The United States and Mexico—Sharing the Flow?


Most people in the U.S. probably don't think much about what water Mexico takes from the Colorado or the Rio Grande Rivers, which originate in the U.S. and flow along the U.S.-Mexico Border for some distance, and, in the case of the Colorado River, flow through Mexico to the sea (Fig. 4). Like the examples above (the Nile and Ganges Rivers), there are treaties that provide for sharing of the flow of these two North American rivers between the U.S. and Mexico. You have already read about the Colorado River Compact of 1922 (Module 8.1). In effect, the flow of the Colorado River is, on average, significantly less that the total amount apportioned to individual states in the watershed.  The 1922 Colorado River Compact was vague about the amount of water that was to be supplied to Mexico. This was rectified in a 1944 Treaty that provided for 1.5 million acre-feet of water per year to flow to Mexico (about 10% of the average Colorado River flow).