Ecmweb 7590 Flood Zones Pr
Ecmweb 7590 Flood Zones Pr
Ecmweb 7590 Flood Zones Pr
Ecmweb 7590 Flood Zones Pr
Ecmweb 7590 Flood Zones Pr

In the Zone

July 15, 2015
Why elevating electrical service equipment in flood plains/areas is critical.

Since the National Flood Insurance Act of 1994, new residential houses in flood zones have to have the first floor living space elevated according to the code of the locality where the new construction takes place. Existing homes being remodeled to more than 50% of their assessed value also must meet these guidelines. Building permits for updating existing homes that value the work more than 50% of assessed value in flood zones typically are issued only if the work conforms to FEMA standards.

FEMA works with local building officials who become responsible for enforcing the rules, and the rules are backed by Congress — requirements contained in Title 44 of the U.S. Code of Federal Regulations, Section 60.3. The rules establish the elevations of a home’s first floor habitable living space and the elevation of the utilities. This also applies to houses being rebuilt in flood zones that suffered major damage in past storms.

This FEMA-recommended installation arrangement is really federal law per the National Flood Insurance Program.

However, the requirement for locating electrical service equipment at these locations has not kept up with the times and the rules according to FEMA. The November 1999 publication, “Principles and Practices for the Design and Construction of Flood Resistant Building Utility Systems,” allowed utility companies to locate service equipment meters where they are easily read and serviced, typically about 5 feet above grade. As you can see in the Figure in its May 2005 publication, “Technical Fact Sheet on Home Builders Guide to Coastal Construction,” FEMA advises that electric lines and meters be installed at a higher elevation.

If the electric service meter box location is in a flood zone — where the expected 100-year flood height would exceed the standard height and location — the flood waters would penetrate the installation and most likely damage the equipment. If the flood water was salt water instead of fresh water, the equipment would certainly be ruined.

This is why electric utility providers should require the location of the customer provided electric meter boxes and incoming service termination and utility meters to be located above the design flood elevation (DFE) and preferably on the landward side of interior support columns and not on breakaway walls. If the service is underground or overhead, it should terminate at the meter box location set above the DFE flood level.

Current electric meter locations are typically set by the utility for convenience so that crews can service them more easily, but it is the homeowner who has to pay the cost to replace the equipment that houses the electric meter. If the electric meter is submerged by floodwaters, the utility has to pay the cost of the meter itself, and it may be self-insured or insured to cover the loss. So why would anyone ever place electric meter boxes in harm’s way in flood zones?

Photo 1. Typical electric meter location in flood zones may violate present FEMA regulations if first floor living space begins where shingles are located.

Photo 1 shows the typical location of an electrical service on a house located in a FEMA VE flood zone. Note that it’s located according to utility standards — typically 3 ft-6 in. to 5 ft-6 in. to the centerline of the meter above grade. However, the first floor living space begins where the siding is grey in color. In this case, the home’s main electrical panel is located back to back with the electrical meter socket box, which means flooding with salt water would probably result in complete replacement of this panel and relocation to a higher elevation after a future flood. Replacement and relocation costs would be very expensive with this equipment.

Photo 2. Although the parking area came after the meter equipment was installed, it violates the requirements of the NEC for being too close to the meter.

Photo 2 shows the electrical service and meter location at a new house constructed in 2014 in a FEMA flood zone. Although it’s not very clear in this photo (the house sits behind the car), the first floor living space of the house has been raised to conform to the FEMA flood level height requirements. However, the electrical meter, which is remote from the house, is below first floor level. Therefore, it could face water damage.

On a separate note, a new 2014 NEC Code item, Sec. 110.26(E)(2)(a), addresses this situation where accidental damage by a vehicle could damage the electrical service equipment. One thing the Code states is that equipment must be protected from accidental contact by vehicular traffic. This is another reason utilities and AHJs should take a good hard look at where and how high electrical service equipment should be located and protected when located in flood zones.

Photo 3 shows the electrical service entrance location on a house that was raised more than 30 years ago with the meter box raised higher than normal heights established by the utility company. This was completed without any objection by the  local utility.

Photo 3. This electric meter location has been placed above the design flood elevation.

So what’s an installer supposed to do? The key is to follow the elevations required by the local building officials in the area the house is being built. For the application of utilities, it’s best to allow for a slightly higher minimum elevation of at least 1 foot above the DFE level set by the authorities and obtained from the local building official.

Electrical contractors working in these types of scenarios need to ask if the property they are working on is located in a flood zone and then adjust accordingly. Referring to FEMA’s “Home Builders’s Guide to Coastal Construction” technical fact sheets and consulting with local building officials is a good start. Most utilities only provide the wire for new services from the pole to the meter box located on the house or underground to a free-standing meter location. Therefore, the contractor can influence the utility location of the meter by referring to FEMA requirements.                                                                                  

Bishop is a retired professional engineer in Glastonbury, Conn. He can be reached at [email protected].

About the Author

George. Bishop, III, P.E. | Retired Professional Engineer

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