Form 81-89A Riverine Hydrology & Hydraulics Form

DEPARTMENT OF HOMELAND SECURITY
FEDERAL EMERGENCY MANAGEMENT AGENCY

O.M.B. NO. 1660-0016
Expires August 31, 2007

RIVERINE HYDROLOGY & HYDRAULICS FORM

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 a vaild OMB control number appears in the upper right corner of this form.
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.
Flooding Source:
Note: Fill out one form for each flooding source studied.
A. HYDROLOGY

1. Reason for New Hydrologic Analysis (check all that apply)
Not revised (skip to section 2)

No existing analysis

Improved data

Alternative methodology

Proposed Conditions (CLOMR)

Changed physical condition of watershed

2. Comparison of Representative 1%-Annual-Chance Discharges
Location

Drainage Area (Sq. Mi.)

FIS (cfs)

Revised (cfs)

3. Methodology for New Hydrologic Analysis (check all that apply)
Statistical Analysis of Gage Records

Precipitation/runoff Model

Regional Regression
Equations

Other (please attach description)

(TR-20, HEC-1, HEC-HMS, etc.)

Please enclose all relevent models in digital format, maps, computations (including computation of parameters), and documentation to support
the new analysis. the document, "Numerical Models Accepted by FEMA for NFIP Usage" lists the models accepted by FEMA. This
document can be found at: http:www.fema.gov/mit/tsd/en_modl.htm.
4. Review/Approval of Analysis.
If your community requires a regional, state, or federal agency to review the hydrologic analysis, please attach evidence of approval/review.
5. Impacts of Sediment Transport on Hydrology
Was sediment transport considered?

Yes

No

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

1. Reach to be Revised

Water-Surface Elevations (ft.)
Description

Cross Section

Proposed/Revised

Effective

Downstream Limit
Upstream Limit
2. Hydraulic Method Used
Hydraulic Analysis
FEMA Form 81-89A, JAN 07

HEC-2, HEC-RAS, Other (Attach description)
MT-2 Form 2 Page 1 of 2

B. HYDRAULICS (continued)

3. Pre-Submittal Review of Hydraulic Models
FEMA has developed two review programs, CHECK-2 and CHECK-RAS to aid in the review of HEC-2 and HEC-RAS hydraulic models,
respectively. These review programs verify that the hydraulic estimates and assumptions in the model data are in accordance with NFIP
requirements, and that the data are comparable with the assumptions and limitations of HEC-2/HEC-RAS. CHECK-2 and CHECK-RAS identify
areas of potential error or concern. These tools do not replace engineering judgement. CHECK-2 and CHECK-RAS can be downloaded from
http://www.fema.gov/mit/tsd/frm_soft.htm. We recommend that you review your HEC-2 and HEC-RAS models with CHECK-2 and CHECKRAS. If you disagree with a message, please attach an explanation of why the message is not valid in this case. Review of your submittal and
resolution of valid modeling discrepancies will result in reduced review time.
HEC-2/HEC-RAS models reviewed with CHECK-2/CHECK-RAS?

Yes

No

4. Models Submitted
Duplicate Effective Model*

Natural File Name

Floodway File Name

Corrective Effective Model*

Natural File Name

Floodway File Name

Existing or Pre-Project Conditions Model

Natural File Name

Floodway File Name

Revised or Post-Project Conditions Model

Natural File Name

Floodway File Name

Other - (attach description)

Natural File Name

Floodway File Name

*Not required for revisions to approximate 1%-annual-chance floodplains (Zone A) - for details, refer to the corresponding section of the
instructions.
The document "Numerical Models Accepted by FEMA for NFIP Usage" list the models accepted by FEMA. This document can be found at:
http://www.fema.gov/mit/tsd/en_modl.htm.
C. MAPPING REQUIREMENTS

A certified topographic map must be submitted showing the following information (where applicable): the boundaries of the effective, existing,
and proposed conditions 1%-annual-chance floodplain (for approximate Zone A revisions) or the boundaries of the 1%-and 0.2%-annual-chance
floodplains and regulatory floodway (for detailed Zone AE, AO, and AH revisions); location and alignment of all cross sections with stationing
control indicated; stream, road, and other alignments (e.g. dams, levees, etc.); current community easements and boundaries; boundaries of the
requester's property; certification of a registered professional engineer registered in the subject State; location and description of reference marks;
and the referenced verticle datum (NGVD, NAVD, etc.).
Note that the boundaries of the existing or proposed conditions floodplains and regulatory floodway to be shown on the revised FIRM and/or
FBFM must tie-in with the effective floodplain and regulatory floodway boundaries. Please attach a copy of the effective FIRM and/or FBFM,
annotated to show the boundaries of the revised 1%-and 0.2%-annual-chance floodplains and regulatory floodway that tie-in with the boundaries
of the effective 1%-and 0.2%-annual-chance floodplain and regulatory floodway at the upstream and downstream limits of the area of revison.
D. COMMON REGULATORY REQUIREMENTS

1. For CLOMR Requests, do Base Flood Elevations (BFEs) Increase?

Yes

No

For CLOMR requests, if either of the following is true, please submit evidence of compliance with Section 65.12 of the NFIP regulations:
* The proposed project encroaches upon a regulatory floodway and would result in increases above 0.00 foot.
* The proposed project encroaches upon a SFHA with BFEs established and would result in increases above 1.00 foot.
2. Does the request involve the placement of proposed placement of fill?

Yes

No

If Yes, the community must acknowledge that the area to be removed from the special flood hazard area, to include any structures or proposed
structures, meets (will meet) all of the standards of the local floodplain ordinances, and is (will be) reasonably safe from flooding in
accordance with NFIP regulation 44 CFR 65.2(c). Please see the MT-2instructions for more information.
3. For LOMR requests, is the regulatoryfloodway being revised?

Yes

No

If Yes, attach evidence of regulatory floodway revised notification. As per paragraph 65.7(b)(1) of the NFIP regulations, notification is
required for requests involving revsions to the regulatory floodway. (Not required for revisions to approximate 1%-annual-chance floodplains
(studied Zone A designation) unless a regulatory floodway is being added. Elements and examles of regulatory floodway revision notification
can be found in the MT-2 Form 2 instructions.)
4. For LOMR requests, does this request require property owner notification and acceptance of BFE increase?

Yes

No

If Yes, please attach proof of property owner notification and acceptance (if available). Elements of and examples of property owner
notification can be found in the MT-2 form 2 instructions.
FEMA Form 81-89A, JAN 07

MT-2 Form 2 Page 2 of 2