Lacs aux Dames - Lac Bleu

4 points of interest

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  Lake

  Humans and lakes

  On this walk, the lakes are both the departure and destination points; often seen as ideal places for outings, both natural and man-made lakes are extremely sensitive to external impacts. The Lac aux Dames (Dames lake) in Samoëns and the Lac Bleu (Blue Lake) in Morillon were both artificially created in the 60s and 90s respectively to accommodate a range of recreational activities: water sports, fishing, relaxation, cold-water swimming, etc. Today, they are home to ecosystems that have developed naturally over time, attracting dragonflies, amphibians, invertebrates, birds and plankton, as well as riparian vegetation (plants that grow along the banks). It is therefore essential to ensure that we, humans, are able to coexist with local flora and fauna harmoniously, so as to preserve good conditions for all living creatures that settle there and embellish these exceptional environments further.

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  Geology

  The Giffre, a dynamic mountain river

  The Giffre is a river that flows from the bottom of the Combe (from the Bout du Monde, starting at the Col du Ruan and other tributaries) to the Arve in Marignier. This mountain river has a wide range of gradients throughout its drainage basin, dropping from an altitude of nearly 3,000m to around 700m at Morillon over a distance of several dozen kilometres. It therefore is highly dynamic, with periods of excessive water flow amplified by climate change (flooding and disruption of low-water periods, increased movement of debris and sediment, etc.) Its riverbed, man-made in some places, has been redesigned (in particular around the Verney footbridge) with a new fish ladder to ensure ecological stability and to limit the risk for white-water rafting(sports people).

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  Flora

  Beautiful invader

  Ornamental plants in our gardens, buddleias (butterfly trees) and other pampas are rather troublesome exotic species. Whether brought in deliberately or not, they colonise natural environments en masse and compete with native plants, leading to the extinction of the indigenous plants, impoverishment of the soil, disruption of waterbanks and infrastructure, and a reduction in ecological diversity. On the banks of the Giffre, certain species - such as knotweed and mugwort - have found a breeding ground for their propagation: wet banks, landscaping and flower-picking are all factors that facilitate their spread. To avoid this phenomenon, it's best to employ professionals: they will pick the right seasons and methods to eradicate them. In this way, the green alders (arcosses, in local dialect), and other indigenous plants can keep their homes!

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  Geology

  Glaciers, the eternal sculptors

  Wonderful landscapes that bear witness to the past, the mountains that surround you have been shaped for thousands of years! The view of the Aouille (needle, in the local dialect) du Criou, particularly when you look in the Morillon - Samoëns direction, provides some insight into the work of the glaciers from a time when they once covered the Giffre valley. Now that the glaciers have completely disappeared from this mountain, the limestone rock and lapies, geological formations that have been heavily eroded by the flow of water, can be seen. Then, as you look up, between the rocky outcrops, mountain pastures, coniferous forests and alpine moors, the sub-alpine and alpine zones reign supreme at an altitude of over 1700 metres.