The river we descended normally has much higher flow, but being late August the flow was down to maybe 3-5 cfs which meant there were some algae blooms. They were mostly vibrant green and I thought quite pretty, especially in the waterfalls where they hung like moss in fluted, highly regular patterns having been shaped by the water. Though, it also meant we had to avoid the blooms in the water, lest we turn into swamp thing.