The reservoir’s water quality usually refers to the degree of eutrophication, commonly known as the Carlson’s Trophic State Index (CTSI).When CTSI is below 40,the water is in oligotrophic state (excellent quality). When CTSI is between 40 to 50, the water is in mesotrophic state (good quality); while over 50 the water is in poor quality (algae breeding and possible algae poisoning and smells will occur).
Over the years, in addition to actively coordinating and promoting catchment related conservation and anti-pollution work with other agencies. The “Storing Clear and Releasing Muddy” operation, aimed at reducing the amount of nutrients from siltation, contributed to the annual average of Mesotrophic state (good quality) measures of CTSI. In recent years, the water quality is in the Oligotrophic state.