Erosion and Sediment Controls Versus La Niña

After this week’s downpour, it is clear that the La Niña cycle is still in full force, so what does this mean for your construction sites?

The key to construction survival in the wet season is to ensure that erosion and sediment control (ESC) measures are being correctly implemented and monitored. Not only will this ensure our water systems are not polluted, but it will also avoid being slapped with a hefty fine for breaching both development approvals and the Environmental Protection Act 1994.

Senior Civil Engineer Nathan Green has provided some top tips on what to keep an eye on to ensure your ESC measures are working effectively.

Dirt/mud on the surrounding roads – If trucks are leaving the site with mud on their wheels, then the construction entry and exit are not working effectively. This could mean that your shakedown grid may need to be adjusted to ensure mud/dirt is removed before trunks are leaving the site.

Dirty water on downstream –  Time to do a thorough check that the measures you implemented at the start of works is still operational. Often erosion and sediment controls can become blocked or damaged during a recent downpour. This may also mean the controls are undersized so you may need to upsize your swales or bolster up your sediment forebays.

Check your sediment fences. Make sure sediment fences are staked at regular intervals, have not been damaged and are not full of sediment. There are several different types of sediment fences you can use depending on where they are located on-site and the site soil type, so ensure that you are using the most suitable one.

So far this cycle of La Niña has not been as detrimental in South-East Queensland as we expected, however, now is not the time to get complacent, as BOM has indicated that La Niña will continue to influence Australia rainfall patterns through February and March¹, so you can expect the heavy rainfall to continue. It will be important to keep an eye on these indicators over the next few months to ensure our water systems are not polluted and to avoid any potential fines.

¹ http://www.bom.gov.au/climate/ahead/outlooks/