Earthquake damage to our wastewater and storm water system can't be seen from above the ground. To understand the damage we need to get inside the pipes. One way to do this is through Closed Circuit Television (CCTV).
Using CCTV cameras mounted on wheeled buggies or boats, we can assess damage up to 200 metres into a pipe opening. SCIRT specialists control the buggies through the pipes from a specially equipped van. The entire journey through the pipes is recorded for later analysis. The operator also takes interim notes of the condition, and records data about the pipe's position and gradient.
Camera inside a wastewater pipe
CCTV investigations in some areas of Christchurch need to happen at night, which can be disruptive for residents due to the noise from the jetting trucks and associated activity. However, this is the best time to do this work, while the flow in pipes is low, with reduced household activity. At night there is also less traffic on busy roads which gives us access to manholes that are in the middle of traffic lanes. When the flows are low the CCTV operators can see more of the pipe and therefore can make a more accurate assessment of damage.
CCTV helps us to piece together the damage caused by the earthquakes. It is a critical part of the design process and will inform SCIRT's five year programme of work. While you might see CCTV investigations happening in your street next week, the repair of the infrastructure may not happen for a number of years. This will depend on how the project is prioritised as the city rebuilds.
Christchurch has almost half the country's CCTV capacity working here currently – around 20 crews employing around 150 staff.
Broken, blocked pipe
Jetting truck which is used to clean the pipe before CCTV
CCTV at night on a busy daytime road