General situation of Chaohu water conservancy

In the thirty-first year of Jiajing in Ming Dynasty (1552), there was a drought in Lujiang County, and farmers built new three weirs and new two weirs on the shore of Chaohu Lake. According to the records of Lujiang County, Shunzhi, Qing Dynasty, during the 200 years, the reclamation area along Chaohu Lake was 6.28 million mu.

1955 and 1960 built a joint levee in Chaohu twice, shortening the original 69-kilometer levee to 10.2 km along the lake. 1955, the small weir in the south of Chaohu city 19 was integrated into a whole, and the southern Dawei was built, and the dike along the lake was shortened to 5.6 kilometers. 1958 in the planning of Chao, Chuhe and Anhui river basins, it is planned to build Chaohu sluice, which is mainly used for flood control, water storage and shipping development. 1963, the preliminary design of expansion is completed. The project was designed by the Design Institute of the Provincial Department of Water Resources and Electric Power, and constructed by the Chaohu sluice project headquarters. 1959 1 1 Start foundation excavation, 1960 12 close the barrage, 196 1 3 open the highway bridge, control the sluice in April and open the lock in May. The whole project consists of sluice, lock, fishway, upstream and downstream approach river and diversion dike, dike and barrage. Chaohu sluice project was completed in February 1962 and accepted in July 1964. The sluice is a breast wall reinforced concrete structure with *** 10 hole. The width of a single hole is 5m, the highest flood level on the sluice13.35m, and the highest flood level under the sluice12.65m, corresponding to the flow of 870 cubic meters per second; In flood season, the maximum flow rate of backward flow is 680 cubic meters per second, the maximum irrigation water level is 8.5 meters, and the corresponding storage capacity is 2 1 100 million cubic meters; The normal water level is 7.5 meters, corresponding to the storage capacity of 65.438+0.38 billion cubic meters. The benefits of flood control and drainage are 2.6 million mu and 350,000 mu respectively, and irrigation is 5.4 million mu. The ship lock is a third-class waterway with a navigation capacity of 1000 tons. The whole project has completed earth and stone work 1.785 million cubic meters and stone work1.400 cubic meters with a total investment of 8.38 million yuan.

198 1 year, the flood control project of Chaohu city will be built, and the comprehensive management of protecting the city and dikes will be implemented, and the dike along the lake will be shortened to 4.7 kilometers in combination with more than a dozen small dikes around it. After the flood of 1983, the dikes along Chaohu Lake were heightened and strengthened according to the flood control standard of once every 20 years. The dangerous sections of the main dikes in each county have been protected by masonry, and the elevation of the top of the dike is above 12.0 meters ... Before the founding of the People's Republic of China, water diversion, irrigation and drainage along the lake dike basically depended on manpower, and the main tool was the dragon bone truck. During the Great Leap Forward from 65438 to 0958, Feidong County used a water truck to lift the lake to a height of 20 to 30 meters in dry years. Because the lake is low and shallow in dry years, it is very difficult to lift water. There is a folk proverb along the lake, "People live by the Chaohu Lake, looking at the water and drying up the fields". After the founding of the People's Republic of China, from 195 1 where the first electromechanical irrigation station was built in Longtang to 1963, 56 electromechanical irrigation stations were built in all districts along the lake. By the 1970s, all the counties and cities along the lake had established their own nest irrigation areas. The nest irrigation areas in Lujiang and Feidong counties have been staggered in Pishihang irrigation area, which complement each other. According to the investigation of 1978, there are 64 organic power stations in 24 towns near the lake. According to the statistics of 1985 county and city water conservancy annual report, there are 49 1 676 electromechanical irrigation and drainage stations (676 do not include Hefei suburbs, including 40 in Feidong, 0/09 in Feixi, and 0/57 in Feixi/kloc) in the Chao irrigation area along the lake. Hefei Suburb 46), * * * Installation 153 1 0.3 million kilowatts (including 373 units in Feidong, 293 units in Feixi, 25,500 kilowatts, and 30 units in Lujiang) Suburb of Hefei 12 1 platform 8 145kW), with a benefit area of 198m mu (including 600,000 mu in Chaohu, 560,000 mu in Feidong, 490,000 mu in Lujiang, 237,000 mu in Feixi and 93,000 mu in suburban Hefei).

