River sides creates spikes in the water

Hello, using the RIver on a Landscape deforms correctly the land, but the RIver itself has spikes in the sides, I tried with the RIver with, fallofs, etc… and the only moment that it dissapears is when I force the Z Offset a lot, but in that case, the deformation of the landscape is incorrect.

I don´t know why the river has that spikes or how to avoid it, does anyone knows how to do it?

Thank you !