Municipal services, such as street sweepers and tank trucks, may also be allowed to use hydrants to fill their water tanks. Often sewer maintenance trucks need water to flush out sewerage lines, and fill their tanks on site from a hydrant.[from wikipedia]

To prevent casual use or misuse, the hydrant requires special tools to be opened, usually a large wrench with a pentagonal socket.[from wikipedia]

In 1896, during a terrible heatwave in New York City, the Chief of Police, Theodore Roosevelt, ordered the opening of the fire hydrants to provide relief to the population.[from wikipedia]

When operating a hydrant, a firefighter typically wears appropriate personal protective equipment, such as gloves and a helmet with face shield worn.[from wikipedia]

Most fire hydrant valves are not designed to throttle the water flow; they are designed to be operated full-on or full-off. The valving arrangement of most dry-barrel hydrants is for the drain valve to be open at anything other than full operation.[from wikipedia]

The user attaches a hose to the fire hydrant, then opens a valve on the hydrant to provide a powerful flow of water, on the order of 350 kPa (50 pounds per square inch gauge (psig); this pressure varies according to region and depends on various factors including the size and location of the attached water main).[from wikipedia]

Before piped mains supplies, water for firefighting had to be kept in buckets and cauldrons ready for use by 'bucket-brigades' or brought with a horse-drawn fire-pump.[from wikipedia]