UST-ILIMSKOYE RESERVOIR

A view of the Ship Island on the lake

Photo.
Photo: I.N.Varfolomeeva


A. LOCATION

  • Irkutsk Region, Russia.
  • 56:25-58:00N, 101:25-104:00E; 296 m above sea level.

B. DESCRIPTION (Q)

    The Ust-Ilimskoye Reservoir is the third reservoir (after Irkutskoye and Bratskoye) of the Angara cascade of reservoirs. It is situated 837 km from the Angara mouth and consists of two parts which are located on the rivers Angara and Ilim.
    The general planner of this reservoir was the Institute "Hydroproject" (Moscow). The man-made lake was filled in October 1974. The Ust-Ilimskoye Reservoir is of the channel type and has seasonal storage regulation. Its water resources are widely used for electric power production, transportation and navigation, fisheries, timber-rafting and recreation.
    The drainage basin of this man-made lake is situated on the Sredne-Sibirskoye plateau. The sedimentary cover of the plateau consists of the Paleozoic, Mesozoic and Cenozoic rocks. The volcanic rocks are widely spread on the reservoir's coasts.
    The total cost of the power plant with the reservoir was 1,257 million rubles, the cost of the reservoir being 127.89 million rubles (in current prices at 1974)(Q, 1).

C. PHYSICAL DIMENSIONS

    Surface area [km2] 1,920
    Volume [km3] 58.9
    Maximum depth [m] 97
    Mean depth [m] 30.7
    Water level Regulated
    Normal range of annual water level fluctuation [m] 2.43
    Length of shoreline [km] 4,000
    Residence time [yr] 0.58
    Catchment area [km2] 785,080 (49,000*)
    * The part of the catchment area between the dams of Bratsk and Ust- Ilim hydroelectric power plants.

D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL
  • Bathymetric map: Fig. ASI-60-1.
  • Number of outflowing rivers and channels (name): 1 (Angara R.).

    Fig. ASI-60-1
    Bathymetric map [m].

D2 CLIMATIC (Q)
  • Climatic data at Ershovo, 1985 1989
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    Mean temp. [deg C] -22.9 -20.8 -11.5 -1.3 7.0 13.3 15.6 14.6 7.7 -0.7 -11.0 -19.6 -2.6
    Precipitation [mm] 20.5 12.3 18.6 19.3 33.0 44.8 64.9 68.5 26.8 27.1 23.4 19.6 379
  • Number of hours of bright sunshine: 1,847 hr yr-1.
  • Solar radiation: 10.2 MJ m-2 day 1.
  • Water temperature [deg C]
    Station 1, 1985
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0.1 4.8 15.6 18.1 11.7 5.9 - -
    2 - - - - - 4.6 14.6 17.7 11.8 6.0 - -
    5 - - - - - 4.2 12.4 17.2 11.8 6.0 - -
    10 - - - - - 3.8 9.0 12.2 11.5 6.0 - -
    15 - - - - - 3.8 6.2 8.6 10.9 6.0 - -
    20 - - - - - 3.6 5.6 7.2 9.6 6.0 - -
    30 - - - - - 3.5 5.3 6.0 7.5 6.0 - -
    50 - - - - - 3.4 4.3 4.8 5.7 5.9 - -
    66 - - - - - 3.3 4.0 4.4 4.9 5.2 - -
    N* 3.0 3.9 4.2 4.7 5.1 - -
    * Near bottom.
    Station 2, 1985
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0.1 - 0.0 0.0 0.4 - 5.1 18.1 21.4 16.1 12.5 - 0.3
    2 - 0.4 0.2 0.8 - 5.0 16.8 19.3 16.0 12.6 - 0.7
    5 - 0.8 0.5 1.0 - 4.9 16.2 18.7 16.0 12.6 - 0.8
    10 - 1.7 1.1 1.4 - 4.5 12.0 16.1 15.9 12.6 - 1.3
    15 - 2.2 1.6 1.8 - 4.2 8.0 10.7 13.6 12.2 - 2.0
    20 - 2.2 1.9 2.0 - 4.2 6.4 8.3 10.3 11.1 - 2.4
    30 - 2.0 1.4 1.3 - 3.6 4.6 5.4 5.8 6.3 - 3.6
    N* - 2.1 1.8 2.0 - 2.6 4.4 4.8 5.5 6.2 - 3.7
    * Near bottom.
  • Freezing period
    10 October 10 November till 20 April 10 May, 135 226 days.
  • Mixing type: Dimictic.

