Elcorock Sandbag Wall at Karāpiro

This project was not just about replacing a wall. While the main task was upgrading the aging tyre wall structure with a Geofabrics Elcorock sandbag wall system, the real challenge lay in doing it safely without contributing to the spread of gold clams during construction.

The highly invasive gold clam were discovered in the Waikato River May 2023. One clam can produce up to 70,000 offspring per year and can clog infrastructure and impact our native species. Our challenge was to prevent any spread of this pest, this meant even a single missed clam could become a serious threat to other waterways. So, strict cleaning and containment protocols shaped every step of the job.

During removal of the old wall, each tyre was thoroughly cleaned and transported off-site in sealed trucks. The Keir Projects crew worked methodically to avoid spreading any larvae or sediment. Once the area was cleared, the new sandbag system was installed to match riverbank levels and flow conditions.

The new wall was built using the Geofabrics Elcorock sandbag system — a durable, high-performance option specifically designed for coastal and waterway protection. These geotextile containers are filled on-site with sand, then placed and stacked to form a stable, erosion-resistant barrier that blends into the natural environment.

Unlike the old tyre wall, which had reached the end of its life, the Elcorock system offers better long-term performance with less maintenance. The bags are engineered to withstand water movement, UV exposure, and heavy use, making them ideal for this kind of riverside application.

Keir Projects is proud to have played a small part in supporting containment efforts during this upgrade. But stopping the spread of freshwater pests like the gold clam takes everyone.

MPI Check, Clean, Dry Guide

Let’s protect our rivers, lakes, and waterways — together.