Form 086-0-27B Riverine Structures Form

Revision to National Flood Insurance Program Maps: Application Forms and Instructions for LOMRs and CLOMRs

FEMA Form 086-0-27B, Riverine Structures Form

OMB: 1660-0016

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DEPARTMENT OF HOMELAND SECURITY
FEDERAL EMERGENCY MANAGEMENT AGENCY

O.M.B. NO. 1660·0016
Expires December 31, 2010

RIVERINE STRUCTURES FORM

PAPERWORK BURDEN DISCLOSURE NOTICE
response, The burden estimale includes the time for reviewing instructions,
Public reporting burden for this form is estimated to average 7 hour
searching existing data sources, gathering and maintaining the
data, and completing, reviewing, and submitting the form, You are not
required to respond to this collection of information unless a valid OMB control number appears in the upper!i~ht corner of this form, Send comments
regarding the
of the burden estimate and any l':1 ~~
'''' for reducing this burden to: Information ("
Management, Department of
Homeland Security,
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.
Flooding Source:
Note Fill out one form for each flooding source studied,
A. GENERAL
Complete and submit the appropriate seclion(s) for each Structure listed below:
Channelization .",,,,., ,,,,complete Section B
BridgefCulvert",,,,, , , "complete Section C
Dam."" ,.,. " " , .. ,,', ",,,,complete Section D
LeveefFloodwall"""" , ,complete Section E
Sediment Transport" ",complete Section F (if
Description of Structure
1, Name of Structure:
Type (check one):

Channelization

Bridge/Culvert

Levee/Floodwall

Bridge/Culvert

Levee/Floodwall

Bridge/Culvert

Levee/Floodwall

Dam

Location of Structure:
Downstream LimiUCross Section:
Upstream LimiUCross Section:

2, Name of Structure:
Type (check one)

Channelization

Dam

Location of Structure:
Downstream LimiUCross Section
Upstream LimitlCross Section:

3. Name of Structure:
(check one):

Channelization

Dam

Location of Structure:
Downstream LimitlCross Section:
Upstream LimitiCross Section:

NOTE: FOR MORE STRUCTURES, ATTACH ADDITIONAL PAGES AS NEEDED.
DHS/FEMA Form 086-0..27B, AUG 2010

PREVIOUSLY FF81-89B

MT-2 Form 3

Page 1 of 9

B. CHANNELIZATION
Flooding Source:

Name of Structure: _ _ _ _ _ _ _ _ _ _ __

1. Hydraulic Considerations

The channel was designed to carry _ __

_ _ _"year flood.

(cfs) and/or the

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

Other locations (specify):

Outlet of

chann~1

At Drop Structures

At Transitions

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):
D

Levees [Attach Section E )Levee/Floodwall)]

Transitions in cross sectional geometry

DWeir

D
D

Drop structures

Debris basin/design basin [Attach Section D (Dam/Basin)]

Superelevated sections

Energy dissipator

Other (Describe):

4. Sediment Transport Considerations
Are the hydraulics of the channel affected by sediment transport? DYes

If Yes, then fill out Section F (Sediment Transport) of Form 3. If No, then attach explanation.
Flooding Source:
Name of Structure:
D

Bridge/culvert not modeled in the FIS

Modified bridge/culvert previously modeled in the FIS

New analysis of bridge/culvert previously modeled in the FIS

2. Hydraulic model used to analyze the structure (e.g., HEC"2 with special bridge routine, WSPRO, HY8):
If different 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):
D

Dimensions (height, width, span, radius, length)

Erosion Protection

Shape (culverts only)

Low Chord Elevations - Upstream and Downstream

Material

Top of Road Elevations - Upstream and Downstream

Beveling or Rounding

Structure Invert Elevations - Upstream and Downstream

Wing Wall Angle

Stream Invert Elevation - Upstream and Downstream

Skew Angle

Cross-Section Locations

Distance Between Cross Sections

4. Sediment Transport Considerations
Are the hydraulics of the structure affected by sediment transport? DYes

If yes, then fill out Section F (Sediment Transport) of Form 3. If no, then attach an explanation.

