CFS Case Analysis & Practical Application 3 — Questions and Answers
Question 1: A surveyor is asked to prepare an Elevation Certificate for a manufactured home located in Zone AE. The home is on a permanent foundation with the lowest floor at BFE + 2 feet. Which NFIP flood insurance rating factor does this positively affect?
- The structure's construction type classification
- The elevation difference between the lowest floor and BFE, which reduces the insurance premium (Correct answer)
- The community's Community Rating System score
- The home's proximity to the nearest stream channel
Correct answer: The elevation difference between the lowest floor and BFE, which reduces the insurance premium
Being elevated above the BFE reduces NFIP flood insurance premiums because the elevation difference is a primary rating factor.
Question 2: During a floodplain analysis, a surveyor discovers that a levee protecting a community has not been certified as providing 1% annual chance flood protection. How should this affect the FIRM?
- The area behind the levee should remain in Zone X because the levee exists
- The area behind the levee should be mapped as Zone AE or Zone A reflecting actual flood risk (Correct answer)
- The levee automatically qualifies the area for Zone X-shaded designation
- FEMA will automatically reclassify the area as Zone D pending levee certification
Correct answer: The area behind the levee should be mapped as Zone AE or Zone A reflecting actual flood risk
An uncertified levee cannot be credited with providing 1% annual chance flood protection, so the area behind it must reflect its true flood hazard.
Question 3: A surveyor is evaluating a structure built in 1975 in a community that entered the NFIP in 1980. The structure is non-compliant with current elevation standards. How is this structure classified under NFIP?
- A repetitive loss property requiring elevation
- A pre-FIRM structure, which may qualify for subsidized flood insurance rates (Correct answer)
- A post-FIRM structure subject to full actuarial rates
- A non-participating structure exempt from NFIP requirements
Correct answer: A pre-FIRM structure, which may qualify for subsidized flood insurance rates
Structures built before a community's FIRM effective date are classified as pre-FIRM and historically qualified for subsidized NFIP rates.
Question 4: A coastal Zone AE area has a wave setup component that adds 1.5 feet above the stillwater BFE. A proposed structure places the lowest floor at stillwater BFE + 1 foot. Is this compliant with NFIP standards?
- Yes, because the lowest floor exceeds the BFE shown on the FIRM
- No, because the lowest floor must account for wave setup and be placed at or above the total BFE including wave effects (Correct answer)
- Yes, because wave setup only applies to Zone VE designations
- No, but only if the community has adopted freeboard requirements above BFE
Correct answer: No, because the lowest floor must account for wave setup and be placed at or above the total BFE including wave effects
In coastal areas, the BFE includes stillwater plus wave effects; the lowest floor must meet the total BFE, not just the stillwater component.
Question 5: A surveyor is hired to assess a subdivision where 40% of lots are shown in Zone AE and 60% in Zone X. A developer wants to regrade the entire subdivision so all lots are at BFE + 1 foot. What is the most appropriate next step?
- Proceed with grading and submit a LOMA for each lot after construction
- Prepare a CLOMR to evaluate the proposed fill and its effect on floodplain hydraulics before any grading begins (Correct answer)
- Submit a LOMR after grading is complete to update flood zone boundaries
- Notify FEMA that regrading will be performed and await written approval
Correct answer: Prepare a CLOMR to evaluate the proposed fill and its effect on floodplain hydraulics before any grading begins
A Conditional Letter of Map Revision (CLOMR) must be obtained before placing fill in the floodplain to evaluate hydraulic impacts and approve the proposed changes.
Question 6: In a riverine floodplain study, the surveyor finds that an upstream dam provides significant flood attenuation. The dam operator announces plans to retire the dam. What is the impact on the downstream FIRM?
- The FIRM remains valid because dams are not credited in NFIP flood studies
- The downstream BFEs and floodplain boundaries will likely need to be updated to reflect loss of attenuation (Correct answer)
- The community must immediately adopt a new ordinance before the FIRM is revised
- FEMA will automatically issue a FIRM revision without the need for an H&H study
Correct answer: The downstream BFEs and floodplain boundaries will likely need to be updated to reflect loss of attenuation
Removing a dam that provides flood attenuation changes downstream hydrology, requiring updated H&H analysis and likely FIRM revision.
Question 7: A surveyor is evaluating a FEMA Flood Insurance Study that uses HEC-RAS modeling. The study shows a 100-year water surface elevation of 485.2 feet at cross-section 1000. The surveyor's field survey shows the natural ground at that cross-section averages 483.8 feet. What does the 1.4-foot difference represent?
- The freeboard margin built into the model
- The depth of flooding at that cross-section during the 100-year event (Correct answer)
- The model's computational error tolerance
- The difference between NAVD 88 and NGVD 29 at that location
Correct answer: The depth of flooding at that cross-section during the 100-year event
The 1.4-foot difference between the modeled water surface elevation and the ground elevation represents the expected depth of flooding during the 100-year flood event.
CFS Case Analysis & Practical Application 3
A surveyor is asked to prepare an Elevation Certificate for a manufactured home located in Zone AE.
The home is on a permanent foundation with the lowest floor at BFE + 2 feet.
Which NFIP flood insurance rating factor does this positively affect?