Fengman Hydropower Station
Fengman Hydropower Station is located on the Second Songhua River 24km away from Jilin city in Jilin Province. It takes its source from the Heaven Pool, the highest peak of Changbai mountain. The catchment area controlled by Fengman Hydropower Station is 42500 square kilometers, 19000 square kilometers of catchment area by Baishan Hydropower Station, which occupies eleven percent of catchment area of the river basin above Haerbin city and several branches including the First Dao River, the Second Dao River, Huifa River and Lafa River. The catchment area includes the south of Jilin area, the north of Tonghua area, the west of Yanbian municipality and the east of Siping area totally 16 area, in Jilin province. The First and the Second Dao River catchment are mostly of high alpine area, having more primary forest, sparse population, less cropland, steep river bed and rapid water flow.
For convenience of reservoir forecast the catchment area was divided into 3 areas. Upriver Baishan is the area 3 or called Baishan area, that controls 19000 square kilometers of catchment. Upriver 5 Daogou is the area 2 or called 5 Daogou area, the catchment area controlling 11600 square kilometers, Hongshi reservoir area and near Fengman reservoir are the area 1, with the controlled area of 11900 square kilometers.
The Fengman catchment area belongs to chilly warm and humid climate, controlled by Pacific Ocean monsoon in summer and by Siberian high air pressure in winter. It is warm, wet and rainy in summer, but cold and dry in winter. The annual rainfall is 500~1020mm, descending from upriver mountainous area to downstream region, rainfall non-uniformly distributing either in various zones or in different years up to the end of 1994, average rainfall in years is 745mm, the minimum annual rainfall being 526mm, the maximum annual rainfall being 1018mm. Rainfall distribution in a year is uneven, concentrating from June to September, it takes sixty percent to ninety percent of year's total. The maximum month rainfall is 358 mm, once maximum rainfall is 201mm, the maximum day rainfall being 110mm. Annual flow and flow in a year also distribute very much nonuniformly, up to the end of 1995, overyear mean runoff is 426m³/s. The maximum annual mean runoff is 737m³/s. The minimum annual mean runoff is 164m³/s. Coming water concentrates in flood season from June to September, and it shares seventy percent of tatal inflow water in a year. It happens 2~6 times of floods in one year, with the time duration of 7~10 days, the maximum instantaneous flood peak runoff being 22800m³/s and the maximum day average runoff being 17200m³/s. They all happen in July 1995, the minimum day runoff being less 10m³/s in winter ice period. In the last 60 years hydrological records, the alternation of low water year and inundation year is uneven.
Fengman Hydrolic Station embraces a concrete gravity dam, a powerhouse and flood-relief structures. The length of the dam crest is 1080m, the maximum height of the dam being 91.7m, the width of dam crest being 9~13.5m. The whole dam is divided into 60 sections, the length of each section being 18m. Serial number is from left to right, the sections No.1~8,20 and 32~60 are nonoverflow sections, the sections No.9~19 are overflow surface spillways, the sections No.21~31 are intake sections with diameter penstock of 5.6m, which bring water from the reservoir into the turbine generators. Besides the 10 main penstocks, there is also a penstock with diameter of 1.6m specifically used by the station itself.
Fengman reservoir is of a long and narrow type. The total capacity of the reservoir is 11.46กม109m³, the largest reservoir area being 550 km², with the backwater length of 180km, the width surface of 10km, and the depth of 75m. According to the design in 1960, the dead water level is 242.00m, flood control level and the normal water level being 261.00m, the highest water level being 267.70m, corresponding to the dead capacity of the reservoir being 2.760กม109m³, or the volumn of water for power generation in which 5.350กม109m³, 3.350กม109m³ volumn of water for flood control. The annual guarranteed output is 166MW. The overyear power generation is 1890GWh.
Fengman Hydropower station was begun to construction in 1937. The dam and station were stained with Chinese People's blood and sweat, The reservoir begun to store water in November 1942, and the first unit were put into operation in March 1943, the dam construction and machine installation were not completed before the liberation in 1948. The dam was completed and control gates were installed as well as the reservoir begun to be controlled in 1953. The last turbine generator for the first stage project was completely installed and put into commissioning in 1959. Then, 8 units were dived into electric network, the total installed capacity being 552.5MW.
From 1970 to 1979, a diversion tunnel with diameter of 9.2m, and a total length of 682.9m was built on left of the mountain, inlet bottom elevation being 205m, the largest flood discharge measure being 1180m³/s. In 1991 it was rebuilt into a flood discharge tunnel.
The second stage project including 9# and 10# units was begun to build in 1988, and installed completely in June 1992. Henceforth, the total installed capacity of the ten main units was 722.5MW. The third stage project began in 1993 and completed in July 1998. Consequently, the total installed capacity of the Fengman Hydropower station is 1002.5MW.
Fengman Reservoir is a mutiple purpose project, which gives the first priority to generating electricity, and then the flood control, irrigation, munical and industrial water supply, navigation, fish farming, tourism and so on. Fengman Hydropower Station is one of the main powerplants in the Northeast China Electric Network, it playing an important role in power supply, peak load regulation, phase modulation and emergency stand-by. It is also a centrum which contacted electric power system to the South and North Electric Networks. Fengman reservoir is able to adjust outflow effectively, cut down flood peak and runoff smoothly, it also brings into an important function for reducing Songhua river disaster of the flood in downriver.
Since Fengman reservoir was completed in 1998, the total power production is 82.6กม109kwh until 1998 and made out positive contribution for the development of the industry and agriculture in the Northeast China. The reservior has experienced 13 times of abundant water year and 18 times of dry year, in which the highest and lowest water levels were 266.18m in 1957 and 225.08m in 1990 respectively.
After Baishan Reservoir being completed, it has improved operation such as the flood control and power generation.
Following the rebirth, rebuilding as well as ceaseless innovation and perfecting, Fengman Hydropower Station will make important contribution to the national economic development of Northeast China.