Otago Regional Council

2026-10882 East Taieri Lower Pond Structure Upgrades

This opportunity involves the remediation of the Lower Pond gravity gates and its associated structure, located in Allanton.

During routine inspection of the floodbanks in early August 2021, Operations staff identified a hole that had opened behind the gabion basket headwalls on the Taieri River side of the Lower Pond Gravity Gates. Upon further inspection it was discovered that corrosion of one of the culverts (at invert level) had allowed water to track through the floodbank and into the culvert behind the gravity gates. A sinkhole has then opened to the surface between the two gravity gates, immediately behind the gabion basket headwall.

A repair was carried out to mitigate the risk of flows through the floodbank as a result of the corroded culvert inverts and sinkhole. This involved filling the void behind the gabion baskets, between the two culverts, with flowable fill, and sealing the base of both culverts with concrete.

This project is located on an operational farm and involves work on flood protection infrastructure that is critical in protecting high value farmland, property, and strategic assets from flood hazard. The work will require careful planning and coordination to meet the needs of the client and landowner in minimising adverse effects on the farming operations and maintaining effective flood protection measure over the duration of the works.

Department/Business Unit: Engineering