Yellow River Water-Sediment Regulation Enters Concentrated Sediment Discharge Phase
The Yellow River’s annual water-sediment regulation operation has entered its most critical stage, with the Xiaolangdi Reservoir dropping to the “connection water level” of approximately 215 meters on July 5 at 21:00, according to CCTV News. Sediment concentration in the discharge tunnel has reached 150 kg/m³, marking the transition into the concentrated sediment discharge phase of the 2026 pre-flood season operation.
A Two-Phase Engineering Operation
The 2026 operation, launched on the morning of June 22, follows a carefully designed two-phase structure. During the first phase, which ran from June 22 through early July, the Xiaolangdi Reservoir released clear water at a rate of 2,600 m³/s to scour the lower Yellow River channel and maintain flood discharge capacity.
Now in the second phase, upstream reservoirs — including Wanjiazhai and Sanmenxia — are creating large-flow processes that scour sediment from the Xiaolangdi reservoir area. This forms density currents that discharge sediment through the outlet tunnels. The operation is expected to discharge over 100 million tonnes of sediment from the reservoir while scouring the lower channel, as reported by China News citing the Economic Daily.
Why the Yellow River Needs Annual Sediment Regulation
The Yellow River carries more sediment than any other major river in the world, with an average annual sediment load of 1.6 billion tonnes. Centuries of sediment deposition have raised the riverbed, creating the infamous “hanging river” — where the channel sits above the surrounding floodplain. As People’s Daily noted, the Xiaolangdi Water Control Project controls 91.2% of the river’s runoff and nearly 100% of its sediment load, making it the linchpin of sediment management.
“Water-sediment regulation is an effective way to change the imbalanced relationship between water and sediment in the Yellow River through artificial means,” Ji Leilei, an Economic Daily reporter, explained via China News. “By using midstream reservoirs to store or release water at appropriate times, it scours and ‘cleans’ the downstream channel, achieving the goal of no further elevation of the downstream riverbed.”
Record Water Levels and Technological Sophistication
This year’s operation benefits from significantly higher water reserves. Li Peng, Director of the Water Dispatch Division at the Xiaolangdi Water Control Project Management Center, stated that the planned initial water level for 2026 is approximately 252 meters — 6 meters higher than the 246 meters in 2025 — with the reservoir holding nearly 1 billion m³ more stored water.
The maximum discharge flow will reach 4,800 m³/s during the operation, which is expected to last approximately 21 days. Reservoir scheduling is expected to conclude around July 12, 2026.
Zhang Bingduo, Director of the Plan Division at the Yellow River Conservancy Commission’s (YRCC) Bureau of Flood and Drought Disaster Prevention, outlined the operation’s goals: “To maintain or expand the medium-flow channel of the lower Yellow River; under the premise of ensuring later drought-relief water security and river flood passage safety, achieve reservoir sediment discharge and deposition reduction, optimize reservoir sedimentation patterns; implement ecological regulation of the Yellow River and ecological water replenishment for the delta.”
Two Decades of Proven Results
Since the program began in 2002, China has conducted 33 water-sediment regulation operations. The results have been transformative: a cumulative 3.69 billion tonnes of sediment discharged into the sea, and the main channel of the lower Yellow River scoured down by an average of 3.1 meters. The channel’s minimum flow capacity has increased from 1,800 m³/s in 2002 to approximately 5,000 m³/s today.
The program has received international recognition, with the YRCC winning the Lee Kuan Yew Water Prize and the “Yellow River Water-Sediment Regulation Theory and Practice” technology earning China’s National Science and Technology Progress First Prize, as documented by Guangming Daily.
Ecological and Flood Control Benefits
Beyond sediment management, the operation serves dual purposes. By drawing down the reservoir ahead of the main flood season, authorities create storage capacity for potential floodwaters. The Yellow River has now entered its main flood season, and authorities are strengthening 24-hour flood duty monitoring and fine-tuning reservoir operation plans in real time.
Ecological benefits are also significant. The program has conducted 17 ecological water replenishments for the Yellow River Delta Nature Reserve, totaling 1.65 billion m³. Since 2020, annual replenishment has been no less than 200 million m³, helping restore wetland areas and increase biodiversity.
What’s Next
As the concentrated sediment discharge phase continues, authorities are leveraging advanced technology including the Digital Twin Xiaolangdi system, which modeled over 50 scheduling scenarios before the operation began. This “Three Yellow Rivers” coordination — integrating physical, model, and digital twin systems — represents China’s growing sophistication in water management.
Looking ahead, China is accelerating preparatory work for additional upstream water control projects, including the Guxian and Heishan Gorge projects, to further enhance the overall water-sediment regulation system. The current operation is expected to conclude around July 13, 2026, after which authorities will assess results and prepare for the remainder of the flood season.