Danau Sentarum National Park is located in Kapuas Hulu, West Kalimantan. It is situated in the upper Kapuas River basin, roughly 700 km upstream from the delta. The geographical position is between 111°55″-112°26″ of eastern longitude and 0°45″-01°02″ of northern latitude. The Danau Sentarum national park covers an area of 132.000 hectares. The area consists of a unique seasonal lake system, which is interspersed with swamp forest, peat swamp forest as well as lowland forest on isolated hills. With its unique lake and swamp forest ecosystem and high valuable biodiversity Danau Sentarum national park is one of the largest and most important freshwater wetlands in Asia.
The topography of Danau Sentarum national park is mainly flat, partially concave shaped, with some isolated hills. It is surrounded by hill and mountain ranges in the west, northeast and east. With its topography and location the area of Danau Sentarum plays also an important role as a water buffer of the Kapuas watershed system: the area mitigates floods during rainy season and buffers water during the dry season.
During rainy season between Octobers to May the water levels of the lakes and streams in the park area increase dramatically and may rise up to 12 meters. As a consequence the lake system may become a single water mass in the rainy season. About 9 months in a year the area is flooded with an average depth of 6.5 meters. However, the depth can vary significantly and may increase up to 14 meters. During the dry season, typically between June and September, water levels fall and many lakes may dry out entirely, while only the deepest water channels remain. But this can vary from year to year as well. During the dry season in 2010 for example the lakes remained “full”, due to heavy rainfall, which occurred almost every day. As a consequence serious flooding occurred even in the upper regions of the Kapuas River, e.g. in Putussibau.