"Flood Storage and Detention Area is the Current Focus of Flood Control" - Observations on the Flood Storage and Detention Area in the East Lake of Hebei, Tianjin, China | Flood | Focus

"A large-scale flood occurred in the Haihe River Basin, and at this stage, it is entering the flood evolution period. What is the flood control area that you are most concerned about?"

"The flood storage and detention area is a key concern, especially the Dongdian flood storage and detention area spanning Hebei and Tianjin. This flood storage and detention area is crucial as it has stored approximately 600 million cubic meters of water since its opening on August 1st, and the final estimated total water volume is conservatively estimated to be over 1 billion cubic meters."

The diversion gate and overflow weir of the Xingaifang Water Conservancy Hub. Photo by Xinhua News Agency reporter Liu Shiping

On the 5th, when the reporter interviewed Yang Zhigang, Director of the Water and Drought Disaster Prevention Department of the Haihe River Conservancy Commission of the Ministry of Water Resources, on the issue of flood prevention and control in the Haihe River Basin, he emphasized that the flood storage and detention area is the current focus of flood control. A total of 8 flood storage and detention areas have been opened in the Haihe River Basin to cope with this flood, with Dongdian having the highest inflow.

The Dongdian Flood Storage and Detention Area covers Bazhou City and Wen'an County in Hebei Province, as well as Jinghai District and Xiqing District in Tianjin City. It is approximately 66 kilometers long from east to west and 2.5 to 9 kilometers wide from north to south, with a total detention area of 379 square kilometers. As one of the main flood storage and detention areas in the Daqing River system, it is also one of the most commonly used flood storage and detention areas in the Haihe River Basin. It plays an important role in defending the flood of the Daqing River and safeguarding the safety of Tianjin and the Beijing Kowloon Railway.

The reporter arrived at the Xingaifang Water Conservancy Hub located in Xiongxian County, Hebei Province. The flood of Daqing River enters the Dongdian flood storage and detention area through the diversion gate and overflow weir of the Xingaifang Water Conservancy Hub, and through the Xingaifang diversion channel.

A corner of the Dongdian Flood Storage and Detention Area in Hebei Province. Photo by Xinhua News Agency reporter Liu Shiping

From the perspective of the water flow of the diversion gate, there is a slight decrease compared to the peak period of the previous few days. But as we entered the Dongdian flood storage and detention area along the diversion channel, the reporter saw that the fields were all underwater, and some houses in lower elevations had already flooded to the first floor.

On the way to Taitou Town, Jinghai District, Tianjin, along the flood storage and detention area, the reporter encountered Han Chaoguang, the leader of the Hydrological Emergency Monitoring Team of the Hydrological Bureau of the State Oceanic Commission, and others conducting flow measurement operations on the Daqing River. In this flood season, the Hydrological Bureau of the State Oceanic Commission strengthened and intensified hydrological surveys, and carried out flood forecasting on a rolling basis. As early as July 26th, they determined that there was a high possibility of the Dongdian Flood Storage and Detention Area being put into use based on survey reports. They use two-dimensional hydraulic calculations to predict flood evolution and retreat processes, providing technical support for flood control decision-making.

The hydrological emergency monitoring team of the Hydrological Bureau of the State Oceanic Commission is conducting flow measurement operations on the Daqing River. Photo by Xinhua News Agency reporter Liu Shiping

After the National Flood Control Administration opened the Dongdian Flood Storage and Detention Zone on August 1st, Taitou Town issued a notice for the evacuation of personnel from 18 villages in the town. As of 12:00 on the 3rd, more than 30000 residents from the Dongdian Flood Storage and Detention Area in Jinghai District, Tianjin, including those evacuated from Taitou Town, have completed resettlement and relocation.

When the reporter passed by Taitou Town, the town was quiet, and apart from the personnel maintaining order, there were hardly anyone else to be seen. Yang Bang, chief forecaster of the Hydrological Bureau of the State Oceanic Commission, told reporters that the water head of the Dongdian Flood Storage and Detention Area has reached Tianjin, with a water discharge area accounting for about three-quarters of the area. It is expected to reach the main water conservancy project for discharging floods in the Dongdian Flood Storage and Detention Area - the Duliu Jianhe Flood Control Sluice from the evening of August 5th to the early morning of August 6th.

The Dongdian Flood Storage and Detention Area, where Taitou Town was located in Jinghai District, Tianjin before the flood arrived. Photo by Xinhua News Agency reporter Liu Shiping

The Duliujian River flood gate is located at the easternmost end of the Dongdian flood storage and detention area, and is a channel for upstream water to enter the sea such as the Daqing River, Ziya River, and South Canal.

"Since the operation of the gate on July 29th, the south and north gates of the flood gate have been open. The flow rate was 558 cubic meters per second at 8:00 am on the 5th. As the water level rose, the flow rate continued to increase, and in the past two days, the water level has continued to rise." said Liu Deyin, Deputy Director of the Management Office of the Duliu Jianhe Flood Gate.

The subsequent floods in the Dongdian flood storage and detention area will mainly be discharged from the Duliujian River inlet gate. The design flow rate of the south and north gates is 3600 cubic meters per second. The staff stated that they will adjust accurately according to the flood water level, and the gates will always be kept above 1 meter of water level.

The south and north gates of the Duliujian River flood gate. Photo by Xinhua News Agency reporter Liu Shiping

Liu Deyin said that 67 kilometers downstream of the Duliujian River flood gate is the Duliujian River moisture-proof gate. The staff of the flood gate and the moisture-proof gate establish close contact, communicate twice a day about the discharge situation and the upstream and downstream water levels, and connect in real-time in case of emergency to ensure that the flood is safely flowing into the sea from the upstream and midstream to the downstream.

"Approximately 2.5 billion cubic meters of flood will be discharged from Tianjin in the Haihe River Basin this time, mainly from the North Canal, Yongding River floodplain, Dongdian flood storage and detention area, and Baiyangdian. Currently, it has flowed 300 million to 500 million cubic meters." Yang Bang said that it is expected that the peak discharge of the Duliu Jianhe River flood gate will reach 1100 cubic meters per second, and the water in the Dongdian flood storage and detention area will recede for more than two months.