Sediment and Erosion


Soil erosion on building sites can be a major source of sediment pollution in our waterways. Although a single block of land may seem a small part of the catchment, the cumulative effect of polluted run off water from a number of building sites can have a dramatic impact on water quality.

Who is Responsible?

The owner and the builder are responsible for controlling soil erosion and preventing sediment from the building site from being washed into stormwater drains. Under section 120 of the Protection of the Environment Operations Act 1997 heavy fines, including on the spot fines ($4000 for individuals and $8000 for corporations) may be imposed if a person allows soil, earth, mud, clay, concrete washings or similar material to be washed or placed in a position from where it is likely to be washed into stormwater drains.

Pollution Prevention Measures

All building sites should adopt the following measures to prevent pollution:

  • restrict vehicle access to one stable entry and exit point
  • install and maintain adequate sediment and erosion controls¬†
  • preserve grassed areas and retain the maximum cover of natural vegetation by minimising the amount of land disturbed by shaping. Mulch or revegetate disturbed areas as soon as possible
  • ensure that stockpiles of sand, gravel, soil and similar materials are located so that material does not spill onto the road or pavement, is not placed in or can be washed into drainage lines, depressions or watercourses
  • clean up accidental spills of soil or other materials on the roadway or gutter
  • never wash excess materials and water from cleaning tools and equipment down stormwater drains
  • locate houses and buildings on the site so that cut and fill operations are minimised and ensure that access driveways are no steeper than necessary
  • minimise on site vehicle activity during wet weather or when the site is muddy
  • do not pump out or allow any unclean water to enter the stormwater system.

Sediment fences are to be laid along the contour as much as possible and are to consist of a suitable geo-textile fabric supported a maximum of every three metres with the lower edge trenched to a depth of 150mm.