Drainage Devices

This layer also includes inspection chambers (circular 200 mm to 600 mm diameter chambers, installed within the drainage service connection pipe at or near the property line to allow inspection of the drainage connection pipe between the building foundation drain and the City's storm sewer pipe). Other devices that control flow include Flow Control (Control Manholes), Sea Dam, and Energy Dissipater.本图层还包含检查井（inspection chambers），即直径200毫米至600毫米的圆形检查井，安装于排水服务连接管内、用地红线处或其附近，用于检测建筑基础排水口与城市雨水管道之间的排水连接管。其余流量控制装置包括流量控制（Flow Control，又称控制检查井（Control Manholes））、挡潮坝以及消能设施。