E. LAKE WATER QUALITY

E1 TRANSPARENCY [m](2)
    Mean for the whole reservoir, 1985
    Spring Summer Autumn
    3.8 2.3 4.1
E2 pH
    Mean for the whole reservoir, 1985: 7.3 7.5.
E3 SS [mg 1]
    Mean for the whole reservoir, 1985: 93 315.
E4 DO [mg 1]
    Whole reservoir, 1990
    Mean Min. Max.
    11.1 2.69 16.4
E5 COD [mg 1](3)
    Determined by KMnO4 method.
    Mean for the whole reservoir, 1990: 2.77 35.63.
E6 CHLOROPHYLL CONCENTRATION [mg m-3](3)
    Mean for the whole reservoir, 1990: 1.70 50.2.
E7 NITROGEN CONCENTRATION [mg l-1]
    Whole reservoir, 1989
    Mean Min. Max.
    NH4-N 0.06 0.00 0.54
    NO2-N 0.002 0.00 0.028
    Whole reservoir, 1990
    Mean Min. Max.
    NH4-N 0.09 0.00 0.95
    NO2-N 0.002 0.00 0.038
E8 PHOSPHORUS CONCENTRATION (Q)(2)
    Whole reservoir, 1978 1983 [mg l-1]
    Mean Min. Max.
    PO4-P 0.036 0.001 0.46

F. BIOLOGICAL FEATURES

F1 FLORA
  • Phytoplankton (dominant species)
    Fragilaria crotonensis, Asterionella formosa, Stephanodiscus hantzschii, S. hantzschii var. pusillus, S. hantzschii var. hantzschii, S. astraca, Tabellaria fenestrata, Melosira granulata var. granulata, Synedra ulna var. danica, Chroomonas acuta, Ceratium hirundinella, Gymnodinium coeruleum, Cryptomonas rostrata, C. marssonii, C. reflexa, Aphanizomenon flos-aquae, Anabaena flos-aquae, A. spiroides f. meyeriana (2).
F2 FAUNA (2)
  • Zooplankton
    Notholca olchonensis, N. grandis, N. restospina, N. acuminata, Keratella quadrata, K. cochlearis, Kellicottia longispina, Synchaeta pectinata, S. lakowitziana, Conochilus unicornis, Polyarthra dolichoptera, P. major, Asplanchna priodonta, Cyclops kolensis, Mesocyclops leuckarti, Eudiaptomus graciloides, Heterocope appendiculata, Daphnia longispina, Bosmina longirostris, Ceriodaphnia quadrangula.
  • Fish
    Coregonus lavarentus, C. tugun, Thymallus arcticus arcticus, Esox lucius, Rutilus lacustris, Leuciscus leuciscus baicalensis, Phoxinus phoxinus, Lota lota, Perca fluviatilis, Gymnocephalus cernua, Cottus kessleri.
F3 PRIMARY PRODUCTION RATE [g O2 m-2 day 2](2) Mean for the whole reservoir, 1980
    Jun-Oct
    Net production 722
    Dark respiration 392
    Gross production 1,114
F4 BIOMASS
  • Biomass of phytoplankton (2)
    Mean for the whole reservoir [g m-3]
    Year Spring Summer Autumn
    1972 7 2 0.1
    1973 2 2 0.5
    1974 1 5 0.5
    1975 10 90 10.0
    1976 5 45 2.5
    1977 15 70 2.5
    1978 8 67 3.0
    1979 15 73 4.0
    1980 22 72 12.0
    1981 15 37 20.0
    1982 13 37 10.5
    1983 20 34 11.7
    1984 142 50 22.0
    1985 120 142 25.0
  • Biomass of zooplankton
    Mean for the whole reservoir, depth 10 m [mg m-3]
    Year Jan Feb Mar Apr May Jun Jul
    1976 - 6.3 34.6 - - 924.5 -
    1977 - - - - - 125.7 -
    1979 - 49.0 - - - - 1,230.5
    1980 - - - - - 181.6 688.1
    1982 - - - - - 185.5 -
    Year Aug Sep Oct Nov Dec
    1976 554.1 327.4 - - -
    1977 673.4 - 296.7 - -
    1979 996.6 - 525.0 - -
    1980 2,321.3 810.2 365.7 - -
    1982 1,908.6 - 477.4 - -
F5 FISHERY PRODUCTS (3)
  • Annual fish catch [kg ha-1]
    1980 1984: 2 6.

