 U.S. Department of Transportation Federal Highway Administration |
MEMORANDUM |
| Subject: | ACTION: Backwater Criterion for Hydraulic Design of Structures | Date: | APR 21, 1992 |
| From: | Associate Administrator for Program Development | Reply to Attn. of: | HNG-31 |
| To: | Regional Federal Highway Administrators Federal Lands Highway Program Administrator |
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Our April 2, 1986, memorandum, Subject: Design Standards for Highways in National Flood Insurance Program Mapped Floodplains, which provided guidance on the use of the 1-foot standard backwater criterion in the hydraulic design of structures over streams, is hereby rescinded for all except Interstate completion and Interstate new construction and reconstruction projects. For all other projects, State highway agencies may use backwater criterion determined in accordance with their respective laws.
/S/ Original signed by
Anthony R. Kane