Major weather events in Westport in 2021 and 2022 had caused widespread flooding around the township. Stormwater infrastructure in some places was severely compromised, as several older outfall structures and culverts were damaged and unable to provide adequate stormwater flow into the Buller and Orowaiti Rivers for which they were originally designed.
We designed structures for WaStop® backflow devices at four locations in the town. In combination with other works – outfall remediation and pipe upgrades, the use of these valves would prevent river backflow into stormwater reticulation and enable Westport’s underground stormwater network to become more resilient during heavy rain. The projects were:
We provided multi-disciplinary services, with deliverables including the detailed design package comprising geotechnical engineering design report, civil and geotechnical design drawings, specifications and schedule of quantities.
Innovations included a proprietary headwall design for Cobden Street – an MSE wall embedded in the riverbank and raked back at a 50-degree angle, with the backfilled slope rock rip rap protected. At Brougham Street, a bespoke shear wall design enabled the 900 mm dia. outfall and new manhole to be connected to the existing brick arch culvert.
Civil engineering Lead Gary Stevenson was regularly in Westport during the design and construction of the projects. Frequently on-site to assist with construction monitoring, he was readily available to provide constructability advice to Buller District Council representatives and the contractor, to ensure a safe and efficient construction.
Major weather events in Westport in 2021 and 2022 had caused widespread flooding around the township. Stormwater infrastructure in some places was severely compromised, as several older outfall structures and culverts were damaged and unable to provide adequate stormwater flow into the Buller and Orowaiti Rivers for which they were originally designed.
We designed structures for WaStop® backflow devices at four locations in the town. In combination with other works – outfall remediation and pipe upgrades, the use of these valves would prevent river backflow into stormwater reticulation and enable Westport’s underground stormwater network to become more resilient during heavy rain. The projects were:
We provided multi-disciplinary services, with deliverables including the detailed design package comprising geotechnical engineering design report, civil and geotechnical design drawings, specifications and schedule of quantities.
Innovations included a proprietary headwall design for Cobden Street – an MSE wall embedded in the riverbank and raked back at a 50-degree angle, with the backfilled slope rock rip rap protected. At Brougham Street, a bespoke shear wall design enabled the 900 mm dia. outfall and new manhole to be connected to the existing brick arch culvert.
Civil engineering Lead Gary Stevenson was regularly in Westport during the design and construction of the projects. Frequently on-site to assist with construction monitoring, he was readily available to provide constructability advice to Buller District Council representatives and the contractor, to ensure a safe and efficient construction.
