This is a combination of the internal grass (which is good enough for distant 'reeds') and 2 versions of my (NWDA) reeds. At first I had them floating just under water level, as I didn't want them to duck in deeper areas (you didn't see the base anyway), but later I made a softer mask of the reed mask and added that to the terrain undulations, so the ground was raised a little where the reeds grow. So then I sat the pops on ground.