Hydro-Sedimentary Operation And Sediment Balance Of Lake Saint-Germain-De-Confolens (Charente, France): Geomorphological Parameters To Be Taken Into Consideration In The Management Of The Lake

Lake Saint Germain was created near Saint-Germain-de-Confolens (Charente, France) for drinking water production in 1972. Since then, various short-term studies have shown water quality to degrade, and sedimentation to gradually fill the lake. The lake appears to have lost 42 % of its initial water capacity due to present mean sedimentation rates nearing 8000 m(3)/year. A sedimentary balance shows that this phenomenon can be attributed to watershed allochtonous particulate inflow for 87 %. Sediment fluxes and their lacustrine accumulation act in turn as in-lake nutrient sources accelerating the eutrophication process. As a conclusion for this study, some solutions are proposed to improve drinking water production sustainability.