Presentation of the project



The EDF company has built many power plants on the French rivers, and each time it represents an upheaval for the ecosystem. Consequently, it is required to make its possible to avoid it. The project that we performed aimed at studying the example of a power plant situated on the Vienne river whose presence prevented the fishes from swimming up the river.  Consequently, EDF had to install a fishing pass downstream the plant, as it is presented below :
 


 
 

The canal is located upstream of the confluence of the Vienne and the Envigne.  Its water flow rate can be adjusted over the value -2 m3/s. The water flow rates of the Envigne and the Vienne are fixed to the values : 1m3/s and 100m3/s. Then, the height of water at the EDF plant level  is 47.75 NGF.

Several studies have shown that the water quality of the Envigne was not as good as the Vienne 's one. Moreover, with such boundary conditions, it turned out that the fishing pass was mostly supplied with the water of the Envigne and could consequently become less attractive and efficient. 
The goal of our study is to modelise this area of confluence  and to find out some solutions for the previous problem.

 
 

Our methods

In order to make a difference between the water of the Vienne and the water of the Envigne, we inject a pollutant at the inlet of the Envigne. Thus, we can observe the mixing of the two rivers, and know how this water evoluates in the canal and pollutes the fishing pass.
The following paragraphs will propose two methods able to solve this problem : firstly, by increasing the water flow rate of the canal, and secondly, by building a sea wall at the confluence level.