For as long as Manawatu Gorge has had transport links through it, they have been subject to slips. Some of them have been cleared in a matter of days. Some have taken several weeks.
With each slip business has been lost by the towns at either end of the gorge. People’s livelihoods have been disrupted, with locals and tourists alike forced to take detours.
A few weeks ago another slip came down. The gorge had not been long reopened after several previous slips. This time it looks like the disruption might be terminal, the patience of the communities having run out and the issue now a political football in election year.
In 2012 after a particularly severe slip event the New Zealand Transport Authority commissioned a report into alternative transport routes in the Manawatu Gorge. There were four options being suggested:
- A direct route that is the shortest and involves building a 5.9 kilometre long straight bypass – COST: $309 million
- Bridging to provide a straight a carriageway in parts of the gorge – COST: $415 million
- Overhaul what is commonly known as the long route, which is about 10 kilometres long and currently carrying most of the traffic, but which is not really suited for the volume of traffic it is carrying – COST: $120 million
- A tunnel, which would be New Zealand’s longest road tunnel and start and end about the same place as the direct route – COST: $1.8 billion
The geological structures and strata that any overhaul would have to be worked on is tricky. Large faults including, but not limited to, the Wellington Fault are nearby. The strata is largely sedimentary in nature and likely uplifted by seismic activity on the nearby faults. Old landslide zones abound along the slopes of the gorge
The report was ignored. It was shelved because despite the frequency of slips closing the gorge, it was not considered to be a priority.
Now, finally, with a slip closing the gorge blocking the road indefinitely, the Government has finally admitted there is a problem. But how do we know that this is not simply a case of electioneering in election year to counter resurgent opposition parties?