April 29 & 30, May 04 & 05, 2011
In the UK and Ireland, hydrants are located in the ground. Yellow "H" hydrant signs indicate the location of the hydrants, and are similar to the blue signs in Finland. Mounted on a small post or nearby wall etc., the two numbers indicate the size of the water main (top number) and the distance from the sign (lower number). Modern signs show these measurements in millimetres and metres, whereas older signs use inches and feet. Because the orders of magnitude are so different (6 inches versus 150 mm) there is no ambiguity whichever measuring system is used.
In areas of the United States without winter snow cover, blue reflectors embedded in the street are used to allow rapid identification of hydrants at night. In areas with snow cover, tall signs or flags are used so that hydrants can be located even if covered with snow. In rural areas tall narrow posts painted with visible colours such as red are attached to the hydrants to allow them to be located during heavy snowfall periods.
In Australia, Hydrant signage varies, with several types displayed across the country. Most Australian hydrants are underground, being of a ballcock system, and a standpipe with a central plunger is used to open the valve. Due to this, hydrant signage is essential, due to their concealed nature.
Painted markers - Usually a white or yellow (sometimes reflective paint) triangle or arrow painted on the road, pointing towards the side of the road the hydrant will be found on. These are most common in old areas, or on new roads where more advanced signs have not been installed. These are almost always coupled with a secondary form of signage.
Hydrant Marker Plates - Found on power poles, fences, or street-signs, these are a comprehensive and effective system of identification. The plate consists of several codes; H (Potable water Hydrant), RH (Recycled/Non Potable), P (Pathway, where the hydrant cover can be found), R (Roadway). The plate is vertically oriented, around 8 cm wide, and 15 cm high. Found on this plate, from top to bottom, are the following features:
The codes listed above, Potable/Non-potable at the top, Path/Roadway on the bottom of the plate.
Below this, a number giving the distance to the hydrant (in meters), then a second number below that giving the size (in millimeters) of the water main.
A black line across the center of the plate indicated the hydrant is found on the opposite side of the road to which the plate is affixed.
Plates for recycled water have a purple background, as well as the RH code, normal potable hydrants are white, with the H code.
Road reflectors or 'Catseyes' - Almost exclusively blue, these are placed on the center line of the road, usually with little indication on which side of the road the hydrant lies. They are visible for several hundred meters at night in heavy rain, further in clear conditions.