One of my pet peeves is building utility elevations. As I drive around my neighborhood and visit other coastal sites, I see countless examples of brand new mechanical equipment (generators, A/C pads, electrical meters, etc.) set below the design flood elevation.
Often, it’s something like these ground mounted utilities:
This is obviously against building codes and flood insurance requirements – but beyond that, it’s just an awful practice. Accordingly, this blog is directed not only at mechanical equipment installers, but homeowners and code officials as well.
I can see that sometimes it’s simply a case of “I need to replace my AC condenser” so the contractor is called. Perhaps the flood zone condition is unknown and they simply replace the AC condenser.
Alternatively, I would recommend:
- Checking the flood map yourself
- Asking the client if they have a recent elevation certificate
- Calling an Engineer or Surveyor
If you know you’re in or near a flood zone (often it’s obvious as the houses have flood vents and are built on piers, or you’re simply near the coast) then there are tons of GIS resources available, the most basic being:
FEMA Maps
https://msc.fema.gov/portal/home
If you’re in Rhode Island, try the RI floodplain mapper:
https://risegis.ri.gov/portal/apps/Styler/index.html?appid=37dc9eac2c154547a4d7d1bc9f1934e7
There are also 3rd party mobile apps available both for IOS and android (not a recommendation of either app):
https://play.google.com/store/apps/details?id=com.rmtheis.flood&hl=en_US&pli=1
https://apps.apple.com/us/app/flood-maps-zds/id908554933
If you see zone “V” or “A”, that’s what we call a high hazard zone, and utilities should be raised above the Design Flood Elevation (essentially the Base Flood Elevation (BFE) + 1’), you should also call an engineer/surveyor to have them “mark” the DFE or set the height of the equipment.
Typically, we aim to design our utilities with a bit more freeboard (3’ – 5’+ depending on the site and predicted future impacts), but that’s not always practical with design and zoning constraints.
“X” zones are still subject to some flood risk, but don’t have a base flood elevation. Colloquially, most people would say these are not in a “flood zone” (more precisely, not a “high hazard zone”).
Here is an example of properly mounted utilities – the AC condensers are mounted on a bracket and set above the DFE:
You’ll notice the bracket (which was engineered using aluminum for longevity) spans the piers and will not interfere with the breakaway walls, nor will it be a hindrance to the functionality of the flood vents.
If you’re a mechanical contractor, you’re putting your work at risk and you’re certainly not helping your clients if you ignore these regulations. Never mind your own liability by failing to check to see if you’re in a flood zone.
Homeowners – yes, it costs more to elevate initially, but you can easily lose your equipment to a “minor” flood and end up having to pay much more than elevating would have originally cost you. It’s certainly questionable whether or not insurance would cover these if they were installed in violation of the building code and FEMA requirements. If a piece of equipment breaks away, floats or is knocked into an abutting house during a storm, then both the installer and the homeowner may face liability.
It’s worth noting that some elements are allowed to be set below the BFE, if they are not mechanical or electrical in nature. Surface mounted propane tanks are an example of this, but it’s critical that these be properly anchored to avoid floating and posing a danger to nearby structures. Here’s a video of a flaming, floating propane tank careening through floodwaters in Louisiana!
https://www.usatoday.com/videos/news/2016/03/16/81852724/
FEMA doesn’t usually have local inspectors that perform site inspections since that role is normally delegated to the local building code official. These folks don’t always catch every single issue, but I would recommend mechanical and building code officials pay very close attention to these installations, for the same reasons cited above. Properly elevated and designed mechanical systems not only protect the homeowner, but also abutters.
Please don’t hesitate to call our office if you have any questions!
And read all of our blog articles here:
https://nei-cds.com/blog/