Chapter Seven: Modernization and long term planning  2008 - present

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7.1 There are many beautiful cities around the world, and more beautiful natural landscapes.  But to find a beautiful city set in a beautiful landscape is a rare thing.  This is what makes Annecy so special.

7.2 The majority of the world’s population now live in big cities where Nature has been very successfully engineered out, so that people can enjoy a comfortable life regardless of the weather or the seasons.  Their only sacrifice losing daily contact with the beauty of the natural world.

7.3 On the other hand,  for a large part of the remaining minority of the global population not fortunate enough to live in a big city, their natural landscapes are often as harsh as conditions were for the majority of mankind 500 years ago.  Here the local population remains exposed to the vicissitudes of the weather and the seasons, with limited access benefits of civilization such as a reliable food supply, hospitals, schools, security, work and not least fresh water.

7.4 But a sizeable urban community in a rural setting faces a great challenge.  Precisely because the natural environment is so attractive, the negative impact of unchecked urban development soon becomes highly visible.  And so managing the interface between the man made world and the natural world – between urban development and the nature biosphere - becomes of critical importance.  This was the vision Dr Servettaz articulated so clearly long before anyone in Annecy, and most of the world,  was thinking about such things. This is the task SILA is now charged with.

7.5 In 2008 Pierre Bruyère became just the fifth president of SILA in fifty years since its foundation (and one of those, Andre Rouge, was president for an interim period of only a few weeks).  He has continued in the energetic and forward thinking tradition of his predecessors.   Recognising the fundamental role SILA plays in managing this interface between the local (and tourist) community and the natural environment, one of his first actions was to put in place a strategic vision for SILA supported by a 15 year planning horizon.

7.6 Waste-water treatment

7.6.1      The waste-water operation for which SILA is responsible has grown significantly since its early days,  and now serves  230000  people from 48 communes organised into 3 subgroups called 'EPCI' (Établissement Public de Coopération Intercommunale).

7.6.2     There are more than 1450 km of sewage collectors connected to a modern water treatment plant called SILOÉ intercepting waste-water from the catchment area of Lake Annecy. The whole system is managed by an up-to-date electronic control system  with continuous remote monitoring of the condition of the pipes and the operation of the 82 pumping stations.  All this represents an investment of more than 400 million euros since the creation of SILA, and each year more than 6 million euro is spent renovating and refurbishing the network.

7.6.3      Just the day-to-day network maintenance of this extensive network is now a formidable task in itself.

7.6.4      Where new pipework is needed there has to be a feasibility study to look at

a) the geological challenges to be overcome

b) the legal issues which may arise with property owners, and

c) the overlap with other utilities who also have installations in the ground.

7.6.5    Next a tender has to be organised for all parts of the work to choose a reliable and cost-effective contractor.   SILA overlooks the whole process, manages the contractors, liaises with other networks, property owners and local communes, and resolves any unanticipated problems.

7.6.6    A department of SILA called SICRA is responsible for surveillance of the network, once it is built, using cameras, pressure gauges etc.

7.6.7    Once new construction has  passed quality control  SILA can apply for a grant towards the costs from various regional agencies. Thereafter, monitoring of pumping stations and preventative and emergency repairs are made by the service “Entretien des réseaux” (maintenance network service).

Extracting methane gas from waste-water

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7.6.4        SILA has become one of the first waste-water treatment plants in France to produce 'Green Energy' by producing bio-methane gas.

7.6.4.1     During the past several years Pierre Bruyère has overseen  a significant general upgrading of the SILOÉ water treatment plant.  One of the main features  has been constructing a biological processing plant to extract biomethane gas from human sludge and waste-water.

7.6.4.2    Its final construction followed two studies promoted by Mr Bruyère as soon as he took office.  A perspective study in 2008 led to a feasibility study in 2011 which produced a plan for the 14.5 million euro investment, of which approximately a fifth is funded by governmental agencies.

