长河闸是北京市城市水系综合治理工程中的重点建筑物，系长河整治工程的渠首工程。该间主要用于防洪挡水，防洪标准为百年一遇，最高设计洪水位为50．157m。此建筑物的设置避免了昆玉段上游洪水从长河口进入长河而殃及下游景区。长河闸闸门为弧起平卧式液压操作，其主要功能除 Changhe sluice is a key building in Beijing’s urban water system comprehensive harnessing project and is the headwork of Changhe River Regulation Project. The room is mainly used for flood control and water conservation, flood control standard is once in a century, the maximum design flood level is 50.157m. The setting of this building avoids the upstream of Kunyu section flood into the river from the estuary and bring disaster to downstream areas. Changhe gate for the arc from the horizontal hydraulic operation, in addition to its main function