FEDERAL EMERGENCY MANAGEMENT AGENCY ACCEPTED NUMERICAL MODELS for the National Flood Insurance Program John Liou FEMA Region VIII

FEDERAL EMERGENCY MANAGEMENT AGENCY Accepted Numerical Models OverviewOverview Model Types/categoriesModel Types/categories Policy and GuidancePolicy and Guidance Accepted modelsAccepted models

FEDERAL EMERGENCY MANAGEMENT AGENCY Model Types/Categories Four sub-categoriesFour sub-categories –Coastal –Hydrologic –Hydraulic –Statistical Up-to-date list and guidance available for download on FEMA’s Flood Hazard Mapping Web siteUp-to-date list and guidance available for download on FEMA’s Flood Hazard Mapping Web site – /en_modl.htm /en_modl.htmhttp:// /en_modl.htm

FEDERAL EMERGENCY MANAGEMENT AGENCY Accepted Numerical Models: Overview Computer models accepted by FEMA for NFIP usage (to perform H&H analyses)Computer models accepted by FEMA for NFIP usage (to perform H&H analyses) –Includes nationally and locally approved models All models on the List meet the requirements of CFR 65.6(a)(6)All models on the List meet the requirements of CFR 65.6(a)(6) –Models must have been reviewed and accepted by a government agency The agency must test the model with measured data or compare the model to other similar models on the List. A summary of the testing methods and results must be provided to FEMA.The agency must test the model with measured data or compare the model to other similar models on the List. A summary of the testing methods and results must be provided to FEMA. –Must be well documented –Must be available to FEMA and all parties impacted by mapping developed or amended through program use

FEDERAL EMERGENCY MANAGEMENT AGENCY Policy and Guidance In addition to the guidance provided in the NFIP regulations, additional policy information and guidance is provided, including the following:In addition to the guidance provided in the NFIP regulations, additional policy information and guidance is provided, including the following: –July 13, 1999 Memorandum providing FEMA's “Policy for Accepting Numerical Models for Use in the NFIP” –“Clarification of National Flood Insurance Program Criteria for Certification of Coastal, Hydrologic, and Hydraulic Models” –“Conditional Permission to Disclose Source Codes and User Manuals” –“Exhibit A - Disclosure Agreement Regarding Source Code and User Manual”

FEDERAL EMERGENCY MANAGEMENT AGENCY Accepted Hydrologic Models Examples TYPEPROGRAM Single EventHEC and up (May 1991) HEC-HMS 1.1 and up (Mar. 1988) TR-20 (Feb. 1992) Continuous EventDR3M (Oct. 1993) HSPF and up (Dec. 1993) MIKE 11 RR (June 1999)

FEDERAL EMERGENCY MANAGEMENT AGENCY Accepted Hydraulic Models Examples MODEL TYPEPROGRAM One-dimensional Steady FlowHEC-RAS 2.2 (Sept. 1988) HEC (May 1991) WSPRO (June 1998 and up) One-dimensional Unsteady FlowHEC-RAS 3.0 UNET 4.0 (April 2001) MIKE 11 HD (June 1999) Two-dimensional Steady/Unsteady Flow TABS RMA2 v. 4.3 (Oct. 1996) and RMA4 v. 4.5 (July 2000) FESWMS 2DH 1.1 and up (June 1995) FLO-2D v (Dec. 2000)

FEDERAL EMERGENCY MANAGEMENT AGENCY Accepted Statistical Models MODEL TYPEPROGRAM HEC-FFA 3.1 (Feb. 1995) PEAKFQ 2.4 and up (April 1998) FAN

FEDERAL EMERGENCY MANAGEMENT AGENCY Locally Accepted H&H Models - Examples MODEL TYPEPROGRAM HydrologicColorado Urban Hydrograph Procedure (CUHPF/PC) (May 1996 and May 2002) Only accepted for usage and the default parameters in the model applicable within the Denver, Colorado, metro area HydraulicDHM 21 (Aug. 1987) Only accepted for usage within the San Bernardino County Flood Control District, California

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