What Types of Water Supplies Exist?

MeyerFire University | FX106.02

By Franck Orset

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TRANSCRIPT

How do we categorize a water supply? 

There are basically two main categorizations of water supply for a given facility: the municipal water supply and the private water supply. 

Municipal water supplies are provided by a water utility and typically supply both domestic and fire protection needs. Private water supplies serve only a private facility and are owned and operated by the facilities. 

For fire suppression systems and manual firefighting, it is essential that water is delivered at the required flow and pressure to meet the needs of the system to function properly. Fixed fire protection systems can be fed directly by a municipal water supply, as long as the required minimum flow and pressure are provided.  

And this should be the case all year long, as there may be fluctuation of the municipality water supply over the year. Fluctuations happen because demands change. Some demands are seasonal, like the need for outdoor lawn irrigation in the spring and summer months, while other demands change hourly, such as higher demand due to morning showers or domestic use before and after dinner.  

The municipal system is used to supply water to both domestic and fixed fire protection system needs. The fire protection needs include sprinkler systems and manual firefighting purposes, such as hydrant and hoses. The municipality water system can be fed by elevated tanks or series of pumps taking suction from dedicated tanks or a combination of both. 

The water supply network close to the facility can be a dead-end pipe, a loop system or a gridded system. Of course, a looped or gridded water supplies are more reliable as they offer redundant paths for water to travel which can overcome parts of the system that are undergoing service or repair. 

When the municipal system is not sufficient, in terms of delivered flow or pressure, water can be supplied to a facility via private systems. 

Private systems can be fed by an elevated tank, a pressure tank, for small systems, or by a combination of a pump and a source of water. 

In that case, the source of water can be a suction storage tank, an elevated tank, a well or an open source of water, such as a canal, a lake, a pond, a river. 

When an open source of water is used, the water is then considered as “raw water” and may present some additional concerns, such as zebra mussels, deposits, sediments, etc.  

Screens or strainers are required to help filter the water. 

A water supply for a given facility may be a combination of a private supply and municipal supply. 

The private supply may be use for the fixed fire protection systems such as sprinkler systems and the municipality system can be used for the hydrants. 

A municipal system may also be combined with a private booster pump. That would be the case when the flow delivered by the city water system is large enough, but not the pressure that is required to meet the hydraulic demand of the sprinkler systems. 

In short, we categorize a water supply in two ways; public and private. Public water supplies often provide both domestic and fire protection system needs for a larger municipal area. Private water supplies are used when the public supply does not meet the needs for a facility. Either can include elevated tanks, pressure tanks, and/or pumps.  

For Franck Orset, I’m Jeff Kelm, this is MeyerFire University.