Shihmen Reservoir

Shihmen Reservoir

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Shimen Reservoir, located in Hanzhong City, Shaanxi Province, is a large (2) reservoir in the middle reaches of Baohe river. The reservoir was started in 1969, impounded in 1973 and completed in 1979. From 2001 to 2006, the dam was reinforced. The reservoir is a large reservoir mainly for irrigation, power generation, flood control and fish culture. The reservoir dam is in the shape of a bow tightly between the two mountains. The drainage area above the dam is 3861 square kilometers, with a total storage capacity of 109.8 million cubic meters. The pivotal project is composed of arch dam, river bed power station, East and west main canal head, anti regulation pool and other buildings. The canal system project includes three main canals, East, West and south, with a total length of 87 km.

The design flow of the East Main Canal is 30 m3 / s, and the designed irrigation area is 270000 mu. After the operation of Donggan canal, it provides water source guarantee for pumping stations and reservoirs in the irrigation area, promotes the development of small water conservancy projects, and plays an important role in changing the basic conditions of agricultural production in urban hilly areas.

geographical position

Shimen Reservoir, located in Hanzhong City, Shaanxi Province, is a large (2) reservoir in the middle reaches of Baohe river.

Main works

Shimen Reservoir, a key project, is composed of arch dam, riverbed power station, East and West Main Canal headworks and anti regulating pool.

reservoir project

The dam is arched tightly between the two mountains, forming a large reservoir mainly for irrigation, taking into account power generation, flood control and fish culture. The drainage area above the dam is 3861 square kilometers, with a total storage capacity of 109.8 million cubic meters, including effective storage capacity of 60.7 million cubic meters, dead storage capacity of 44.3 million cubic meters, and flood detention capacity of 04.8 million cubic meters. The water area for fish culture is 4050 mu, and the backwater from the reservoir area reaches qingqiaopu (qingqiaopu village, qingqiaoyi Town, Liuba county), which is 17 km long.

The dam is located at the stone gate of the ancient plank road in the south entrance of Baogu, Hanzhong City, Shaanxi Province. As a secondary structure, the dam is a reinforced concrete double curvature arch dam with variable center and radius. The maximum dam height is 88 meters, the maximum bottom width is 27.3 meters, the dam top width is 5 meters, the dam top arc length is 254 meters, the dam top elevation is 620 meters, and the normal water retaining level is 618 meters. In the middle of the dam, there are 6 spillway gates with a height of 8 meters and a width of 7 meters, and a flip bucket is set at the outlet, with a maximum discharge of 5250 m3 / s.

Power station engineering

The river bed power station adopts diversion type, with the maximum diversion flow of 68.1 m3 / s. The powerhouse of the hydropower station is located 250 meters downstream from the West Bank of the dam. It is an underwater closed structure. Three 12500 kW axial-flow turbine generator units are installed. Two 1250 kW units are installed at the head of the East Main Canal and one 500 kW unit is installed at the head of the West Main canal. The total capacity of six units is 40500 kW and the designed annual power generation is 142 million kwh.

Canal system engineering

Including East, West and South three main canals, with a total length of 87 km. The designed water diversion capacity of the three main canals is 56 m3 / s, and the designed irrigation area is 515000 mu. The benefit area of the East and south main canals accounted for 90.3%. The effective irrigation area is 449000 mu, and the effective irrigation area of Hanzhong city is 259200 mu. In 1989, the actual irrigation area was 224800 mu.

West Main Canal

Mianxian County benefited from the west main canal.

The west main canal of Shimen Reservoir diverts water from Shimen Reservoir of Baohe river. It was built in 1970 and completed in 1972. The main canal is 14.6 km long; there are 27 doucanals, 73.7 km long; there are 327 Dou, sluice, bridge, culvert and other buildings. The designed water diversion flow is 6 m3 / s, the designed irrigation area is 50000 mu, the effective irrigation area is 24800 mu, and the yield guaranteed by drought and flood is 21000 mu. The state invested 2.5 million yuan, and the commune team invested 2.7 million workdays. 27 villages in four townships (towns) of Hongmiao, Changlin, duanjiaba and Laodaosi benefited. In 1987, the irrigated area was 9400 mu (including 3300 mu in Nanzheng County). The average yield of rice and wheat was 550Kg and 291kg respectively.

South Main Canal

The South Main Canal is Baohui canal.

In 1934 (23 years of the Republic of China), Li Yizhi, the director of water conservancy of Shaanxi Province, proposed the plan of rebuilding Baohe river diversion project when he inspected the water conservancy of Southern Shaanxi, but the long-standing discussion was still unresolved. In 1937, the people of Nanzheng County, Baocheng county and Chenggu County petitioned repeatedly before they decided to build Baohui canal. In 1938, Shaanxi water conservancy survey and design team carried out preliminary survey and design, and in 1939, it carried out re survey, and Baohui canal engineering office was established in September. In the winter of 1940, the construction of the project was started in two phases. The first phase of the project mainly includes the headworks and the main canal. A mortar masonry dam with a length of 135.3 meters and a width of 8.55 meters was built. The first section of desilting channel is 443 meters long, and the third section of canal head is 1212 meters long. From the head of the canal, the main canal passes hedongdian, Zongying, Lizigou, fujiamiao, Shizigou and Honggou rivers into Chenggu Wenchuan River, with a total length of 32.3 km and 28.8 km in the city. Under the main canal, there are 3 branch canals and 46 Dou and sub canals, with a total length of 61.6 km. In March 1942, the canal was completed for water test, and water was supplied in June. In that year, 84000 mu of farmland was irrigated. The second phase of the project is the renovation and reinforcement of the completed project, with some additional buildings to be completed in 1946. More than 80 buildings of various types were built in the two phases, 1.15 million of them were put into operation, 1.26 million cubic meters of earthwork and 20000 cubic meters of masonry were completed, with a total investment of 4.09 million yuan. With the improvement of the project year by year, the irrigation area was expanded to 127400 mu by 1949.

