The valleys of Altganat, Urt, Uvurmoilt, Bayan, Tariat, Jargalant, and Ust are fed with springs. Some of the springs freeze in winter. The south part of the Tuul River lying with the HNP area is a water source for nomad families and their livestock from spring to autumn. The past few years, it was noted that the springs’ sources have decreased in volume, and some have dried likely due to climate change with more frequent extreme heat in summer. A geo-hydrological research published in 2000 reported that HNP’s ground surface decreased by 1m to 1.5m in a decade. The degradation of birch trees and dried water sources contribute to this change.