Tsimlyanskaya Hydroelectric Power Plant () is a hydroelectric power station on the Don River in Rostov Oblast, near the cities of Volgodonsk and Tsimlyansk. It was built in 1949–1954 as part of the program to construct the Volga–Don Shipping Canal, mainly using the labor of Gulag prisoners, and is one of the "Great Construction Projects of Communism". It has significant economic importance, providing large-tonnage navigation on the lower Don, operation of the Volga–Don Canal, irrigation of large areas of arid lands, water supply, flood protection, and electricity generation. The owner of the HPP facilities (except for the navigation locks) is LLC "Lukoil-Ekoenergo".
Natural conditions The Tsimlyanskaya HPP is located on the Don River 309 km from its mouth and is the only hydroelectric power station on this river. The catchment area of the river at the dam axis of the HPP is 255,000 km2 (about 60% of the river's total drainage basin area). The climate in the area of the HPP location is continental, and the reservoir is located in the dry steppe and semidesert zones with their characteristic droughts and sukhoveys. The average annual precipitation is 350–400 mm, while evaporation from the reservoir surface is about 1,000 mm. The Don's water regime is characterized by a clearly expressed spring flood during which an average of 72% of the annual runoff passes. The average annual water flow in the river at the Tsimlyanskaya HPP axis is 655 m3/s, and the average annual runoff is 20.66 km3. The maximum water flow with a recurrence interval of once every 10,000 years is estimated at 21,532 m3/s, and the maximum recorded flow over the entire observation period was 14,436 m3/s. Below the Tsimlyanskaya HPP on the Don are the Nikolaevsky, Konstantinovsky, and Kochetovsky hydro nodes, which do not include hydroelectric power stations. Their main task is to maintain navigable depths.Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 2–4, 41, 45. The Don River at the Tsimlyanskaya HPP axis has an elevated right bank and a lowland left bank. The HPP building and spillway dam are built in the floodplain on the left bank (with the dam partially located within the former Susorovo Lake), which allowed solving the problem of passing the river's runoff during construction naturally, as well as reducing the volume of work on temporary cofferdams. The earthen dams from the left bank are mostly located on floodplain terraces, and the right-bank dam is on the floodplain. The foundations of the HPP structures located within the floodplain and riverbed consist of fine-grained alluvial sands underlain at a depth of 25–30 m by a layer of clay marls. The floodplain terraces are composed of loess-like loams.Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 64–65
Construction The Tsimlyanskaya HPP is a low-head run-of-river hydroelectric power station (the HPP building is part of the head front). The hydroelectric power station structures are of Class I capital class and include three earthen dams, a concrete spillway dam, the HPP building with a fish ladder, navigation locks, the headworks of the Don Main Canal, a 110/220 kV switchyard; the total length of the backwater structures of the hydro node is 13,460 m. An automobile and railway pass over the HPP structures. The installed capacity of the power station is 211.5 MW, the designed average annual electricity generation is 659.5 million kWh, and the actual average annual generation for the period 1980–2010 was 613 million kWh.Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 23, 25, 54.
Earthen dams The majority of the head front of the Tsimlyanskaya HPP is formed by three earthen dams—left-bank Nos. 90 and 91 and right-bank No. 92, into which a total of 31.614 million m3 of soil was placed. The left-bank dam No. 90 is located between the left floodplain bank of the Don and the navigation locks, with the headworks of the Don Main Canal embedded in the dam body. The dam length is 2,740.73 m, crest width is 20 m, maximum base width is 115 m, maximum height is 11.8 m. The dam is built from loess-like loams, the upstream slope is secured with reinforced concrete slabs on a sand layer, and the downstream slope with gravel and crushed stone fill. There are no anti-seepage devices in the dam body and foundation; drainage devices include a toe drain consisting of a 1 m thick sand layer on the downstream slope, a strip collection drain of riprap with transverse sand drains in the dam foundation, and a drainage ditch.Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 58–59. The left-bank dam No. 91 is located between the navigation lock and the HPP building. The dam length is 6,760.21 m, crest width is 20 m, maximum base width is 327.5 m, maximum height is 25 m. The dam is hydraulically filled with fine-grained sand, the upstream slope is secured with reinforced concrete slabs, and the downstream slope with gravel fill. There are no anti-seepage devices in the dam body and foundation (except for the section adjoining the HPP building, where two diaphragms of steel sheet piling are installed). Drainage devices include a horizontal closed pipe drain in the lower part of the downstream prism of the dam (concrete pipe with diameter 0.8–1.6 m), a drainage ditch along the downstream slope, and vertical drainage (relief wells).Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 59–60. The right-bank dam No. 92 is located between the spillway dam and the right floodplain bank of the Don. The dam length is 3,171.04 m, crest width is 20 m, maximum base width is 345.55 m, maximum height is 35 m. The dam is hydraulically filled with fine- and mixed-grained sands, the upstream slope is secured with reinforced concrete slabs, the downstream slope with gravel fill; the reservoir bank adjoining the dam is also secured with 80 m of reinforced concrete slabs. There are no anti-seepage devices in the dam body and foundation, and drainage devices include a horizontal closed pipe drain in the lower part of the downstream prism of the dam (concrete pipe with diameter 0.8 m), a drainage ditch along the downstream slope, and vertical drainage (relief wells).Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 60–61.
