The
Serre-Ponçon dam
the
largest earth dam in Europe
Past and present
in the history of men and women,
"from sickle to windsurf" |
The
river Durance
is after the river Saône, the main affluent of the Rhone.
Its 14200 sqkm drainage area represents the sixth of the hydrographic
area of the Rhone.
The annual average contribution of the river
Durance is 6000 m3 under the bridge of Mirabeau, below the confluence
with the river Verdon. The river Durance flows across five departments:the
Hautes-Alpes, the Alpes de Hautes-Provence, the Var, the Vaucluse
and the Bouches du Rhone. |
The area before the dam. Pictures taken on March 5, 1956
|
History
The devastating floods of 1843 et 1856,
followed by summer shortages and their consequences on agriculture
in Basse-Provence, drew attention on the necessity to mitigate the
flow rate of the river. The site of Serre-Ponçon (2 km below
the confluence with the river Ubaye) forms a relatively narrow bottleneck,
making the building of a dam easier and creating a large capacity
reservoir,
Probings are made as soon as 1856, then again in1895,
1912 and 1927, but the technical problems encountered are insuperable
at that time, because of the thickness of the alluvial deposit (up
to 100 m).
The probings made by EDF enabled an exact definition
of the shape of the river bed and technical progress achieved by
1960 made the building of a dike possible. Work began in 1955 and
ended in 1961, following the schedule established by EDF. The filling
of the dam began on November 16, 1959 and went on until 1960. Two
of the four generators were started in August 1961 and the whole
plant at the beginning of 1961. |
The works. Winter 1959/60
Serre-ponçon
today |
|
Interest
of the building
Serre-ponçon
is the most important engineering piece on the river Durance. Its
water capacity is 1.200Mm3, with 900Mm3 live capacity representing
30 % of the average annual intake.
_ Electricity: Serre-ponçonproduces 700 million
kWh a year.
_ Agriculture : it feeds with water the
irrigation channels in Basse Durance and gives drinking water to
cities like Marseilles
_ Protection: against floods, which were
diminished after its edification.
_ Tourism: not taken into account at the
time of the project; today, EDF makes permanent efforts to integrate
that point in the management of the dam (constant level of the lake,
visits of the subterranean plant ...)
|
Localization
of the dam and blueprint
Serre-ponçon
|
a concrete
train
|
temporary
change of course of the river Durance
|
The
plant. Access excavation.
|
Technical
data:
- drainage
area 3600 km²
- average altitude
of the drainage area 2020 m
- annual contribution
of the river 2700 Mm3
- live capacity 900
Mm3
- plant output 300 Mm3 seconde
- maximum drop 125
m
- average drop 107 m
- total power 360 000 kWh
- average annual production 700 M.kW |
The
plant , turbine room, status on March 14, 1960
|
The
plant
|
Cross
section of the dam
|
Bridge
of Savines. Status in February 1960
The
bridge today |
Serre
-ponçon disrupted the lives of two generations of inhabitants
from that area and valley. Many left and those who decided to stay
had to adapt to a different environment and to mass tourism after
1960. |