G. SOCIO-ECONOMIC CONDITIONS

G1 LAND USE IN THE CATCHMENT AREA (4) (1981)
    Area [km2] [%]
    Natural landscape
    - Woody vegetation 47,530 97
    - Swamp 1,176 2
    Agricultural land 294 1
    Total 49,000 100
  • Types of important forest vegetation: Pine, fir, silver-fir, larch.
  • Main kinds of crops: Spring wheat.
  • Levels of fertilizer application on crop fields: Moderate.
G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE (4)
    1981: 70,000 peoples are employed in industries.
G3 POPULATION IN THE CATCHMENT AREA* (7) (1984)
    Population Population density [km 2] Major cities
    Urban 105,000
    Rural 34,000 0.68 Ust-Ilimsk
    Total 139,000 2.84
    * Part of the catchment area between the dams of Bratsk and Ust-Ilim hydroelectric power plants.

H. LAKE UTILIZATION

H1 LAKE UTILIZATION
    Water supply of Ust-Ilimsk and Zheleznogorsk cities, navigation (3,500 passengers per year in 1984), transportation (1,170,000 tons in 1984), timber rafting (1,121,000 m3 in 1984), and recreation (capacity of long-rest resort houses, 505 persons; swimming, sport fishing).
H2 THE LAKE AS WATER RESOURCE (2) (1984)
    Use rate [1.0E+6 m3 yr-1]
    Power plant 99,650

I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS

I1 ENHANCED SILTATION
  • Extent of damage: Not serious.
  • Supplementary notes
    Erosion of the banks varies from 50 m to 200 m during 25 years in different parts of the reservoir.
I2 TOXIC CONTAMINATION
  • Present status: Serious.
  • Main contaminants, their concentrations and sources (Q)
    Mean for the whole reservoir, 1990
    Name of contaminant Range of concentrations in water [mg l-1] Main sources
    Mean Max.
    Phenol 0.001 0.012 Submerged trees
    Oil products 0.13 1.25 Navigation and transportation
    BOD 1.52 5.77 Submerged trees
    NH4 0.009 0.95 Industry
    NO2 0.002 0.038 Industry
    Methylmercaptan 0.008 0.149 Industry
    Formaldehyde 0.032 0.219 Industry
    Lignin 3.96 29.2 Industry
I3 EUTROPHICATION
  • Nuisance caused by eutrophication
    Unusual algal bloom (dominant species of algae: Anabaena flos-aquae, Aphanizomenon flos-aquae); harms to fishery products; low concentration of O2 (hydrosulphide zones, areas with secondary pollution).
  • Nitrogen and phosphorus loadings to the lake [t yr-1] (1990)
    T-N: 2,946,200.
    T-P: 388,700.
I4 ACIDIFICATION
  • Extent of damage: None.

J. WASTEWATER TREATMENTS

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA (Q)
    (d) Measurable pollution with limited wastewater treatment.
J2 APPROXIMATE PERCENTAGE DISTRIBUTION OF POLLUTANT LOADS
    [%]
    Non-point sources (submerged trees) 40
    Point sources
    - Municipal 10
    - Industrial 50
    Total 100

K. IMPROVEMENT WORKS IN THE LAKE

K3 OTHERS (Q)
    Cleaning the reservoir from submerged and floating trees; reinforcing shorelines to prevent erosion.

M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS

M1 NATIONAL AND LOCAL CONCERNED
  • Responsible authorities
    1. The administration for the rational utilization of the Ust-Ilimskoye Reservoir
    2. Roskomgidromet
    3. Ministry of Energy, Russia
  • Main items of control
    1. Determination of permissible degrees of the parameters of water pollution.
    2. Monitoring of quality and quantity of surface waters.
M3 RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES
  1. The State Hydrological Institute, St. Petersburg
  2. Bratsk Hydrometeorological Observatory

N. SOURCES OF DATA

  1. Questionnaire filled by Dr. T. P. Gronskaya, Ms. T. E. Litova, Ms. I. Varfolomeeva, State Hydrological Institute, St. Petersburg, Russia.
  2. The Reservoirs of Siberia (Angara-Enisei drainage basin) (1987) 280 pp. Krasnoyarsk.
  3. Biology of the Ust-Ilimskoye Reservoir (1987) Novosibirsk.
  4. Geological and Ecological Predictions (1984) 250 pp. Novosibirsk.
  5. Atlas of the USSR (1984) 260 pp. Moscow.

    6. * Publications cited were printed in Russian. The titles are tentatively translated into English.