landscaping.
How to execute this stage
Micro-stage control plan
Work through each applicable step in order. A hold point means pause the dependent decision or work until the stated evidence and authorised review are complete.
01Confirm service locations, connection approvals, pipe routes, gradients, bedding, inspection openings, separation, and protectionLevel 2 · Groundworks
TaskCheckHold pointEvidenceRecordNext actionSimple explanation
Confirm service locations, connection approvals, pipe routes, gradients, bedding, inspection openings, separation, and protection.
Technical context
Coordinate this work against Drainage plan, Drainage specification, the current consent status, and the actual site condition. Confirm interfaces before releasing dependent work.
Why it matters: The main recorded risk is: Incorrect falls. A missed check can create rework, delay, hidden defects, an inspection failure, or a departure from approved project documents.
Prerequisites
- Drainage plan is current, approved for the intended use, and available to the people doing the work.
- Drainage specification and relevant product information have been checked.
- Access, responsibility, safety controls, preceding work and the council drainage inspection sequence are confirmed.
Checks
- Check the completed work against Drainage plan and Drainage specification.
- Check specifically for: Incorrect falls.
- Avoid this known mistake: Backfilling before inspection.
Evidence to save
- Wide, location-identifying and close-up photographs of the completed drainage and underground services work before it is concealed.
- Marked-up Drainage plan or a precise drawing/detail reference.
- Council drainage inspection result, consultant record, trade QA record or written not-applicable reason.
Hold point
Do not cover, backfill, load, connect, certify or release the next activity until Council drainage inspection and the required project evidence are complete or the authorised reviewer confirms what may proceed.
Stop or escalate when
- Incorrect falls
- Backfilling before inspection
- The current drawing, approval, competent reviewer or required evidence cannot be confirmed.
Documents and records
- Drainage plan
- Drainage specification
- Current RFI/site-instruction/change record
- Inspection and evidence register
- Cost effect
- Rectification, reinspection, delay, damaged follow-on work, access loss and changed scope can increase the cost of drainage and underground services. Record the cause and obtain written pricing before approving a commercial change.
- Programme effect
- This activity controls the release of dependent work. Update the lookahead programme and notify affected trades if the hold point, information, inspection or evidence is not ready.
Next action
Install and test underground drainage and service sleeves before backfill.
Applicability: Apply when this work package is included in the current project scope. Confirm project-specific consent, contract, design, site and authority requirements.
Use the current consented/issued project documents and competent site review. BuildPath does not approve work.
02Install and test underground drainage and service sleeves before backfillLevel 2 · Groundworks
TaskCheckHold pointEvidenceRecordNext actionSimple explanation
Install and test underground drainage and service sleeves before backfill.
Technical context
Coordinate this work against Civil plan, Council/utility requirements, the current consent status, and the actual site condition. Confirm interfaces before releasing dependent work.
Why it matters: The main recorded risk is: Pipe damage during backfill. A missed check can create rework, delay, hidden defects, an inspection failure, or a departure from approved project documents.
Prerequisites
- Civil plan is current, approved for the intended use, and available to the people doing the work.
- Council/utility requirements and relevant product information have been checked.
- Access, responsibility, safety controls, preceding work and the pressure/water test sequence are confirmed.
Checks
- Check the completed work against Civil plan and Council/utility requirements.
- Check specifically for: Pipe damage during backfill.
- Avoid this known mistake: No photos/as-built measurements.
Evidence to save
- Wide, location-identifying and close-up photographs of the completed drainage and underground services work before it is concealed.
- Marked-up Civil plan or a precise drawing/detail reference.
- Pressure/water test result, consultant record, trade QA record or written not-applicable reason.
Hold point
Do not cover, backfill, load, connect, certify or release the next activity until Pressure/water test and the required project evidence are complete or the authorised reviewer confirms what may proceed.
Stop or escalate when
- Pipe damage during backfill
- No photos/as-built measurements
- The current drawing, approval, competent reviewer or required evidence cannot be confirmed.
