Driving the strategy is the short-term need to address the effects of earthquakes on the wastewater system and the long-term need to provide for future growth, without ruling out technologies and opportunities that are not yet available.

Wastewater Strategy 2013 [PDF 1.5MB]

Wastewater is made up of water collected from interior drainage systems, for example toilets, laundries and kitchens, as well as commercial and industrial premises. We want a wastewater system that’s socially and culturally acceptable and sustainable for the whole community. Our wastewater system also needs to be affordable, reliable and resilient as well as reduce risks to public health. 

We’ve also got some new challenges following the earthquakes, challenges we need to manage in the future. With this in mind, the question Christchurch faces is ’how do we sustainably manage our wastewater over the next 10, 30 and 100 years’?

The Wastewater Strategy considers these factors, and the views of the community, to establish a strategic direction and long-term vision for wastewater in Christchurch.


Goals

  • protecting public health effectively
  • being resilient enough to meet community needs for environmental, social and cultural sustainability
  • supporting the future growth and economic wellbeing of the city.

Principles

  • minimising the effect on the environment
  • working collaboratively
  • planning and implementing affordable maintenance, renewal and expansion work
  • optimising the resilience of infrastructure
  • taking a flexible approach to new technology
  • delivering cost effective wastewater services
  • supporting a sustainable economy.

Issues

  • Sewer system resilience: The wastewater system was damaged in the earthquakes. We want to make the most of this opportunity to work towards a more resilient system that uses more flexible materials and is easier to repair
  • Wet weather overflows: Wastewater sometimes overflows into the Avon and Heathcote Rivers during wet water. This is more likely to happen with earthquake-damaged pipes. We want to minimise or reduce the frequency and volume of wastewater overflows
  • Long-term wastewater treatment and disposal in Christchurch and Bank’s Peninsula: We’ll need more wastewater treatment facilities around 2035 if Christchurch’s population keeps growing. Reuse of treatment products (e.g. treated wastewater, biosolids) Reusing resources is good for the environment. The strategy looks at expanding the reuse of treated wastewater at the treatment plant in Bromley and reusing biosolids.

Wastewater in the future

The strategy considers these timeframes:

  • Short-term - The next 10 years will see the city’s existing wastewater system return to normal operations, and Christchurch’s geography and demographics transition to take on a new shape.
  • Mid-term - The next 30 years are likely to see non-uniform population growth, reflecting the red zones and accelerated development areas in the south, west and north of the city.
  • Long-term - A focus on the next 100 years reflects the long-life nature of wastewater assets – particularly gravity sewers and rising mains. Where these assets are located will be determined by post-quake urban development patterns over the next 10 years. By forecasting what the 100 year wastewater system will look like, including treatment plants and receiving environments, the Council can ensure the 30 year system plan fits with the long-term vision and the major decisions that will be made over the next 10 years.

The strategy suggests a number of ways we can sustainably manage wastewater including:

  • supporting long-term treatment options
  • reducing and improving discharges to marine environments
  • reusing biosolids and treated wastewater
  • controlling overflows
  • building resilience into the system
  • fixing damaged infrastructure
  • being affordable.