Songhuaba Reservoir was built at 1958. 1995 After reinforcement and expansion, the total designed storage capacity is 2? 65.438+09 billion cubic meters, with a storage capacity of 654.38+0? 05 billion cubic meters. The average daily water supply in recent five years is 450,000 cubic meters, accounting for more than 50% of the daily water supply in Kunming. It is the main project of flood control and drinking water source in the main city of Kunming. The water quality safety of Songhuaba Reservoir is directly related to the safety and social stability of Kunming. Since 199 1, the water quality of Songhuaba Reservoir has fluctuated between Class II and Class III. From 1996, they all belong to Class III. Although it meets the requirements of the national centralized drinking water source, the primary and secondary total nitrogen indexes in the monthly monitoring values all exceed the Class III standard. If management and protection are not strengthened immediately, the water quality will further deteriorate.