The environmental impacts of the mining operations on salmon-spawning rivers' basins in the Kamchatka Peninsula are analyzed. Three main groups of factors, caused by the mining operations, and producing negative environmental impact on salmon spawning-and-feeding rivers' ecosystems, are distinguished: direct man-induced changes in water bodies' channel operation; man-induced changes in watercourses' hydroregime; man-induced changes in water streams' turbidity, increase in suspended sediments and silt-filling of water bodies' stream-bed deposits. It is noted, that the impact of the first two groups of factors is locally spread — within the boundaries of the rivers' reaches in the mining-leased area. The third group of factors, leading to long-termed changes in aquatic life habitats, is of the highest hazard, because, in this case, decrease in commercial-fishing streams ecosystem productivity is of stable and irreversible character. The calculation method of production-induced suspended matter discharge rates from a mining operation is presented.