[Code of Federal Regulations]

[Title 44, Volume 1]

[Revised as of October 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 44CFR65.7]



[Page 345-346]

 

              TITLE 44--EMERGENCY MANAGEMENT AND ASSISTANCE

 

 CHAPTER I--FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND 

                                SECURITY

 

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 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



[[Page 346]]



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]