Warta Mouth National Park is located at the western border of Poland, in a fragment of Toruń-Eberswald proglacial stream valley, the so-called Gorzów Valley. Flat, wide terrains of the Park are situated within the lower bench of Warta River. Contrary to what the Park’s name may suggest, the mouth of Warta River to Odra River lies outside its borders. Park’s name refers to the times when Warta had a character of a anastomosing river and it disgorged to Odra by many beds (18th century).
During the melioration and regulation work conducted in the 18th century the present Warta River bed was dug together with a system of canals and ditches. The rich local hydrographic net is composed of numerous oxbow lakes as well as lakes that formed after peat extraction.
The Warta River flowing through the middle of the Park is a natural border between two areas: Northern Polder and the floodland.
The floodland is a semi-natural area in which annual water level fluctuations may reach up to 4 meters with its maximum in the spring months (March and April). The Northern Polder is separated from a direct influence of Warta by a levee build along the river bed. The water level is here definitely lower than at the left bank and relatively stable.
The soils of the Park mainly consist of peat and gyttja, and their layer in some places may reach a thickness up to 6 meters, and alluvial soils. Small areas close to Warta River bed are covered by river sands. The soils generally belong to two types: hydrogenic and alluvial soils. Among them are peat, mud, muck (first group) soils that appear mainly in the Northern Polder and alluvial soils (second group) that appear at the floodland in the southern part of the Park.