DHS/FEMA Form 086-0·27B, AUG 2010

PREVIOUS!.Y FF81·89B

MT·2 Form 3

Page 2 of 9

D. DAM
Flooding Source: _ _ _ _ _ _ _ _ __
Name of Structure: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

1. This request is for (check one):

Existing dam

New dam/basin

Modification of existing dam/basin

2. The dam/basin was designed by (check one):

Federal agency

State agency

Local government agency

Federal Dam

State Dam

Name of the agency or organization:

3. The dam was permitted as (check one):

Provide the permit or identification number (10) for the dam and the appropriate permitting agency or organization
Permitting Agency or Organization _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Permit or 10 number
D

Local Government Dam

Private Dam

Provide related drawings, specifications and supporting design information.
DYes

4 Does the project involve hydrology?

If yes, complete the Riverine Hydrology & Hydraulics Form (Form 2).
Was the damlbasin designed using critical duration storm? (Must account for the maximum volume of runoff?)
D

Yes, provide supporting documentation with your completed Form 2.

No, provide written explanation and justification for not using the critical duration storm.

5. Does the submittal include debris/sediment yield analysis?

DYes

If Yes, then fill out Section F (Sediment Transport).
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?
DYes

If Yes, complete the Riverine Hydrology & Hydraulic Form (Form 2) and complete the table below.

FEQUENCY (% annual
chance)

Stillwater Elevation Behind the Dam

REVISED

£is

1O-year (10%)
50-year (2%)
1OO-year (1 %)

500-year (0.2%)
Normal Pool Elevation

7. Please attach a copy of the formal Operation and Maintenance Plan

E. LEVEE/FLOODWALL
1. System Elements (continued)
a. This levee/Floodwal1 analysis is based on
(check one):

upgrading of an existing
levee/floodwall system

reanalysis of an existing D
levee/floodwall system

a newly constructed
levee/f1oodwall system

b. Levee elements and locations are (check one):
D

earthen embankment, dike, berm, etc.

Station

structural f100dwall

Station

other (describe)

Station

DHS/fEMA form 086-0-278, AUG 2010

PREVIOUSLY ff81-898

MT-2 form 3

Pago 3 of 9

c, Structural Type (check

one):

monolithic cast-in place reinforcement concrete

reinforced concrete masonry block D

sheet piling

other (describe)

d, Has the levee/floodwall system been certified by a Federal agency to provide protection from the base flood?

Yes

If yes, by which agency? _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

e, Attach certified drawings containing the following information (indicate drawing sheet numbers):
1, Plan of the levee embankment and f100dwall structures.

Sheet Numbers:

2, A profile of the levee/floodwall system showing the

Base Flood Elevation (BFE), levee andlor wall crest and
foundation, and closure locations for the total levee system,

Sheet Numbers:

3. A profile of the BFE, closure opening outlet and inlet
invert elevations, type and size of opening, and kind of closure,

Sheet Numbers:

4, A layout detail for the embankment protection measures.

Sheet Numbers:

5, Location, layout, and size and shape of the levee embankment

features, foundation treatment, floodwall structure, closure structures Sheet Numbers:

and pump stations.

2. Freeboard
a. The minimum freeboard provided above the BFE is:
~

3.0 feet or more at the downstream end and throughout
35 feet or more at the upstream end
4.0 feet within 100 feet upstream of all structures andlor constrictions

Yes

DYes

Ves

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),

D Yes

2.0 feet above the 1%-annual-chance stillwater surge elevation

D Ves

Please note, occasionally exceptions are made to the minimum freeboard requirements, If an exception is required, attach documentation
addressing Paragraph 6510(b)(1 )(ii» of the NFIP Regulations,
If No Is answered to any of the above, please attach an explanation.
can affect the BFE?

b. Is there an indication from historical records that

DVes

If Yes, provide Ice-jam analysis profile and evidence that the minimum freeboard discussed above still exist.

a. Openings through the levee system (check one):

exist

does not exist

If opening exist. list all closures:

Opening Type

Channel Station

Highest Elevation for
Openina Invert

Type of Closure Device

(Extend table on an added sheet as needed and reference)

