SHIAWASSEE COUNTY, MICHIGAN (ALL JURISDICTIONS) Community Community Community Community Name Number Name Number *ANTRIM, TOWNSHIP OF 261162 NEW LOTHROP, VILLAGE OF 260924 BANCROFT, VILLAGE OF 260520 *OVID, VILLAGE OF 260318 BENNINGTON, TOWNSHIP OF 261163 OWOSSO, CHARTER 260809 BURNS, TOWNSHIP OF 260762 TOWNSHIP OF BYRON, VILLAGE OF 260601 OWOSSO, CITY OF 260596 CALEDONIA, CHARTER 260300 *PERRY, CITY OF 261182 TOWNSHIP OF *PERRY, TOWNSHIP OF 261156 CORUNNA, CITY OF 260602 RUSH TOWNSHIP OF 260522 *DURAND, CITY OF 261181 *SCIOTA, TOWNSHIP OF 261157 *FAIRFIELD, TOWNSHIP OF 261164 SHIAWASSEE, 260523 HAZELTON, TOWNSHIP OF 260925 TOWNSHIP OF Shiawassee County *LAINGSBURG, CITY OF 260950 VENICE, TOWNSHIP OF 261158 *LENNON, VILLAGE OF 261183 VERNON, TOWNSHIP OF 261159 MIDDLEBURY, TOWNSHIP OF 261155 VERNON, VILLAGE OF 260524 *MORRICE, VILLAGE OF 261184 *WOODHULL, 261160 NEW HAVEN, TOWNSHIP OF 260521 TOWNSHIP OF *No Special Flood Hazard Areas Identified Preliminary: FLOOD INSURANCE STUDY NUMBER 26155CV000A NOTICE TO FLOOD INSURANCE STUDY USERS Communities participating in the National Flood Insurance Program have established repositories of flood hazard data for floodplain management and flood insurance purposes. This Flood Insurance Study (FIS) report may not contain all data available within the Community Map Repository. Please contact the Community Map Repository for any additional data. The Federal Emergency Management Agency (FEMA) may revise and republish part or all of this FIS report at any time. In addition, FEMA may revise part of this FIS report by the Letter of Map Revision process, which does not involve republication or redistribution of the FIS report. Therefore, users should consult with community officials and check the Community Map Repository to obtain the most current FIS report components. Selected Flood Insurance Rate Map panels for this community contain information that was previously shown separately on the corresponding Flood Boundary and Floodway Map panels (e.g., floodways, cross sections). In addition, former flood hazard zone designations have been changed as follows: Old Zone(s) New Zone Al through A30 AE B X C X Initial Countywide FIS Effective Date: To Be Determined TABLE OF CONTENT S 1.0 INTRODUCTION ................................................................................................................ 1 1.1 Purpose of Study............................................................................................................. 1 1.2 Authority and Acknowledgments ................................................................................... 2 1.3 Coordination ................................................................................................................... 4 2.0 AREA STUDIED .................................................................................................................. 5 2.1 Scope of Study................................................................................................................ 5 2.2 Community Description.................................................................................................. 6 2.3 Principal Flood Problems................................................................................................ 6 2.4 Flood Protection Measures ............................................................................................. 7 3.0 ENGINEERING METHODS .............................................................................................. 7 3.1 Hydrologic Analyses....................................................................................................... 8 3.2 Hydraulic Analyses....................................................................................................... 11 3.3 Vertical Datum.............................................................................................................. 13 4.0 FLOODPLAIN MANAGEMENT APPLICATIONS ..................................................... 14 4.1 Floodplain Boundaries.................................................................................................. 15 4.2 Floodways..................................................................................................................... 16 5.0 INSURANCE APPLICATIONS ....................................................................................... 21 6.0 FLOOD INSURANCE RATE MAP ................................................................................. 21 7.0 OTHER STUDIES .............................................................................................................. 22 8.0 LOCATION OF DATA ...................................................................................................... 