Smarter wastewater systems
Before the earthquakes Christchurch’s wastewater network relied largely on a gravity system. Gravity wastewater pipelines are laid at a gradient (slope) to make the wastewater flow downhill. In some areas of the city the gravity system has performed well in the earthquakes and will only need repair.
In other areas the earthquakes have challenged us to find smarter ways of dealing with our wastewater. Our new wastewater systems need to be able to withstand future earthquake activity and be easier to repair if they are damaged.
The way the City’s wastewater system is rebuilt depends on the nature of the damage. Each area of the city is unique. The best solution for the rebuild of the wastewater network varies from area to area. When we design a new wastewater system for an area, we look at enhanced gravity, pressure and vacuum wastewater systems.
In some areas the rebuild of the gravity network may not be the best option. It could be less resilient to future earthquakes, might cause significant disruption to residents during construction, and the construction costs could be high.