Moir St Stormwater Culvert Emergency Repair

Urgent Response

On the night of Wednesday 23^rd January a rain event caused an existing brick culvert to blow out under a property in Moir St. The culvert was a 640mm dia. brick structure pre-dating the property that was constructed in 1892. An amazing piece of engineering that is at the end of it’s life.

The asset had been blocked with debris that was caught on a communications service that had been drilled through the culvert. The resulting blow out undermined some of the foundation piles of the house, undermined the driveway and lifted the concrete footpath. It caused debris to blow out into the basement and into the street. A bit of a mess.

Citycare attended the site on the 24^th January and did a great job of cleaning up the debris and making the road safe. Wellington Water Limited (WWL) arranged their own CCTV investigation to investigate the problem and called G P Friel Ltd. (GPFL) to see if we could provide any assistance.

On 25^th January Malcolm Giles and Gerry Friel attended to site to put together a plan to repair the damage and get the culvert back into operation. By 7^th February the culvert was back in operation, the house foundations had been repaired, the manhole had been replaced and the road had been put back together. Concrete for the footpath and driveway followed over the next couple of weeks.

Operational Solution

In only 2 weeks from the initial report WWL and it’s supply chain had the asset back up and running; the damage had been repaired and the risk of a follow on incident had been mitigated. A good effort by all involved.

GPFL slip lined the existing culvert with a 560OD PE100 SDR17 pipe – the largest that could be fitted. They enlisted the help of E Carson & Sons (ECS) to weld the lengths of pipe into one continuous string that could be pulled through the culvert. This task was a real challenge as there is no access to the upstream end of the existing culvert. A pipe of this diameter is fairly inflexible and the available space for a launch pit was limited. With a can do attitude and a bit of Kiwi ingenuity the team on site got the job done.

An Engineering Solution that put People First

With no access to the upstream end of the repair; connecting the liner to the existing pipe and manhole was another puzzler. GPFL and WWL wanted to eliminate any requirement for a person to enter the pipe so we installed a CIPP patchliner to seal the liner to the existing culvert and manhole. An engineering solution that put People First.

Collaboration & Customer Experience

A key feature that made this project a success was the way the way that all of the parties in the supply chain were able to collaborate and deliver a solution that was the best outcome for the customer. In particular it was an opportunity for GPFL to work together with our new CAPEX Panel Partner – ECS; and Tom Carson added to the project with his welding skills and his team working abilities.

On Moir St the delivery of the product was complimented by a strong focus on the customer experience. GPFL undertook to get to know the property owners and tenants who had been affected by the incident and would be affected by the work. Gerry Friel distributed regular email updates so that the stakeholders were kept up to date with progress. They understood who to talk to if they had any issues to raise and the project was able to work with them to manage access to the street and to the properties as required.

Feedback has been excellent:

I was impressed with the prompt and effective management of the problem by WWL and GP Friel Ltd.  Communication during the event was well done and there good management of the site during the works.

Ross Jones
The Street Property Management Limited

WWL, City Care, GPFL, ECS and other members of the Wellington Water family should be proud of the work they did in Moir St, the way they delivered it and of the impression that they made on the affected customers.