Guide To Building Over Hamilton City Council's (HCC) Wastewater And Stormwater Pipes.
If you are thinking about or planning a new building project, a garage, a sleep out or an extension to your house you should check to see if a Hamilton City Council wastewater or stormwater pipe runs through or near the area that you wish to build within.
This is very important as any structures built over the pipes are likely to apply loading to the pipelines or disturb fill material around the adjacent areas. These factors could result in pipe failure and subsequent wastewater/stormwater blockages and flooding.
Such incidents can affect nearby structures and cause significant damage to personal property and stress to people’s day to day lives.
Even if there are pipes running through the area you may still be allowed to build over wastewater/stormwater pipes if conditions are suitable. These include structural designs that meet HCC’s requirements.
Note: wastewater and stormwater manholes and service pipes (connections) cannot be built over in any circumstance, please contact HCC Water and Waste Services on 838 6999 if you wish to discuss any alternatives such as relocation of manholes or connections.
Step 1: Identify the HCC assets (pipes / manholes / catchpits / service connections) that are located in the immediate area.
You can do this by visiting the Council office at Garden Place and for a small cost receive a copy of the service plans from ground floor Building Department or by accessing the wastewater/stormwater plans for the area in question by logging on to
Step 2: Detailed Investigation
Once you have identified the HCC assets that are located on your proposed building site, further investigation will be required.
This investigation will accurately identify where the assets are located in relation to your proposed building site, the depth and current condition of the assets. This is done by CCTV (Close circuit TV) inspection of the pipe and by accurately marking (this is normally done by pegs from boundary to boundary) on the site the location of the pipe where it is laid and any connections attached to the pipe.
You are required to contribute to the cost of this investigation. A 5 working days notice is required for this service and can be requested as part of your Building Consent process.
You may also apply for the CCTV inspection prior to lodging your Building Consent by visiting Water and Waste Services on the 6th Floor of the HCC offices in Garden Place.
Step 3: CCTV Results & Building Structure Design
So the CCTV has been done, now what? It is important that the pipe is in good condition. If not, the required repair must be carried out before any building activities commence on site.
HCC will endeavour to undertake any repairs to accommodate your building programme. However HCC reserves the right to carry out the repair works at a time that is suitable to HCC. Your Building Consent may be delayed until the repair work is completed.
If the pipe is in good condition you will be granted permission to build over it. You will need to engage a structural engineer to design a foundation that places no loading on the pipe. The final design must be approved by HCC.
HCC's Water & Waste Services mandatory Conditions for Design:
- No manholes or service connections are located under the intended building or structure. Adequate clearance must be allowed for maintenance activities. The distance can be determined when the depth of pipe is known.
- The intended building is specifically designed so that no structural load is placed on the pipeline.
- If piling is required, all piles must be located no less than 1.0m clear of the outside of the pipeline.
All piles from 1.0m-2.0m from the pipeline must be drilled to at least 1m below the invert level of the pipeline before pile driving can commence
Step 4: The Building Process
Once the design is approved you can then proceed with lodging your Building Consent with the HCC's Building Department. If you have already lodged your Building Consent prior to the CCTV inspection the results of the inspection need to be obtained before your consent is processed.
What else do you need to know?
A CCTV inspection is a vital tool in minimising damage to public wastewater/stormwater networks while allowing people to build where they wish to.
A CCTV inspection is required for the following:
- Where the proposed building platform is within five meters of any public wastewater/stormwater pipe.
- Where there is uncertainty regarding the location of a wastewater/stormwater asset in relation to the proposed building site.
- If unsure about whether you require a CCTV inspection please contact the HCC's Water & Waste Services, 838 6999 for further information.
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