First bridged in 1869, the Ōpaoa river has been both the northern gateway and boundary of Blenheim for the best part of 150 years. The existing structure, a concrete bowstring arch bridge, was built in 1914. It was an engineering achievement in its day but unfortunately over a century, and many earthquakes later, it can no longer comfortably handle the ever-increasing demand of modern traffic. The new Ōpaoa river bridge makes up for the obstacles its predecessor presented to the growing town of Blenheim.
The new bridge is 188m long, 10m wide, and curved on the southern three spans,with 700m of realigned approaches including retaining walls both sides of the southern approach, noise attenuation walls, extensive landscaping and artwork, with the existing heritage bridge reverting to a walking and cycling facility to complement the new bridge.
WSP was involved in every step of the development and construction process with the business case developed, detailed design formed, regulatory authority applications and management, tender management, and construction monitoring for the replacement bridge alongside heritage works on the historic bridge downstream.