The waterproofing of the bottom began in the Bolshoe Lebyazhie lake: 9000 sq. m. is already covered by a shield

(KZN.RU, June 21, Alsu Safina). Recently, the installation of the waterproofing shield began on the Bolshoe Lake in Kazan. This is the next stage of work on ecological rehabilitation of the Lebyazhie lake systems. Ilsur Metshin, the Mayor of Kazan, inspected the restoration of a unique natural facility the previous night.

The project of ecological rehabilitation of the Lebyazhie lake systems includes a number of large-scale measures, coordinated with ecologists: deepening of the bottom of the Svetloe and Bolshoe, and its waterproofing so that later water does not flow away into the sand and the lakes do not dry up.

Since June 15, waterproofing material is being laid at the Bolshoe. A special brigade of about 20 people leads waterproofing works. In total, 272 thousand square meters will be covered in two lakes. The work is done on 9 thousand square meters at the moment.

Albert Zaripov, the chief engineer of OAO “TC “Tatmelioratsiya”, which carried out the project of eco-rehabilitation, told the Mayor of Kazan about the technology of waterproofing and the features of the materials used. Before spreading a special shield, the soil was compacted. The waterproofing shield itself consists of three layers.

Albert Zaripov assured the Mayor that the technology excludes the passage of moisture through the shield. The strength of the waterproofing will be checked by the electric spark method using a special tester and selective filling of air. The Mayor asked if the waterproofing shield could be deformed and damaged in the future under the pressure of water. The chief engineer of the “TC “Tatmelioratsiya” assured that the pressure is calculated for the planned volume of water. He also added that a 50-70 cm of thick soil will be laid on top of the shield.

“The bottom of both lakes will be laid according to this technology. This will save the entire volume of water and prevent it from flowing into the sand”, said I. Metshin.

Previously, these natural lakes existed at the expense of surface waters. The catchment was carried out from the entire adjoining territory. Subsequently, during the construction of roads and industrial structures, the water balance of the Lebyazhie Lake was broken, and their desiccation began. Due to the work carried out during the eco-rehabilitation, surface waters that are collected in the spring will remain in the lake, as well as rainwater, said the Mayor.

The deepening of the lake bottom continues up to 4 m simultaneously with the waterproofing. Albert Zaripov informed the Mayor that about 180 thousand cubic meters of sand have been removed from the Bolshoe and Svetloe lakes for today, which is 40% of the planned volume. There are another 240 thousand cubic meters remain to be removed. More than 80 units of machinery are involved in the works: load-lifting machines, excavators, KAMAZs.

The chief engineer of the project organization told I. Metshin that the removal of the soil is planned to be completed by July 1. In addition, from the middle of July, waterproofing works will begin on the Svetloe Lake. All works are expected to be completed by September 15, including the laying of a 70-centimeter layer of soil over the waterproofing shield. After that, the lakes will be filled with water. Water will flow in the Svetloe Lake through the water pipe from Isumrudnoe Lake. Lakes Svetloe, Bolshoe and Maloe Lebyazhie are connected by channels so the water will fill the entire territory. It takes 2-3 months to completely fill the area with water.

I. Metshin asked the designers whether this technology was ever used on other water facilities. As it turned out, it is the first time when it is used on such a scale and in this version in the republic.

Natalia Fishman, the assistant to the President of the RT, Igor Kulyazhev, the deputy head of the Executive Committee and the chairman of the Committee for External Improvement, Sergey Mironov, the head of the Kirovsky and Moskovsky districts’ administration, Damir Sharafiev, the head of the forest “Lebyazhie”, and others also attended the event.