La Rigole de la Montagne
July 15
Riquet caught my imagination at the Toulouse
La Voûte de Vauban. (Vauban’s tunnel) In order to improve the water supply for the canal, Vauban extended the rigole by 7.2 kilometers. But not simply by digging. Here he dug a tunnel,
Next we arrive at the Bassin de Saint-Férreol, which is where this lot of water is stored before moving on to the junction of the Laudot and the rigole de la plaine at Les Thomasses. Before the water actually gets to the lake, there are various mechanisms to adjust how
Considering the dam is 17th century, it is amazingly large and modern-looking. We didn’t go right across – It is almost a kilometre - as the wind blowing was fit to compete with the time we walked along the south coast towards the seals and my glasses were blown off my head. All very well in Wellington
The Sor, meanwhile, has been taking its own route, and at Pont Crouzet waters destined for the Canal du Midi are sorted from the Sors, which then continues on to flow into the Agout (the river which flows through Castres ) while the rigole de la plaine takes the water to the meeting point mentioned above. If there is too much water coming down towards the canal from the rigole, it can be diverted into the Laudot, which is about to head off on its own towards the Atlantic . If not enough, water from the Laudot will be diverted into the rigole de la plaine. And then the water is off on its journey again, down to the holding basin in Narouzes.
July 15
Riquet caught my imagination at the
The concept is simple: take water which is destined for the Mediterranean and lead it astray so that in the end it will flow to the Atlantic , thus creating sufficient water for the canal system. The practice is rather more complex and has been upgraded over time, by both Vauban and 20th century engineers who have made provision for irrigation and drinking water from the same sources.
The beginning. La prise d’Alzeau, where water is first taken out of the Alzeau river into a smallish channel called La Rigole de la Montagne. A rigole is a channel. Cunningly, if there is a flood, the Alzeau just keeps on rushing down the mountainside and the rigole continues to be fed with just enough water.
Next: the dam at Cammazes. This is a modern creation which provides irrigation and drinking water but also allows for the collection and dispersal of winter flood waters. The river Sor continues below the dam. It isn’t part of the rigole system
La Voûte de Vauban. (Vauban’s tunnel) In order to improve the water supply for the canal, Vauban extended the rigole by 7.2 kilometers. But not simply by digging. Here he dug a tunnel,
changing the course of the water from the Sor's side of the hill to the
Laudot's, thus joining the rigole to the Laudot. Ingenious, non? You
can walk through the tunnel, which we did. It is 120 metres long, nearly 3 metres wide and rather dark in the middle, which when combined with the uneven surface makes you wary to avoid an unexpected dip. When you get to the bit where the rigole flows into the head of the Laudot there would be a massive drop of water (very destructive for the place it lands on), which has been made into a series of smallish waterfalls, first by using wooden supports and later concrete. I find all this stuff fascinating. I hope someone else reading this does too. There are photos of this series of gentle cascades.
Next we arrive at the Bassin de Saint-Férreol, which is where this lot of water is stored before moving on to the junction of the Laudot and the rigole de la plaine at Les Thomasses. Before the water actually gets to the lake, there are various mechanisms to adjust how
much water will flow into it and how much will by-pass the system and flow on down on past the lake, (using another rigole) joining up with the Laudot beyond the dam. The lake is a great playground for water sports, cycling and walking.
Considering the dam is 17th century, it is amazingly large and modern-looking. We didn’t go right across – It is almost a kilometre - as the wind blowing was fit to compete with the time we walked along the south coast towards the seals and my glasses were blown off my head. All very well in
some of the water is directed to a pipe below the dam and it immediately tries to regain the height it has lost, resulting in a spectacular and continual fountain. Some practical physics lesson here.
The Sor, meanwhile, has been taking its own route, and at Pont Crouzet waters destined for the Canal du Midi are sorted from the Sors, which then continues on to flow into the Agout (the river which flows through Castres ) while the rigole de la plaine takes the water to the meeting point mentioned above. If there is too much water coming down towards the canal from the rigole, it can be diverted into the Laudot, which is about to head off on its own towards the
But that is another story for another day.
Photos at:
