The sugarcane is generating on the river or in the sea

Expected result:

The sugarcanes should only generate on a grass block/sand and a river beside it

Actual result:

The sugarcanes are generating directly above the river or directly above the sea

How to reproduce:

1. Load up a world
2. Search nearby river or sea
3. And look around. You will notice some group of sugarcanes 

While big bug, it will cause a ton of lag if the sugarcanes is updated