Here's how volume changes with height:

* Volume of a Cylinder: The volume of a cylinder is calculated by:

* V = πr²h

* Where:

* V = Volume

* π = 3.14159 (approximately)

* r = Radius of the base

* h = Height

* Changes in Height:

* If the height is reduced, the volume of the cylinder decreases proportionally.

* The amount of the decrease depends on the new height.

Example:

Let's say the new height is 6 feet:

1. Original Volume: Assume the radius is 2 feet. Original volume = π * (2²) * 12 = 48π cubic feet.

2. New Volume: New volume = π * (2²) * 6 = 24π cubic feet.

3. Change: The volume is halved (reduced by 50%) when the height is halved.

To give you a specific answer, please provide the new height of the barrel.