Page - 378 - in Book of Full Papers - Symposium Hydro Engineering

4. INITIAL RESULTS 4.1. WATER RELEASES DESIGN The flow wave of each release was well propagated downstream. The discharge at Maury dam was equal to the flow generated at the downstream reach. On the other hand, the gradual ascent carried out to prevent aquatic fauna impact and ensure the safety alert was not observable at the downstream station. The flow rate quickly rose to the maximum nominal flow rate designed during the tests. The duration of the hydrograph was sufficient to export the suspended sediment. The SSC was divided by 4, 3 and 2 after the three releases after only 2.5 hours of release, whereas the release has a plateau of 4 hours at maximum flow. During each release, the SSC rates became similar after 1h20 of maximum flow (Fig. 4). 4.2. SUSPENDED SEDIMENT TRANSPORT The SSC reached 2.1 g/l, 1.6 g/l to 1 gl/l respectively for releases of 10,15 and 20 m3/s (Fig.4), which is substantial given the morphological context of the valley. The SSC observed immediately downstream the dam were less than 0.1 g/l during the three releases carried out. These results illustrate the effectiveness of the releases on the suspended sediments, which primarily come from the wetted channel, starting at only 10 m3/s, as the particle size analysis show silt was infrequent along the cross- sections. Fig. 4 SSC observed at the downstream station during each water release. 378