8 Nov 2020

NZTA finds way to relieve flooding risk in Roxburgh

12:22 pm on 8 November 2020

Relief could be on the way for people in Central Otago, with the Transport Agency announcing that it will replace a flood prone culvert.

Flooding forced the evacuation of at least 6 houses.

This flood caused at least six homes in Roxburgh to be evacuated. (file pic) Photo: Central Otago District Council facebook page

Waka Kotahi NZ Transport Agency said work is expected to begin early next year on the culvert, known as Pumphouse Creek, which is under State Highway 8, north of Roxburgh.

Senior network manager John Jarvis said the new concrete culvert is four metres wide and two metres high, and will replace the existing one which is only one square metre.

"Following a series of floods over recent years in the Roxburgh area, a catchment study was conducted by Otago Regional Council, and Waka Kotahi has been working closely with council staff to help improve the resilience of this section of SH8," he said.

Roxburgh is currently inaccessible from the south.

This 2017 flood in Roxburgh cut the town off from the south. Photo: Central Otago District Council facebook page

Jarvis said Pumphouse Creek was identified as a waterway with an ongoing risk of flooding.

"Gravel was accumulating and blocking this undersized culvert following heavy rain in the hills which has occurred more frequently over recent years," he said.

"Not only is the existing culvert unable to deal with these heavy rain events, an existing water treatment pumphouse owned by the Central Otago District Council immediately downstream also becomes vulnerable to damage and possible outages to the residents of the town when it floods."

Jarvis said the larger culvert will help channel flood waters and gravels under the road and below the pumphouse to the Clutha River once it is operational.

Get the RNZ app

for ad-free news and current affairs