Sedimentation and erosion
What is Sediment?
Sediment is a pollutant caused by erosion and works near our waterways.
Eroded soils discharge into Auckland's waterways polluting and causing problems for animals and plants in the water and people wanting to enjoy them.
The ARC is required to sustain and protect fish habitat and ecosystems and maintain and enhance the quality of water bodies and coastal water.
Please note - As at December 2007 TP90 has been updated and can be viewed via this link.
- earthworks
- vegetation removal
- quarrying
- building activities
- road construction
- trenching.
These activities can generate over 2000 times the amount of sediment than forested land, potentially washing more sediment into our waterways every rainy day. The ARC is responsible for the control of discharges of contaminants into or onto water.
Why is sedimentation such a problem?
Sediment can harm plants and animals and their habitat.
Insects shellfish and fish help to maintain good water quality in streams and estuaries, sediment interferes with their vision, digestion, gills and oxygen intake and can make them vulnerable to predators. If the waterway is no longer suitable to live in these animals will die or if possible move to other areas.
Fish passage within waterways must be maintained to protect populations of native New Zealand species (15) that live, feed, reproduce and migrate between fresh and saltwater.
How can erosion and sedimentation be minimised?
- Work within the driest season.
- Coordinate with other services (roading, gas, power, telephone drainage) and put erosion protection measures in place.
- Stage earth works and a combination of control methods.
For more information on sediment management guidelines and control methods.
