STOCKAGE A LA SOURCE - WWF Belgium

Recensement des actions de stockage de l’eau en amont des bassins hydrographiques
drained, dried and exploited during the last centuries. Leafy forests have been replaced
by conifer forests, more economically profitable. That’s why an alternative soil usage
is immediately needed to increase the storage capacity. Conifer forests should give way
to leafy forests and a wider space should be dedicated to peat bogs to allow their
restoration. Fitting-outs in the forest pathways can favour the flow slowdown.
Transition from intensive agriculture and breeding to more extensive farms would lead
to the re-dynamization of the previously exploited humid areas.
5. The experiments collection
To obtain a satisfying result, it is necessary to multiply those soil modifications and to
increase the adsorption surfaces. The collection we conceived during this training
course shows that examples of actions exist in the field of the storage at source and that
it is possible to multiply them at the local level with help of every actor involved.
Departing from the WWF network, our research has quickly widened to other
European, national (France, Great-Britain, Germany…) and regional projects.
Following contacts making, meetings and visits in the field, twelve types of land
settlement have been reviewed across different countries. These techniques can serve
as example and inspiration for future fitting-outs increasing water retention and storage
upstream from the rivers. These twelve “techniques” can be split up into several
categories:
• Worksheet n°1 “Drainage ditches filling”, worksheet n°2 “Water retentions”
and worksheet n°3 “Retentions thresholds” essentially refer to the humid areas
and particularly to the high peat bogs as those that can be seen in the Hautes-
Fagnes.
• Other techniques are related to small catchment areas, which can’t accept
excess water too important. This category contains worksheets n°4 “Transverse
hedges”, n°5 “Temporary retentions”, n°6 “Mountainside benches”, n°7
“Transverse ditches” and n°8 “Vegetalized or weeded bands”.
• A third group refers to the fitting-outs that can be realised both in humid areas
and on small catchment areas (worksheet n°9 “Woods management”, worksheet
n°10 “Extensive pasture” and worksheet n°11 “Complementary ditches and
other dale-bottoms fitting-outs”).
• Worksheet n°12 entitled “Road ballasts and forests paths” reviews the works
that can be set up near forest roads and paths.
In this work, we have reviewed various and original experiments conducted by
different organisations. The different land settlements have been chosen considering
their reproducibility on most of the catchment areas in Europe.
Some experiments reviewed in this collection are unique and haven’t yet been the
object of a scientific monitoring aiming at confirming the realisation of their
objectives. That’s why it will be needed to consider with caution the information
provided here through the twelve worksheets. Indeed, this document isn’t a technical
guide for the building of the different land settlements. So through the worksheets, the
reader will note that the pieces of information provided stay superficial considering the
purely technical and scientific points of view. It is indeed about allowing the great
majority of people to understand each worksheet and by the way sharing and
discussing their content, whatever could be their personal training or role in the
realisation of a considered land settlement. Finally, we don’t want here to give strict
directives through this document, but rather to propose a basis for reflection, debate
and consciousness.
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