Transmission Gully

AR & Associates was commissioned by the Greater Wellington Regional Council (GWRC) (through a strategic alliance with Koru Environmental Consultants Ltd), to undertake technical review and specialist stormwater inputs on operational and (to a lesser extent) construction stormwater management for the Transmission Gully Project in the Wellington Region.
The project, which is currently under construction, involves some 28km of State Highway formed to an expressway standard, and is a project of national significance that was consented through the Environmental Protection Authority (EPA) Board of Inquiry (BoI) process.
The work mainly includes the overall review of the operational stormwater design for the project, in terms of primary and secondary flow conveyance, stormwater quality, stream / outfall erosion protection, stream diversions and stormwater quantity / flood mitigation, so as to ensure the design meets the general intent of the Board of Inquiry conditions and is in line with NZTA’s design criteria.
As part of the work, AR & Associates have acted as a key adviser on technical stormwater engineering matters to GWRC, including recommendations around compliance with the design criteria and conditions, and working with the design-build team to achieve mutually agreeable outcomes.