Cavern construction: Sand, cement fill Allendale Road underground cavity

Construction work continues to repair the cavern — likely created by a broken water pipe — discovered underneath Allendale Road last year.
The underground cavity, found in August during an inspection of a manhole near Allendale Road and Calgary Trail, measures seven metres wide, with an estimated size of 700 cubic metres.
“We believe that there was an underground pipe failure that occurred which created a pathway for water, which eventually would have eroded the ground around t