7.6.5       Its purpose is to implement the requirements of the new French Environmental law “Grenelle de L’environment” (Agreement on the Environment)  which aims to increase the value extracted from human-produced waste whilst also reducing related atmospheric emissions and residual waste.  It does so in the following ways:

7.6.5.1     Biomethane gas produced by this plant from the bacterial digestion of waste sludge is a renewable source of energy.   Since January 2017 this gas is being purified and injected directly back into the existing gas supply to houses in the neighbouring town.

7.6.5.2    This biological process involves dehydrating the sludge which leads to a reduction in its volume of around 30% before it is incinerated.   This in turn leads to two further savings a) reducing the amount of energy needed to incinerate the sludge and b) reducing the fuel consumption of lorries transporting the sludge.

7.6.5.3    A third benefit of this process is reduction of offensive smells emanating from the sludge in transportation.

7.6.5.4    Fourthly, by-products of this solid waste are also recovered – for instance sand is cleaned and can be used as ballast in road building.

7.6.5.5    Finally, the whole plant has been designed to be ergonomically efficient and secure, and to blend in with the surrounding environment.

7.6.7      Another major stream of work undertaken by Pierre Bruyère, is one of the largest of its kind in the whole history of SILA:  the reinforcement of the network of collectors to cope with the ever increasing volumes of wastewater from the left bank of the lake.

7.6.7.1   One of  the first major projects within this stream, was the construction from 2008-2010 of an underground sewage mains, 1500 metres long and 2.2 metres wide, through the centre of Annecy - right under the main SNCF railway station!

7.6.7.2   By tunnelling deep underground SILA were able to  render obsolete Sépulcre, one of the largest and most expensive pumping stations, and replace it with simple gravity feed. 

7.6.7.3   This was a work of engineering prowess through a highly built-up area, protecting the foundations of all  buildings along the way, and causing minimum disruption on the surface, whilst at the same time ensuring continuity of service.

7.6.7.4   This section of pipework now forms one of the critical links between the left bank network and the treatment plant at Cran-Gevrier.

7.6.8     Pierre Bruyère  has also continued the effort  to replace old, or establish new, local treatment facilities in the outer reaches of the catchment area where geographical difficulties make connection to the main network unfeasible.

7.6.8.1  These tactical facilities capture and process waste-water locally and discharge into nearby mountain rivers and streams, including at:

Sallenoves (2010)  a facility for between two and four thousand people, and at

Montmin (2015) for seven hundred inhabitants and the largest at

Champs Froid at Marlens which serves 15,000 inhabitants, discharging treated water into the river Chaise.

7.7 Household waste 

7.7.1      The largest project undertaken so far by Pierre Bruyère is the modernization of the household waste treatment plant at Sinergie.  After work is completed in 2017  the plant will have the capacity to treat 96,000 tonnes of waste and 20,000 tonnes of mud from up to 290,000 inhabitants. Initiated in 2009 as part of Pierre Bruyère's strategic vision for SILA for next 15 years, the cost is estimated at 78 million euro and will include generation of electricity and heat from waste, a reduction in smells and other emissions, and making use of waste products for road building.  This work will ensure Sinergie continues to be in compliance with national environmental laws which require reductions in household waste and an increase in the conversion of waste into energy.  This energy recovery will enable Sinergie to produce and sell electricity as well as to produce enough energy to heat 4000 dwellings nearby.  It will reduce pollution taxes (introduced to incentivize exactly this kind of investment).  Finally, it will improve logistics within the site, reduce the impact of the facility on the environment from atmospheric emissions and improve working conditions.

