I’ve read that when firemen arrive at a blaze they search for a hydrant that has water. Then they phone the water company, tell them where the fire is and then the water company reduces the flow to other areas to give the firemen as much pressure as they can.
This photo was taken in a business park that was built from the ground up to house BPO (Business Process Outsourcing) and Call Center jobs. The infrastructure needed to be as high quality as possible to attract foreign companies. This is the only place in the country where I’ve seen hydrants with pressure gauges. I guess it saves the firemen time.
That gauge is reading zero PSI.