Sewer Overflow
The 2006 NSW State of the Environment (SoE) report notes that overflows from sewerage reticulation systems continue to present a challenge for urban waterway quality.
Dry weather discharges occur due to chokes caused by tree roots and breakages, while wet weather overflows are due to infiltration of stormwater through breaks, combined systems and illegal connections.
Within the City of Sydney, Sydney Water is the responsible authority for the sewer system. Acknowledging the environmental impacts of sewer overflows, Sydney Water has initiated a program to separate combined stormwater and sewer systems still located within the LGA.
Sydney Water sewage overflow abatement works over recent years have reduced wet-weather overflows from 608 in 2002–03 to 168 in 2004–05. However the 2006 SoE report indicates that dought conditions in recent times are leading to lower flows, resulting in dryweather 'sewer chokes', with over 19,000 occurances over 2004/05.
Urban stormwater management programs have increased public awareness of the impacts of urban discharges and resulted in nearly 100 artificial wetlands being constructed to reduce the flows of nutrients and sediment to waterways.
The State Government also recently announced deregulation of the waste water system. This means there may be potential for local or regional projects to treat sewer for non-drinking purposes.
Last Updated: Monday 27 April, 2009
