Engineering Harmony: How a Mega-Dam Protects Tibet’s Rare Fish

The Huaneng Zangmu Hydropower Station, a 100-meter-high structure, provides nearly 26 percent of the Xizang Autonomous Region’s electricity. To mitigate the impact on local species, designers constructed a specialized fishway—a zigzagging, 400-meter-long artificial channel that allows fish to bypass the dam. Since 2015, this system has facilitated the migration of approximately 570,000 fish, including nationally protected species like the black-spotted catfish.

Design engineer Zhang Lianming noted that the facility’s success stems from respecting the specific biological needs of native cold-water species. Unlike migratory fish in North America, those in the Yarlung Zangbo have lower swimming endurance, necessitating a gentler gradient and specific water velocity of 0.9 to 1.2 meters per second. This approach earned the team a first prize in the 2023 Science and Technology Award in Xizang, challenging the industry convention that dams exceeding 40 meters in height cannot effectively accommodate fish passage.

Beyond physical infrastructure, the station utilizes a "fish face recognition" system. Using optical and sonar technology, the AI tracks migration patterns with 95 percent accuracy. These insights, combined with a 12-year stock enhancement program that has released 1.97 million fry, suggest the local population remains stable. Monitoring reports indicate that the presence of otters and mergansers has increased, signaling a broader recovery in the gorge’s biodiversity as the facility balances industrial output with ecological stewardship.