Chapter Two:
Lake Annecy - 68 years to restore an ecosystem
Patrice van Eersel and Martine Castello Dossier de magazine Clés - July 2011
From the website of French journal - CLES
2.1 "It was at the end of spring. It was still cool, but the walk had warmed my blood and the water was so beautiful that I could not resist. I undressed behind a bush and in 30 seconds I was splitting the lake. It was very cold, but I thought: "Deliciously frozen!" - with age I appreciate more and more this kind of bath.
2.2 I swam about a hundred yards. Then when I turned around the experience became fantastic. The massif of La Tournette, still snow-covered, stood out near the blue sky, dominating the village of Talloires. Suddenly, the feeling of being part of this grandiose landscape invaded me. The lake carried me and the mountain offered itself to me! I shouted with gratitude and, burning skin, I plunged. The water was of an amazing transparency. We could see the rays of the sun going down ten or twelve meters. It looked like crystal. Returning to the bank, I swam with my mouth open, to taste the delightful water.
2.3 I had been told that after a long period of degradation Lake Annecy had become pure, and even the purest in Europe. What I did not know, was the colossal work that had to be undertaken to regain that vitality. No less than sixty-eight years of struggle and hard work - and the work is not yet finished! Today, the "Blue Lake" has regained its reputation and is a model for the rehabilitation of all European lakes. Even the Russians responsible for Lake Baikal - the largest expanse of fresh water in the world, tragically polluted by cellulose and cement plants - visited to see what the Annéciens had done. In short, the history of the resurrection of Lake Annecy is worth telling. It sheds light on the complexity of ecosystems and the openness required to understand them; On the necessity of a very long-term policy if we are to recover a lost ecological equilibrium; But first of all, of the power of stubborn clairvoyants.
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake
1943-1957: the clairvoyant and stubborn pioneers
2.4 "It all began in 1943, when a doctor from Annecy, Paul Servettaz, alerted his fellow citizens: the city's sewage had begun to kill the lake. To get people’s attention, he dived in front of the crowd, in a particularly dirty creek, to go symbolically to plug a sewer outlet. His demonstration was strictly scientific as he explained later at a conference. Although fed by several small rivers and by a powerful sub-lacustre source, the waters of the lake, which are refreshed approximately once every four years, have to cope with ever increasing discharges from the local population. Dr. Servettaz, who had the flair of a true pioneer, realized this before everyone else – in fact one by one all the lakes of the world were about to suffer the same fate. In the 1940s, if wastewater from the city of Annecy was polluting, it was less due to industrial poisons (heavy metals, hydrocarbons, acids, solvents) or agricultural discharge (nitrogenous fertilizers, pesticides), which were still rare in the region at the time, and more because of discharges of household waste (detergents, phosphates, organic sewage). These substances accelerate the growth of certain algae that fall to the bottom of the lake when they die, being decomposed by bacteria in a process consuming large amounts of dissolved oxygen and so gradually asphyxiating most other living species. This biological chaos, called "eutrophication", results in foul smelling slime from whose stench the local inhabitants suffer.
1957-2001: a very long-term policy to purify the lake
2.5 In the middle of the 20th century, ecological consciousness was not yet born. An understanding of the complex interactions between humans and the rest of nature was beyond most people. At the time, everything was seen simply from the viewpoint of health. This was necessary: all the sewers end in the lake! However, it would take 14 years for the efforts of Dr Servettaz and his friends to persuade the authorities of eight of the eleven communes around the lake to create a grouping of these communes called "the Intercommunal Syndicate of Lake Annecy" (SILA) in 1957. His first task was to plan a sewer pipe around the lake to capture wastewater for treatment before being discharged into the river Fier, a tributary of the Rhône, downstream from the lake, at Cran-Gévrier, on the outskirts of Annecy. As Pierre Bruyère, current president of the SILA recounts, "the task was not easy. It was necessary to get the residents to accept a high remediation tax to carry out this work, estimated at the equivalent of 350 million euros" - a fortune for the time. It was to be managed by a grouping of local communes - what private entity could have played this role?"
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake
2.6 "In 1961, construction began on the gigantic path of the first sewage pipe which was to stretch 38 km around the lake’s shores. It was not to be completed until 1976, after fifteen years of work - and thirty-three years after Dr. Servettaz's cry of alarm. Gradually, the entire region was to join in the endeavour - for, of course, even the distant creeks end up in the lake. Since 2001, 113 municipalities, representing a population of more than 250 000 inhabitants, are connected to the collective sanitation network. Nearly thirteen million cubic meters of wastewater are now treated and discharged every year far from the lake after having passed through 1350 km of collectors, 81 pumping stations and 7 depollution plants. Since 2002 these have been connected to a waste treatment plant of "energy recovery" that transforms their sludge to generate electricity and feed the urban network with heat and hot water.
