Evaluating the impact of the South-to-North water diversion project on regional grain production

Water resources are fundamental to agricultural production and food security. Mega water infrastructure project play a critical role in addressing regional water allocation imbalances and meeting agricultural water demands. This study focuses on the Middle Route of the South-to-North Water Diversion Project (MR-SNWDP) in China. Using the Synthetic Control Method, it analyzes the MR-SNWDP’s impact on agricultural water consumption in Henan, a major grain-producing province. The results reveal that the MR-SNWDP has led to a consistent increase in both total water supply and agricultural water consumption in the region from 2010 to 2020 based on the comparative analysis of counterfactual simulation. The MR-SNWDP has significantly boosted grain production, with positive effects becoming evident from 2015, and culminating in a marked increase in grain output post-2017. This study advances the theoretical framework for evaluating large-scale water infrastructure projects and offers actionable insights to improve global water management and agricultural sustainability.