The accumulated material flowed through the haulage level and took the shortest path via the main shaft into the mine.
After blasting a barricade plug is placed at the bottom of the stope from which muck is withdrawn.
This barricade plug has a draw out pipe fitted at bottom with a V notch for proper decantation and monitoring.
15 stopes had already been filled successfully, indicating sufficient experience and reliability of method and equipment used.
Nobody noticed that 50 meter of filling slurry head had been created inside the stope over days/months.