Erosion control

Introduction

Builders and contractors, like the rest of the community, are responsible for ensuring that their activities do not pollute or disfigure the environment. Conditions will be included in approvals to address issues of erosion and sediment control.

Most urban erosion occurs in a short period during and immediately after construction. The sediment removed by stormwater erosion damages lower land, blocks Council's stormwater drains, and is eventually deposited into watercourses.

The result is turbidity in natural water bodies, a reduction of recreational value, and damage to aquatic life. Sediment is also a primary carrier of chemical pollutants.

Activities leading to soil erosion

Whilst most building sites are a relatively small area, erosion is a major problem due to the intense activity on the site. Typically these are:

  • Earthworks associated with the construction of foundations and other excavations
  • Earthworks for terracing, levelling, landscaping
  • Stockpiles of soil and sand
  • Movement of machinery and vehicles on and off building sites
  • Soil disturbance and grass cover removal by site scraping, trenching and similar building activities

Some ways to prevent soil erosion

Builders and contractors can prevent a lot of soil loss with a common-sense approach to site works.

Access to the allotment

  • Limit access to the site by establishing a single stabilised entrance/exit
  • Lay a 100mm bed of blue metal gravel over the one entrance point to the allotment to prevent bogging and limit tracking of mud off-site during wet conditions
  • When building, preserve as much grassed area as possible
  • Tell sub-contractors and delivery drivers to only use the one stabilised entrance/exit point and not use the footpath area for access or storage of equipment and materials

It may be necessary to provide temporary fencing along the front boundary.

Excavation

  • Confine all cut and fill operations only to the areas of the allotment where it is required
  • Reinstate trenches as soon as possible, compact the back-fill and replace top soil
  • Do not strip and excavate the site until you are ready to begin building
  • Remove excess soil from the site

Stockpiles

  • Confine stockpiles to the subject allotment
  • Place buildilng materials at their final position and not on the roadway or footpath

Erosion and Sediment Control Plans

In some instances it may be that Erosion and Sediment Control plans will be required.

Sediment control measures

Runoff and soil erosion controls are to be installed prior to work commencing on the site and the controls shall incorporate:

  • Diversion of uncontaminated upsite runoff around cleared and/or disturbed areas
  • Sediment control fences at the downslope perimeter of the cleared and/or disturbed area to prevent unwanted sediment and other debris escaping from the land
  • Maintenance of all erosion control measures at maximum operational capacity until the land is effectively rehabilitated
  • Protection of any kerb inlet pit located downstream of the site

Note

  • Any roof drainage system is to be connected to the required discharged point at the building frame inspection stage
  • Any material spilled or deposited on the road reserve or in the gutter is to be removed immediately
  • Provide single stabilised access to site
  • Regularly maintain the installed sediment filters