Water network
The area described is entirely within the Vistula river basin. The main rivers flowing through Mazovia are the Vistula and its tributaries: Narew, Bzura, Drill, Skrwa Prawna and Skrwa Lewa. The larger tributaries of the Narew are: Bug, Wkra, Orzyc i Omulew, Wkra – Płonka, Raciąż-nica, Mlawka, Łydynia and Sona, Printing – Liwiec, Governs and Brok, in Bzury – Pisia and Utrata. In the north. there is a hydrographic junction from Warsaw, that is, the place, to which the waters of the Vistula rivers flow from various directions, Narew (among them the waters of the Bug and Wkra river) i Bzury.
The rivers of Mazovia are generally not regulated. Only some of them have flood embankments. Rivers have repeatedly been the source of catastrophic floods – recently Narew in 1979 r. (flooding of Pułtusk) and the Vistula in 1982 r. (flooding Płock-Radziwia). The lakes are found only in the vicinity of Gostynin (Gostynińskie Lake District), Sierpc (Urszulewska plain, Dobrzyn Lake District) and Lidzbark (Urszulewska plain). The largest natural water reservoirs are lakes: Great Lidzbark, Urszulewski, /courtly, Lucienskie, White, Górskie and Ciechomickie. Along major rivers, np. Vistula and Bug, there are lakes formed in depressions formed by disused river beds. These include, among others. Lakes: Kiełpińskie, Dziekanowskie, Klucz and Bużysko.
Among the artificial water reservoirs, the two largest are Włocławski on the Vistula (the pow. 7000 ha i 60 km long) and Zegrzyńskie Lake on the Narew River (the pow. 3000 ha i 40 km long). The reservoirs on Skrwa Lewa are among the smaller ones (Lens) and Pisi Tuczna (Grzemek).
There are relatively many fish ponds that often form large complexes, but there are few water channels.
Only the Żerański Channel connecting the Vistula is of nautical significance (from the Żerań estate) and Narew (Nieporet). The other channels basically fulfill the drainage function.