Documents and records
- Civil plan
- Council/utility requirements
- Current RFI/site-instruction/change record
- Inspection and evidence register
- Cost effect
- Rectification, reinspection, delay, damaged follow-on work, access loss and changed scope can increase the cost of drainage and underground services. Record the cause and obtain written pricing before approving a commercial change.
- Programme effect
- This activity controls the release of dependent work. Update the lookahead programme and notify affected trades if the hold point, information, inspection or evidence is not ready.
Next action
Photograph routes with measurements to fixed points before burial.
Applicability: Apply when this work package is included in the current project scope. Confirm project-specific consent, contract, design, site and authority requirements.
Use the current consented/issued project documents and competent site review. BuildPath does not approve work.
03Photograph routes with measurements to fixed points before burialLevel 2 · Groundworks
TaskCheckHold pointEvidenceRecordNext actionSimple explanation
Photograph routes with measurements to fixed points before burial.
Technical context
Coordinate this work against Services layout, Plumbing and drainage standards referenced by consent, the current consent status, and the actual site condition. Confirm interfaces before releasing dependent work.
Why it matters: The main recorded risk is: Service clash. A missed check can create rework, delay, hidden defects, an inspection failure, or a departure from approved project documents.
Prerequisites
- Services layout is current, approved for the intended use, and available to the people doing the work.
- Plumbing and drainage standards referenced by consent and relevant product information have been checked.
- Access, responsibility, safety controls, preceding work and the as-built drainage survey where required sequence are confirmed.
Checks
- Check the completed work against Services layout and Plumbing and drainage standards referenced by consent.
- Check specifically for: Service clash.
- Avoid this known mistake: Wrong pipe route due to old drawing.
Evidence to save
- Wide, location-identifying and close-up photographs of the completed drainage and underground services work before it is concealed.
- Marked-up Services layout or a precise drawing/detail reference.
- As-built drainage survey where required result, consultant record, trade QA record or written not-applicable reason.
Hold point
Do not cover, backfill, load, connect, certify or release the next activity until As-built drainage survey where required and the required project evidence are complete or the authorised reviewer confirms what may proceed.
Stop or escalate when
- Service clash
- Wrong pipe route due to old drawing
- The current drawing, approval, competent reviewer or required evidence cannot be confirmed.
Documents and records
- Services layout
- Plumbing and drainage standards referenced by consent
- Current RFI/site-instruction/change record
- Inspection and evidence register
- Cost effect
- Rectification, reinspection, delay, damaged follow-on work, access loss and changed scope can increase the cost of drainage and underground services. Record the cause and obtain written pricing before approving a commercial change.
- Programme effect
- This activity controls the release of dependent work. Update the lookahead programme and notify affected trades if the hold point, information, inspection or evidence is not ready.
Next action
Close the drainage and underground services stage, link its evidence, resolve outstanding defects and release only the next applicable stage.
Applicability: Apply when this work package is included in the current project scope. Confirm project-specific consent, contract, design, site and authority requirements.
Use the current consented/issued project documents and competent site review. BuildPath does not approve work.
Trade-to-trade control
Interfaces and release gates
Use the actual consented design, specification and authorised reviewers. These controls help expose gaps; they do not approve work.
Civil drainage, building services and final ground levels
Prerequisites
- • Civil, drainage, architectural and landscape drawings use coordinated levels
- • Connection approvals, easements and authority requirements are known
- • Service crossings, retaining, access and future maintenance zones are resolved
Interface checks
- • Pipe grades, cover, bedding, separation and test points meet the approved design
- • Finished ground/paving falls do not compromise cladding, thresholds or overland flow
- • As-built survey can identify every buried service and connection
Evidence before release
- • Open-trench photographs and test results
- • Survey/as-built information
- • Authority/council/engineer acceptance required for the actual project
Next team: External works, landscaping and close-out teams
Open the related Workspace control →What happens in this stage
- Confirm service locations, connection approvals, pipe routes, gradients, bedding, inspection openings, separation, and protection.
