What is the difference between a wet riser and a dry riser system?

A Dry Riser is an empty pipe system containing landing valves that has no permanent water connection. Firefighters must connect their fire truck pumps to the inlet breach at the ground level to pump water up the building. A Wet Riser is a pipe network permanently charged with water from a high-pressure pumping station.

Under Maharashtra Fire Services laws, a wet riser is mandatory for any commercial or residential building exceeding 15 meters in height. Dry risers are generally only permitted for low-occupancy residential structures up to 15 meters.