When Typhoon No. 13 struck China in August with record-breaking intensity, the flood control strategies for Miyun Reservoir were already being tested and refined in a digital replica of reality. Powered by a digital twin platform built through post-disaster reconstruction, thousands of sensing devices now transmit monitoring data in real time, enabling the system to complete multi-scenario flood simulations within minutes and generate over a dozen forecast-based dispatch options. This technological backbone provides scientific decision-making support for balancing water storage and discharge while mitigating downstream risks.
Advancing flood control through digital intelligence
If the "one-year basic recovery" phase addressed immediate symptoms, the "three-year comprehensive upgrade" targets the root causes. Beijing launched all 90 projects under the comprehensive upgrade category in the first half of 2024, with 54 completed by the end of July this year. In terms of major flood control infrastructure, the city has reinforced 10 reservoirs and sluice gates, upgraded automated monitoring systems, and repaired dam bodies, spillways, and water conveyance tunnels to eliminate safety hazards in aging hydraulic structures and ensure stable operation.
The restoration work goes beyond restoring original functions to enable remote dispatch and smarter flood control management. Before this year's flood season, Miyun Reservoir not only replaced the trash rack at the Baihe power generation tunnel — often called the "underwater gatekeeper" — but also launched its digital twin platform, making it possible for flood dispatch plans to be simulated digitally before floodwaters even arrive.
On the night of August 11, heavy rain lashed the Miyun mountain area as floodwaters surged toward the reservoir. Inside the digital twin consultation room at the Miyun Reservoir Management Office, Chu Xu from the dispatch operations section monitored the fluctuating data and swiftly operated the platform. "The system integrates data from over 1,000 monitoring sensors covering rainfall, water conditions, and engineering status," said Hao Hao, head of the Miyun Reservoir Digital Twin Office. Relying on these sensitive "sensory nerves" and hydrological-hydrodynamic models, the platform enables intelligent flood forecasting and dispatch responses. "Traditional manual calculations took tens of minutes or longer; now they're compressed to minute-level response times."
"Massive data streams help identify and alert reservoir safety risks early, capturing warning signs like dam deformation and seepage. The moment indicators exceed thresholds, alerts are triggered immediately," Hao explained. During heavy rainfall, the digital twin platform receives over 40,000 data entries daily. Simultaneously, more than 200 high-definition cameras keep constant watch over upstream dam faces, downstream slope toes, and spillway gate chambers. With AI recognition algorithms, the system can automatically detect anomalies such as floating debris upstream of the gates. The successful response to this typhoon demonstrated the platform's comprehensive support capabilities, as Hao noted: "The platform integrates flood routing and engineering safety into unified simulations, helping the reservoir find the optimal balance between storage and release. During rainfall events, it generated over 10 flood forecasts under different rainfall scenarios and ran hundreds of simulated dispatch drills."
Around-the-clock construction delivers 59 restoration projects on schedule
The destructive force of floods demands swift action, and the first major battle was ensuring damaged water conservancy and supply-drainage projects regained pre-disaster flood control capacity — and then exceeded it — before the 2024 flood season. This was a race against time. The Beijing Water Authority prioritized 59 restoration projects under the "one-year basic recovery" category.
During the "7.23" catastrophic basin-wide flood, sections of the Yongding River's Beijing embankments and other facilities were severely damaged. After emergency repairs, the Beijing Water Authority organized comprehensive restoration projects in the post-flood period of 2023. By May 2024, the downstream diversion dike that had been breached by massive flood peaks had been fully renovated. "The construction site for the Yongding River main channel embankment restoration at times employed several hundred workers, and the project was essentially completed before the flood season arrived," said Guo Yijian, then-deputy director of the Lugouqiao Flood Diversion Hub Management Office under the Beijing Yongding River Management Office. By June of that year, the Yongding River's Beijing section had resumed normal flood discharge functions.