22 9.0 BIBLIOGRAPHY AND REFERENCES ......................................................................... 22 i TABLE OF CONTENTS ( Continued ) FIGURES Figure 1 - Floodway Schematic ........................................................................................................ 17 TABLES Table 1 - Streams Studied by Detailed Methods ................................................................................ 5 Table 2 - Summary of Discharges ...................................................................................................... 9 Table 3 - Vertical Datum Conversion............................................................................................... 14 Table 4 - Floodway Data................................................................................................................... 18 Table 5 - Community Map History................................................................................................... 23 EXHIBITS Exhibit 1 - Flood Profiles Holly Drain Profile 01P Misteguay Creek Profiles 02P-05P Owosso Drain Profiles 06P-08P Shiawassee River Profiles 09P-12P Exhibit 2 - Flood Insurance Rate Map Index Flood Insurance Rate Map ii FLOOD INSURANCE STUDY SHIAWASSEE COUNTY, MICHIGAN (ALL JURISDICTIONS) 1.0 INTRODUCTION 1.1 Purpose of Study This Flood Insurance Study (FIS) revises and updates information on the existence and severity of flood hazards in the geographic area of Shiawassee County, including the Cities of Corunna, Durand, Laingsburg, Owosso, and Perry; the Charter Townships of Caledonia and Owosso; the Townships of Antrim, Bennington, Burns, Fairfield, Hazelton, Middlebury, New Haven, Perry, Rush, Sciota, Shiawassee, Venice, Vernon, and Woodhull; and the Villages of Bancroft, Byron, Lennon, Morrice, New Lothrop, Ovid, and Vernon (referred to collectively herein as Shiawassee County), and aids in the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. This study has developed flood-risk data for various areas of the community that will be used to establish actuarial flood insurance rates and to assist the community in its efforts to promote sound floodplain management. Minimum floodplain management requirements for participation in the National Flood Insurance Program (NFIP) are set forth in the Code of Federal Regulations at 44 CFR, 60.3. Please note that the Village of Lennon is geographically located in Genesee and Shiawassee Counties and the Village of Ovid is geographically located in Clinton and Shiawassee Counties. Only the portions of the Villages of Lennon and Ovid that are located in Shiawassee County are included in this countywide FIS. The FIS report and Flood Insurance Rate Map (FIRM) for areas outside of Shiawassee County are printed separately. Please note that the Cities of Durand, Laingsburg, and Perry; the Villages of Lennon, Morrice, and Ovid; and Townships of Antrim, Fairfield, Perry, Sciota, and Woodhull have no mapped flood hazard areas. In some states or communities, floodplain management criteria or regulations may exist that are more restrictive or comprehensive than the minimum Federal requirements. In such cases, the more restrictive criteria take precedence and the State (or other jurisdictional agency) will be able to explain them. The Digital Flood Insurance Rate Map (DFIRM) and FIS report for this countywide study have been produced in digital format. Flood hazard information was converted to meet the Federal Emergency Management Agency (FEMA) DFIRM database specifications and Geographic Information System (GIS) format requirements. The flood hazard information was created and is 1 provided in a digital format so that it can be incorporated into a local GIS and be accessed more easily by the community. 1.2 Authority and Acknowledgments The sources of authority for this FIS are the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. Precountywide Analyses Information on the authority and acknowledgements for each jurisdiction included in this countywide FIS, as compiled from their previously printed FIS reports, is shown below: Caledonia, The hydrologic and hydraulic analyses for the Charter Township of: Shiawassee River for the November 17, 1981, FIS report (FEMA, 1981) were performed by Commonwealth Associates, Inc., for FEMA, under Contract No. H-4729. The work was completed in August 1980. Corunna, The hydrologic and hydraulic analyses for the City of: Shiawassee River for the January 17, 1986, FIS report (FEMA, 1986) were performed by the U.S. Army Corps of Engineers (USACE), Detroit District, for FEMA, under Interagency Agreement No. EMW-E-0941, Project Order No. 11. The work was completed in February 1984. Hazelton, The hydrologic and hydraulic analyses for Township