- Install and test underground drainage and service sleeves before backfill.
- Photograph routes with measurements to fixed points before burial.
Before work starts
- Confirm the latest issued-for-construction and consented documents for drainage and underground services are on site, including Drainage plan.
- Check Drainage specification, approved product data, RFIs, minor variations, and amendment status before work starts.
- Confirm the subcontractor understands the scope, hold points, access, protection requirements, H&S controls, and quality evidence required.
- Check the programme sequence so this stage does not start before earlier work, inspections, testing, or concealed-work photos are complete.
- Confirm materials delivered to site match the specification, are dry/undamaged, and are stored according to manufacturer instructions.
During the work
- Walk the work face early, mid-shift, and before close-up. Compare actual work with the consented drawings, specification, and manufacturer details.
- Check set-out, levels, falls, clearances, penetrations, fixings, bracing, waterproofing, or protection points that will be difficult to see later.
- Ask trades to show their own quality checks rather than only saying the work is complete.
- Keep weather, site condition, delivery, delay, inspection, RFI, variation, and safety notes in the daily report.
- Photograph any work before it is covered, backfilled, lined, clad, tiled, painted, or otherwise hidden.
After the work
- Complete a close-out walk with the subcontractor and mark defects immediately while access is still available.
- Confirm required inspection bookings, council results, producer statements, LBP Records of Work, warranties, test certificates, or installer declarations are obtained.
- Update as-built notes where service routes, drainage, fixings, penetrations, or dimensions differ from the design.
- Confirm the area is protected from weather, other trades, impact damage, contamination, or premature loading.
- Update the lookahead programme and tell affected trades what is ready, what is blocked, and what must not be covered.
Common problems and step-by-step solutions
Incorrect trench depth
- 1Stop the affected drainage and underground services activity if continuing could hide defective work, create unsafe work, or move away from the consented design.
- 2Photograph the condition from wide, medium, and close-up angles. Include a tape, level, datum mark, gridline, or drawing reference where useful.
- 3Check the latest consented architectural, structural, civil, services, and specification documents before giving an instruction.
- 4Ask the subcontractor to explain the cause, proposed fix, timing impact, and whether the fix changes consented work.
- 5Escalate to the builder/project manager, designer, engineer, council inspector, or client when the fix affects structure, weathertightness, drainage, H1, fire/safety, cost, programme, or consent.
- 6Record the decision, responsible person, drawing/RFI/variation reference, photos, and follow-up inspection in the daily report.
Service clash
- 1Stop the affected drainage and underground services activity if continuing could hide defective work, create unsafe work, or move away from the consented design.
- 2Photograph the condition from wide, medium, and close-up angles. Include a tape, level, datum mark, gridline, or drawing reference where useful.
- 3Check the latest consented architectural, structural, civil, services, and specification documents before giving an instruction.
- 4Ask the subcontractor to explain the cause, proposed fix, timing impact, and whether the fix changes consented work.
- 5Escalate to the builder/project manager, designer, engineer, council inspector, or client when the fix affects structure, weathertightness, drainage, H1, fire/safety, cost, programme, or consent.
- 6Record the decision, responsible person, drawing/RFI/variation reference, photos, and follow-up inspection in the daily report.
Failed drainage inspection
- 1Stop the affected drainage and underground services activity if continuing could hide defective work, create unsafe work, or move away from the consented design.
- 2Photograph the condition from wide, medium, and close-up angles. Include a tape, level, datum mark, gridline, or drawing reference where useful.
- 3Check the latest consented architectural, structural, civil, services, and specification documents before giving an instruction.
- 4Ask the subcontractor to explain the cause, proposed fix, timing impact, and whether the fix changes consented work.
- 5Escalate to the builder/project manager, designer, engineer, council inspector, or client when the fix affects structure, weathertightness, drainage, H1, fire/safety, cost, programme, or consent.
