Alex Houston
Transboundary Waters
February 23, 2012
T HE R HONE R IVER B ASIN
B ACKGROUND
The Rhone River Basin is shared by
Switzerland, France, and Italy (the Italian
part is negligible). The basin covers a
surface area of 98,000 km2—France
occupies 92% of the area, while
Switzerland occupies the other 8%. The
Rhone River, small by many standards
(800 km), is the largest river that feeds
freshwater into the Mediterranean Sea
after the Nile River. The source of the river
is the Rhone Glacier in the central part of
the Alps. It flows into the Lake of Geneva
and crosses into France to the west of the
city of Geneva. The river is bordered by a
total of 16 million people (1.2 million in
Switzerland).
Approximately 70% of the surface water
withdrawn in the basin is used for
agricultural purposes. Domestic use and
industry both use about 15%. Some other
uses of the water include hydropower in
the Alps, cooling thermal and nuclear
reactors in France, recreation, and
navigation (from the Mediterranean Sea to Lyon).
The basin is characterized by low winter discharge due to snow detention and high spring and summer discharge
due to the melting of snow and ice. The average annual discharge of the Rhone into Lake Geneva is about 180
m3/s with the winter discharge being less than 100 m3/s and the summer discharge exceeding 600 m3/s. Flood
events can produce flows greater than 1,000 m3/s. The average annual discharge from Lake Geneva is 570 m3/s.
The Rhone enters the Mediterranean at an average flow of 2,300 m3/s, with a flood peak of 13,000 m3/s. The
erratic changes in flow along with a relatively high gradient explain why the Rhone has been known for its poor
navigability but good for hydroelectric potential. The flow of the Rhone is regulated by several large storage
reservoirs (7 billion m3, which represents about 7.3% of the annual runoff of 96 billion m3). Almost 80% of this
storage is located downstream of Geneva. 43% of the storage capacity is provided by the Serre- Ponçon dam on
the Durance. The dam is one of the largest in Europe.
L AKE G ENEVA
Lake Geneva is a transboundary lake (580 km2) shared between Switzerland (59.5%) and France (40.5%). It is the
largest lake of Western Europe and is a vast drinking water reservoir. The anthropogenic impact is strong on
both sides of the lake. Only 3 % of the lakeshores are still natural due to agriculture, industries, and
urbanization. Eutrophication and industrial pesticides are the most serious water quality problems. In 1957, a
group of scientists became concerned with the growing pollution and introduced systematic monitoring of the
water quality. In 1962, an agreement was signed by the governments of France and Switzerland to form the
International Commission for the Protection of Lake Geneva (CIPEL). As of today, CIPEL is still around and
working to protect the lake waters and surrounding areas.
L AKE E MOSSON
Lake Emosson is another transboundary lake located in the Rhone River Basin, but this one is formed by a dam.
A treaty was signed in 1963 between France and Switzerland to build a hydro-electric facility. The parties agreed
to establish a Standing Supervisory Commission compromised of officials and experts from the competent
authorities of the two states. The Commission supervised the construction and operation. Each country receives
about 50% of the power produced.
G ENEVESE A QUIFER
The Genevese Aquifer is the transboundary aquifer in the basin. Natural groundwater supplies Lake Geneva
about 789,000 m3/yr and the Rhone River about 1.9x106 m3/yr. The main use of groundwater is domestic use
(65%). Industry and agriculture use 25% and 10%, respectively. A new agreement (signed by the French and
Swiss governments) that went into force in January 2008 deals with the use, recharge, and monitoring of the
Genevese Aquifer. The agreement set up a joint commission to identify the roles and responsibilities of both
countries and to determine the financial modalities governing the use of the resource. Groundwater levels have
been lowering in the past years but not a substantial amount, so this agreement shows advanced cooperation.
F UTURE I SSUES
Due to climate change, the hydrology and the water balance of the Alpine region is predicted to be substantially
affected. According to the climate scenarios available for the Alpine area, precipitation is predicted to increase
during winters and decrease during summers. Overall annual precipitation is predicted to decrease by 5-10%.
Hard rain and the number of days without rain in summertime could increase. Models indicate an increase of 4
°C in winter and more than 6°C by 2100. The temperature rise and the significant reduction in the extent and
volume of the snow cover will lead to changes in the hydrological run-off—stronger and longer lasting low-flow
conditions in the summer and higher run-off in the winter (causing more frequent high floods in the lower part
of Switzerland).
The safety of hydropower, economical attractiveness, and the want to migrate towards environmentally friendly
energy are leading to increased hydropower production in the basin. This increase might lead to the changes of
run-off condition and cause depletion in habitats in and around water bodies.
Q UESTIONS
o
o
Is there anything we can learn from the Rhone River Basin and apply to other basins?
What do you think is behind the cooperation of the two countries? Do you see anything in the future
happening to break up the cooperation?
S OURCES
http://ocid.nacse.org/
http://rosenberg.ucanr.org/documents/Bravard_Rhonecanada.pdf
http://www.unige.ch/climate/Publications/Beniston/ESP2011.pdf
http://www.unece.org/fileadmin/DAM/env/water/publications/assessment/English/J_PartIV_Chapter6_En.pdf
http://www.cipel.org/sp/spip.php?page=secteur&id_rubrique=3
http://cmsdata.iucn.org/downloads/france.pdf
http://www.agroparistech.fr/IMG/pdf/syn08-eng-llanes.pdf
Iza, Alejandro. International Water Governance: Conservation of Freshwater Ecosystems Vol.1 International
Agreements Compilation and Analysis. Gland, Switzerland and Cambridge, UK: IUCN, 2004. Google Book
Search. Web. 22 Feb. 2012.