The Piława is the largest river in the Borne Sulinowo commune. Its source and upper reaches are located here. The river flows from Lake Komorze and passes through lakes Rakowo, Brody, Strzeszyn, Kocie (Małe and Duże), Pile, Długie, and the Nadarzyce Reservoirs.
It flows from north to south and is the largest tributary of the Gwda River. Its total length is 79.9 km, including 37.9 km in the Borne Sulinowo commune. The average riverbed gradient is 0.4%, and the current speed is 0.8 m/s. There are two weirs on the Piława River – the first below Lake Długie, the second enclosing the Nadarzyce Reservoirs. Both dams were built in the 1930s and were intended to create natural barriers along the Pomeranian Wall fortifications by slowing the current and raising the water level.
Due to its exceptional natural and landscape values, the Piława River Ecological Corridor has been legally protected through the designation of the "Piława Valley" Protected Landscape Area. It overlaps with the NATURA 2000 site. This area contains plant species recommended for special protection by the European Union, and breeding sites for rare and protected bird species such as: little grebe, bittern, mute swan, greylag goose, gadwall, goldeneye, common teal, garganey, tufted duck, goosander, marsh harrier, water moorhen, common snipe, crane, kingfisher, green woodpecker, black woodpecker, grey wagtail, great wagtail, great reed warbler, and penduline tit.
Source: it.bornesulinowo.pl