How we plan our work
There are many things to consider when planning infrastructure rebuilding work. Sometimes it might look like we're not being efficient. For example, when you see us dig up the same piece of road we've already dug up and filled. It's in everyone's interests to save money and time wherever we can. We are very focussed on getting value for money, so we wouldn't double-up on work unless we had to.
Before outlining our approach, let's look at some of the complex planning factors we have to weigh up.
Urgent temporary repairs
We have to restore essential services to homes and businesses as soon as possible after they fail. That's why they're called essential services: fresh water, wastewater, storm water, and safe transport corridors. Aftershocks often damage these services, so each severe aftershock typically brings us a new batch of urgent unscheduled rebuilding work.
These repairs may be only temporary in nature. For example, we may need to patch pipe breakages, but in the long term we plan to replace large sections of the pipe with much stronger materials.
We distinguish between permanent rebuilding work and temporary repairs.
Sometimes we cover over our temporary repairs just enough to make the surface above safe until we return to fix the problem permanently and make the infrastructure stronger. That's why you sometimes see us dig up a section we've already filled over.
Most need first
When we're not urgently restoring an essential service, we try to identify which infrastructure is most needed and provides the greatest benefit. It should always be considered first.
Red zone infrastructure
The most unstable land in Christchurch has been classified as the red zones. We need to ensure that infrastructure is working while people are still living in the red zones. In those areas, repairs are temporary in most cases unless the infrastructure also services areas outside the red zones.
Co-ordination with other works
A lot of the infrastructure we're rebuilding operates alongside other important infrastructure that we're not rebuilding, like telecommunications and power. By co-ordinating with other rebuild organisations, wherever possible we plan our non-urgent rebuilding work so that all of this work can be done in a single dig (excavation). Doing this saves everyone a lot of time and money, reduces waste and impact on the environment, and minimises disturbance to the community.
We also try to avoid the situation where the minor impacts of two nearby projects at the same time, together cause an unacceptable disruption. For example, we don't want to perform work that requires us to divert traffic into areas affected by other roadworks that are happening.
We have to be mindful that Christchurch people and businesses use the areas we work in and want to go about their normal business. We think very hard how to cause the least disruption, balanced with other considerations like cost, safety, and sustainability.
Safety, sustainability, value for money
Safety is our first priority in designing our rebuild work.
We aim for the smallest environmental, social, and cultural footprint when we rebuild.
We have a responsibility to deliver our rebuild services at the highest value for what they cost. Sometimes it is possible to save money by taking measures like hiring equipment when it is cheaper.
Some infrastructure, notably roads, is positioned directly above others, like pipes. It wouldn't make sense to permanently rebuild roads until we are happy that the infrastructure underneath is properly and permanently repaired and strengthened. So roads will tend to be sealed properly only at the very end of the process. If we need to temporarily get a road working again, we may apply a safe, temporary surface to the road for the short term.
Prioritising our work
If you read about the kinds of priorities we need to consider, it should be clear just how challenging it can be to balance them when we schedule rebuilding works. You may wish to explore specific details about the nature of road, fresh water, wastewater, storm water, and other infrastructure work we do.
- Operational priorities - e.g. reducing sewage overflows or fixing major roads.
- Interdependencies - e.g. repairing downstream wastewater lines before upstream ones.
- Key services - e.g. maintaining access to emergency, medical and educational facilities and major transport networks.
- External factors - e.g. rebuild plans of other utility service providers (for example power), and other recovery projects (for example housing rebuild programmes).
- Constraints - e.g. the availability of resources and materials.
- Common sense check - SCIRT reviews the decision and decides 'is this the right thing to do now?'
This process will help to create a detailed short to medium term planning process while allowing flexibility to respond to influences from outside in the medium to long term.
The process will help deliver the rebuild as quickly as possible. It provides a strategic city-wide perspective to minimise the impact on the people of Christchurch and create value for money.
The rebuild is a huge task and not everything can be done at once. SCIRT has a robust prioritisation process in place to drive the programme of SCIRT works.