The 1,285 MW Xayaburi Hydroelectric Power Project is the run-of-river project along the Mekong River. The project comprises of a Navigation Lock, Spillway, Powerhouse, and a complex system facilities for upstream and downstream fish migration.
As run-of-river project, Xayaburi is constructed in two stages, stage 1 being the time from start of construction to river diversion, and stage 2 from river diversion to completion. The stage 1 comprises of the Navigation Lock, the Spillway and parts of the Intermediate Block. The second stage includes the remaining part of the Intermediate Block together with the Powerhouse, the permanent Left Bank Fish Passing Facilities and the Transmission System. During the stage 2, while the Fish passing facilities are constructed, the Navigation Lock is used as a passway for the fish to migrate upstream
For that the Navigation Lock was modified by adding a specific water feed system to generate the required attraction flows within downstream of the lock. This way upstream migrating fish can easily find the entrance of the lower lock chamber. Increased flow in the Upper Lock Chamber guides fish out of the Lock.
Since May 2015 upstream migration through the Navigation Lock has taken place on regular basis. Normally several locking cycles are performed during the day and the night. The number of cycles depends on the season and the observed migration patterns.
In order to allow monitoring of the actual fish migrating through the Navigation Lock and to improve the operating cycles, the number and sizes of fish are monitored and determined by means of a hydro acoustic camera.
This camera is installed at the upper lock exit that all of fish exiting the lock must pass this camera.
The paper will focus on the monitoring techniques and data evaluation which is aided by special software like Echoview.