Approximately 40 million people rely on the Colorado River for water, 5% of them, or 2 million are in Nevada. However, the state gets only 1.8% of the river’s water. How did this happen? In 1922, Nevada signed onto the Colorado River Compact. It divided the river between the upper basin (part of Arizona, Colorado, New Mexico, Utah and Wyoming) and the lower basin (the rest of Arizona, California, Nevada, and New Mexico). … Nevada getting the least, while more than half of the water goes to two states: California and Colorado.