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Stormwater

Good management of stormwater runoff from worksites is important to prevent contamination of waterways or groundwater.

This page discusses stormwater runoff from industrial or trade sites. See the earthworks page for information on the stormwater management requirements for development or building sites.

Best practice

  • Plan your site carefully.
  • Construct drains or slope your site so that rainfall runoff doesn’t cross your working areas. This keeps uncontaminated water separate from waste water, and reduces the amount of contaminated water you need to manage.
  • Monitor and maintain your runoff control measures. Reassess and adjust if necessary.

Consent requirements

You won’t need a resource consent to discharge stormwater to land or to water if you can meet these requirements:

  • The discharge is not into a significant wetland.
  • You have a stormwater interception system (a roof and guttering, for example) to keep rain from areas where there may be contaminants, if your site is bigger than half a hectare.
  • Your interception system can pick up any contaminated stormwater and either treat it adequately or divert it to a trade waste discharge system.
  • You have a spill contingency plan and interceptor system maintenance plan and keep them regularly updated.
  • The discharge is not from a quarry site.
  • The discharge will fit through a 900mm pipe.
  • The discharge does not cause significant erosion, scouring or deposition.
  • The discharge falls within set technical limits relating to acidity (pH level), oil and grease content, suspended solids, biological oxygen demand (BOD) and ammonia and chlorine levels. Refer to Rule 23 of the Regional Fresh Water Plan, call 0800 736 22 or email consents@trc.govt.nz for details.
  • The discharge does not result in environmental impacts such as oil or grease films, discolouration or adverse effects on aquatic life.

If these conditions cannot be met, you must apply to the Council for a resource consent.

Note that no consent will be granted for applications relating to the Stony River catchment, where it is prohibited to discharge any water or contaminants into water.