DHS/FEMA Form 086-0-27B, AUG 2010

PREVIOUSLY FF81-89B

MT-2 Form 3

Page 4 of 9

E. LEVEE/FLOODWALL (continued)
Note: Geotechnical and geologic data
In addition to the required detailed analysis report, data obtained during field and laboratory investigations and used in the design analysis
for the following system features should be submitted in a tabulation summery form. (Reference U.S. Army Corps of Engineers [USACE]
EM-110-2-1906 Form 2086)1
4. .E.mba(~m!.!Dt E[Ql!l!;;liQD
a. The maximum levee slope landside is:
b. The maximum levee slope floodside is:
(max.)

(min) to

c. The range of velocities along the levee during the base flood is:
d. Embankment material is protected by (describe what kind):
e. Riprap Design Parameters (check one):

Velocity

Tractive stress

Flow
Depth

Curve or
Straight

Attach references
.",

Reach

Sta

Sia

Stone Riprap

0100

D 50

Thickness

Depth of Toedown

4. Embar~m!.!nl E[QlediQO CQolim,!!lQ
f. Is a bedding analysis and design attached

Yes

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:

ft.

, height

Sta.:

Limiting foundation soil strength
Sta.:

,depth

Strength G'"

degrees, c '"

Slope: SS

(h) to

psf
(v)

(Repeat as needed on an added sheet for additionalloca!ions)
b, Specify the embankment stability analysis methodology used (e.g., circular arc, sliding block, infinite slope, etc.):

c, Summary of stability analysis results:
Case

Loading Conditions

Critical Safety Factor

Critical Min.)

End of construction

1.3

Sudden drawdown

1.0

~flood"'9'

1.4

seepage at flood stage

uake (Case I)
(Reference:

1.4

1,0

USACE EM-111 0-2-1913 Table 6-1)

DHS/fEMA form 086-0·278, AUG 2010

PREVIOUSLY ff81·898

MT·2 form 3

Page 5 of 9

E. LEVEE/FLOODWALL (continued)
DYes

d. Was a seepage analysis for the embarkment performed?

If Yes, describe methodology used :
e. Was a seepage analysis for the foundation performed?

DYes

f. Were uplift pressures at the embankment landside toe checked?

DYes

0
0

g. Were seepage exit gradients checked for piping potential?

DYes

No
No
No
hours.

h. The duration of the base flood hydrograph against the embarkment is
Attach engineering analysis to support construction plans.
6. EIQQdwall aDd EQI,mdaliQD SlaQility

a. Describe analysis submittal based on Code (check one) :

o
o

b. Stability analysis submitted provides for:
c. Load ing included in the analysis where :

o
o
o
o
o

Surcharge-Slope @

Overturning

UBC (1988)

Sliding

Other (specify):

If not, explain :

lateral earth @ PA=
surface

psf; Pp = psf
psf

psf

Wind@Pw=

Seepage (Uplift):

Earthquake @ Peq =

1%-annual-chance significant wave height

ft.

1%-annual-chance significant wave period

sec.

d. Summary of Stability Analysis Results: Factors of Safety.
Itemize for each range in site layout dimension and loading condition limitation for each respective reach .
Criteria (Min)
Loading Condition

Overturn

Sliding

Dead & Wind

1.5

Dead & Soil

1.5

Dead, Soil, Flood , &
Impact

1.5

Dead , Soil, & Seismic

1.3

Sta

Overturn

Sliding

Overturn

Sliding

(Ref: FEMA 114 Sept. 1986; USACE EM 1110-2-25020
Note: Extend table on an added sheet as needed and reference)
e. Foundation bearing strength for each soil type:
Sustained Load (psf)

Bearing Pressure

Short Term Load (psf)

Computed design maximum
Maximum allowable
f. Foundation scour protection

Dis,

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 specific construction elevations to maintain the established
freeboard margin?
DYes
No

b. The computed range of settlement is

FEMA Form 086-0-27B, AUG 2010

ft. to

PREVIOUSLY FF81-89B

ft .

