When you talk about Paper chromatography, you should know that it is not a very precise technique, and it is pretty much limited to the demonstrations. And water is a highly polar molecule. It does not modify the polarity of the non-polar solvents. Also, you can take an example of cellulose, which is polar, so there’s no difference between the water and cellulose to separate the compounds.  You can find more about this in the online classes of chemistry, where experts have explained it in detail.