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Deficient Fire Flows

Reference Number: MTAS-1897
Reviewed Date: 10/02/2023

Why Communities Have Deficient Fire Flows
A community that discovers it has areas with deficient fire flows may wonder how that happened, and wonder why the water system and fire hydrants were installed while being inadequate for the community's fire protection needs. The reasons are many, but a common and recurring reason a community has deficient fire flows is poor planning.

Water mains of four inches in diameter are adequate for supplying water for domestic use, such as for drinking, cooking, bathing, etc. In many rural areas, four-inch mains were installed to allow for the development of homes. However, a four-inch water main is incapable of supplying enough water to fight a fire. In addition, TDEC regulations require water mains of six inches or larger for the installation of fire hydrants. It is possible that developers, planners, builders, and others who are not aware of the need for adequate fire flows did not consult with the local fire department during the planning and design phase of a project. This is a key reason why it is critical that the fire department be involved in the review of proposed residential and commercial developments in a community.

Another reason is that needed fire flows are not always available during the design phase of a water system project. Many other factors also determine actual flows and water main sizes to certain areas. Fire hydrants are also used to flush public water systems and many hydrants have been installed for this sole purpose. Nevertheless, inadequate and unmarked fire hydrants provide a false sense of security to the fire department and property owners.