A fluent material confinement system configured to receive a granular fluent material to form a temporary barrier structure is disclosed, wherein the fluent material confinement system includes a plurality strips, the plurality of strips including a plurality of lengthwise strips and a plurality of widthwise strips coupled with each other to define a plurality of open cells, wherein the plurality of lengthwise strips includes at least one wider lengthwise strip configured to extend into cells of a next-lowest fluent material confinement system when the fluent material confinement system is stacked on the next-lowest fluent material confinement system, and a stacking error indicator associated with the wider lengthwise strip, wherein the stacking error indicator is configured to be effective in low visibility conditions to indicate to a user a location of an error in stacking of the fluent material confinement system on the next-lowest fluent material confinement system.