First appears in: The Stone Flame
The Columbus Avenue Water Storage Facility is a utility destination located deep within the Under of City Three. It is accessible via the city’s labyrinthine sewer network, specifically through a "sewer mixture tunnel" that branches off toward the facility. During a desperate flight from the Tenderloin Crew, Beam identified the left branch of this tunnel as the path leading to the storage facility.
While the facility itself is not described in exhaustive detail, it represents the vital infrastructure that underkids navigate to move through the city undetected. Beam noted that taking the path toward Columbus Avenue was a tactical choice to avoid the Den, even though it would require a long journey toward Old Fisherman’s Wharf to hitch a subway or find a tunnel back to their home territory.