National Water Level Service operates within the framework of the National Water Authority (OVF) (OVSZ) prepare for each day of the year the water level forecasts for major domestic vízmércéire streams and contribute to the current wading information. The water level forecasts for the production takes into account current and expected evolution of the meteorological situation, and to carry out major rivers basins of domestic sections of ice forecasts and the Danube main heat accumulation calcula