It is formed by: rivers, brooks, lakes, ponds, swamps as well as important underground water reserves. It counts a total length of 3.092 km and it has a density that often exceeds 1 km/km2 in the mountain area, decreasing under 0,5km/km2 in the plateau area. All the waters that drain the county territory are tributary to Siret River. The main affluent are Suceava, Moldova, Bistrita and Dorna, rivers which spring from the crown of high mountains from the west and north­west, while the smaller tributary streams have their sources in the hilly area.

The longest hydrographical basin is the one of Moldova River, which together with its tributary streams drain 35% of the county’s surface. It follows as length Bistrita (30%), Suceava (30%) and Siret (10%).

Still waters take the form of small natural lakes, anthropic lakes, pisciculture ponds, industrial accumulations and swamps. The most important anthropic accumulations are the 6 lakes along Somuzul Mare, amongst them the well-known lake “Nada Florilor”.

The County’s underground waters are quartered in the storages of some flysch crystalline- Mesozoic structures, in the Miocene storages and especially, in the quaternary alluvial formations.