What is stormwater?
Stormwater is rainwater that falls to earth, runs off the surface into streams, waterways or underground aquifers and eventually ends up in the sea.
Good stormwater management systems are needed to reduce the potential for flooding. They are also necessary to deal with pollution that can have an impact on water quality in streams and oceans.
View the natural water cycle and urban water cycle in our See also box.
The following contaminants are found in stormwater and need to be dealt with so they have less impact on the environment:
- Zinc from tyres and roofing material
- Copper from vehicle brake pads
- Oil, grease, fuel
- Industrial and domestic chemicals and detergents.
Stormwater ponds:
- Provide water quality treatment
- Detain stormwater and slow the rate of flow so the potential for flooding and stream erosion is reduced
- Minimise downstream channel erosion
- Enhance open space in urban areas by being planted with native vegetation.
Growing populations and economic development often increase the amount of contaminants in stormwater systems. This presents stormwater quantity and quality management challenges.
Stormwater objectives
Council's stormwater management objective is to have effective stormwater asset management plans and programmes that protect people, property and the environment.
This can be achieved through planning at various levels and the implementation of effective stormwater policies and strategies.
Our policies and strategies
- Planning - District Plan and Integrated Catchment Management Plans
- Asset Management Plan including capital works and maintenance
- Engineering standards to manage stormwater quantity including flooding
- Stormwater contaminants, quality issues, and treatment
- Financial contributions to support growth and demand on stormwater assets
Relevant links
back to top