Gangcha county is rich in surface water and evenly distributed. The average self-produced runoff for many years totals 0.8 1 100 million cubic meters. * * * There are two major water systems: Huangshui River System in the Yellow River Basin and interior drainage around Qinghai Lake. The Huangshui River system in the Yellow River Basin includes: Datong River, which originates from Tianjun County and the eastern foot of Muli Mountain in Shule Mountain in the northeast of Cuogagongka, and crosses the northern part of the county seat, and is the boundary river between Gangcha and Qilian counties. The territory is 90 kilometers long, with a drop of 228 meters and a catchment area of 2,282 square kilometers. The annual runoff is 548 million cubic meters, and the runoff depth is 174.8 mm.

The internal water system around Qinghai Lake is: Buha River-Ganggele Xiaoheli Ice Peak, which originates from Shule Nanshan in Tianjun County and flows into Qinghai Lake from northwest to southeast. Its source is 4513m above sea level, and its estuary is 3195m above sea level, with a drop of1318m. It is the largest river in Qinghai Lake system, with a drainage area of 14337 square kilometers and a total length of 286 kilometers, most of which are in Tianjun County, with a length of 2 18 kilometers. 68 kilometers downstream is the boundary river between Gangcha and Tianjun counties. The left and right banks of the area near the estuary belong to Gangcha, * * * and two counties respectively. Jill Meng He is a tributary of the lower reaches of Buha River. Located in gangcha county, there is a section about15km long at the bend of the middle and lower reaches of the river, which is the boundary river between Gangcha and Tianjun County. Bahawulan River-also known as Uhalan River, also known as Quanji River. Located in gangcha county, it originated in Delmagong, and its source is 4308 meters above sea level. From north to south, the river is 65 kilometers long, with a drainage area of 567 square kilometers and 2 tributaries/kloc-0. The water system is dendritic. The elevation of the estuary is 3 195m, the drop113m, and the average gradient 17‰. The river divides into two streams and flows into Qinghai Lake. The average annual flow is 0.75 cubic meters per second, and the annual runoff is 55 million cubic meters. June-September is the flood season every year, and the freezing period is about 5 months. Liusha River-also known as Ekran River. Originated in Datong Shanksonia. Hargil River-also known as Hargil Canal, Hashik River, Harrigan River and Haji River. Originated in the north of Zanbaohua Xiushan, southwest of the county, and northwest of Taibu Temple. Hargil River has three main tributaries: Qingdama River, Zhala River and Chaidal River.