After 8 years of operation, Baohui canal found that: the overflow dam was on the low side, part of the dam body was out of joint, and the west end of the dam was destroyed 15 meters by the flood in 1949; the section design of the main canal was too small to meet the needs; the design standard of the main and branch canal buildings was not high, and some projects needed to be repaired; the irrigation area drainage project was not matched, and the drainage of more than 10000 mu farmland was difficult.

After liberation, Baohui canal was renovated in an all-round way. In October 1950, southern Shaanxi water conservancy administration formulated the renovation plan for Baohui canal project. From March 1951 to March 1952, the state invested 368800 yuan, 2713000 projects were put into operation, 215900 cubic meters of earthwork were completed, and 68 water diversion, water conveyance and water diversion projects were renovated. The Baohui canal has been maintained and improved year by year, and the benefit of facilities has been continuously improved. The diversion flow of the canal has been increased from 15 S.M. in 1949 to 21.5 S.M. In order to regulate the water quantity in the irrigation area, 16 reservoirs, such as Baliqiao, Shizigou, huangbayan, and 42 pumping stations, such as Yuanshang, Wuxiang and Dongfanghong, have been built in succession, which has basically formed a long vine shaped irrigation network with the combination of "diversion, storage and lifting". The irrigation area of Baohui canal has increased from 107500 mu in 1949 to 165300 mu in 1979. After 1971, Baohui canal was assigned to Shimen Reservoir irrigation area. Because the head of the main canal is located in the south of Shimen Reservoir hub, it is renamed as the South Main Canal of Shimen Reservoir, which is under the unified management of Shimen Bureau.

East Main Canal

1. Project scale: Donggan canal is the main canal of Shimen Reservoir irrigation area, with a total length of 40.59 km, and Hanzhong City accounts for 21.26 km. Since November 1969, Hanzhong and Chenggu counties have been constructed in sections, which was completed in 1976. The total investment of the project is 10.2666 million yuan, including 6.7664 million yuan in Hanzhong City, accounting for 65.9%. Hanzhong City has invested 4.7144 million units, completed 2.0577 million cubic meters of earthwork, consumed 7681 tons of cement, 2062 cubic meters of timber and 216 tons of steel. The average investment of each kilometer of main canal is 221800 units, with an average cost of 318900 yuan. The average investment of irrigation area is 42 yuan per mu, with 28.8 units. The Donggan canal crosses the hilly area in the north of Hanzhong City. It has a tunnel in every mountain and an aqueduct in water. From the head of the canal, it goes by mountains and rivers. Across lishuigou, it winds eastward along the southern foot of Qinling Mountains, passes through Xigou, yutanggou, shizihe, Xuejiazhuang, xingjiaba, Ganhe, Wuxiang Town, Wangjiahe, Lijiaying and majiacun, enters Chenggu County, and retreats into Junmin reservoir at Funiu Mountain. From the canal head to majiaya reservoir, the main canal section and six branch canals in the city are 53.9 km long, with 438 buildings, among which the larger ones are as follows:

(1) Headworks. The canal head is composed of intake tower, diversion tunnel and power house. The intake tower is located at the dam abutment on the East Bank of the reservoir, with a height of 33 meters and an elevation of 588.5 meters at the bottom sill of the inlet. The main diversion tunnel is 3 meters in diameter and 106.2 meters in length. The power adit is 26.96m long, the powerhouse and erection bay are 24.4m long and 11.5m wide, and two 1250KW water turbine units are installed. The elevation of canal bottom is 589.74m, and the design flow is 30m3/s.

(2) Lishuigou aqueduct. It is located at the entrance of the 2145m stone canal section of the Donggan canal, with a maximum water delivery capacity of 32m3 / s. It was started in September 1970 and completed in May 1972. In October 1973, the No.1 bank pier sank due to the landslide of the mountain. In order to ensure the safety of the aqueduct, the first span aqueduct box was added in April 1974. The aqueduct has 8 spans, with a total length of 161 meters and a height of 43 meters. It is composed of well frame foundation, fabricated reinforced concrete bent and superimposed prestressed reinforced concrete aqueduct box. The aqueduct components are prefabricated on site, and the maximum weight of the aqueduct box is 32 tons. The engineering and technical personnel cooperated with the migrant workers in Shayan and Zhaozhai townships, and used the terrain to bury the soil on the hillside of the south bank

Chinese PinYin : Shi Men Shui Ku