There is a graphic bug that allows to see water streams underground if you stay in water

I tested it on 1.16.4 forge 35.0.0 with only this mod loaded

Are you using Fabulous graphics? If you do, switching to them should have shown a warning telling you that you should disable stencil in the IE config.

Also: "with only this mod" is very vague. What version of "this mod"?

Please provide a debug crash, as as requested in the issue template, which you blatantly ignored

The Fabulous graphic was the problem.
And i didn't put the mod version in because there is only one version for 1.16.4 but i didn't think of next updates.
(I didn't put in crash log because i don't know how to do it)

(I didn't put in crash log because i don't know how to do it)

Hold F3+C while ingame until it crashes