Reservoir eutrophication has become a serious issue to us. Who lived next to water emission lots of chemical composition with element N and P in to water. The element “N” and “P” make algae grow fast and cover the lake’s surface , which expenses lots of oxygen and makes the creature live under the water can’t get nutrition. To easterner, Water Lily represents clean and pure. The part under the water surface stirs and purifies the water; the part above the water surface emits clean water, circulate the procedure to solve reservoir eutrophication.