CFS Floodplain Mapping & Elevation Determination 3

Question 1

In a FIRM revision, what is the significance of a 'Limit of Moderate Wave Action (LiMWA)' line?

Accepted Answer

It marks where wave heights transition from less than 1.5 ft to 1.5 ft or greater

Answer

The LiMWA separates coastal areas with moderate wave action (waves 1.5 ft or greater) from those with lesser wave action, distinguishing Zone AE from Zone VE construction standards.

Question 2

When performing a Hydraulic Structure Analysis for a culvert, which condition typically controls the design water surface elevation?

Accepted Answer

Inlet control or outlet control, whichever produces the higher headwater elevation

Answer

Both inlet and outlet control headwater elevations are computed, and the higher value governs the design since it represents the more restrictive condition.

Question 3

A surveyor finds that a structure's Lowest Adjacent Grade (LAG) is 342.1 ft NAVD 88 and the BFE is 341.5 ft NAVD 88. What is the freeboard above BFE?

Accepted Answer

0.6 feet above BFE

Answer

LAG (342.1) minus BFE (341.5) = +0.6 ft, meaning the lowest adjacent grade is 0.6 feet above the BFE.

Question 4

What does 'effective' versus 'amended' mean on a FIRM panel?

Accepted Answer

Effective is the current legally adopted panel; amended refers to draft revisions not yet adopted

Answer

The effective FIRM is the currently adopted, legally binding map, while an amended panel has been modified through a formal LOMA or LOMR but may still await community adoption.

Question 5

Which statement best describes the relationship between the 1% annual chance flood and the 100-year flood?

Accepted Answer

They are equivalent terms describing a flood with a 1% probability of occurrence in any given year

Answer

The '1% annual chance flood' and '100-year flood' are synonymous, both describing a flood magnitude with a 1-in-100 probability of being equaled or exceeded in any year.

(CFS) Certified Floodplain Surveyor Practice Test

(CFS) Certified Floodplain Surveyor Practice Test

CFS Floodplain Mapping & Elevation Determination 3