Do the water using the 3's in order from up to down. start with the two 3's in column 16 and use the single 1 in col. 15 in between them. then continue with the two 3's in col. 17 and use the 1 from column 16 in between them. finally use the two 3's in the last column and the 1 in col. 18 to fill between.
Took me a bit to decipher Fatmazehra's clues, but once I got the hang of it the water made more sense. I guess an added tip would also be start up to down, and left to right.