On this day 67 years ago, on November 18, 1958 (October 8, 1958 lunar calendar), the Haihe Lanhe Dam closed. On the morning of November 18, 1958, the Haihe Lanhe Dam was successfully closed; the fishing boat lock, one of the key projects of Haihe's construction, was opened on the same day to release water, and the concrete pouring project to control the lock was also completed. The closure of the Lanhe Dam marks that the Haihe River, the largest river in North China, has tamed into a new historical period. The dam cut off the natural connection between the Haihe River and the Bohai Sea, so that the fresh water injected into the Haihe River by the five inland rivers in North China no longer flows into the sea, and the seawater containing salt no longer goes back to the river, realizing the purpose of the "salinity separation" of the Haihe River. In this way, the Haihe River has become a large-scale river reservoir, which can better serve industrial and agricultural production according to people's wishes. The barrage dam is one of the main projects of Haihe River's dam construction. The dam is 300 meters long, 13 meters high, with a bottom width of more than 260 meters and a top width of 10 meters. It requires more than 6,000 firewood and stone pillows and more than 90,000 cubic meters of soil to fill. Its large scale and arduous construction are rare in the history of construction projects in Tianjin. It usually takes about half a year to build such a barrage, but the tens of thousands of laborers who fought on the Haihe River construction site showed great energy to make the mountains bow and the river make way. It only took 44 days and nights to successfully complete the task. When the barrage closed at 10:30 a.m. on the 18th, the two red flags on the dam head were planted together. The flag read "Heroes meet teachers, lock the flood dragons, transform the Haihe River, and make great contributions." At this time, the boiling cheers, thunderous firecrackers, and the songs of the artists on the loudspeaker merged into a symphony of victory on the construction site. That afternoon, the laborers at the Haihe construction site held a celebration meeting in Xingang to celebrate the completion of the closure of the barrage, the release of water from the fishing boat gate, and the control of the concrete pouring of the gate.