2.7 The effort paid off. The bathing is safe again and people come from far to enjoy such clear water. "Transparency is the best measure of the purity of a lake," Pierre Bruyère rejoices, "Ours was three meters in 1957; It is fourteen meters today! " Lake Annecy is now considered one of the purest urban lakes the world - that will one day be recognized by the Unesco World Heritage Convention. A reputation that has earned it frequent visits from international experts. Its regeneration serves, for example, as a road map for those of Lake Bourget and Lake Geneva, whose water quality remains far below its own.
Years 2000: the requirements of ecological complexity
2.8 But case is still not settled. A lake is not just a mineral entity, it is a living being. Chemically pure, Lake Annecy has not yet however regained its original biodiversity. It remains fragile, at the mercy of the least chemical, thermal or biological imbalance. A number of residents and pressure groups do not want to admit it, but the evidence is obvious at the turn of the years 1990-2000: a new stage must be crossed, in the lake of course, but first in people's minds."
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake
2.9 "An alliance of scientists and anglers has played a key role in raising this awareness. The research was carried out by the Hydrobiology Station of the National Institute for Agronomic Research at Thonon-les-Bains.
2.10 Scientific monitoring of the lake began in 1966 and was initially based on the monitoring of physicochemical parameters (levels of dissolved oxygen, nitrate, phosphorous), but, increasingly from 1992, it encompassed biological indicators measuring the phytoplankton, zooplankton, fauna and flora in the water and on shorelines. This is a huge task that requires, fifteen times a year, taking thousands of samples at different depths – ( the "big lake", to the north, reaches a depth of 65 meters).
2.11 All these data would confirm what the fishermen - an important pressure group - have long claimed for themselves: in 1980, in the waters of the lake (although increasingly transparent), there were almost no whitefish, no pike, no monkfish, no lake trout, no Arctic char ...Gradually over the years, the diversion of sewage and treatment of wastewater has slowed down and even stopped this reduction of the lake’s biodiversity and the fish are slowly beginning to reappear. But not all of them and their situation remains delicate."
A green deal for the 21st century
2.12 But now there is disappointment for the Annéciens and their neighbours who were convinced that the natural and wild life of the lake was somehow guaranteed by the creation in 1974 of the protected reserve known as the "Bout du lac" at the opposite end of the lake away from the town of Annecy, in an area where, for millennia, has grown a vast marshland, a stretch of reeds, bulrushes and water lilies.
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake
2.13 "This time the culprits are no longer the polluters - domestic, industrial and agricultural - but public works, urbanization and tourism - those who, like us, come from all over to swim in the Blue lake! In a century, stabilization of water levels (through upstream dams), creation of embankments, building of pontoons and harbours has reduced the area of reed beds from 110 hectares to less than 10 - with a peak degradation between 1950 and 1980. "The reedbeds," explains Damien Zanella, ecologist responsible for protection of the natural environment at SILA, "play a fundamental role in the lake's ecosystem. The fish spawn or shelter there. They also serve as a niche for birds and many insects, such as dragonflies, which live in these transitional areas between land and water."
2.14 The area of the reed beds is now stabilized and is once again inhabited by mallards, coots, grebes, swans and beavers. But the security of their ecological status remains worrying. In collaboration with the Conservatory of Natural Areas of Haute-Savoie (Asters), SILA is trying to regenerate these wild areas. Different techniques of vegetable engineering are about to be tested: physical protection of the shore by driving in wooden piles to form a wall again the waves, rebuilding of the banks with various plantations, all in collaboration with the agricultural college of Poisy.
2.15 Ideally, this reserve should be enlarged. This would have a double benefit: besides the protection it affords to species, reedbeds could play the role of a natural filter for the entire lake, like a giant version of phyto-purification systems that today equip green houses. A project to extend the "Bout du lac" was launched in the early 2000s, supported by the municipal opposition of Annecy and most environmental associations. But their action may be hampered by an amendment, voted in 2005 under the pressure of various lobbies, which modifies the law managing the coastline of mountain lakes and allows a reduction of protected areas and "green borders" between the municipalities.
2.16 In sixty-eight years, the situation has changed enormously and Lake Annecy is much better. But it is not yet fully resurrected. Decisive battles are taking place at this very moment, which will decide its fate in for the long term."
Article originally published in CLES No. 70 (April-May 2011)
Since the beginning of 2016 CLES has regrettably had to close down due to declining advertising revenues. It had positioned itself as a journal that "breaks away from ephemeral news to deal with the essentials" which is well illustrated in the article above and so its going will be sorely missed.
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake