FEMA Form FF-206-F Riverine Structures (Form 3)

DEPARTMENT OF HOMELAND SECURITY

Federal Emergency Management Agency

OMB Control Number: 1660-0016
Expiration Date: 1/31/2024

RIVERINE STRUCTURES FORM (FORM 3)
PAPERWORK BURDEN DISCLOSURE NOTICE
Public reporting burden for this form is estimated to average 3.5 hours per response. The burden estimate includes the time for
reviewing instructions, searching existing data sources, gathering and maintaining the needed data, and completing, reviewing, and
submitting the form. You are not required to respond to this collection of information unless it displays a valid OMB control number.
Send comments regarding the accuracy of the burden estimate and any suggestions for reducing this burden to: Information
Collections Management, Department of Homeland Security, Federal Emergency Management Agency, 500 C Street, SW,
Washington, DC 20472 , Paperwork Reduction Project (1660-0016). Submission of the form is required to obtain or retain benefits
under the National Flood Insurance Program. Please do not send your completed survey to the above address.

PAPERWORK BURDEN DISCLOSURE NOTICE
AUTHORITY: The National Flood Insurance Act of 1968, Public Law 90-448, as amended by the Flood Disaster Protection Act of
1973, Public Law 93-234.
PRINCIPAL PURPOSE(S): This information is being collected for the purpose of determining an applicant's eligibility to request
changes to National Flood Insurance Program (NFIP) Flood Insurance Rate Maps (FIRM).
ROUTINE USE(S): The information on this form may be disclosed as generally permitted under 5 U.S.C § 552a(b) of the Privacy Act
of 1974, as amended. This includes using this information as necessary and authorized by the routine uses published in DHS/FEMA/
NFIP/LOMA-1 National Flood Insurance Program (NFIP); Letter of Map Amendment (LOMA) February 15, 2006, 71 FR 7990.
DISCLOSURE: The disclosure of information on this form is voluntary; however, failure to provide the information requested may
delay or prevent FEMA from processing a determination regarding a requested change to a (NFIP) Flood Insurance Rate Maps
(FIRM).

DRAFT

Flooding Source:

NOTE: Fill out one form for each flooding source studied.

A. GENERAL

Complete the appropriate section(s) for each Structure listed below:
Channelization:
Bridge/Culvert:
Dam:
Levee/Floodwall:
Sediment Transport:

Complete Section B
Complete Section C
Complete Section D
Complete Section E
Complete Section F (if required)

DESCRIPTION OF MODELED STRUCTURE
Name of Structure:
1.

2.

3.

Type (check one):
Channelization

Bridge/Culvert

Levee/Floodwall

Dam

Levee/Floodwall

Dam

Levee/Floodwall

Dam

Location of Structure:
Downstream Limit/Cross Section

Upstream Limit/Cross Section:

Name of Structure:

Type (check one):
Channelization

Bridge/Culvert

Location of Structure:
Downstream Limit/Cross Section

Upstream Limit/Cross Section:

Name of Structure:

Type (check one):
Channelization

Bridge/Culvert

Location of Structure:
Downstream Limit/Cross Section

Upstream Limit/Cross Section:

NOTE: FOR MORE STRUCTURES, ATTACH ADDITIONAL PAGES AS NEEDED.
FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

Page 1 of 9

B. CHANNELIZATION
Flooding Source:
Name of Structure:
1. HYDRAULIC CONSIDERATIONS
The channel was designated to carry

(cfs) and/or the

-year flood and/or the

% annual-chance.

The design elevation in the channel is based on (check one):
Subcritical flow

Critical flow

Supercritical flow

Energy grade line

If there is the potential for a hydraulic jump at the following locations, check all that apply and attach an explanation of how the
hydraulic jump is controlled without affecting the stability of the channel.
Inlet to channel
Outlet to channel
At Drop Structures
At Transitions
Other locations (Specify):

DRAFT

2. CHANNEL DESIGN PLANS

Attach the plans of the channelization certified by a registered professional engineer, as described in the instructions.
3. ACCESSORY STRUCTURES

The channelization includes (check one):

Levees [Attach Section E (Levee/Floodwall)]
Drop structures
Superelevated sections
Energy dissipater
Transitions in cross sectional geometry
Weir
Debris basin/detention basin [Attach Section D (Dam/Basin)]
Other (Describe):
4. SEDIMENT TRANSPORT CONSIDERATIONS

Are the hydraulics of the channel affected by sediment transport?

Yes (If "Yes," then fill out Section F (Sediment Transport) of Form 3)
No (If "No," then attach your explanation for why sediment transport was not considered)

C. BRIDGE/CULVERT

Flooding Source:
Name of Structure:
1. This revision reflects (check one):
Bridge/Culvert not modeled in the FIS
Modified Bridge/Culvert previously modeled in the FIS
Revised analysis of Bridge/Culvert previously modeled in the FIS
2. Hydraulic model used to analyze the structure (e.g., HEC-RAS, 1-D, or 2-D; unsteady or steady flow conditions):
If different than hydraulic analysis for the flooding source, justify why the hydraulic analysis used for the flooding source could not
analyze the structures. Attach justification.
3. Attach plans of the structures certified by a registered professional engineer. The plan detail and information should include the
following (check the information that has been provided):
Dimensions (height, width, span, radius, length)
Shape (culverts only)
Material
Beveling and Rounding
Wing Wall Angle
Skew Angle
Distance between Cross Sections
Erosion Protection
Low Chord Elevations - Upstream and Downstream
Top of Road Elevations - Upstream and Downstream
Structure Invert Elevations - Upstream and Downstream
Steam Invert Elevations - Upstream and Downstream
Cross-Section Locations
4. Sediment Transport Considerations
Are the hydraulics of the channel affected by sediment transport?
Yes (If "yes," then fill out Section F (Sediment Transport) of Form 3)
No (If "No," then attach your explanation for why sediment transport was not considered)

FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

Page 2 of 9

D. DAM/BASIN
Flooding Source:
Name of Structure:
1. This request is for (check one):
Existing Dam/Basin

New Dam/Basin

Modification of Existing Dam/Basin

2. The Dam/Basin was designed by (check one):
Federal Agency

State Agency

Private Organization

Local Government Agency

Name of the Agency or Organization:
3. The Dam was permitted as (check one):
Federal Dam

State Dam

DRAFT

Provide the permit or identification number (ID) for the dam and the appropriate permitting agency or organization.
Permit or ID Number:
a.

Local Government Dam

Permitting Agency or Organization:

Private Dam

Provided related drawings, specification and supporting design information.
4. Does the project involve revised hydrology?

Yes (If "Yes," complete the Riverine Hydrology & Hydraulics Form (Form 2))

No

Was the dam/basin designed using Probable Maximum Flood? (must account for the maximum volume of runoff)
Yes, provide supporting documentation with your completed Form 2
No, provide a written explanation and justification for not using the Probable Maximum Flood
5. Does the submittal include debris/sediment yield analysis?

Yes (If "Yes," then fill out Section F (Sediment Transport))
No (If "No," then attach your explanation for why debris/sediment analysis was not considered)

6. Does the Base Flood Elevation behind the dam/basin or downstream of the dam/basin change?

Yes (If "Yes," complete the Riverine Hydrology & Hydraulics Form (Form 2) and complete the table below)

No

STILLWATER ELEVATION BEHIND THE DAM/BASIN
RECURRENCE INTERVAL (% ANNUAL CHANCE)
10-YEAR (10%)
50-YEAR (2%)
100-YEAR (1%)
500-YEAR (0.2%)
NORMAL POOL ELEVATION

FIS

REVISED

7. Please attach a copy of the formal Operation and Maintenance Plan.
8. Is the dam in an area where seismic events could cause hazardous condition for the dam?
Yes (If "Yes," provide seismic study conducted on potential ground motion effects on project features)

No

E. LEVEE/FLOODWALL
1. SYSTEM ELEMENTS
A. This Levee/Floodwall analysis is based on (check one):
Upgrading of an existing levee/floodwall system
Reanalysis of an existing levee/floodwall system

A newly constructed levee/floodwall system

B. Levee elements and locations are (check one):
Embankment/floodwall reaches and locations
Structured floodwall
Other (Describe):
FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

Stationed
Stationed
Stationed

to
to
to
Page 3 of 9

E. LEVEE/FLOODWALL (Continued)
1. SYSTEM ELEMENTS (Continued)
C. Floodwall Type (check one):
Monolithic cast-in reinforced concrete
Other (Describe):

Reinforced concrete masonry block

Sheet piling

D. Has this levee/floodwall system been certified by a Federal agency to provide protection from the base flood?
Yes

No

If "Yes," by which agency?
If "Yes," then no other sections of this form needed to be completed.
E. Attach certified drawings containing the following information (indicate drawing sheet numbers):
1. Plan of the levee embankment and floodwall structures.
2. A profile of the levee/floodwall system showing the Base Flood Elevation (BFE), levee
and/or wall crest and foundation, and closure locations for the total levee system.
3. A profile of the levee/floodwall system showing the Base Flood Elevation (BFE), levee
and/or wall crest and foundation, and closure locations for the total levee system.
4. A layout detail for the embankment protection measures.
5. Location, layout, and size and shape of the levee embankment features, foundation
treatment, Floodwall structure, closure structures, and pump stations.

Sheet Numbers:
Sheet Numbers:

DRAFT
Sheet Numbers:
Sheet Numbers:
Sheet Numbers:

2. FREEBOARD

The minimum freeboard provided above the BFE is:
Riverine

3.0 feet or more at the downstream end and throughout
3.5 feet or more at the upstream end
4.0 feet within 100 feet upstream of all structures and/or constrictions
Coastal

1.0 foot above the height of the one percent wave associated with the 1%-annual-chance stillwater surge
elevation or maximum wave runup (whichever is greater).
2.0 feet above the 1%-annual-chance stillwater surge elevation

Yes
Yes
Yes

No
No
No

Yes
Yes

No
No

Please note, occasionally exceptions are made to the minimum freeboard requirement. If an exception is requested, attach
documentation addressing Paragraph 65.10(b)(1)(ii) of the NFIP Regulations.
If "No" is answered to any of the above, please attach an explanation.
Is there an indication from historical records that ice-jamming can affect the BFE?

Yes

No

3. CLOSURES
Openings through the levee system (check one):
Exists

Does not exist

If opening exists, list all closures:
CHANNEL STATION

LEFT OR RIGHT
BANK

OPENING TYPE

HIGHEST ELEVATION
FOR OPENING INVERT

TYPE OF CLOSURE
DEVICE

(Extend table on an added sheet as needed and reference)
NOTE: Geotechnical and geologic data.
In addition to the required detailed analysis reports, data obtained during field and laboratory investigations and used in the design
analysis for the following system features should be submitted in a tabulated summary form.
FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

Page 4 of 9

E. LEVEE/FLOODWALL (Continued)
4. EMBANKMENT PROTECTION
A. The maximum levee slope land side is:
B. The maximum levee slope flood side is:
C. The range of velocities along the levee during the base flood is:

(min) to

(max)

D. Embankment material is protected by (describe what kind):
E. Riprap Design Parameters (check one):
Velocity

Tractive Stress

Attach references
REACH

SIDESLOPE

FLOW
DEPTH

VELOCITY

CURVE OR
STRAIGHT

D 100

STONE RIPRAP
DEPTH OF
D 50
THICKNESS TOEDOWN

DRAFT

Sta
to
Sta
to
Sta
to
Sta
to
Sta
to
Sta
to
(Extend table on an added sheet as needed and reference each entry)
F. Is a bedding/filter analysis and design attached?
Yes

No

G. Describe the analysis used for other kinds of protection used (include copies of the design analysis):

Attach engineering analysis to support construction plans.
5. EMBANKMENT AND FOUNDATION STABILITY

A. Identify locations and describe the basis for selection of critical location for analysis:

Overall height:
Limiting foundation soil strength:

STA:
, height
ft.
Strength ϕ =
degrees, c =
psf
Slope: SS =
(h) to
(v)
(Repeat as needed on an added sheet for additional locations)

B. Specify the embankment stability analysis methodology used (e.g., circular arc, sliding block, infinite slope, etc.):

C. Summary of stability analysis results:
D. Was a seepage analysis for the embankment performed?
Yes

No

If "Yes," describe methodology used:

FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

Page 5 of 9

E. LEVEE/FLOODWALL (Continued)
5. EMBANKMENT AND FOUNDATION STABILITY (Continued)
F. Were uplift pressures at the embankment landside toe checked?
Yes

No

G. Were seepage exit gradients checked for piping potential?
Yes

No

H. The duration of the base flood hydrograph against the embankment is:

hours

Attach engineering analysis to support construction plans.
6. FLOODWALL AND FOUNDATION STABILITY
A. Was a stability analysis performed?
Yes

No

DRAFT

B. Design water elevations =

Design wave height and period =

ft. and

sec.

C. Was the foundation bearing or pile capacity checked?
Yes

No

E. Level of Design

is,

is not provided.

If provided, attach explanation and supporting documentation. Attach engineering analysis to support construction plans.
7. SETTLEMENT

A. Has anticipated potential settlement been determined and incorporated into the specified construction elevations to maintain the
established freeboard margin?
Yes
No
B. The computed settlement range is

ft. to

ft.

C. Settlement of the levee crest is determined to be primarily from:
Foundation consolidation

Embankment compression

D. Differential settlement of floodwalls

has

Other (Describe):

has not been accommodated in the structural design and construction.

Attach engineering analysis to support construction plans.
8. INTERIOR DRAINAGE
A. Specify size of each interior watershed:
Drainage to pressure conduit:
Drainage to ponding area:

acres
acres

B. Relationship Established:
Ponding elevation vs. storage
Ponding elevation vs. gravity flow
Differential head vs. gravity flow

Yes
Yes
Yes

No
No
No

C. The river flow duration curve is enclosed:
Yes

No

D. Specify the discharge capacity of the head pressure conduit:

FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

cfs.

Page 6 of 9

E. LEVEE/FLOODWALL (Continued)
8. INTERIOR DRAINAGE (Continued)
E. Which flooding conditions were analyzed?
Gravity flow (Interior Watershed)
Common storm (River Watershed)
Historical ponding probability
Coastal wave overtopping

Yes
Yes
Yes
Yes

No
No
No
No

If "No" for any of the above, attach explanation.
F. Interior drainage has been analyzed based on joint probability of interior and exterior flooding and the capacities of pumping and
outlet facilities to provide the established level of design.
Yes
No
If "No," attach explanation.

DRAFT

G. The rate of seepage through the levee system for the base flood is:

cfs.

H. The length of levee system used to drive this seepage rate in item G:

ft.

I. Will pumping station be used for interior drainage?
Yes

No

If "Yes," include the number of pumping stations:
For each pumping station, list:

PUMPING STATION #1

PUMPING STATION #2

The number of pumps
The ponding storage capacity

The maximum pumping rate
The maximum pumping head
The pumping starting elevation

The pumping stopping elevation
Is the discharge facility protected?
Is there a flood warning plan?
How much time is available between the
trigger to operate the pump station and
potential flooding?

