Controlled fine sediment release from a reservoir by a hydrodynamic mixing device

Following the preliminary implementation carried out in the Mauvoisin reservoir in Valais, we will implement a project with HP industry with the goal of demonstrating the effectiveness of technologies to artificially stir the water stored in a dam reservoir to prevent sediment from settling and allow for the sediment to be conveyed downstream at acceptable rates through the turbines. The mobile mixing devise (demonstrator) will be tested at several dams (1 to 3) to show its efficiency in different conditions.

Expected outcome from real-size field demonstrator will be to:

• validate flushing efficiency (per m3 of water release, per kWh of energy forced into the reservoir) as compared to laboratory development conditions;
• characterize dependence from local conditions (reservoir morphology, arrangement of reservoir inlets & outlets);
• identify practical difficulties and shortcomings of field implementation and deployment;
• control the modifications to the sediment regime in the river downstream of the powerhouse as well as in the residual flow streth,
• and the resulting environmental impacts.

We will seek funding for industry and SFOE to initiate the demonstrator in 2017.