Page 1 of 5 Issue Date: September 22, 2008 Effective Date: September 29, 2008 Case No.: 08-09-1758P LOMR-APP Washington, D.C. 20472 Federal Emergency Management Agency LETTER OF MAP REVISION DETERMINATION DOCUMENT COMMUNITY AND REVISION INFORMATION PROJECT DESCRIPTION COMMUNITY APPROXIMATE LATITUDE & LONGITUDE: 34.664, -118.137 SOURCE: USGS QUADRANGLE DATUM: NAD 83 City of Palmdale Los Angeles County California COMMUNITY NO.: 060144 BASIS OF REQUEST IDENTIFIER NO PROJECT FLOOD INSURANCE STUDY REPORT UPDATE Amargosa Creek Avenue M - Avenue K Reissuance ANNOTATED MAPPING ENCLOSURES ANNOTATED STUDY ENCLOSURES NO REVISION TO THE EFFECTIVE FIRM* DATE OF EFFECTIVE FLOOD INSURANCE STUDY REPORT: September 26, 2008 SUMMARY OF DISCHARGES TABLE: 7 Enclosures reflect changes to flooding sources affected by this revision. * - Flood Insurance Rate Map FLOODING SOURCE(S) & REVISED REACH(ES) Amargosa Creek Tributary - from just upstream of Southern Pacific Railroad to just upstream of Valleyline Drive SUMMARY OF REVISIONS This Letter of Map Revision (LOMR) is an update to Volume 2, Pages 112 - 113, of the Flood Insurance Study (FIS) report for Los Angeles County and its incorporated areas, scheduled to become effective on September 26, 2008. The new FIS report only partially incorporated modifications made to the Summary of Discharges Table 7 from a LOMR dated May 20, 2005 (Case No. 04-09-0375P), which revised the Special Flood Hazard Areas (SFHAs), the areas that would be inundated by the base (1-percent-annual-chance) flood, and the Summary of Discharges Table. This LOMR does not revise the SFHA boundaries or discharges from the May 20 LOMR along the revised reach. DETERMINATION This document provides the determination from the Department of Homeland Security's Federal Emergency Management Agency (FEMA) regarding a request for a Letter of Map Revision for the area described above. Using the information submitted, we have determined that a revision to the flood hazards depicted in the Flood Insurance Study report and/or National Flood Insurance Program (NFIP) map is warranted. This document revises the effective NFIP map, as indicated in the attached documentation. Please use the enclosed annotated map panels revised by this LOMR for floodplain management purposes and for all flood insurance policies and renewals in your community. This determination is based on the flood data presently available. The enclosed documents provide additional information regarding this determination. If you have any questions about this document, please contact the FEMA Map Assistance Center toll free at 1-877-336-2627 (1-877-FEMA MAP) or by letter addressed to the LOMR Depot, 3601 Eisenhower Avenue, Alexandria, VA 22304. Additional Information about the NFIP is available on our website at http://www.fema.gov/nfip. 112553 10.3.1.08091758 102-D Craig S. Kennedy, CFM, Program Specialist Engineering Management Branch Mitigation Directorate Page 2 of 5 Issue Date: September 22, 2008 Effective Date: September 29, 2008 Case No.: 08-09-1758P LOMR-APP Washington, D.C. 20472 Federal Emergency Management Agency LETTER OF MAP REVISION DETERMINATION DOCUMENT (CONTINUED) OTHER COMMUNITIES AFFECTED BY THIS REVISION CID Number: 060672 Name: City of Lancaster, California AFFECTED MAP PANELS AFFECTED PORTIONS OF THE FLOOD INSURANCE STUDY REPORT DATE OF EFFECTIVE FLOOD INSURANCE STUDY REPORT: September 26, 2008 SUMMARY OF DISCHARGES TABLE: 7 NO REVISION TO THE EFFECTIVE FIRM This determination is based on the flood data presently available. The enclosed documents provide additional information regarding this determination. If you have any questions about this document, please contact the FEMA Map Assistance Center toll free at 1-877-336-2627 (1-877-FEMA MAP) or by letter addressed to the LOMR Depot, 3601 Eisenhower Avenue, Alexandria, VA 22304. Additional Information about the NFIP is available on our website at http://www.fema.gov/nfip. 112553 10.3.1.08091758 102-D Craig S. Kennedy, CFM, Program