open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello, I created a simple project tomawac to simulate the propagation of waves in a computational domain closed. On the boundary I imposed a liquid frontier where I defined a value of height of water on the boundary of 2 meters (BOUNDARY SIGNIFICANT WAVE HEIGHT = 2).

I set a duration of the simulation of 500 seconds (TIME STEP = 1, NUMBER OF TIME STEP = 500).

The simulation work correctly. But the result shows that the propagation of waves in the time runs out, that is, passes from a value set to 2 meters at a value of about zero meters. This in theory should not happen because the condition on the contour is constant in time.

Someone I can solve this problem?
How do I prevent the wave vanishes over time?
I sbaglaito or I forgot to put some keywords?

I hope for your help

regards

Luca

Ps: I attach the file cas tomawac the project and the file conlim boundary conditions