Perhaps the biggest challenge will be making sure the region gets enough water for the tigers and their prey to thrive. Before the Ili River reaches Kazakhstan, it flows through Xinjiang, China, where water consumption is growing. Between 1995 and 2003, Paltsyn's study notes, the area of irrigated lands increased by 364 percent. That means less water downstream, and if water consumption continues to grow, it could spell disaster for the tiger restoration. And that's not even taking into account climate change, which is expected to make the region drier. The tiger restoration project's success hinges on whether China can be persuaded to curb its consumption.