南水北调中线工程
南水北调工程是世界上规模最大的调水工程，东、中、西线干线规划总长度达4350千米，构成以“四横三纵”为主体的总体布局，以实现中国水资源南北调配、东西互济的合理配置格局。其中，中线工程从汉江中上游横跨湖北和河南两省的丹江口水库取汉江水，输水干渠地跨河南、河北、北京、天津4个省、直辖市，一期工程于2003年年底开工，2014年12月正式通水。
中线工程全长1432千米，沟通长江、淮河、黄河、海河四大流域，穿过黄河干流及其他集流面积10平方千米以上河流219条，跨越铁路44处，需建跨总干渠的公路桥571座。其中，穿黄隧洞是南水北调工程中规模最大、单项工期最长、技术含量最高、施工难度最复杂的交叉建筑物。在中线工程涉及的省（市）中，河南省境内干线长度731千米，线路最长，建设任务最重，移民搬迁人数最多。
南水北调中线工程可极大地缓解中国中、北部地区的水资源短缺问题，改善受水区域的生态环境和投资环境，推动区域经济社会发展。截至2021年，南水北调中线一期工程向豫冀津京累计调水超过441亿立方米，有效缓解了地下水超采的局面，使经济发展格局得到优化，并取得十分显著的生态环境效益。
2021年9月，在“生物多样性100+案例”全球征集与评选活动中，“河南丹江南水北调中线水源地保护与修复”案例，从全球26个国家的258个申报案例中脱颖而出，成功入选“生物多样性100+全球典型案例”名单。
Middle Route of the South-to-North Water Diversion Project
The South-to-North Water Diversion Project is the largest of its kind in the world with its eastern, middle and western routes measuring 4,350 kilometers in total and a massive network of these three vertical routes connecting four major rivers. The project is designed to divert the water resources between the south and the north, the east and the west for a relatively reasonable redistribution.
The middle route draws water from the Danjiangkou Reservoir, which is located in the middle and upper reaches of the Hanjiang River, a tributary of the Yangtze. The canal water runs through two provinces (Henan and Hebei) and two municipalities (Beijing and Tianjin). Phase I of the middle route started construction at the end of 2003, and water diversion officially began in December 2014.
The 1,432-kilometer middle route connects four river basins: Yangtze, Huaihe, Yellow, and Haihe, crosses 219 rivers that each have a drainage area of 10 square kilometers, including the trunk stream of the Yellow River, and runs beneath railways at 44 spots. A total of 571 road bridges have to be built over the main diversion channel. Of all the structures, the tunnel beneath the Yellow River is the largest, most technically demanding, and most complicated and difficult with the longest construction period for a single structure. Of all the provinces and municipalities along the middle route, Henan possesses the longest trunk line (731 kilometers), which implies the most onerous work and the largest number of relocated people.
The middle route can largely mitigate the water scarcity in central and northern China, improve the ecological and investment environment in the water-receiving areas, and promote their socioeconomic development. By 2021, Phase I had cumulatively provided 44 billion cubic meters of water to Henan, Hebei, Tianjin, and Beijing, effectively easing their over-exploitation of underground water, bettering their economic landscape, and creating remarkable ecological and environmental benefits.
During the "100+ Biodiversity Positive Practices and Actions Around the World" campaign held in 2021, the "protection and restoration of water sources in the middle South-North water diversion route, Danjiang, Henan" was selected to be one of the global model cases, out of 258 candidates from 26 countries.