At the end of the 20th century, there were 6.6 million mu of cultivated land in Chaohu Lake Basin, and the irrigation area needed by Chaohu Lake, including the way to divert the river to the nest, was 4.34 million mu, plus 460,000 mu pumped from Chaohu Lake to the upper reaches of Chihe River and Chuhe River, it was 4.8 million mu. Among them, 2.85 million mu above Chaohu Gate and 6.5438+0.95 million mu below Chaohu Gate; According to the topography, the northern hills of Chaobei 1.85 million mu, the southern hills of Chaobei, 850,000 mu, and the polder area, 2 1 10,000 mu. The existing water supply area of Chaohu Lake is 3.3 million mu, accounting for 68% of the total cultivated land area in the basin, including 6,543.8+0.24 million mu in the hills north of the nest, 450,000 mu in the hills south of the nest and 6,543.8+0.6/kloc-0.00 million mu in the polder fields. There are 2.06 million mu of hilly land south of the Jianghuai watershed, and 690,000 mu of polder land along the lake and river, totaling 2.85 million mu, of which 6.5438+0.98 million mu is guaranteed by drought and flood. First, Chaohu Gate

Located at the intersection of Chaohu Lake estuary and Yuxi River in the southwest of Chaohu City, it is a comprehensive project to control the water level, navigation, fishing line and highway of Chaohu Lake. The sluice was designed by the Design Institute of Anhui Hydropower Department, and started in June 1959, completed in February 1962, and accepted and used in July 1964. The total investment is 8.38 million yuan, and the earthwork is 6.5438+0.785 million cubic meters, the stonework is 3.65438+0.4 million cubic meters and the concrete is 6.5438+0.5 million cubic meters. Chaohu sluice project consists of sluice, lock, upstream and downstream approach channel, fishing channel, highway and diversion dike, dike and barrage. The sluice has a total of 10 holes, with a hole width of 5m, a lock chamber length of 14.5m, a total gate body width of 73. 12m, a gate bottom elevation of m and a bridge deck elevation of 21m.. The sluice foundation is in good condition, with dense gravel layer and bearing capacity of 30 tons/m2.

The lock chamber is195m long and15m wide. The head and bottom elevation of the upper sluice is 4.5m, and the head and bottom elevation of the lower sluice is 3.5m. The bottom width of the upstream and downstream waterway is 50m, the upstream straight section 160m, and the downstream straight section is 750m. Upstream and downstream navigation walls are 20 meters long. The river bottom elevation is 3 meters. Navigation capacity1000t, which is a third-class waterway.

The bottom elevation of the upper and lower reaches of the approach river is 3m, the bottom width is 70m, and the slope is 1: 3. The upstream approach river is 280 meters long and the downstream is 2200 meters long. The crest elevation of closure dam is 12m, the crest elevation of barrage dam is 1 1.5m, the crest width is 5m, and the length is 190m, so it is a homogeneous earth dam. The upstream crest elevation of diversion dike is 14m, the downstream crest elevation of 380m is 13m, and the length is 440m. The fishway was added by 1976, but it didn't work because it didn't dig about 300 meters into the lake.

The check standard of sluice is once every 300 years. The flood discharge level is14.48m above the sluice and13.5m below the sluice. The designed maximum flow is 870 seconds cubic meters, and the control area is 9 130 square kilometers (on the sluice), so that the normal water level of the lake is 7.5 meters, and the minimum is not less than 7 meters. At present, the effective flood control area is 2.6 million mu, the drainage area is 350,000 mu, the irrigation area is 5.4 million mu, and the annual navigation is 500,000-600,000 tons.

After the completion of Chaohu sluice fishway, it has not played a practical role and needs to be rebuilt urgently. The designed maximum discharge capacity of sluice is 870 seconds cubic meters, and the actual maximum discharge capacity is 780 seconds cubic meters, which is not suitable for emptying Chaohu Lake before flood season and rushing to discharge in flood season. At the top of the gate is a pavement, which is the only place in the nest where there is no road. The road surface is 6.5 meters and needs to be widened.

The Chaohu sluice and Yuxi sluice on the lake channel are jointly controlled and utilized to form the Chaohu and Yuxi cascade water control projects.

Second, Yuxi Gate

Located at the mouth of Yuxi River. 1969 (fishway 1972) was completed, and the flood control standard is once every 300 years. The flow of the overpass is 1400 second cubic meter. The existing drainage area is 2.2 million mu, the irrigation area is 3.28 million mu, and the flood control area is 2.6 million mu. The navigation capacity of the lock is two1000t barges. The fishway has a total length of 250m, a clear width of 3m, and a designed normal water depth of 2.5m. The big fish hole is 2m, and the small fish hole is1m.. There are 96 sub-zones of Dayudao, with a spacing of 2.4m; Xiaoyu Island has 192 subareas, with a spacing of 1.2m and a clear height of 3m.

The sluice is used for flood control in flood season, and the water level of the sluice is controlled at 7.5 ~ 8 meters, which is convenient for irrigation. During the dry season, the upper water level is controlled at 6.5 ~ 6 meters, which can ensure navigation throughout the year.

