I wonder, how to change speed of water streams, but did not found any setting related to. I use "LandscapeWaterHoriz01", but other strems in Landscape folder are too fast.

That would be an animation with in the nif file as far as I know. Not really a modeller but you could try seeing if you can change the animation speed from within nifskope.

Thanks, I'll try this right now, a good idea. Altough I wonder that in-game streams why streming so slow, I mean the vanilla streams. Anyway, we'll see...