Sustainable management of leisure and professional fisheries at the ...

At Serre-Ponçon, the principle implemented would
thus consist of placing a geotube and then covering
it with a geotextile membrane, so that a 80 - 300 kg
rip-rap can be laid on top of it that can withstand
wake waves (3H/1V).
The bar/tube and the pocket of water created would
then be partially planted with suitable vegetation
(Carex hirta, Carex stricta, Phalaris arundacea,
Phragmites australis, Ropippa sylvestris), and even
commercial trees and shrubs that are also suitable
(willows, poplars, alders, etc.).
The tubes would be laid out in lines so that the
h = 0.30m to 0.50m:
1. Manufactured items: “Geotube” type sleeves
laid out/aligned in situ and filled by pumping alluvial
material in the lake.
2. Creation in situ: Execution and placement of
geotextile sleeves by turning them over and burying
them in trenches that are 0.50m to 0.70m deep and
filled by pumping alluvial materials into them.
To this end, the vegetation planting experiment
conducted by SMADESEP on the tail of the
Serre-Ponçon containment works under the
framework of nautical development works on the
Chadenas Plateau enabled the suitability and
strength of certain types of these plants to be
tested. Feedback has to be obtained from the
sub-contracting company in order to determine a
vegetation planting protocol that can be applied to
other sectors.
Propagation using cuttings of willows and carexes planted on backfill on the tail of the containment works under
the framework of execution of works for the Chadenas channel (October 2010, SMADESEP)
C. POTENTIAL SITES FOR THE DEVELOPMENT OF ARTIFICIAL SPAWNING
GROUNDS AT SERRE-PONÇON
The conditions for restoring and developing
spawning grounds are linked to the presence of
water and permanent humidity enabling good,
rapid plant recolonisation.
The choice of experimental sites must therefore
take these imponderables into account, as well as
fulfilling the 5 criteria identified in RHUL, 2004:
- A substantial humidity rate, guaranteeing a
good humidity level for the plants. Sites in the
proximity of permanent influents must therefore
be given priority;
- A gentle topography (selection of a site with a
gentle slope) enables the risks of soil leaching
due to wake waves to be limited, as well as
enabling humidity to be maintained for a longer
time during periods when the land is above the
water line;
- An altitude of between 773 and 780 m NGF
(French General Levelling System), with the pikes
spawning in shallow zones in June and with
vegetation that is “adaptable” to variations in the