Lake Lukomskoje EUR-51

Lat.54.665 Lng.29.087 Alt.165.1
Riparian Nation(s) Belarus
Surface Area 37 km2 Mean Depth 6.6 m Volume 0.24 km3
Shoreline 36.4 km Catchment Area 179 km2 Residence Time 7 yr
Frozen Period Dec-Apr Mixing Type Polymictic Morphogenesis/Dam
Related Info/Site

Description

The Lake Lukomskoje belongs to the system of the River Ulla, a left-bank tributary of the River Zapadnaya Dvina flowing into Baltic Sea. The town of Novolukoml is situated on the picturesque river bank.

The lake's basin is in a glaciated zone of the last Ice Age. Lake shores are generally low (0.5 2.0 m in height). Foreshore shallows are usually covered by sand, or less frequently by shingle, while siliceous organic ooze spreads over deeper parts of the lake bottom.

The River Zytranka and several other streams flow into the lake. The outflow of water through the River Lukomka is regulated by a dam, by which the lake water level is raised by 1.5 m. The annual range of water level fluctuation is 0.4 0.8 m. Since 1969 the lake has been used as the cooling pool for thermal discharge from Lukomskaya Hydroelectric Power Station (2,400 MW). The water warmed up by 8 12deg C is directly drained into the lake and 7% of its area are affected by the thermal pollution.

The whole lake water mass is fully mixed up and homogeneously oxygen-saturated during the ice-free period. Transparency amounts to 10 m during the freezing season and is reduced to 3 4 m in summer. The total mineral content of the lake water is 220 240 mg l-1.

About 17% of the lake surface is covered by macrophytes, which consist of 31 species. The phytoplankton flora includes 101 species and has an average biomass of about 4 g m-3. The number of species and biomass of zooplankton are 69 and 1.4 g m-3, and those of zoobenthos (except Dreissena polymorpha) are 202 and 8 g m-3, respectively. The biomass of D. polymorpha is estimated to exceed 5,000 tons, and this mussel population filters an amount of water equivalent to the whole lake volume in less than two months. There are about 20 species of fish (dominants: Lucioperca lucioperca and Abramis brama) and crayfish in the lake (1).

Photo of Lake Lukomskoje
Photo: Res. Lab. Limnol., Belarus State Univ.