This dataset comprises water samples collected in the surrounding of Pontianak (0.09°N, 109.24°E) on the island of Borneo. Two sampling campaigns were conducted in June 2013 (drier period) and January 2014 (wetter period). Using a boat, samples were collected in the center of the river, from the origin of the Ambawang river (BR, black river sites) to its downstream confluence with the Landak and Kapuas KecilKecil (WR, white river sites). White river samples collected upstream of the confluence with the white river (WRu, white river upstream). Drainage canals (DC) flowing into the black river were also sampled during the second sampling campaign. In January 2014, a rain collector was installed on the roof of the Pontianak's meteorological station to collect rain samples for lead isotopic analysis
