All system designers considering discharges shall refer to the current relevant Network Discharge Consent and Catchment Management Plan.
Refer to Section 4.2.6 for more information on catchment planning.
Stormwater runoff caused by an increase in impermeable area as a result of development shall not be permitted to discharge across footpaths or berms, or from or to adjacent properties. Sheet flow from upstream lots or sub-catchments shall be intercepted by either the primary drainage system or the secondary overland flow paths wherever such sheet flow may create a nuisance to downstream lots.
Natural intermittent streams and overland flow paths are generally the responsibility of landowners, and there is an obligation on downstream landowners to accept these natural flows from upstream properties. Therefore where development within these systems causes unacceptable effects on downstream properties or where the existing primary drainage system has failed, the landowner of that development property shall be responsible for rectifying the situation by mitigating any negative impacts, based on the pre-development condition.
The council has the ability, under Section 459 of the Local Government Act 1974, to require the land owner to execute, provide, and do generally any works, materials, and things which in the opinion of the council are necessary or expedient for the efficient drainage of the premises and every part thereof.
220.127.116.11. Stormwater Disposal from Development in Brownfield Areas and New Developments in Greenfield Areas
The developer shall always discharge into the public stormwater network (subject to capacity assessment) at the point approved by the council. In designated soakage areas, discharge shall be to private soakage (subject to satisfactory percolation testing in accordance with Auckland Council technical report TR2013/040 (Stormwater Disposal via Soakage in the Auckland Region)).
If discharge to the public system is not possible, other site-specific discharge options may be discussed with the council and submitted for specific approval. The preferred solution will be developed on a case-by-case basis in consultation with Auckland Council and/or Watercare and/or Auckland Transport.
In order of preference, options include:
1. Discharge to the public network, or to private soakage for designated soakage areas
2. Discharge to a watercourse or coastal area
3. A connection may be made to a catchpit lead, subject to the conditions specified in Section 4.3.11. Connection may not be made to a lead discharging to soakage.
4. Discharge to either:
- The kerb (subject to Auckland Transport approval). Discharge of stormwater to the road kerb shall not be permitted in greenfield areas unless it forms part of a Water
- Sensitive Design solution for the wider subdivision
- A combined sewer line (subject to Watercare approval).
- In either case, an approved on-site mitigation device will be required.
18.104.22.168. Stormwater Disposal from Combined Sewer Areas
On-site mitigation devices are required when stormwater disposal is in an area which is both:
- Defined as a combined sewer area
- An area where Auckland Council’s programme for sewer separation does not indicate a new stormwater network upgrade within 5 years of building consent application.
22.214.171.124. Disposal Methods Not Permitted
Stormwater from any improvement shall never be discharged into the following:
- A wastewater-only system
- Footpaths, berms, or adjacent property
- An area with insufficient soakage (refer to Auckland Council technical report TR2013/040 (Stormwater Disposal via Soakage in the Auckland Region)).