Planning for construction sites
Key points to consider in the site design include:
- Direct stormwater flow around the building and disturbed areas rather than through the site. Diverted stormwater should be discharged onto stable areas of land and not onto adjoining properties. Avoid directing stormwater to the site’s exit and entry point.
- Minimise the area to be cleared, leave as much vegetation as possible on the site, and only clear vegetation when work is about to commence. If required, plant temporary vegetation on site, fence off areas of the site that don’t need to be disturbed and stabilise earth banks.
- Install sediment control fences on the low side of the site before work commences. During the construction phase, ensure you regularly inspect fences for tears and breaks and repair any faults immediately. Grass filter strips are also suitable on sites with a low gradient. Leave or lay a kerbside turf strip (nature strip) to slow water flows and trap sediment.
- Hay bales are not an acceptable substitute for sediment fencing. Hay bales are not particularly efficient at removing sediment from water, and can easily break down, themselves becoming a source of stormwater pollution. Hay bales placed in gutters can cause localised flooding, as well as obstructing pedestrians and traffic.
- As an additional means to prevent pollutants getting into the stormwater drain, surround drain entry pits with a sausage made of gravel or sand fully enclosed by geotextile fabric. When soil and sand builds up around gravel sausage, it should be disposed on-site. Do not hose it down the drain.
- Ensure that stockpiles are stored within the boundaries of the sediment fence, and limit the amount of material stockpiled on site to what is needed at any one time. Locate stockpiles on highest part of the site and away from drainage lies and street gutters. Cover stockpiles to protect them from erosion.
- Don’t excavate if rain is forecast.
- Install a waste bin on site. Dispose solid materials in land fill or send them to a building recycler where possible.
- Sweep the road and footpath every day and put soil behind the sediment controls. Do not hose down roads and footpaths. Signs of escaped sediment may alert you to any deficiencies in your sediment controls.
- Excess materials such as cement, water from tool cleaning, paint brushes and brick and concrete slurry must not be washed into the stormwater system. All water pumped from the site must look clear and be free of any visible suspended sediment and oil and grease. If possible, clear water discharged from site should be pumped onto grassed areas.
- Where possible, construct a depression or earth dam below brick, concrete or tile cutting. If this is not possible, pass water through a filter.
- Limit vehicle access to the site using a single entry point, stabilised to prevent the tracking of sediment onto roads and footpaths. Avoid long, steep and unstable driveways. Access points must be constructed of aggregate of either recycled concrete or blue metal gravel.
- Educate site workers of legal responsibilities for preventing on-site erosion. Ensure that delivery drivers are made aware of your entry/exit points.
- Upon completion of work, remove all excess material from the site as soon as possible.
- Connect downpipes to the stormwater drain as soon as possible. Fill in and compact all trenches immediately after services (such as electricity and gas) have been laid.
- Revegetate the site as soon as possible. All sediment and erosion control devices must be kept in place until at least 70% of the site has been revegetated.
For more information on the environmental effects of stormwater pollution, refer to the Stormwater page on this website.