Description: This report describes the role of glaciers in the stream flow of the rivers of the Aral Basin. The study area contains the mountain basins at the headwaters of the Amu Darya and Syr Darya, located primarily in the Pamir, Hindu Kush, Karakoram, and western Tien Shan mountains. The Amu Darya study area includes the mountain basins of the Vakhsh and Panj rivers; the Syr Darya study area includes the mountain basins of the Naryn, Kara, and Chirchik rivers, and a number of small basins on the north-facing slopes of the Alai Range. There are presently no credible conceptual models describing the hydrometeorological environments of the high mountains of Asia that quantify the glacier melt component. Furthermore, there is a general lack of sufficient data to test hypotheses that relate glaciers and rivers, either as a result of a lack of a current monitoring program, or as a result of a reluctance to share these data on the part of some governments. The purpose of this study is to assess the role of the glaciers in the Pamir, Hindu Kush, Karakoram, Alai, and Tien Shan mountains in the volume and timing of stream flow of the Amu Darya and Syr Darya, and, in terms of these finding, to discuss the implications of the general retreat of glaciers for the water resources. Results are presented primarily in graphical and tabular form, and only the most salient conclusions are drawn.