Sediment & erosion control

We will control sediment in danger of being washed away by rain to mitigate any potential effects on the freshwater and marine environments of the Mahurangi and Pūhoi Rivers and their tributaries.

Exposed areas of land where work is being undertaken will be limited to ensure sediment generated is kept to a minimum. Areas which give rise to a lot of potential erosion, such as steep slopes and highly-erodible soils, will be avoided where possible.

Earthworks will be staged and monitored to determine when these areas can be stabilised by landscaping and plantings. Exposed areas will be progressively stabilised as work moves along the site. If no active work is taking place, for instance where the soil in a new embankment needs to settle, the exposed surface will be temporarily stabilised.

Where sediment is generated, a number of measures will be put in place, including ponds where the sediment can settle and be contained, silt fences (fine mesh screens), and diversion drains and earth bunds (land contours which divert fresh water flows away from exposed soil).

A dedicated team of environmental professionals will be deployed in the field to monitor all these measures and Auckland Council will be monitoring at least weekly to ensure the desired standards are met.