Stormwater Resource Consents

May 1, 2020 | Insights

Finding it difficult to navigate your way through Council’s rules on stormwater or the requirements for obtaining resource consent for a stormwater discharge? Or finding it difficult to understand which stormwater management device you should be specifying or where it should be positioned on-site?

GWE’s stormwater team is widely experienced in the design of stormwater systems and obtaining resource consents for residential and commercial properties in both urban and rural settings. The following notes should help you gain a better understanding of the process.

Eight requirements for a resource consent application for stormwater management and discharge

A development plan that provides a detailed outline of the proposed development including:

#1  Existing Site Overview

An overview of the existing site and how it is intended to be developed. In particular, Council is looking for the change in impervious area in the before and after development scenario. The impervious area includes roofs, driveways, parking areas and footpaths

#2  Property Search Results

The results of any search of the property files including the location of existing services, any existing resource consents and the identification of the site on planning maps showing zoning and overlay information

#3  GeoTech Appraisal

The results of investigations undertaken on the site including a geotechnical appraisal (of the stability of the site and the soil types and their respective permeability) and a site survey mapping natural features and contours

#4  Drainage Plan

A drainage plan showing the stormwater catchment in which the development site is located and the primary and secondary drainage systems, overland flow paths, existing streams and or open channels and the location of any stormwater treatment devices e.g. stormwater ponds or wetlands in the vicinity of the site

#5  Stormwater Run-off Calculations

Calculations for stormwater run-off from the site for the before and after development conditions and the method by which the increase in stormwater flow and change in stormwater quality (if this applies) is mitigated with the use of stormwater management devices

#6  Details of Stormwater Management Device

Plans showing the location, type and details of the stormwater management device(s) selected for the site to demonstrate that they have been sized appropriately

#7  Stormwater Management Plan

A stormwater management plan that summarises the above regulatory requirements and a description of the way stormwater will be managed on site, including what alternatives were considered and why the preferred method was adopted as the best practicable option

#8  Assessment of Environmental Effects

An assessment of the effects that the stormwater discharge from the site will have on the receiving downstream environment and how the proposed development is affected by the upstream stormwater catchment

We’re here to help

Need a site appraisal carried out or storm water run-off calculations prepared? Need a stormwater management report or stormwater management devices sized, give Colin Cranfield at GWE Consulting Engineers a call on 021 776 393