Northside Storage Tunnel status report

Learn the tunnel's current status

The Northside Storage Tunnel minimises the impact of wastewater overflows by:

• maximising flow in the Northern Suburbs Ocean Outfall System
• reducing wet weather wastewater overflows to the environment
• maximising the volume of overflow captured at the 4 connection sites.

We report on its status in terms of inflows, overflows, venting and total inflow volume by updating this table regularly during wet weather, and periodically during dry weather.

Filter testing and monitoring

We constantly monitor hydrogen sulfide (H₂S) levels from the Scotts Creek and Lane Cove River West vents. The ventilation systems at both sites have filter beds. Tunnel air must pass through the beds before being expelled to the atmosphere.

Air quality information for the sites is available with our pollution monitoring test results and licence details

Check the table below to see:

• where wet weather wastewater flows into the tunnel from a connection site
• if wet weather wastewater overflows out of the tunnel from a connection site
• if the tunnel vents at a connection site, '-' means not applicable
• how much wet weather wastewater has flowed into the tunnel since it began operating.