It is helpful
For something to be helpful, it must have an intention to help. A river is an inanimate object with no intentions and therefore it can not be helpful.
The noun form of the adjective 'helpful' is helpfulness.The word 'helpful' is the adjective form of the noun help.
Jelly Fungi is Helpful.
Bacteria can be both harmful and helpful
If you need help I recommend you type in the specific question you need help with
more helpful, most helpful
most helpful, more helpful
not helpful
not helpful
not helpful
Not Helpful
not helpful
not helpful
Not Helpful
helpful
There's not one wave that can be helpful but it can be helpful if you go surfing.