SH31 is the only sealed road in and out of the harbourside town of Kāwhia, and various slip sites have required repairs in 2023 and 2024.
A mix of hard sandstone and ash in the area creates problems for road-building, with the ash prone to slipping. An engineering technique called soil nailing has been used to strengthen several sites, some under stop/go, others requiring daytime closures.
SH31 is the main route in and out of Kāwhia and about 800 vehicles a day use the road, with 13 per cent being trucks.
CloseWhen a slip developed on SH31 Kāwhia Road, NZ Transport Agency Waka Kotahi System Manager for Waikato Cara Lauder was well placed to be involved. While completing her Masters of Science degree in 2002 her thesis was on the unstable geology of Kāwhia Road.
