Edgewood, WA Real Estate Blog

The risks of holding raw land have never been higher.

FEMA recently updated their flood maps. More area is now included in floodplains. The Tacoma News Tribune ran an article on it yesterday worth reading. What they didn’t mention was that Pierce County recently updated their floodplain building requirements that may make your undeveloped raw land located in a floodplain worth a whole lot less… in some cases it may now be unfeasible to develop.

If you have a home located in a floodplain (again they just increased in size so even though you didn’t used to be located in a flood plain, you might now), the value of your home just decreased because of the need for flood insurance (averages about $771 in Milton and $680 in Fife per year for those property owners who have it), plus you may unable to make any additions to the structure. You can make improvements to your property (not additions) so long as they don’t exceed 40% of the it’s value. After that, it’s called a major improvement and you’ll need to bring the entire property up to new standards.

Pierce County now requires a home located in a floodplain to have a concrete stem wall (or pier or pile) extending 2 feet above the 100 year base flood elevation (BFE). Figure you’ll need to add about a foot on top of that to build your floor (don’t forget rim joists, floor joists, wiring, heating ducts, insulation, etc.). That means if your land lies 5 feet below the BFE your first floor will end up 8 feet above ground level. From page 10 of Be Flood Safe – click to enlarge.

And, as a bonus, your driveway must be one foot above BFE. Suppose you have a 50 foot driveway that’s 15 foot wide. Using the example above, assume you’re 5′ below BFE. That means you’ll need about 138 cubic yards of fill. But wait, there’s more. Due to the requirement of what’s called compensatory storage, you have to remove 138 cubic yards of dirt from somewhere else on your property. Hopefully, your soil is satisfactory for use as fill and you can use the same dirt you dug up to build your driveway (don’t count on it).

Pierce County says this is necessary to ensure that you or any future occupants can safely leave and enter the site in the event of a flood. Of course there is no requirement that public roads meet the same qualification. So although you may be able to reach the end of your driveway, you may be able to go no further. I’m not sure how you are supposed to transition from the end of your driveway to the road which could be 10′ below… maybe there’s also a requirement you own a 4 wheel drive that I missed.

Flood Insurance Rates based on height above/below BFE – click to enlarge

As a side note, if you find your land now located in a floodplain, you’ll want to review your tax assessment. Even though the County has reassessed floodplain property down 25% for developed property and 50% for undeveloped property, that may not be enough.