Tuesday, december 1 2009

Natural water retention in the Ardennes

Maïté FOURNIER (EPAMA) | Water courses conservation in Ardennes

Riou (partner 11) is one of the partners dealing with natural water retention. In fact floods and droughts are two aspects of just one problem. The idea is that sources areas and floodplains in the upper parts of the catchment basin can play an important role for the whole of the Meuse basin. Condition is they can function in a natural way. When the bog, moor and fen vegetation is well developed it acts as a sponge for the sky-water. This presents a double benefit. First, in case of high water the flood is slowed down because the water will saturate the natural sponges first. Only when the sponge is full will the extra water flow into the brooks and the rivers. Second, as the water is kept in the sponges it also has enough time to infiltrate the soil. The water thus kept in the system presents a welcome reserve in times of drought.

In the Ardennes a number of small tributaries of the Meuse are being restored to their natural situation by Riou s local partner Natagora/BNVS.
The key question now is: has the restoration of the river valleys as it is carried out an influence on the discharge of the brooks? In other words: does a more natural hydrological situation help us retaining more water in the system thus avoiding drought problems? In AMICE an hydrological study will be carried out in order to answer these questions.
In this same philosophy it is also important to know which vegetation types correspond with more natural brook ecosystems. Put in a more simple way: which plants build up the natural sponges? In order to build up a solid ecological knowledge, last summer a large number of botanical releves were made in the Emmels valley.

Hydrological data combined with ecological knowledge will give us precious information on the possibilities of small scale natural water retention.