Introduction

Water is our most abundant and least expensive fire fighting agent. When fire companies arrive at a working fire, they need to be able to quickly determine which tactics they should employ and how best to supply themselves with water. There are several vital bits of information which we need.

Primarily, we need to know how much water is available from the closest hydrant so that we may select the appropriate size hose lines for the size and complexity of the fire, but not select lines which would exceed the capacity of the hydrant and thus be ineffective. This information is known as "available flow."

We also need to know the water pressure in each hydrant so that we can immediately implement the correct pumping operation at the supply hydrant. Water pressure is effected by elevation. The communities that we serve are spread over many elevations so pressures found in hydrants vary greatly. By knowing the pressure range in advance of connecting our hoses, we can implement the proper pumping operation and compensate for nearly every low pressure situation using the pumps in our fire engines.

There are also a few other bits of information which are important to us, which are discussed below.

We have found the most efficient means to convey this important information to our engine companies is to paint the hydrant tops and caps using standardized color codes. These colors give us a reasonably accurate picture as to how the hydrant should perform. They are easy to recognize and as fire crews travel the streets performing their various duties, they see these hydrants and get a feel for where the problem areas exist well in advance of a fire alarm being called in.

Top Colors

NFPA 291 BLUE 1500 GPM or more Very good flows GREEN 1000-1499 GPM Good for residential areas ORANGE 500-999 GPM Marginally adequate RED Below 500 GPM Inadequate





We are located in a high risk urban-wildland intermix area. Our design criteria is for the water system to deliver no less than 2250 GPM from three nearby hydrants simultaneously flowing. We do not consider it a significant problem in those areas which have hydrants adequately placed throughout if an isolated hydrant here or there is an "orange top"... so long as it is surrounded by strong hydrants. It is in those locations where the abundance of the hydrants are weak that we are concerned with a fire rapidly building up beyond our ability to control it.

Due to the wide range of hydrant pressures that we experience, we also color code hydrants for pressure. These indicators are used primarily to streamline our operations. We don't need to tie up a fire engine pumping out of a high pressure fire hydrant, however with a low pressure hydrant, we need to position an extra engine at the hydrant to ensure maximum delivery of water to the fire engine operating at the scene. We have chosen to color code the outlet caps for this purpose to provide some consistency with our neighbor, the Oakland Fire Dept.