Summary:

Zelazny Most tailings pond is one of the biggest objects of such type in the world. Due to the present height of the dams constructed from post flotation mate-rials as well as location of the pond, „Żelazny Most" is a challenging task for en-gineers. Dam design is based on observational method, which is an active design method accounting for current observations. Therefore careful monitoring of the tailings pond is required that includes both visual inspections and instrumentation aimed at analyses of vast amount of different data. Monitoring of dam operation (i.e. seepage, deformations, pore pressure, seismicity, some ecological parameters like groundwater salinity and more). Data collected from monitoring equipment and visual inspections are used for everyday technical state and safety assessment of the dams as well as for designing process. „Żelazny Most" tailings pond is an example of hydrotechnical object where monitoring results are on the current basis used for design, construction and development.