Specialist Engineering Management Branch Mitigation Directorate Page 3 of 5 Issue Date: September 22, 2008 Effective Date: September 29, 2008 Case No.: 08-09-1758P LOMR-APP Washington, D.C. 20472 Federal Emergency Management Agency LETTER OF MAP REVISION DETERMINATION DOCUMENT (CONTINUED) COMMUNITY INFORMATION APPLICABLE NFIP REGULATIONS/COMMUNITY OBLIGATION We have made this determination pursuant to Section 206 of the Flood Disaster Protection Act of 1973 (P.L. 93-234) and in accordance with the National Flood Insurance Act of 1968, as amended (Title XIII of the Housing and Urban Development Act of 1968, P.L. 90-448), 42 U.S.C. 4001-4128, and 44 CFR Part 65. Pursuant to Section 1361 of the National Flood Insurance Act of 1968, as amended, communities participating in the NFIP are required to adopt and enforce floodplain management regulations that meet or exceed NFIP criteria. These criteria, including adoption of the FIS report and FIRM, and the modifications made by this LOMR, are the minimum requirements for continued NFIP participation and do not supersede more stringent State/Commonwealth or local requirements to which the regulations apply. NFIP regulations Subparagraph 60.3(b)(7) requires communities to ensure that the flood-carrying capacity within the altered or relocated portion of any watercourse is maintained. This provision is incorporated into your community’s existing floodplain management ordinances; therefore, responsibility for maintenance of the altered or relocated watercourse, including any related appurtenances such as bridges, culverts, and other drainage structures, rests with your community. We may request that your community submit a description and schedule of maintenance activities necessary to ensure this requirement. COMMUNITY REMINDERS Your community must regulate all proposed floodplain development and ensure that permits required by Federal and/or State law have been obtained. State or community officials, based on knowledge of local conditions and in the interest of safety, may set higher standards for construction or may limit development in floodplain areas. If your State or community has adopted more restrictive or comprehensive floodplain management criteria, those criteria take precedence over the minimum NFIP requirements. We will not print and distribute this LOMR to primary users, such as local insurance agents or mortgage lenders; instead, the community will serve as a repository for the new data. We encourage you to disseminate the information in this LOMR by preparing a news release for publication in your community’s newspaper that describes the revision and explains how your community will provide the data and help interpret the NFIP maps. In that way, interested persons, such as property owners, insurance agents, and mortgage lenders, can benefit from the information. This determination is based on the flood data presently available. The enclosed documents provide additional information regarding this determination. If you have any questions about this document, please contact the FEMA Map Assistance Center toll free at 1-877-336-2627 (1-877-FEMA MAP) or by letter addressed to the LOMR Depot, 3601 Eisenhower Avenue, Alexandria, VA 22304. Additional Information about the NFIP is available on our website at http://www.fema.gov/nfip. 112553 10.3.1.08091758 102-D Craig S. Kennedy, CFM, Program Specialist Engineering Management Branch Mitigation Directorate Page 4 of 5 Issue Date: September 22, 2008 Effective Date: September 29, 2008 Case No.: 08-09-1758P LOMR-APP Washington, D.C. 20472 Federal Emergency Management Agency LETTER OF MAP REVISION DETERMINATION DOCUMENT (CONTINUED) COMMUNITY INFORMATION (CONTINUED) We have designated a Consultation Coordination Officer (CCO) to assist your community. The CCO will be the primary liaison between your community and FEMA. For information regarding your CCO, please contact: Ms. Sally M. Ziolkowski Director, Mitigation Division Federal Emergency Management