I have set water height in every ******* cell of a big lake and now I don't have LOD for this lake while in CK I see water is at its right height. furthermore the other water heights different from the default height are shown in the world map how you can see in http://s1295.photobucket.com/user/PelinalWhitestrake/media/2013-06-04_00001_zps1c263dce.jpg.htmlat the top right there is a river correctly shown, in the red cricle there should be the lake.

Any idea why?

Did you regenerate terrain LOD after changing the lake's water height?

yes. I made river and lake's LOD at the same time after changing both their water heights