7.7.2      Dr Servettaz warned 50 years earlier not just about the need to divert sewage away from the lake, but also to keep it free from all sorts of rubbish dumped there by local inhabitants and businesses.  He went as far as setting up a divers club named “Club aquatique subalpin” to explore the lake floor and seek out evidence of such dumping.  (DRS 151) “The immense submerged universe of this ‘little lake’ which is so blue and so apparently clean at its surface reflected like a mirror the mentality of the local population... This hotel had used the lake as a tip for throwing out its old bedding, that hotel, in course of its renovation had dumped its old toilets, broken bidets, plaster board stuck with bits of old fashioned carpet... At the foot of another we could count among the vegetation, dozens and dozens of rotting wooden crates full of detritus, rubbish, bottles, large tins of preserve piled up – faced with this inventory one could with little imagination reconstitute their gastronomique menus!”  What pleasure it must have given Dr Servettaz eventually to see laws passed in 1974 to outlaw such dumping,  together with making individual communes responsible for setting up a rubbish-recycling and collection service.  And to see a modern waste-processing plant built in 1986 must have given him even greater satisfaction. Dr Servettaz sadly passed away in 2003, but what pleasure it would have given him had to see Sinergie upgraded to become one of the most environmentally friendly and energy efficient waste-treatment plants in the country!

7.8 Annual scientific monitoring

7.8.1     Pierre Bruyère has continued the SILA tradition of annual scientific surveys  designed not just to give independent  assessment of the quality of the lake water but also to gain an understanding of the evolution of the lake over time. Studying these trends  enables SILA to detect and respond promptly to any signs of deterioration in the quality of the water.

7.8..2      These studies confirm that Lake Annecy continues to be in good health and biologically stable, and meets the physical and chemical requirements of the European Water Directive to be  classified as in “good condition”.

7.8.3      These studies measure among other things:  amounts of nitrogen and phosphorus present, concentrations of oxygen at different depths in the lake. the pattern of growth of plankton during the year, the levels of chlorophyll, and also an analysis of the fish population, the state of the littoral vegetation, and the crustacean.   This additional information, which is required by the European Directive on Water,  was first included in 2010.

7.8.4      Additionally SILA, in liaison with the national government, carried out a study of persistent organic pollutants, (PCB and HAP).  The conclusions showed that concentrations of both were well below the relevant norms, and that Lake Annecy measures closer to what is normally found in isolated lakes at high altitude.

7.8.5      SILA regularly participates at a European and global level with other towns and overseas public bodies.  This cooperation allows reflection on common challenges and best practice as well as supporting other towns on their path of development.  SILA's experience in treating waste water, managing household waste and protecting the natural environment attracts visitors from all over the world including China and Russia.

7.8.7      Following successful participation in the network of alpine lakes (Alplakes) in 2005 – 2007, SILA participated in another association of Alpine lakes called 'SILMAS' 2008 - 2012, led by the Rhone Alps region.

7.8.8      These two organisations aimed to share experience, skills and best practice in the sustainable management of lakes and their catchment area. Amongst themes discussed were climate change, the changing states of lakes, lake usage and the management of conflicts between users, extracting value from the environment, promotion of eco-tourism and the creation  of associated educational materials.

7.8.9      SILA also acted for several years as a coordinator of the scientific programme “Climasilac” which brought together researchers from various disciplines, and different European universities, as well as local interest groups such as fishermen and divers.  The purpose of these meetings was to strengthen scientific expertise of the lake and, by investigating the sediment on the lake floor, further understand the history of the lake’s evolution.

7.9   Regulation of local construction

7.9.1    Having constructed the new dry dock at Sevrier, the question arose what to do with its now disused hangar.  Pierre Bruyère responded to the commune's request to refurbish the hangar for all-purpose use and so from September 2010 to Spring of 2012 SILA undertook its reconstruction at a cost of  750,000 euro.

7.10 Protection of flora and fauna

7.10.1      Mr. Bruyère also initiated a programme in 2011 to restore and protect the reed beds around the lake, particularly at Bout du Lac and Saint Jorioz. The reed beds play a vital role in preserving the health of the lake.  This is one part of a programme of actions to protect the environment around the lake which also includes organising regular meetings of the lake's users, control over moorings and navigation, occasional environmental presentations, and a teaching day involving a variety of activities for local people to develop their awareness of the lake’s environment.

