The region has more than 1,000 rivers, including China's second largest, the Yellow River, which enters Inner Mongolia from Ningxia's Shizui Mountain and forms a U-shape.

The region has more than 1,000 rivers, including China's second largest, the Yellow River, which enters Inner Mongolia from Ningxia's Shizui Mountain and forms a U-shape. There are 107 rivers with a drainage area of more than 1,000 km sq and nearly 1,000 lakes.

Its surface water is about 40.66 billion cubic meters and its total water resources, 54.6 billion cu m, or 1.92 percent of the country's total. The Yellow River has about 5.86 billion cu m and the Heihe River, 800 million. Annual available water resources are about 28.5 billion cu m with an annual per capita of water estimated at 2,200 cu m. The average water per hectare of cultivated land is 7,600 cu m.

The quantity of annual underground water resources in the autonomous region is 23.6 billion cubic meters, of which 9.7 billion cubic meters is also surface water. With the influence of atmospheric precipitation as well as human activities, the distribution of underground water differs in that plains are rich in access whereas hilly regions and continental rivers are rare.