Balkhash-Alakol Basin covers an area of 512,000 km2, and its average surface water runoff is 27.76 km3/year, of which 11.5 km3 come from the territory of China. The area of drainage basin of the lake is about 413,000 km2; with 15% belonging to the north-west of Xinjiang region in China and a small part in Kyrgyzstan. Lake Balkhash takes 86% of water inflow from Balkhash-Alakol basin. Ili River accounts for 73-80% of the inflow with the total volume quoted as either 12.3 km3/year or 23 km3/year. The river originates in Tian Shan mountains and is mainly fed by glacier. This results in daily and seasonal fluctuations of its water level with a strong increase during the glacier melting season in June-July. The river forms an extended delta which covers the area of 8,000 km2 and serves as an accumulator, providing water in the drought years.