Restoring the reed beds - a vital component of a healthy lake

7.10.2  During the 20th century the aquatic reed beds around Lake Annecy have been severely depleted, shrinking from an area of a hundred hectares to just ten.  This problem was described in Louis Lagrange's report on SILA's 25th anniversary, in an article by Mr Jean-Pierre Courtin Engineer from Dept. of Agriculture.

7.10.3   And yet the same reed beds play a vital role in the preservation and improvement of the quality of the lake's water by acting in its purification.

7.10.4  They also make a habitat for the lake's fauna (fish, frogs, insects and birds) by protecting them from predators and providing a safe place for nesting.  And not least they play a landscaping role, helping to prevent the erosion of the lake shore.

7.10.5   In response SILA has launched a 1 million euro programme of action to preserve the reed beds, financed 50% by l'Agence de l'eau Rhône-Méditerranée et Corse and 30% by the Conseil Départemental de la Haute-Savoie.  This action is carried out in collaboration with ISETA and CNR and is focussed on three pilot zones: Bout de Lac at Doussard, and the Marais de l'Enfer and the Roselières pathway both at Saint-Jorioz.

7.10.6  The work involves planting new reeds, and driving in wooden piles by the lake shore to create barriers protecting the reedbeds from the continuous impact of waves.

7.10.7  In parallel with this action, and in collaboration with the State, SILA has launched a public inquiry into the management of the water level of the lake.  This is because allowing the water level to rise and fall more naturally with the tides and the seasons would be beneficial for the reed beds.  This is because at present the lake's water level is kept more or less constant by mechanical sluice gates, which means that waves are constantly striking at the same part of the individual reed stem.  This leads to the reeds weakening and eventually breaking, at which point water enters the reed stem and the reed and its root system rots and dies.  A discussion with the riverside communes and the lake's users is in process in order to find a balance between these ecological and their socio-economic interests.

7.10.8  In a related project SILA is encouraging the installation of "ecological moorings" which protect the vegetation on the lake bed where anchors are dropped.  This is one of the first examples in the world of such moorings since they only exist in lake settings and have to be adapted to the specific body of water. 

7.11  Access           A further section of the cycle path, from Angon to Talloires, was  constructed in 2010 - 2011, with a view to one day encircling the lake. 

©  Gw. P. / SILA

7.11.1      SILA is working with the Conseil Départemental de la Haute-Savoie to develop in due course a cycle path all the way around the lake.  This work is in progress and will take several years to complete.  With a total cost estimated at the planning stage of more than 22 million euros, this project has been underway in discrete sections along the east side of the lake since 2010.  Several sections with a total cost of 9.6 million euros have already been completed or are in process of completion, namely: Talloires - Angon, la Côte de Talloires, Annecy-le-Vieux - Chavoires, Menthon-Saint-Bernard - Haut de Talloires.

7.11.1.2   The next stage concerns the section where the roads RD1508 and RD 909 meet at Doussard as well as the section from Balmettes to Talloires.   Three other sections remain to be implemented before the final complete encirclement of the lake.

7.11.1.3   The Conseil Départemental de la Haute-Savoie which is responsible for managing the construction work, and SILA are jointly financing the majority of the work. The Région Rhône-Alpes has already given financial assistance to the first sections. The communes through which the cycle path passes also participate in certain aspects of the work (e.g. moving utility pipes and cables).

7.11.1.4   Once finished, the Cycle Path will allow a complete circuit of the lake with various passages adapted according to the particular constraints of the terrain.

