Before

After

Soggy Carpet from a Water Leak

Often carpet can be extracted and dried in place.  This is better for the carpet with less handling and manipulation.  It also reduces the handling and manipulation of the furniture and belongings in the affected areas.  This is called top down drying or in place drying. 

The key to being able to dry the carpet in place is the padding under neath the carpet.  If the water can be extracted through the pad and remaining water vapor can evaporate through the pad it can usually be dried right in place.  This does require a special extraction tool, not just a wand as one would use to clean carpets.

Some pads are sold now with a heavy moisture barrier coating on one side.  That side is installed up and against the carpet.  The idea being if liquid gets spilled on the carpet it won't go down through the pad.  This is meant for small "spills".  In a water damage, water will go over the pad barrier and under the pad barrier making removal of the pad necessary.