Third, Zhao Hemen

Located in the northwest of Muji Township, Chaohu City, on the Zhao He River in the southeast of Qili Township, Lujiang County. 1956 65438+It was built in February to prevent floods from flooding into Chaohu Lake, and it was completed in August of the following year. With a total investment of 723,000 yuan, 565,438 cubic meters of earth and stone, 5,952 cubic meters of stone and 365,438 cubic meters of concrete were completed. The sluice has three holes, each with a width of 9.3 meters, a chamber length of 20 meters, a gate bottom elevation of 6 meters, a total gate body width of 35.9 meters, an upstream diversion river bottom elevation of 6 meters, a downstream diversion river bottom elevation of 5.9 meters, and a nearby dike top elevation of 17.50 meters.

The design water level difference of Zhao He sluice is 5.5m, and the highest flood control water level is16.5m above the sluice and 1 1 m below the sluice. The designed maximum flow rate is 260 seconds cubic meters. The sluice not only prevents the flood from entering the lake, but also controls the backward flow of the lake, ensuring the irrigation and drainage of the cultivated land in the upper reaches, especially the Baihu farm. When the hole of the gate is horizontal, navigation can be unimpeded, and when the water level drops, navigation will be dangerous.

Fourth, the lake embankment

The construction of Chaohu Lake embankment began in the Three Kingdoms period. With the reclamation of the past dynasties, the lake embankment continued to extend to the center of the lake. The Tongjiang River in Chaohu Lake is used for flood storage, and the lake embankment is particularly important for the protection of the surrounding polder fields. Kangxi's Annals of Chaoxian County Water Conservancy states: "There are dikes, gates and dams along the lake to stop water, which is of great benefit to the people." Today, most of the banks of Chaohu Lake were built in the Qing Dynasty and the Republic of China. According to "Anhui Tongzhi Draft Hydraulic Examination", the Tongdi, which was built in the light years of the Qing Dynasty, is more than 5,400 feet long, which is related to the safety of more than 4,500 mu of farmland. Now Dongdawei, a suburb of Hefei, is also near the lake, with a dike length of more than 5,900 feet. Wu Chengwei, Chaohu City (under the jurisdiction of William Zhongyan) has a 43-mile-long dike, which "protects the Chaohu Lake water" and protects more than1.4000 mu of farmland. Wujia dike is 8 miles long, and Tang Jia dike is 7 miles long, all of which block the lake.

Before the founding of the People's Republic of China, in addition to heightening and widening the lake embankment, reeds and willows were planted along the lake to stop the impact of lake waves and cultivate skins to strengthen the embankment. Some polder areas also organize rotation maintenance. At the end of the Qing Dynasty and the beginning of the Republic of China, each polder was divided into several rows, and the first row was divided into ten rows, which were built in turn. There are also a few gentlemen who donated money to repair the dike, and Wen Jinbo, a gentleman from Qingchao County, donated money to repair the Zhongyan Dike. Masonry is used for protection, glutinous rice mixed with lime is used for joint filling, and embankment can be built according to local conditions and water to prevent lake waves. In the early Qing Dynasty, the Tang Jia levee, which was built by gentlemen from Chaoxian County, was zigzag because of the different topography and water potential, so as to avoid the direct impact of lake waves. Farmers in the polder area along the lake, in case of flood, rushed to rescue. Due to the long dike and limited manpower and material resources, in case of flood, especially in spring, the lake rises, the water level is high and it bursts.

After the establishment of People's Republic of China (PRC), dams have been reinforced and heightened year by year. By the early 1960s, the crest elevation of the levee along the lake exceeded 1954 flood line 1 ~ 3m. Although the number of dams has increased, many dams still collapsed in floods such as 1969, 1980 and 1983. In the future, counties will jointly build dikes, shorten dikes and improve flood control capacity. Now there are nearly 20 joint dikes along the lake, and the defense line will be shortened by 40 kilometers.

The wind and waves in Chaohu Lake are often coiled waves, which have a strong scouring force on the embankment, and the earth embankment can not withstand long-term impact. In the early Qing Dynasty, when the Tang Jia levee was built, it was "there were stones outside and stones inside". Before the founding of the People's Republic of China, except for the benefit of Tang Jia and Feixi, most of the bricks and stones of Lotus were earth dikes. After the founding of People's Republic of China (PRC), some major dangerous areas were protected with masonry. 1983 After the flood, according to the standard of once every 20 years, the masonry protection will be heightened. At the end of the 20th century, Feidong dike, Xianlian dike and other dangerous sections of main dikes were built and protected. The elevations of main dike tops are all above 12m. Reach the standard of once in 20 years.