Gorge clean up costly

The cost of clearing slips in the Manawatu¯ Gorge is rising with more slips falling since the road was shut more than a year ago.

Dozens of slips have come down on State Highway 3 through the gorge since it closed in April last year, including slips on both sides of Kerry’s Wall – an area identified as the site of a potential mass landslide – near the Ashhurst end.

The New Zealand Transport Agency (NZTA) has predicted as much as 630,000 cubic metres of material could drop at that site.

NZTA regional transport systems manager Ross I’Anson said the current estimate to clear the slips and deal with the Kerry Wall issue was $50 million.

The estimated timeframe to deal with the issue was almost three years, and could start only once the wall stopped moving.

‘‘There are approximately another five slips in the gorge, including ongoing slips at Kerry’s Wall.’’

The NZTA announced in March its preferred new route would go north of the gorge, but south of the Saddle Rd bypass.

Traffic will use the bridge already going across the Manawatu River east of Ashhurst, but veer north just before the Manawatu Gorge entry, go east across the range, then head down the other side into Woodville.

NZTA director of regional relationships Emma Speight said the chosen route was safer than the southern one, in which the road would have gone between two fault lines at one point.

The chosen route was shorter by 6.6 kilometres, would be a quicker trip than the old gorge route, shaving nearly four minutes off, and would not be as steep as the Saddle Rd, she said.

Resource consents were needed, but construction was expected to begin in 2020 and be completed by 2024, Speight said.