7.11.2 At the same time a separate pedestrian path is being developed.  It will  be signposted and secure the whole 42 km circumference of the lake offering original and interesting viewpoints.  It will comprises 30 km of paved walkway, nearly 10 km of which will be accessible to persons of limited mobility, and 12 km of unpaved path.   Sections can be combined with short trips on the lake ferry, which runs every few hours between different landing stages, to create a variety of walking tours to explore the natural environment around the lake. The path is interrupted between Doussard and Angon but this will be completed in conjunction with the work on the cycle path mentioned above.   The project was undertaken in 2012 in response to strong demand from both the local population and tourists and is expected to cost 418 000 euro.  Finance is being provided by the European Union (43%), the Rhone-Alps region  (28 %), SILA (21 %) and the Conseil Départemental de la Haute-Savoie (8 %).

7.11.3 With a similar aim of improving access to the lake to all, SILA is also building a path for the disabled in the nature reserve of Bout du Lac at Doussard.

7.12  Health and Safety

7.12.1      As with many lakes around the world, lake Annecy is affected by the “dermatite cercarienne”. This infection which is considered benign although it can cause skin rashes on certain bathers who have an allergic reaction. In order to develop this parasite needs to infect the snails on the floor of the lake and then the ducks on the surface of the lake.

7.12.2      In order to investigate this parasite in more detail SILA applied to the University of Reims and the Museum of Natural history. As a result of the steps put in place to tackle this issue the number of bathers affected has fallen from several hundred at each beach in the years around the turn of this century, to several dozens from all beaches combined in recent years. This plan involves a reduction in the number of snails by up to 90% in shallow areas, as well as control over the populations of mallards in collaboration with hunting societies as well as the League for the protection of birds.  SILA has produced a detailed report on these activities available to all members of the public.

7.13 Education

7.13.1      One of SILA's educational events was a discovery day on Lake Annecy’s Green Pathway for local students.  This was a full day of education covering practical tuiton riding bikes, outdoor exercise, respect for safety and discovery of the ecosystem of the lake.

7.13.2      First organised in 2002 this day brings together 600 – 700 students who spend the whole day riding and participating in various activities including identifying birds, flowers, road safety etc.  It is open to all schools in the communes participating in SILA.

7.13.3      Another annual public education activity organised by SILA in Autumn 2016 was an event called ‘sharing the lake”.  It enabled participants to discover another view of the lake and look afresh at this exceptionally beautiful heritage.

7.13.4      Activites were organised in general around three communes which lent great logistical support to the event.  Passenger boats and free taxis provided transport for participants to make it easy to move around during the day. The activities were also accessible by bike along the Green Pathway or the path along the lake side.  Activities in 2016 included a quiz with prizes to be won at the end of the day and a performance entitled 'Hymn to the Lake in Annecy'.

7.14 In all these various ways SILA continues to develop and implement best practice in Lake Management – a modern science arguably first conceived seventy years ago in the mind of one Dr Paul Louis Servettaz in a small provincial town in France.

7.14 Coordinating users of the lake

7.14.1     One of SILA’s responsibilities is to ensure the harmonious collaboration of all users of the lake, the security of users and the protection of the natural environment in the long term.

7.14.2     To ensure this, SILA and the national government created in 2008 a grouping of  people representing all types of state bodies, such as elected officials, police, firemen, conservation body Aster,  users of the lake and scientists,  called the Commission for the lake and its future.  In total, there are about 250 people in this Commission. There are 3 subgroups: elected members and representatives of the State and other public bodies (70 people), those representing users of the lake such as fishermen, boat companies, local property owners (150 people) and scientists.

7.14.3     This commission creates a forum for receiving opinions on activities current or planned, communicating information to users and getting support for proposed projects.

7.14.4     40 years ago Dr. Servettaz wrote down his vision for the lake's future (DRS 221):

"Along with all the work undertaken [by SILA] to protect the lake from waste water and household waste, I see here the development of a new mentality of protection, a kind of jealousy, or justified pride, amongst all the various users of the lake. This is to be rejoiced at and preserved from generation to generation, because much more effective than official rules and regulations, this spirit of pride will watch over the lake for potential treacherous threats of damage."

SILA helps balance the interests of all users of the lake

and given the demands on the lake, this can be a challenge

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