Flood zone X, shaded and unshaded

What zone X means

Shaded X covers moderate risk areas in the 0.2 percent annual chance floodplain and areas a levee protects from the 1 percent annual chance flood.

Moderate risk zones can include shallow flooding, with water usually less than 1 foot deep or covering less than 1 square mile.

Unshaded X (Zone C on older maps) is the minimal risk area outside both the 1 percent and 0.2 percent annual chance floodplains.

Flood maps do not show BFEs or base flood depths in shaded or unshaded X zones.

In moderate and minimal risk zones, flood insurance is available in participating communities but is not required by regulation.

Buildings in X zones can still flood from heavy, concentrated rain combined with poor local drainage. Local storm drain systems are not normally part of the flood study.

Zones B and shaded X carry a moderate flood risk.

Sources: B and X: moderate or future conditions hazard; What shaded X covers; Shallow flooding can still be shaded X

Older maps: zones B and C

On older maps, today's Zone X is labeled Zone C and shaded Zone X is labeled Zone B.

Source: Older map labels

Flood insurance in zone X

Regulated lenders may not make, increase, extend or renew a loan secured by a building in a special flood hazard area unless it carries flood insurance for the loan term.

Federal rules require flood insurance purchase in the A zones (A, A1 to A30, AE, A99, AO, AH, AR) and the V zones (V1 to V30, VE, V, VO), among others.

Regulated lenders must accept private flood insurance when its coverage meets the federal requirement.

If a map update puts a building into an SFHA, the NFIP offers a Newly Mapped discount when a policy is bought or renewed within 12 months of the update.

FEMA says one in three flood insurance claims comes from low and moderate risk zones.

Sources: Lenders must require flood insurance in SFHAs; Zones where purchase is mandatory; Newly mapped discount