MT-2 Form 3

Page 6 of 9

E. LEVEE/FLOODWALL (continued)

7. Settlement (continued)
Foundation consolidation

c. Settlement of the levee crest is determined to be primarily from:

Embarkment compression

Other (describe):

d. Differential settlement of flood walls

has not been accommodated in the structural design and construction.

has

Attach engineering analysis to support construction plans.

8. Interior Drainage
a. Specify size of each interior watershed:
Draining to pressure conduit:

acres

Draining to ponding area:

acres

b. Relationships Established
Ponding elevation vs. storage

Yes

Ponding elevation vs. gravity flow

Yes

Differential head vs. gravity flow

Yes

c. The river flow duration curve is enclosed:

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

cfs

e. Which flooding conditions were analyzed?
Yes

• Gravity flow (interior Watershed)

DYes

* Common storm (River Watershed)

• Historical ponding probability

Yes

o No

* Coastal wave overtopping

Yes

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 flood protection.
Yes
No If No, attach explanation

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:

I. Will pumping plants be used for Interior drainage?

ft.

Yes

If Yes, include the number of pumping plants:

For each pumping plant. list:

Plant #1

Plant #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 warning
and flooding?
Will the operation be automatic?

FEMA Form 086-0-27B, AUG 2010

Yes

PREVIOUSLY Ff81-89B

MT-2 form 3

Page 7 of 9

E. LEVEE/FLOODWALL (continued)
8. Interior Drainage (continued)
If the pumps are electric, are there backup power sources?

DYes

(Reference: USACE EM-111 0-2-31 01, 3102, 3103, and 3105)
Include a copy of supporting documentation of data and analysis. Provide a map showing the flooded and maximum ponding elevations for all
interior watersheds that result in flooding.

9. Other Desion Criteria
a. The following items have been addressed as stated:
Uquification

Hydrocompaction

is not a problem

Heave differential movement due to soils of high shrink/swell

is not a problem

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

Attach supporting documentation.
c. If the leveellloodwall is new or enlarged, will the structure adversely impact flood levels and/or flow velocities floodside of the structure?
Yes

Attach supporting documentation.

d. Sediment Transport Considerations?

Was sediment transport considered?

Yes

If Yes, then fill out Section F (Sediment Transport). If No, then attach your explanation for why sediment transport was not considered.
10. Operational Plan and Criteria
a. Are the plannedlinstalled works in full compliance with Part 65.10 of the NFIP regulations?

Yes

b. Does the operation plan incorporate all the provisions for closure devices as required in Paragraph 65.1 O(c)(1) of the NFIP regulations?
Yes

c. Does the operation plan incorporate all the provisions for interior drainage as required in Paragraph
Yes
11

of the NFIP regulations?

No If the answer is No to any to the above, please attach supporting documentation.

Maintenance plan
Please attach a copy of the formal maintenance plan for plan for the leveelfloodwall.

12. Operations and Ma.i.o1en.alJ.l6LE'.lM
Please attach a copy of the formal Operations and Maintenance Plan for the leveelfloodwall.

FEMA Form 086-0-278, AUG 2010

PREVIOUSLY ff81·898

MT·2 Form 3

Page 8 of 9

CERTIFICATION OF THE LEVEE DOCUMENTATION

CERTIFICATION BY REGISTERED PROFESSIONAL ENGINEER
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 65.1 O(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
statements may be punishable by fine or imprisonment under Title 18 of the United States Code, Section 1001

License No.

Certifier's Name

{;ompany Name

Signature

elepnone No.

Date

Fax No.

E-Mail Address

Date

F, SEDIMENT TRANSPORT

Flooding Sourca:
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
docu mentation:

Sediment load associated with the base flood discharge: Volume
Debris load associated with the base flood discharge: Volume
Sediment transport rate

acre-feet

-----

_ _ _ _ _ _acre-feet

concentration by volume)

Method used to estimate sediment transport:

---------------------------------------------------------------

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,

fEMA form 086-0-278, AUG 2010

PREVIOUSLY fF81-898

MT·2 Form 3

Page 9 of 9

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File Modified	2010-10-20
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