The Town of the XXI Century
Series of reports on ecological situation in Central Asia

THE SOURCE OF LIFE ON THE PLANET

Lakes, rivers and seas of Kazakhstan

The foundation of water resources of Kazakhstan is formed by rivers, which in the average year has the volume of more than 100 cubic kilometers (101,9 cubic kilometers) and 57% (58,4 cubic kilometers) of which are formed on the territory of the Republic and the rest of the water supply is carried from the adjacent territories (China, Uzbekistan, Kyrgyzstan, Russia). Because of the particularities of the climate 90% of the water in the rivers passes in spring. Disposable resources of on-the-ground waters are estimated to be 46 cubic kilometers.

It estimated that there 85 thousand rivers and temporary streams in Kazakhstan. The largest water arteries are represented by the rivers Irtish, Ural, Ishim, Tobol. In deadlocked regions of southern and Central Kazakhstan - Syrdaria, Ili, Sarysu.

The water supply in many of the rivers is varied at the level of average multi-year indicators ("normal").

Underground waters are widely used in the Republic of Kazakhstan as sources of drinking water for cities, villages, as suppliers of water for industrial installations, for watering crop lands and pastures and for other purposes. Natural underground water resources are formed by infiltration of atmospheric precipitation, filtration of river water losses.

The Republic of Kazakhstan has significant underground water resources, the annual exploitation volume of which is estimated to be at the level of 41,6 cubic kilometers.

As a result of continuing technical pollution the conditions of water supply have worsened in Karaganda, Jambyl, Shymkent, Almaty, Aktubinsk.

Intensive exploitation of underground waters by large water consumers has led to decrease in the levels of underground waters and to development of subsiding soil effects.

Underground water resources are strongly affected by pollution originated as a result of human activities. 456 clusters of polluted underground waters have been identified in the Republic. Out of this number 103 objects have been taken under constant control. The squares of these territories vary from several square kilometers to tens and hundreds of square kilometers.

The substances polluting underground waters are dominated by sulphur containing combinations, nitrogen containing combinations, phenols, heavy metals. On the territories where metallurgical plants are located, the underground waters contain selenium, mercury.

In connection with the fact that not al sources of pollution are observed and studied and the list of controlled substances is not clearly defined, characteristics of pollution of underground waters are very approximate. At the same time higher level of protection of underground waters from pollution and consequently better condition of the waters in comparison with the on-the-ground waters determines the opportunities for maximum use of underground waters as a source of supply of drinking and technical water and as a replacement for the polluted on-the-ground sources.

Three unique continental bodies of water are situated on the territory of Kazakhstan: Aral sea, Caspian sea and lake Balhash.

Aral sea - unusual body of water, possessing properties of a sea and of a lake.

Caspian sea - the largest locked body of water on Earth. The total length of its shore is 7 tousand kilometers, including 2,3 thousand kilometers on the territory of Kazakhstan. Caspian sea is characterized by cyclical fluctuations of its level, which is determined by climatic factors. Ecological condition of the sea worsens.

Lake Balhash - within last several years the level of water in the lake has not changed and stays at 341,3 absolute meters.

The level of pollution of lake Balhash by metals is determined by liquid wastes of production union "Balhashmed", which annually throws into the lake 91041 thousand cubic meters of wastes containing up to 0,362 tons of copper, 0,435 tons of lead, 0,465 tons of arsenic.

The quality of Balhash's water is significantly influenced by consumption of water from the main sources of the lakes' water inflow - rivers Ili, Karatal, Lepsy; it is necessary to note that during the vegetation period the streams of Lepsy and Karatal rivers are very shallow. Overall annual fluctuations of the water levels in the lake are characterized by increase in the water level taking place until May and significant decrease of the water level registered from June till October.

The main pollutants of the lake are represented by heavy metals and oil products, to a lesser degree by phenols. During any year concentration of copper at all vertical levels exceeds maximum limits of concentration (MLC) and in 13% of the cases reaches high levels of pollution. During the year repeated exceeding of zinc's MLC was 48%, of oil products' - 62%, of phenols' - 20%.

Under the influence of wastes thrown by "Balhashmed" the highest level of pollution was registered at Bertys harbor. Here in 60% of the cases concentration of copper reaches high levels of concentration. The average concentration of copper at the vertical levels closest to the places where the wastes are thrown reaches 32-35 MLC, the maximum levels are at 45-55 MLC. In 36% of the cases the concentration of zinc was registered at the level of 1,2-2,3 MLC and the maximum levels of 7,3 MLC. MLCs of cyanides, lead and csantagenates were not exceeded during the year.

In the open part of the lake copper pollution levels are much lower. Average annual concentration of copper in the Southern part of Balhash is registered at the lowest level of 9-11 MLC. In the central part of Balhash region it grows to 10-13 MLCs and drops again to 9-11 MLC in north-eastern part. Average concentrations of zinc were less than 2 times higher than the MLC and in the majority of the cases did not exceed the limits.

Overall the following trend is registered at the lake Balhash: despite actions to preserve water from pollution, which included a decrease in the amounts of standard-clean waters of the production union thrown into the lake, the level of pollution of Bertys harbor remained the same - in accordance with the water pollution index the quality of water is determined as "dirty". This happens because the standard-clean waters of the plant are negatively influenced by drain waters accumulated within the long period of existence of the silt layer. Moreover, the water supply and sewage systems built tens of years ago have significantly deteriorated and pollutants enter the streams of clean water.

The quality of water is significantly influenced by accumulation of pollutants in these layers, which act as the sources for secondary pollution of the lake by heavy metals. Since 1990 the trend of moving from polluted to moderately polluted waters is registered at the vertical levels of the open part of the lake Balhash.