The western route would link the mountainous headwaters of the Yangtze and Yellow Rivers and transfer the most water of the three lines: 17 billion cubic meters per year. It is expected to offset severe desertification and irrigate 2 million hectares across four provinces. Another benefit, proponents say, is that infusing water near the Yellow River’s headwaters will reduce sediment buildup along the riverbed and avert or mitigate seasonal floods. However, complicated engineering and unanswered ecological questions are likely to delay construction until at least 2020, says Liu.