stormwater engineering project for Auckland Council

Client name: Auckland Council – Stormwater Engineering upgrade

Site: William Souter Street, Forrest Hill, Auckland

Project overview:

Auckland Council asked for our engineering design services and a business case analysis for the upgrade of the existing network, plus a network extension to include upstream properties. We created a desktop study, followed by intrusive site investigations of existing infrastructure to confirm the suitability of proposed works to service the catchment.


To relieve the increased stormwater burden which can be a result of denser housing developments.

stormwater engineering in Forrest Hill


Our principal engineer led the technical aspects, ensuring smooth execution with experienced oversight. Our senior and intermediate engineers tackled design, drafting, and construction monitoring with regular checks for quality. Assessment inputs included data sourced from public drainage and utility records, topographical survey, geotechnical investigation, CCTV pipe inspection, site visits, and liaison with asset owners. A storm during construction caused minor property damage, drilling damage, but the site was protected well and things got back on track quickly.

The value that Thomas Consultants team added:

Our engineering team kept Council stakeholders informed throughout the project (regular updates). Strong communication ensured a smooth working relationship with all parties (client, contractor, engineer). Keeping the client informed through frequent milestone and progress updates fostered transparency, leading to smoother acceptance of necessary variations.

Our Principal Engineer identified early on that directional drilling could minimise excavation for some pipes. This reduced environmental and social impact on the nearby community. Additionally, we proposed new alignments to avoid damaging properties and for easier future maintenance.

Services provided:



The improved and extended stormwater network has played a major part in the community’s social and economic well-being. The extended network is now ready for future housing developments, and can cope with heavy rainfall and flood events.

Project completion: 

July 2022



William Souter Street stormwater engineering