It is the third tunnel planned under the 2009 Maipu Integration and Cooperation Treaty, which aimed to ease freight and movement of people between the countries. Sub-textually, it also aimed to ease territorial and political friction.
The other projects are the Agua Negra road tunnel, and an as yet unnamed "low-altitude" rail tunnel, a trans-Andean base tunnel. Discussion and feasibility studies have been ongoing, but local media suggests there is political will to improve connectivity between the two countries. The relevant bi-national entities have been formed.
For the Las Leñas project, data will now be gathered from both sides of the border to decide an optimal alignment.
More detail is known about Agua Negra, which has called for expressions of interest. It will be a twin 13.9km twin tunnel road project with 70m2 excavation faces some 40 to 50m apart. The Argentinean portal is at 4,085m above sea level, while the Chilean portal is at 3,620m; an average gradient of 3.37 per cent. It is expected to cost approximately USD 1.4bn. Over two thirds of the tunnel will fall on Argentina’s side of the border, so it will pay close to USD 1bn of the cost.
