Henan Activates Flood Detention Area Amid Typhoon Rain
Henan Province activated the Nihewa flood detention area at 2:00 AM on August 13 in response to rising water levels in the Sha Ying River system, triggered by heavy rainfall from Typhoon “White Dolphin.” The activation, carried out under the province’s Flood Storage and Detention Area Application Plan, came after the river’s flow rate at the Luohe station exceeded 3,000 cubic meters per second with water levels continuing to climb, according to Xinhua News.
A Critical Flood Control Measure
The Nihewa flood detention area, located in Wuyang County within Luohe City, sits between the Sha River and Li River. It is one of 98 national flood storage and detention areas in China and serves as a critical component of the Huai River basin’s Sha Ying River flood control system, with a designed flood storage capacity of 2.38 billion cubic meters, as reported by China News Service.
The decision to activate the detention area reflects the severity of the current weather event. Typhoon “White Dolphin,” the 13th typhoon of the 2026 Pacific season, made landfall in Zhejiang Province on August 9 with maximum wind speeds of 151.2 km/h—nearly breaking the record set by Typhoon “Red Xia” two weeks earlier. According to BBC Chinese, the storm traveled approximately 6,000 kilometers before landfall, more than three times the average typhoon lifespan, and forced the evacuation of over one million residents from Shanghai and surrounding areas.
Widespread Evacuations and Emergency Response
As the typhoon’s residual circulation moved inland, heavy rainfall swept across much of Henan Province. From August 10 at 16:00 to August 12 at 17:00, Luohe City experienced sustained downpours with an average precipitation of 270.1 millimeters and a maximum of 434.2 millimeters, with all monitoring stations recording over 100 millimeters, Xinhua reported.
Local authorities relocated 4,567 people from 10 villages across two townships—Beiwudu Town and Jiangdian Township—ahead of the detention area’s activation. An additional 281 people were transferred beyond the emergency plan scope, bringing the total evacuated to 4,848. Province-wide, Henan had cumulatively relocated 65,593 people and activated 332 resettlement sites as of 9:00 AM on August 12, according to CNR.
The emergency response has been swift and layered. Henan Province activated a Level 2 flood emergency response at 8:00 AM on August 12, while the Henan Meteorological Station issued a red rainstorm warning at 7:30 AM the same day. Luohe City escalated to a Level 1 flood emergency response at 1:30 PM on August 12, the highest level in China’s four-tier emergency response system.
Regional Impact and Broader Context
The storm’s impact extends well beyond Henan. The typhoon’s heavy rainfall caused 74 rivers in the Taihu Lake basin and eastern Zhejiang coastal areas to exceed warning levels, with 37 rivers exceeding protection levels and five rivers recording their largest floods ever, as China News Service reported. The Ministry of Water Resources had earlier identified the Huai River basin—which includes the Sha Ying River system—as a high-risk area for potential numbered floods.
From August 11 at 7:00 to August 12 at 7:00, heavy to torrential rain fell across most of Henan Province, with the maximum point rainfall reaching 469 millimeters at Pinggou station in Lushan County, Pingdingshan City. The China Meteorological Administration forecast additional heavy rainfall across Henan, Shandong, Shanxi, Hebei, and Beijing over the following days.
A Year of Extreme Weather
The activation of the Nihewa flood detention area comes amid an unusually intense 2026 flood season in China. This is a strong El Niño year, with experts warning of more intense typhoons. Earlier in July, Typhoon “Red Xia” struck Guangdong, forcing the evacuation of over 710,000 people, while Typhoons “Maysak” and “Bavi” also affected China. The Nihewa area itself has been used for flood detention in previous major flood events, including the 2004 Huai River floods, when approximately 83 million cubic meters of water was stored.
What to Watch For
As the typhoon’s residual system continues to interact with weather fronts, the Ministry of Water Resources has warned that the Taihu, Yangtze, Huai River, Yellow River, and Hai River basins may all experience numbered floods. The Sha Ying River system remains under close monitoring, and authorities are maintaining heightened vigilance across central and eastern China. The coming days will be critical as the region contends with the ongoing flood threat and begins the process of recovery and damage assessment.