Civil Engineering Design Needs
5 Principals for Erosion and Sedimentation Control Plans
Prepare an Erosion and Sediment Control Plan for your site before works start and submit it with your building application. The Plan should show how you will prevent stormwater pollution throughout the construction phase and until the site landscaping has been completed,
i.e. the erosion hazard has been reduced to an acceptable level. Different controls might be necessary at different stages over the construction phase as the nature of the site changes, e.g. changing drainage patterns, moving stockpiles to different places, etc. If
such changes are likely, these must be shown on the Plan. A model Plan is overleaf. Note that it is made up of both a Commentary and Drawings and relates to a specific site.
- Installation of Controls
Before works start, set up the erosion and sediment controls and install a sign warning everyone of the penalties of pollution (this may be provided by council). Make sure that all site workers understand their individual responsibilities in preventing pollution. A recommended sequence for setting up controls is:
(i) Establish a single stabilised entry/exit point to the site;
(ii) Install sediment fences along the low side of the site;
(iii) Divert upslope water around the site and, if necessary, stabilise the channels and outlet;
(iv) Clear only those lands that must be disturbed during the building works. Put up a barrier fence around areas where the vegetation is to not be disturbed;
(v) Ensure that any stockpiles are on your land – not the footpath or the next-door neighbours land. Where necessary, seek approval from Council or your neighbour(s) for any offsite stockpiles. Ensure stockpiles have appropriate erosion and sediment controls;
(vi) Install onsite waste receptacles, such as skips or bins, and wind-proof litter receptacles, etc.;
(vii) Start building works;
(viii) Install and connect roof downpipes before the frame inspection; and
(ix) Stabilise any exposed earth banks when the building works are completed.
- Maintenance of Controls
All erosion and sediment control works should be checked at least once each week and after each rainfall event to ensure they are working properly. Maintenance might include:
(i) Removing sediment trapped in sediment fences, catch drains or other areas;
(ii) Topping up the gravel on the stabilised access;
(iii) Repairing any erosion of drainage channels; and
(iv) Repairing damage to sediment fences. Remember that the erosion and sediment control works
might need to change as the slope and drainage paths change during the development phase. Best practice includes anticipation of the likely risks and being prepared for unusual circumstances, e.g. having spare sediment fence material on the site.
- Finalisation of Works
Ensure that the site is stabilised and no exposed soil remains before removing the erosion and sediment controls. If landscaping is not completed before hand-ing over the site to the owners, ensure they are aware of their responsibilities to prevent pollution.
- Four Basic Principles
(i) Make sure everyone working on the site understands how important it is to not pollute stormwater.
(ii) Do not disturb more of the site than you have to.
(iii) Install erosion and sediment controls before starting work.
(iv) Maintain your erosion and sediment control works throughout the construction phase