Will the operation be automatic?
Yes
No
If the pumps are electric, are there backup power sources?
Yes
No
Include a copy of supporting documentation of data and analysis. Provide a map showing the flooded area and maximum ponding
elevations for all interior watersheds that result in flooding.
9. OTHER DESIGN CRITIERIA
A. The following items have been addressed as stated:
is
is not a problem
Liquefaction
is
is not a problem
Hydrocompaction
Heave differential movement due to soils of high shrink/swell

is

is not a problem

B. For each of these problems, state the basic facts and corrective action taken:

Attach supporting documentation.
FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

Page 7 of 9

E. LEVEE/FLOODWALL (Continued)
9. OTHER DESIGN CRITIERIA (Continued)
C. If the levee/floodwall is new or enlarged, will the structure adversely impact flood levels and/or flow velocities waterside of the
structure?
Yes
No
D. Sediment Transport Considerations
Was sediment transport considered?
Yes (If "Yes," then fill out Section F (Sediment Transport) of Form 3)
No (If "No," then attach your explanation for why sediment transport was not considered)
10. OPERATIONAL PLAN AND CRITIERIA
A. Are the planned/installed works in full compliance with Part 65.10 of the NFIP Regulations?
Yes

No

B. Does the operation plan incorporate all the provisions for closure devices as required in Paragraph 65.10(c)(1) of the NFIP
regulations?
Yes
No

DRAFT

C. Does the operation plan incorporate all the provisions for interior drainage as required in Paragraph 65.10(c)(2) of the NFIP
regulations?
Yes
No
If "No" for any of the above, please attach supporting documentation.
11. MAINTENANCE PLAN

Please attach a copy of the formal Maintenance Plan for the levee/floodwall.
12. OPERATIONAL AND MAINTENANCE PLAN

Please attach a copy of the formal Operations and Maintenance Plan for the levee/floodwall.

CERTIFICATION OF THE LEVEE DOCUMENTATION

This certification is to be signed and sealed by a licensed registered professional engineer authorized by law to certify elevation
information data, hydrologic and hydraulic analysis, and any other supporting information as per NFIP regulations paragraph
65.10(e) and as described in the MT-2 Forms Instructions. All documents submitted in support of this request are correct to the best
of my knowledge. I understand that any false statement may be punishable by fine or imprisonment under Title 18 of the United
States Code, Section 1001.
Certifier's Name:

License No.:

Company Name:

Telephone No.:

Signature:

Date:

Expiration Date:
Fax No.:

E-mail Address:

F. SEDIMENT TRANSPORT
Flooding Source:
Name of Structure:
If there is any indication from historical records that sediment transport (including scour and deposition) can affect the Base Flood
Elevation (BFE); and/or based on the stream morphology, vegetative cover, development of the watershed and bank conditions,
there is a potential for debris and sediment transport (including scour and deposition) to affect the BFEs, then provide the following
information along with the supporting documentation:
Sediment load associated with the base flood discharge: Volume

acres-feet.

Debris load associated with the base flood discharge:

acres-feet.

Sediment transport rate

Volume

(percent concentration by volume)

Method used to estimate sediment transport:
FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

Page 8 of 9

F. SEDIMENT TRANSPORT (Continued)
Most sediment transport formulas are intended for a range of hydraulic conditions and sediment sizes; attach a detailed explanation
for using the selected method.
Method used to estimate scour and/or deposition:
Method used to revise hydraulic or hydrologic analysis (model) to account for sediment transport:
Please note that bulked flows are used to evaluate the performance of a structure during the base flood; however, FEMA does not
map BFEs based on bulked flows.
If a sediment analysis has not been performed, an explanation as to why sediment transport (including scour and deposition) will not
affect the BFEs or structures must be provided.

DRAFT
FEMA Form FF-206-FY-21-102 (formerly 086-0-27B) (1/24)

Page 9 of 9