An Inaccessible Gorge

FE16_Gorge-blue-bluff-slipThe Ōtaki Gorge Road destructive slip at Blue Bluff, which cut off all access to Ōtaki Forks and the Tararuas, is still moving.

The closure of the gorge road at Blue Bluff, 13 kilometres inland from State Highway 1, has cut all access to the camping ground, Tararua tramping tracks and DOC huts. Kapiti Coast District Council still has no time frame for when the road would be reopened, or an alternative route constructed.

Meantime the Department of Conservation (DOC) has recently opened a walking track starting at Shields Flat Historic Reserve carpark, this has been cut and marked and can now be used. It goes well above the slip site, through private land and forestry to Roaring Meg. Trampers can then walk along the road to Ōtaki Forks. The track is 5.1km and takes two hours, it is considered only suitable for experienced trampers as the section through native forest is very steep. This walking track does allow access to the Tararua’s and DOC huts.

There is also walking access from the forest carpark at the end of Mangone South Road in Reikorangi, this 25km long track takes six to eight hours walking time to complete.

Council is urging people to keep well away from the slip site, after reports of people crossing the site over the weekend 20–21 February. More debris had come down following heavy rain during the week and further falls could occur at any time. People are advised not to attempt to walk through the slip site or go close to have a look. They are taking a great risk if they do. Council workers were installing more fencing and signage to deter unauthorised access.

Tony Martin, acting Group Manager Infrastructure Services, told the ŌCB members at their February 2nd meeting, that the engineer and geologists had reported significant continued movement in the slip, to the end of January and a bulge developing in the rock face on the slip near road level. Since then there have been reports of continued movement plus a further large amount of rocks and soil coming off the bank overnight Friday February 19 following heavy rain, leaving big areas of debris hanging precariously above the road, which could come down at any time.

Mr Martin showed Board members recent photographs of deep cracks in land 100m above the main slip and spoke of where they were at and hopes for the near future for some access to the Tararuas.

The slip face is covers an area of 7,000 square metres, it is much higher than the Manawatu Gorge slip and higher above the river. Between August and December last year approximately 7,500–8,000 cubic metres of rubble was removed from the Ōtaki Gorge, with a further 3–5,000m3 debris falling during the most recent slip (19–20 Feb). In comparison, the Manawatu 2011 slip started at 9,500m3 with 30,000m3 material removed and by May 2012 had cost $11 million to clear. KCDC did not have final figures for costs or volume of material removed from the Blue Bluff slip.

“We desire to have the road reopen but need to gather facts — are there solutions and costs,” Mr Martin told the ŌCB.

The Ōtaki Gorge Road has been closed to all traffic from west of Blue Bluff since mid-December when the most recent slip came down and engineers and geologists found more cracking in the cliff face as well as severe cracking above the actual slip. People are requested to keep well clear of the site for their own safety.