River walk
UNIL was founded in 1537. In the 1960s, the State of Vaud bought the land of the Dorigny estate from a family of notables, the Loys. This family had settled in this area, thanks in particular to its proximity to the Mèbre, Sorge and Chamberonne rivers.
Here's a walk along the water, but also along time, between past and present.
Starting and ending: The great chêne of Naples, an extreme example of the Unithèque
Length: 1h15, including 30 minutes of actual walking (10 min more with the loop)
Length: 2 km
Walk designed by Pierre Corajoud, version 2 - July 2018
The ballad
From the trunk of the Napoleon oak, walk down to the stone bench nearby.
Behind the Unithèque is a beautiful ring of trees on a ridge, an ancient glacial moraine. Behind this moraine flows the river Chamberonne. At this point, the river has a gentle gradient and is dependent on the local topography. In particular, it bumps up against this moraine hill before making its way to the lake alongside the UNIL sports grounds.
Etymologically, Chamberonne means 'rivière à écrevisses' (crayfish river). Does it still have any?
At the bottom of the pebble-covered driveway, continue straight downhill. Go under the plane tree avenue and continue in a straight line.
You will then come to a roadside path. At the end of this path, at the next crossroads, go left.
You will soon see the Chamberonne on your left. As they entered the lake, the rivers deposited sediments. They thus created a delta which, as the level of the lake fell, became a kind of rather flat terrace, located around ten metres upstream of the current lake level.
The rivers, which flow into the lake, created a series of sediments.
When the Anthropolis was being built, sediments were extracted from the foundations, which have been dated using carbone 14 and confirm this 10,000-year age.
Before the massive arrival of coal in the 19th century and then oil, water played a vital role for small factories, mills and so on. This was also the case at the Dorigny mill, where, under the impetus of Jean-Rodolphe de Loys, the power of water was used.
In 1706, a paper mill was set up in the loop of the Chamberonne in place of today's Château de Dorigny. It was connected to the river by a canal. A few decades later, this paper mill was joined by a laundry (for hemp cloth) and a swift (a forge). This small industrial activity was soon abandoned in the second half of the 18th century.
About 1770, Etienne-François-Louis de Loys began the work that would lead to the construction of the Château de Dorigny.
Just after the bridge, take the path to the right and cover the trees along it at the next point.
Proceed with a short presentation of the trees along the path between the two bridges, from the side of the river.
The first tree is a chestnut tree with its palm leaves.
A little further on, the large tree with a trunk that splits in two is a frêne with its large compound leaves, made up of several small leaves (leaflets).
The next tree is a and a flat tree, followed by a and a flat tree with almost identical leaves to the one on the flat tree, but a different trunk, with irregular patches of blotchy skin.
Finally, a beautiful and a flat tree with large compound leaves, made up of several small leaves (leaflets).
The next tree is a and a flat tree, followed by a and a flat tree with almost identical leaves to the one on the flat tree, but a different trunk, with irregular patches of blotchy skin.
Finally, a beautiful charme with toothed leaves completes and ends this beautiful végétal picture. This is a species that can be found, with smaller individuals, on the other side of the path.
Of all these trees, the frêne is the one that most likes to être along watercourses in the countryside of the region.
At the end of the path, cross the bridge on the right, then follow the small road uphill. A little further up on your left, there is a vineyard below.
At this point, it is not uncommon to see a few clumps of plants on the banks of the river. These are Japanese knotweed. This exotic plant is on the blacklist of invasive plants recognised in Switzerland (one of around twenty plants). A plant is said to be invasive because it takes the place of native species, upsetting the balance of the site.
At UNIL, knotweed is the invasive plant causing the most concern. It can be found in several places: along the Chamberonne, by the lake, near the Villa des Sports, etc.
Now banned from sale in garden centres since 2008 (it came from there, spreading from the private gardens of villas), this plant still reproduces wonderfully thanks to its suckering root system. What's more, as its above-ground parts disappear in winter, bare soil is highly exposed to erosion.
One solution seems to be emerging: cut it down and intensify the planting of native species.
At the top of the hill, at the end of the road, continue straight on along the railway line. This path then descends steeply to the left (stairs). This path then descends steeply to the left (stairs). At the end of the path, go left along the wide driveway.Cross the pedestrian crossing, take the left and then the right.
After 1 minute, turn right onto the woodland track which you will follow straight ahead. A little further on, cross the Chamberonne by means of a footbridge.
At this point, the river is home to several species of fish such as the river trout, the barbel and the minnow. Trout are migratory species that most often live as adults in the lake, but return to the rivers in winter to reproduce.
The fish pass, here in the form of successive weirs, is an improvement that will make this migration possible on a section that previously remained impassable, due to differences in height that were too great (due to a large waterfall, for example). Weirs are generally no more than 40 cm high, so that trout can easily cross them. They are an integral part of river renaturalisation schemes.
The Mèbre is a river that rises in the Jorat woods, flows through Cheseaux and then on to Crissier and Renens, after winding its way through some surprising gorges.
The Sorge also rises near Cheseaux, passes near Villars-Ste-Croix, then Crissier and Ecublens. Near its source, it is known as the Chamberonne!
After crossing this footbridge, you can take a short ten-minute loop to discover the Mèbre upstream (skip a paragraph to continue your walk without taking this loop).
The loop is described below. Here's a description of the loop: after the footbridge, turn right, then right again along the road, which you cross at the first pedestrian crossing.
Cross the railway tracks in front of you. Cross the railway tracks opposite, then go left. At the next junction, go right and then immediately left into the wood. At the next junction, go left along the unsurfaced track. La Mèbre is on the right behind the trees. At the end of the path, take the outward path in the opposite direction to finish this loop. At the footbridge, continue along the Sorge (the waterway on your left), which you will cross further on by means of a third footbridge.
The beaver disappeared from the Lake Geneva basin in the early 19th century. Begun in the late 1950s in the Versoix near Geneva, its reintroduction continued two decades later in the Venoge. Since then, a few beavers have taken up residence in the Sorge, not far from here. Perhaps you will see here and there the characteristic marks of trees that have crossed the teeth of these fearsome rodents?
In the watercourse, you can also meet the dipper, a brown and white bird the size of a blackbird, which has the particularity of fishing by walking on the bottom of the water against the current when the river is not too deep.
There are plenty of birds in the Dorigny woods: scrub jays, tawny owls and so on. Their presence is encouraged by the installation of nest boxes.
These woods are also home to foxes, badgers, hedgehogs, redpolls and bats.
Then head up the main woodland path, which drops down in a staircase. At the top of this path, at the junction, go right to join the woodland edge. Take the left-hand path. At the next crossroads, head downhill on the left to reach the majestic Napoleonic castle.