Water distribution systems have been developed and operated for a variety of reasons.
In the past, many communities recognized the need for safe, potable water that
could be used for drinking and cooking. Governmental agencies or private enterprise
promptly took on the responsibility of providing safe water to meet these basic human
requirements.
The need for nonpotable water arose because of an increasingly sophisticated
lifestyle. In many cases, the water systems established to provide potable water were
augmented and enlarged to provide water for irrigation, car washing, industrial processes,
and other purposes. It also became necessary to provide an adequate supply
of water for fire protection and suppression. Systems that provide for fire protection
needs have frequently been incorporated into the systems that provide potable water
service as well as nonpotable service. As technology advances, many alternatives to
this basic water supply configuration can be found. A notable alternative is the use of
dual distribution systems.
The American Water Works Association has published standards for materials
used in the field of fire protection for many decades. However, it was not until the
early 1980s that AWWA’s Committee on Fire Protection developed the first edition of
this manual, which addresses the planning, design, and maintenance of distribution
systems that supply water for fire protection and suppression.
This manual provides specific guidance on the design, operation, and maintenance
of water distribution systems as they relate to fire protection and fire suppression
activities. When the governing body of a community makes a conscious decision
to use the available water supply system for fire suppression purposes, this manual
should be consulted, judiciously applied, and tempered as local conditions require.
This edition of the manual updates the information, clarifies some topics, and
deletes material that is no longer essential. The manual still closely parallels the first
edition prepared by the Fire Protection Committee.
As was the case with the first edition, this fourth edition does not intend to describe
how firefighters should use water to control fires, but rather how water utilities
should design and operate their systems to maximize fire protection benefits while
delivering safe, potable water to customers. The emphasis is on public water
systems
and not on water systems exclusively designed for fire protection. Similarly, this manual
does not intend to reproduce material available elsewhere in AWWA publications
such as Manual M17, Installation, Field Testing, and Maintenance of Fire Hydrants, or
Standards C502, Dry-Barrel Fire Hydrants, and C503, Wet-Barrel Fire Hydrants.
The adequacy of a water distribution system for fire protection depends on the
fire flows required. Chapter 1 describes several methods for determining required fire
flows. Once fire flow requirements are determined, these are added to the other water
system demand requirements. Chapter 2 discusses the impact of fire protection on distribution
system design. Chapter 3 focuses on distribution storage in terms of both sizing
and location. Chapter 4 discusses reliability issues arising because systems must
remain in operation even when individual components are out of service. Chapter 5
describes fire suppression sprinkler systems and their effect on water requirements,
particularly because they affect how water is used for fire fighting.
AWWA M31-2008 history
2008AWWA M31-2008 Distribution System Requirements for Fire Protection Fourth Edition
1998AWWA M31-1998 Distribution System Requirements for Fire Protection Third Edition