CFM CFM Hydrology & Hydraulics 3

Question 1

A Detailed Flood Insurance Study uses the term 'Q100' to refer to:

Accepted Answer

The peak discharge of the 1% annual chance flood

Answer

The 100-year return period storm duration

Answer

The 100-year cumulative rainfall depth

Answer

The volume of runoff from a 100-year storm

Question 2

Which soil hydrologic group has the highest runoff potential in the SCS method?

Accepted Answer

Group D

Answer

Group A

Answer

Group B

Answer

Group C

Question 3

What is the purpose of a 'starting water surface elevation' (tailwater) in a HEC-RAS steady-flow analysis?

Accepted Answer

To define the downstream boundary condition from which water surface profiles are computed upstream

Answer

To set the upstream boundary condition for the model

Answer

To establish the normal depth for culvert design

Answer

To calibrate the Manning's n value

Question 4

Which of the following is the correct interpretation of a 26% probability of flooding over a 30-year mortgage period?

Accepted Answer

Approximately equivalent to a 1% annual chance flood over 30 years

Answer

A 26% annual chance of flooding

Answer

The property is in Zone X (shaded)

Answer

The property floods every 4 years on average

Question 5

What is the primary distinction between a 'riverine' flood and a 'coastal' flood in NFIP mapping?

Accepted Answer

Riverine flooding is driven by overbank discharge from streams; coastal flooding includes tidal surge and wave action

Answer

Riverine floods occur only inland; coastal floods can occur anywhere

Answer

Riverine floods are mapped with Zone AE; coastal floods are mapped with Zone X only

Answer

Riverine floods have no BFE; coastal floods always do

Question 6

When a levee is shown on the FIRM as providing protection from the 1% annual chance flood, what accreditation standard must the levee meet under 44 CFR Part 65?

Accepted Answer

Both B and C

Answer

The levee must be certified by the Army Corps of Engineers only

Answer

The levee must meet FEMA freeboard and design criteria, including a minimum 3-foot freeboard above BFE

Answer

The levee must have an active Operations, Maintenance, Inspection, and Emergency Action Plan