Spillway dam
The spillway dam, located between the right-bank earthen dam and the HPP building, is intended for passing water during strong floods or when the hydro units are stopped. By design, the spillway dam is a gravity concrete dam with a heavily protruding upstream foundation slab. The dam length is 495.5 m, crest width is 12.5 m, maximum base width is 60.5 m, maximum height is 43.65 m, and 888,000 m3 of concrete was placed in the dam. The dam has 24 spillway openings 16 m wide each, closed by main segmental gates and flat emergency-repair gates; gate operation is performed using two gantry overhead cranes with a lifting capacity of 75 t each. The dam is designed to pass 16,200 m3/s of water at normal backwater level and 23,300 m3/s at forced level. The energy of the discharged water is dissipated on a stilling basin 50 m long and 4.5 m thick, on which chutes, stream-deflecting piers, and a stilling wall are located. Behind the stilling basin is a riprap 280.7 m long, made of concrete slabs 1.25–2.5 m thick. The initial section of the riprap is horizontal, then gradually slopes down and ends with an embedded chute.Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 57–58. The body of the spillway dam consists of a 60.5 m long foundation slab and piers heavily developed toward the upstream side. A gallery is constructed in the dam body, also serving to drain seepage water through the dam. In addition to the gallery, the dam's anti-seepage devices include a 50 m long apron, three rows of steel sheet piling in the foundation, a double sheet pile diaphragm at the junction with the right-bank dam, drainage wells under the stilling basin and riprap, as well as two rows of drainage wells at the end of the riprap. On the upstream side, steel spans of a railway bridge are laid on the dam piers, and on the downstream side, a road bridge.
HPP building
The HPP building is of run-of-river type (perceives water head); it is combined with the fish ladder. The building length is 116.6 m, width 56.5 m, height 48.7 m. Structurally, the HPP building is made of monolithic reinforced concrete, divided into four unit blocks, a fish ladder block, and an assembly platform. Two galleries are constructed in the foundation slab of the HPP building (56.5 m long). Below the building is a stilling basin 0.3–1 m thick and 50 m long, followed by a riprap 60 m long made of reinforced concrete slabs. Protection of the HPP building from seepage is provided by an apron consisting of a 40 m long reinforced concrete slab covered with two layers of bitumen mats overlain by a 1.5 m thick loam layer, as well as three rows of steel sheet piling.Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 61–62. The machine hall of the HPP building houses four vertical hydro units with Kaplan turbines: three with a capacity of 52.5 MW each and one with 50 MW. The 52.5 MW units are equipped with PL-30/877-V-660 turbines (two units; manufactured by Leningrad Metal Works (LMZ)) and PL 495-VB-660 (one unit; manufactured by Andritz), operating at a designed head of 22 m. The turbines drive hydro generators SV 1040/120-68 manufactured by the "Electrosila" and "Elsib" plants. The 50 MW unit is equipped with a PL 495-VB-660 turbine (operating at a designed head of 17.5 m) and an SV 1030/120-68 generator; the equipment was manufactured by LMZ and "Electrosila". Assembly and disassembly of the hydro units is ensured by two bridge cranes with a lifting capacity of 150 t each located in the machine hall. On the upstream side, the turbine water intake openings are equipped with trash racks, flat wheeled emergency-repair gates, and flat repair gates. Operation of the emergency-repair gates is performed using winches, and of the repair gates and trash racks using a gantry crane. The turbine draft tubes are closed by flat repair gates.Правила использования Цимлянского водохранилища [Rules for the Use of the Tsimlyansk Reservoir]. M.: Росводресурсы. 2014. pp. 61–62, 65–67. Hydro units of Tsimlyanskaya HPPUnit number12345Unit capacity, MW5052.552.552.54Commissioning year19522001199920121953Turbine typePL 495-VB-660PL-30/877-V-660PL-30/877-V-660PL 495-VB-660PL 495-VB-225Turbine manufacturerLMZLMZLMZAndritz HydroUralgidromashGenerator typeSV 1030/120-68SV 1040/120-68SV 1040/120-68SV 1040/120-68VGS-325/64-24Generator manufacturerElectrosilaElectrosilaElectrosilaElsibElectrosila