Assuming you are planting sugar cane (saccharum officinarum) I've never heard of it being planted as a feature in a water garden, I'd be curious to hear if its roots can cope with growing below the water level
A typical plant to do the purpose, to create a good screen effect to block out eyesores or prying eyes, is tall forms of miscanthus, it likes wet to moist ground but probably wouldnt cope with a submerged position
Regards, Andy
