[Code of Federal Regulations]
[Title 44, Volume 1]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 44CFR65.7]

[Page 344-345]
 
              TITLE 44--EMERGENCY MANAGEMENT AND ASSISTANCE
 
             CHAPTER I--FEDERAL EMERGENCY MANAGEMENT AGENCY
 
PART 65--IDENTIFICATION AND MAPPING OF SPECIAL HAZARD AREAS--Table of Contents
 
Sec. 65.7  Floodway revisions.

    (a) General. Floodway data is developed as part of FEMA Flood 
Insurance Studies and is utilized by communities to select and adopt 
floodways as part of the flood plain management program required by 
Sec. 60.3 of this subchapter. When it has been determined by a community 
that no practicable alternatives exist to revising the boundaries of its 
previously adopted floodway, the procedures below shall be followed.
    (b) Data requirements when base flood elevation changes are 
requested. When a floodway revision is requested in association with a 
change to base flood elevations, the data requirements of Sec. 65.6 
shall also be applicable. In addition, the following documentation shall 
be submitted:
    (1) Copy of a public notice distributed by the community stating the 
community's intent to revise the floodway or a statement by the 
community that it has notified all affected property owners and affected 
adjacent jurisdictions.
    (2) Copy of a letter notifying the appropriate State agency of the 
floodway revision when the State has jurisdiction over the floodway or 
its adoption by communities participating in the NFIP.
    (3) Documentation of the approval of the revised floodway by the 
appropriate State agency (for communities where the State has 
jurisdiction over the floodway or its adoption by communities 
participating in the NFIP).
    (4) Engineering analysis for the revised floodway, as described 
below:
    (i) The floodway analysis must be performed using the hydraulic 
computer model used to determine the proposed base flood elevations.
    (ii) The floodway limits must be set so that neither the effective 
base flood elevations nor the proposed base flood elevations if less 
than the effective base flood elevations, are increased by more than the 
amount specified under

[[Page 345]]

Sec. 60.3 (d)(2). Copies of the input and output data from the original 
and modified computer models must be submitted.
    (5) Delineation of the revised floodway on the same topographic map 
used for the delineation of the revised flood boundaries.
    (c) Data requirements for changes not associated with base flood 
elevation changes. The following data shall be submitted:
    (1) Items described in paragraphs (b) (1) through (3) of this 
section must be submitted.
    (2) Engineering analysis for the revised floodway, as described 
below:
    (i) The original hydraulic computer model used to develop the 
established base flood elevations must be modified to include all 
encroachments that have occurred in the flood plain since the existing 
floodway was developed. If the original hydraulic computer model is not 
available, an alternate hydraulic computer model may be used provided 
the alternate model has been calibrated so as to reproduce the original 
water surface profile of the original hydraulic computer model. The 
alternate model must be then modified to include all encroachments that 
have occurred since the existing floodway was developed.
    (ii) The floodway analysis must be performed with the modified 
computer model using the desired floodway limits.
    (iii) The floodway limits must be set so that combined effects of 
the past encroachments and the new floodway limits do not increase the 
effective base flood elevations by more than the amount specified in 
Sec. 60.3(d)(2). Copies of the input and output data from the original 
and modified computer models must be submitted.
    (3) Delineation of the revised floodway on a copy of the effective 
NFIP map and a suitable topographic map.
    (d) Certification requirements. All analyses submitted shall be 
certified by a registered professional engineer. All topographic data 
shall be certified by a registered professional engineer or licensed 
land surveyor. Certifications are subject to the definition given at 
Sec. 65.2 of this subchapter.
    (e) Submission procedures. All requests that involve changes to 
floodways shall be submitted to the appropriate FEMA Regional Office 
servicing the community's geographic area.

[51 FR 30315, Aug. 25, 1986]