The Gan River, a tributary of the Nenjiang, experienced Flood No. 1 in 2026.

Due to rainfall, the water level at the Hydrological Station of the Ganhe River, a tributary of the Nen River in Heilongjiang Province, rose to the warning level at 9 a.m. on August 2nd. According to the flood numbering regulations for major rivers, this flood is designated as "Ganhe No. 1 Flood of 2026."