Most of large-scale melioration works took place in the southern part of Belarus, in Polesye. This resulted in destroying the natural ecosystems of the whole unique region. Not only was the spatial integrity of the geobotanical cover disturbed, but also its radical structural-functional integrity has been transformed. It manifested itself in the spatial simplification of landscape structures, the extinction of aquatic and mire vegetation and utilization of wetlands for agriculture.

In the Soviet period melioration works were carried out with dramatic intensiveness. Especially during the melioration works in 60s and 70s, biological diversity decreased drastically on the levels of species and ecosystems. Over 2641,8 ha of wetlands were tured into agricultural lands, among them 1140,0 ha were drained for cropland.

Growth of drained lands has sharply reduced during the last decade. Productivity of the drainage systems constructed 20-30 years ago on the agricultural lands started to decline. Reconstruction and upgrade of the majority of hydro-technical installations and machinery is required. In the modern context reconstruction and modernization of drainage and drainage-dampening systems are taken due account of. This is also true for irrigation systems serving 115, 000 ha, but not operating in full capacity for organizational, economic and technical reasons.