- 6Record the decision, responsible person, drawing/RFI/variation reference, photos, and follow-up inspection in the daily report.
Verification
Source / where to check
Use current official information and the controlled documents for the actual project.
Check stormwater, surface water, drainage paths, and council/engineer stormwater design.
Check hot/cold water supply requirements, plumber producer statements/certificates where applicable, and consented plumbing layouts.
Auckland Council explains local building consent processes, CCC, related certificates, producer statements, LBP notification, and whether resource consent may also be needed.
The issued consent drawings, stamped specifications, engineering drawings, RFIs, minor variations, and amendments control the specific project.
Use the exact current installation manual, warranty requirements, BRANZ/Appraisal information where applicable, and product data sheet for the product on site.
Insufficient data to verify — confirm against the current consented drawings, specifications, Auckland Council requirements, Auckland Unitary Plan, NZ Building Code, relevant NZ Standard, consultant advice, manufacturer instructions, insurance broker, insurer, lender, lawyer, accountant or project contract.
Project-specific consented documents and professional advice override generic guidance.
Common inspections required
- Council drainage inspection
- Pressure/water test
- As-built drainage survey where required
Common risks
- Incorrect falls
- Pipe damage during backfill
- Service clash
- Future access impossible
- Cross-connection
Common mistakes
- Backfilling before inspection
- No photos/as-built measurements
- Wrong pipe route due to old drawing
Required documentation
- Latest consented drawings and specifications
- Relevant RFIs, site instructions, amendments, minor variations, and variation approvals
- Subcontractor scope, QA checklist, delivery dockets, product data, and installation records
- Inspection booking/result records and photos before cover-up
- Daily site report notes covering labour, weather, progress, delays, risks, and decisions
Photos or diagrams needed
- Wide photo showing where drainage and underground services is happening on the site
- Close-up photos of critical details, fixings, laps, seals, penetrations, clearances, levels, or falls
- Photo of product labels, batch numbers, delivery dockets, and installer marks where relevant
- Marked-up drawing or simple diagram showing any changed location, clash, defect, or agreed remedial detail
Construction manager checklist
- 1Scope, drawings, specification, product data, and latest revision confirmed
- 2Trade briefed on hold points, tolerances to verify, evidence required, and inspection sequence
- 3Access, storage, protection, temporary works, and safety controls in place
- 4Work checked against drawings during installation, not only at completion
- 5Photos and records captured before work is concealed
- 6Defects, RFIs, delays, and variations recorded with owner and due date
- 7Inspection/producer statement/warranty/Record of Work requirements tracked for CCC
Questions to ask the subcontractor
- Which drawing, detail, or manufacturer instruction are you working from?
- What needs to be checked before this is covered or handed to the next trade?
- What could stop you today: weather, access, materials, information, inspections, or other trades?
- Does anything on site differ from the drawings or specification?
- What evidence will you provide for the quality file and CCC file?
Red flags to stop work
- Work differs from consented drawings or specification and no approved variation/RFI exists
- A structural, weathertightness, waterproofing, drainage, fire/safety, or H1 detail is unclear
- The trade wants to cover work before inspection, testing, or photos are complete
- Specified materials are missing, substituted, damaged, wet, expired, or installed outside manufacturer instructions
- A safety control is missing for excavation, heights, plant movement, electrical work, asbestos, silica, or public protection
What to record in the daily report
- Exact location and quantity of work completed
- Trade headcount, company names, plant used, deliveries, and material batch/product details
- Weather, site conditions, delays, instructions received, RFIs raised, and inspections booked/passed/failed
- Photos taken before cover-up and any defects or non-conformances found
- Next-day lookahead, blockers, and who is responsible for each action
Use this in my project
Turn drainage and underground services into controlled action
Open the relevant workspace register, create the project-specific record, link the controlling documents and preserve evidence. The guide does not automatically approve or verify the action.