Four rivers flow into the area controlled by the Upper-Tisza Regional Environmental and Water Directorate. The Tisza from the Ukraine, and the Szamos (Somes), the Kraszna (Crasna) and the Túr (Tur) from Romania. These rivers are rather special because they can produce floods very quickly in any season, leaving very little time for a flood defence response. Thus a timely, precise, reliable flood forecast is crucial, and so is direct, fast communication. The communication system built with the support between Nyíregyháza and Szatmárnémeti serves this purpose, and thus increases the security of the inhabitants of the region.