Agency, Region IX 1111 Broadway Street, Suite 1200 Oakland, CA 94607-4052 (510) 627-7175 STATUS OF THE COMMUNITY NFIP MAPS We are processing a FIRM and FIS report in countywide format for Los Angeles County, California and Incorporated Areas. The countywide FIRM and FIS report, which include flood hazard information for your community, will become effective on September 26, 2008. Because the effective date has already been established, we will not incorporate the modifications made by this LOMR into the countywide FIS report before it becomes effective. However, the modifications made by this LOMR will supersede the new countywide FIS report after it becomes effective. This determination is based on the flood data presently available. The enclosed documents provide additional information regarding this determination. If you have any questions about this document, please contact the FEMA Map Assistance Center toll free at 1-877-336-2627 (1-877-FEMA MAP) or by letter addressed to the LOMR Depot, 3601 Eisenhower Avenue, Alexandria, VA 22304. Additional Information about the NFIP is available on our website at http://www.fema.gov/nfip. 112553 10.3.1.08091758 102-D Craig S. Kennedy, CFM, Program Specialist Engineering Management Branch Mitigation Directorate Page 5 of 5 Issue Date: September 22, 2008 Effective Date: September 29, 2008 Case No.: 08-09-1758P LOMR-APP Washington, D.C. 20472 Federal Emergency Management Agency LETTER OF MAP REVISION DETERMINATION DOCUMENT (CONTINUED) PUBLIC NOTIFICATION OF REVISION This revision will become effective on September 29, 2008. Any requests to review or alter this determination should be made within 30 days and must be based on scientific or technical data. This determination is based on the flood data presently available. The enclosed documents provide additional information regarding this determination. If you have any questions about this document, please contact the FEMA Map Assistance Center toll free at 1-877-336-2627 (1-877-FEMA MAP) or by letter addressed to the LOMR Depot, 3601 Eisenhower Avenue, Alexandria, VA 22304. Additional Information about the NFIP is available on our website at http://www.fema.gov/nfip. 112553 10.3.1.08091758 102-D Craig S. Kennedy, CFM, Program Specialist Engineering Management Branch Mitigation Directorate Table 7 – SUMMARY OF PEAK DISCHARGES Peak Discharges (cfs) Drainage Flooding Source Area and Location (sq. mi.) 10-Percent-Annual-Chance 2-Percent-Annual-Chance 1-Percent-Annual-Chance 0.2-Percent-Annual-Chance 3,500 feet Northeast of the Intersection of Via Montana and Country Club Drive 0.7 -- -- 600 -- At the Intersection of Alameda Avenue and Main Street 1.2 -- -- 750 -- At the Intersection of Chestnut and Lake Streets 1.3 -- -- 670 -- Amargosa Creek At Outlet of Ritter Ranch Detention Pond 23.8 -- -- 1,856 -- At Vineyard Ranch 26.5 -- -- 2,063 -- At Elisabeth Lake Ford Crossing 28.6 -- -- 2,288 -- REVISED DATA At 25th Street West Bridge 30.0 -- -- 2,341 -- At 10th Street West 32.0 -- -- 2,364 -- Intersection of Avenue K-8 and 10th Street West 35.7 -- -- 2,460 -- Amargosa Creek Tributary Intersection of Avenue I and Spearman Avenue 5.6 -- -- 212 -- Intersection of Avenue L and 3rd Street East 1.2 -- -- 95 -- 112 Table 7 – SUMMARY OF PEAK DISCHARGES Peak Discharges (cfs) Drainage Flooding Source Area and Location (sq. mi.) 10-Percent-Annual-Chance 2-Percent-Annual-Chance 1-Percent-Annual-Chance 0.2-Percent-Annual-Chance Amargosa Creek Tributary (continued) Avenue M and Valleyline Drive 0.6 -- -- 89 -- Anaverde Creek REVISED DATA California Aqueduct 8.25 -- -- 2,440 -- 0.75 Miles Downstream of California Aqueduct 11.79 -- -- 3,050 -- 1.47 Miles Downstream of California Aqueduct 12.79 -- -- 3,200 -- 1.85 Miles Downstream of California Aqueduct 15.66 -- -- 3,630 -- Antelope Freeway 16.35 -- -- 3,730 -- Anaverde Creek Tributary Division Street between Avenue P and Avenue P-8 1.4 300 1,100 1,600 3,000 Antelope Valley Amargosa Creek at 90th Street West 6.9 580 2,000 3,100 4,500 113