8 July 2015 update to the Tunnel du Chambon and the impact on the Tour de France.
The latest on the Tunnel du Chambon is that work on the tunnel has totally stopped, since they expect the side of the mountain above to fall at any moment. Small sections of rock have already fallen and some people are camped up high on the far side of the reservoir hoping to witness the collapse of the mountain. Access to the path on the far side is strictly closed and the ferry service has been stopped due to the fear of waves that would be caused by the rockfall. Local residence below the dam have been warned to keep doors and windows closed in the event of warning sirens, in the unlikely event that a wave could flow over the dam and flood villages downstream. A helicopter service has been put in place available to locals trapped on the far side in the case of emergencies.
The area of unstable rock is about25 – 30 metres deep and 600k to 1 million cubic metres. Since April it had been moving between 5 to 10 cm per day. More recently it been moving at 12 cm to 15 cm per day. Since 2nd July a section of 100k cubic tonnes has been moving at 25 cm per day which is looking like the first area to slide..
As an impact of this road closure Stage 20 of the Tour de France on the 25th July between Modane and Alpe d’Huez no longer passes over the Col du Galibier, but via the Col de la Croix du Fer.
Many people booked into accommodation in La Grave or Briancon hoping to see the Tour de France on Alpe d’Huez, have been asking about the possibility to bypass the tunnel my mountain path or track. As mentioned before, then path along the other side of the reservoir is closed and this is being strictly enforced by local police. The quickest road route is via the Col du Galibier and the Col de la Croix du Fer. However there is a very long, but beautiful option above the tunnel via the Plateau de Emparis. This track is unpaved, generally used by walkers and mountain bikers and will take a long time, but is spectacular. Details of this route can be found via the following link under Tour du Plateau d’Emparis – itineraire 4.
The closure of the Tunnel du Chambon in April, linking Bourg d’Oisans to the Col du Lautaret and beyond, has sparked widespread discussions amongst the locals and cyclists planning to visit the region, such as when will it reopen, are they building a new road and can cyclists use the ferry to bypass the tunnel?
On the 10th April the Tunnel du Chambon was deemed to have an extremely high chance of collapsing and was immediately closed, with initial reopening dates suggested for early July. More recent surveys have shown that up to 100 000 m2 or 250’000 tonnes of rock are shifting around 10cm everyday, threatening collapse the entire tunnel. As such the reopening of the tunnel is very much in doubt, but the authorities hope to have a solution in place prior to the opening of the ski season in December.
One of the solutions put forward, is to build a reinforced structure within the existing tunnel. However the extent of the problem has forced the local authorities to sign off on a new road on the south side of the lake, which they hope to have built by the winter. Whether they intend to build and maintain two roads up the valley, or to concentrate their efforts on building one reliable route remains to be seen.
The consequences of this for cycling tourism is that the only road leading from Le Bourg d’Oisans towards La Grave, Col du Lautaret, Col du Galibier and Briancon is essentially cut off. This has already lead to the rerouteing of La Marmotte Granfondo and almost certainly the penultimate stage of the Tour de France from due to race from Modean to Alpe d’Huez over La Galibier on the 25th July. La Marmotte will now return to the Alpe d’Huez valley via the Col du Mollard and the Col de la Croix de Fer. The Tour de France is very likely to follow suit.
One of the most talked about topics amongst locals and cyclists planning a trip to the region, is the possibility of using a ferry to bypass the tunnel and get to up to the Col du Galibier. The ferry has been provided for locals stranded on the La Grave side of the tunnel to access shops and schools in Bourg d’Oisans and Grenoble. However I recently spoke to Kevin from Cycling Ascents in Bourg who, last week with some of his cycling clients, successfully used the ferry without a problem and achieved one of the most magical climbs of the Col du Galibier, thanks to almost zero traffic. However he went on to add that yesterday (21st June) his guests were turned away and told that “that due to the risk of a rockfall into the reservoir they weren’t taking anyone with bikes – only locals on business.”
So officially, for the moment, the ferry is not an option for cyclists. However pressure from business owners in La Grave, at the Col du Lautaret and the Col du Galibier, that are experiencing a catastrophic effect to their trade from the closure, may force some changes here in the future.
With all this in mind, the Oisans region still has more than enough routes to keep every cyclists satisfied. Including amongst many others, routes to the following places. Col du Galibier, Col de la Croix de Fer, Alpe d’Huez and the Sarenne valley, Les Deux Alpes, Col de La Morte, Col d’Ornon and La Berarde.
Bike Lodging is based in Le Bourg d’Oisans and helps cyclists find and book bike friendly accommodation such as that of Cycling Ascents. We still have options for La Marmotte, the final week of the Tour de France and for the Alpe d’Huez Triathlon.