Preventing sewerage overflows

Why stop stormwater going to sewer?

Too much rainwater is entering the sewerage system. Stormwater that enters the sewerage system can overload the treatment system and can cause sewerage to overflow.

How is stormwater entering the sewer?

Rainwater is entering the sewerage system via roof downpipes and ponded stormwater. A gully trap is the most common point where stormwater enters the sewerage system.

What is a gully trap?

Gully traps are usually located outside bathrooms, kitchens and laundries. The purpose of gully traps is to collect wastewater from these utilities and discharge it into the sewerage system. Rainwater from roofs and section run-off should not enter the sewerage system.

The top of any gully trap of the top surface of a raised lip should be at least 25 mm above the ground on paved areas and at least 100 mm above the hearth in unpaved areas.