One of the most important ways to prevent erosion is to plan works appropriately before stripping vegetation and exposing the site. Where possible, divert upstream water around the site to prevent additional water from entering your site. Erosion and sediment control measures, such as silt fencing, stabilised site accesses and clean water diversions, should be the first steps of construction on site and should be fully installed before to any other earthworks activities start. Even for works not requiring resource consent, it is a requirement to put in controls to prevent the loss of sediment from your site.
High-risk sites
If your works are going to be close to a waterway (such as a drain channel, river or stream) or your site is on a slope, it is likely that you are working on a high-risk site and will need additional controls to prevent erosion and offsite discharge. Please consult your Erosion and Sediment Control Plan (ESCP) and get in contact with the Porirua City Council’s monitoring and enforcement team if you need advice.
At a minimum for sites containing a stream, river or drainage channel, silt fences running parallel to the stream flow will likely be required – along the entire length of the stream where the works are taking place. The majority of waterways in Porirua discharge into the harbour and protecting these waterways is a very important step to reducing the sediment loads entering the harbour.
Stream works
If your works involve any works within a stream, you may require a resource consent from Greater Wellington Regional Council. You can contact them on 0800 496 734.
Materials
You need to have all required materials on site, well before rainfall is predicted. If your Erosion and Sediment Control Plan requires silt socks and geofabrics, make sure you have a stockpile of these materials on site in case unpredicted events occur. A lack of preparation is no excuse for non-compliant discharges.
