SFCA-WMS-006 - Drain Line Cleaning and Camera Inspection at Morden Dam

Cleaning and camera inspection of drainage lines under the spillway at Morden Dam.
There are 6 pipes marked L1 to L6 (on attached drawing) and vary in length from 138’ to 147’. The pipes are 6" in diameter and consist of a steel section that is coupled to a perforated P.V.C. lateral drain. These pipes are accessed by 1200mm diameter manholes varying from approximately 15ft to 29ft in depth. Manhole no. 6 typically contains about 11 ft of water, the other manhole are typically dry or contain a few inches of ponded water. All pipes are capped at the end so all material will need to be flushed out of the pipe access. The granular bedding material surrounding the pipe is not to be disturbed so a low pressure method of flushing is required. The material inside the pipes is mostly silty clay with some granular and one pipe has several golf balls. A CCTV inspection of the pipes shall take place after the cleaning to confirm pipes have been completely flushed. Pipes found to still contain flushable material shall be re-flushed until the pipes are clear, or the Project Manager directs flushing to cease.