Council invests in flood resilience

Over $4 million for infrastructure repairs and the establishment of an Infrastructure Resilience Team to lead flood recovery were major outcomes from the Waimakariri District Council’s September meeting.

The Council received a report on the 2023 July flooding event that saw over 150mm of rain fall over three days and resulted in the establishment of a Civil Defence Emergency Operations Centre (EOC), a precautionary self-evacuation of Tuahiwi at its peak, numerous road closures and widespread surface flooding.

“We know severe weather events are happening more regularly and during each event we learn more about our stormwater, wastewater and roading networks and where they need be strengthened and investment focused,” says Mayor Dan Gordon.

“Rather than engaging consultants to work alongside staff, we’ve decided to recruit and put in place a specialist team to work on current known issues and improve the resilience of our entire network.”

During the 2023 rain event the Council received over 335 requests for service from affected residents. In 2022 during a more severe event the Council received over 800 requests.

“Residents have told the Council they’re concerned about flooding during heavy rain events – especially now they are happening more regularly – and want assurance we’re doing what we can to reduce the likelihood of flooding.

“This fund is an important step in the right direction. It provides a budget to fix known issues and puts skilled people in place as part of the Infrastructure Resilience Team who will prioritise work where it’s most needed.

The $4 million is earmarked to respond to 2023 issue areas, including:

  • The Cam River/Ruataniwha, where breakout flow occurred at numerous locations causing road and property flooding
  • Tuahiwi area, where there was extensive flooding from the Tuahiwi Stream/Waituere
  • Waikuku Beach, where the Taranaki Stream backed up behind the flood gates causing road and property flooding
  • Roading repairs including Lees Valley Road.

Over the past three years $22.3M was spent in Kaiapoi on flood protection works such as pumping stations, drain and culvert improvements and mains replacement.

“We’ve already seen the benefit of these improvements during the July 2023 flooding - known low-lying areas in Kaiapoi remained safe. We want to continue to build on this momentum with this new team and new fund,” says Mayor Gordon.

Requests from residents to solve issues often involves on-site visits, discussion with property owners, looking at Council infrastructure and putting in place fixes, or improvements where possible. While every attempt is made to improve drainage where possible, events of this nature can cause major damage which can take months or even years to implement upgrades

“These severe events are not ‘one-offs’ any longer, they’re happening more regularly and it’s not uncommon to have one or more severe weather events per year,” says Gerard Cleary, General Manager of Utilities and Roading.

Because of this we are preparing a Long Term Plan report for the Council to consider formalising an ongoing programme of resilience projects and improvements.

“This would mean that when we have a severe weather event that causes damage to our stormwater, wastewater and roading networks, or shows vulnerability in our system, we have the means and people to rectify this quickly before another event comes along.”