Collectively, the "one-year basic recovery" projects completed restoration of 12 reservoirs, 8 sluice gates, over 500 kilometers of river channels, 580 kilometers of mountain torrent channels, and 127 hydrological stations with monitoring facilities. The flood control capacity of damaged structures now meets or exceeds pre-disaster levels. Meanwhile, water supply and drainage services were fully restored. After the floods, water facilities in Fangshan, Mentougou, Changping, and Yanqing districts suffered varying degrees of damage. Through emergency water delivery and urgent repairs, basic "road-open, water-flowing" service was achieved within a week; stable water supply was largely restored within a month; and within the first year, 130 water plants and approximately 1,100 kilometers of pipelines were rebuilt. All flood-affected areas in Beijing have returned to normal, stable water supply, eliminating lingering safety risks and restoring urban and rural water supply capacity to pre-disaster standards, safeguarding the public's basic water needs.
Expanding buffer capacity with eight flood detention zones
The comprehensive upgrade also involves significantly expanding the "buffer space" for basin-wide flood control. Beijing has focused on flood control vulnerabilities in the Yongding River and North Canal basins, constructing or upgrading eight flood detention zones that add approximately 35 million cubic meters of new storage capacity — equivalent to 17.5 Kunming Lakes. The innovative "dual-use for normal times and emergencies" approach allows these zones to serve both ecological recreation and flood prevention functions.
Before this year's main flood season, the Wennan South Weir project was completed and put into operation, filling the final piece of the "upper storage" component in the "Tongzhou Weir" flood control system. This completed the comprehensive Wenyu River Park flood management framework of "one park, three rivers, six gates and weirs," capable of storing up to 12 million cubic meters of floodwater — the equivalent of six Kunming Lakes. Located approximately one kilometer downstream from where the Qing River meets the Wenyu River, a new gray gate-weir structure now stands firm beneath a bridge. "This is the Wennan South Weir, one of the core control structures in the 'north-south zoning' dispatch strategy for the Wenyu River Park detention zone. It's also the 'last line of defense' for the Wenyu River against exceedance floods," said Li Wenyu, head of the Beijing Water Authority's Wenyu River Park Coordination Office.
With the Wennan South Weir complete, the tiered flood storage model for the Wenyu River Park detention zone has become a reality. Working in coordination with the completed Xinbao Gate, Qing River Weir, and Wennan North Weir, the system can now absorb floods in stages — from moderate to extreme events — and release water in an orderly manner after the peak passes. This fully closed-loop control significantly enhances joint flood dispatch capabilities for the Wenyu and Qing rivers, strengthening the flood defense barrier upstream of Beijing's sub-center.
In fact, Beijing began systematically planning these eight detention zones three years ago, distributing them across key river basins in the south, west, and east of the city. They cover multiple dimensions including river channel management, gate-weir construction, ecological restoration, and smart management. Today, these eight zones have largely taken shape, with 35 million cubic meters of added storage capacity substantially expanding the basin's flood buffer capacity.
Completing urban-rural water supply and drainage for safe drinking water
Infrastructure reconstruction goes beyond flood safety — it also protects household water security for millions of residents. Over the past three years, Beijing has continuously strengthened its urban and rural water supply and drainage systems to ensure residents have access to safe drinking water.
To date, Beijing has completed and put into operation the Mengtougou District Mengcheng Water Plant and upgraded the Chengzi Water Plant, further enhancing the resilience of urban and rural water supply facilities. More profound changes have occurred in mountain areas. For key disaster-affected regions, standardized renovations of over 170 mountain village water supply stations have been initiated to address weaknesses in disaster resistance from the source. By the end of 2025, Beijing will have progressively completed standardized upgrades at 300 mountain village water stations, maximizing the achievement of unified water sources, networks, quality, services, and supervision between urban and rural areas.
Wastewater treatment and reclaimed water utilization capacity have also been enhanced. Fifteen reclaimed water plants, including those in Fatou and Wulituo, have been newly built or upgraded, with 56 kilometers of sewage pipelines and 18 kilometers of reclaimed water pipelines now operational. Beijing's wastewater treatment capacity has reached 8.19 million cubic meters per day, laying a solid foundation for continued improvement of the city's water environment.