Stormwater - frequently asked questions.

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1. Who is responsible for the maintenance of open drains and natural watercourses?

   A watercourse on private property is the responsibility of the landowner. This includes:

   • clearing obstructions under the property owner's control
   • keeping all 1 in 10 year storm flow paths clear at all times
   • regular maintenance of drains
   • where possible preventing erosion of open drains by riparian planting of the banks.

   Manukau City Council's responsibilities include:

   • maintaining the public stormwater system as approved and constructed by the council
   • serious erosion due to upstream development approved or carried out by council that can be reduced by maintenance works.
2. What is a Stormwater Catchment Study and do I need to prepare one for my proposed development?

   A stormwater catchment study will determine a stormwater service proposal for the proposed development and contributing upstream catchment. Also whether your work and proposed development generates any overland stormwater flows that will affect the adjacent properties. A stormwater catchment study needs to include:

   • A stormwater service proposal
   • A site area and contributing upstream catchment to the proposed stormwater disposal
   • Pipe capacity calculation to estimate a stress level of the existing stormwater system
   • Stormwater system upgrade proposal (if is required)
   • Overland flow assessment if it is required in accordance with MCC Land Information Register (LIR) and Concept Catchment Plan
     You can consult an engineer at MCC Environmental Services or call Manukau City Call Centre on 262 5104.
3. Who can prepare a Stormwater Catchment Study? Does the Council have those studies already?

   You will need to engage a registered engineer to do a detailed study. Council’s studies are desk top studies with the concept catchment plans where the pipe routes and diameters are indicative only and subject to design.

4. How far the existing system needs to be investigated in terms of its service capability?

   The scope of the assessment depends of the current stress level in the system and extent of additional catchment area to be served by the system.

5. What is a Stormwater Financial Contribution and what it covers?

   Council implements the provision of the Resource management Act (RMA) 1991 and its Operative District Plan to collect stormwater financial contributions ($/additional building site or $/hectare) to cover all its growth related expenditure on stormwater infrastructure (replacement and new infrastructure) in the catchments.

   Stormwater financial contribution flow chart (JPEG 255k.

6. What is the Cost Share Arrangement and how it works?

   If there is a cost share scheme in place the costs for the required stormwater upgrade works will be shared between the developers and Council. The developer’s share is a financial contribution imposed to the proposed development. The Council’s share is balance between the construction costs and financial contribution for the proposed development.

   Refer to the stormwater financial contribution flow chart (JPEG 255k).

7. Can we use for a new development the existing soakage pit on the property?

   Every development should be individually connected to the piped stormwater system. Manukau City Council allows soakage pit as stormwater on-site disposal only in the designated areas in Mangere Ward.

   Plan showing areas allowed for soakage pits & example for soakage pit in regards of soil type.

8. Can we pipe the existing stream running across the property?

   Generally the Council does not support piping of the open streams. These proposals are considered on a case by case basis and usually subject to Auckland Regional Council consent.

9. The existing stormwater system is not capable to cater for more runoff. Can we install a water tank to retain the stormwater runoff from the property?

   Council does not allow water tanks to be connected to the public stormwater system.

10. We are doing a minor household unit at the back yard of our property. Can we use the existing stormwater connection for this development?
    • If the minor household unit is located on a subdividable site, a separate connection to the public system is required.
    • If the site is not large enough to subdivide under the current District Plan rules, the minor household unit can connect into the approved “private” system
11. How can I report a stormwater problem?

    You can report stormwater problems by contacting the Manukau City Council Call Centre on 262 5104.

12. Who do I contact for stormwater advice?

    You can contact the Manukau City Council Contact Centre on 262 5296.

    Further information about stormwater financial contribution is available on MCC website under Operative District Plan, Chapter 9.

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