FORT BEND COUNTY, TEXAS AND INCORPORATED AREAS Community Community Name Number ARCOLA, CITY OF 481619 FAIRCHILDS, VILLAGE OF 481675 FIRST COLONY L.I.D. 481583 FORT BEND COUNTY L.I.D. NO. 2 481485 FORT BEND COUNTY L.I.D. NO. 7 481594 FORT BEND COUNTY M.U.D. NO. 2 481272 FORT BEND COUNTY M.U.D. NO. 23 481590 FORT BEND COUNTY M.U.D. NO. 25 481570 FORT BEND COUNTY M.U.D. NO. 34 481520 FORT BEND COUNTY M.U.D. NO. 35 481519 FORT BEND COUNTY M.U.D. NO. 41 481591 FORT BEND COUNTY M.U.D. NO. 42 481605 FORT BEND COUNTY UNINCORPORATED AREAS 480228 COMMUNITIES WITH NO SPECIAL FLOOD FULSHEAR, CITY OF 481488 HAZARD AREAS IDENTIFIED HOUSTON, CITY OF 480296 Community Community KATY, CITY OF 480301 KENDLETON, CITY OF 481551 Name Number KINGSBRIDGE M.U.D. 481567 BEASLEY, CITY OF 481654 MISSOURI CITY, CITY OF 480304 BIG OAKS M.U.D. 481596 NEEDVILLE, CITY OF 480820 CHELFORD CITY M.U.D. 481568 PEARLAND, CITY OF 480077 FORT BEND COUNTY M.U.D. NO. 30 481601 PECAN GROVE M.U.D. 481486 MEADOWS PLACE, CITY OF 481563 PLEAK, VILLAGE OF 481615 MISSION BEND M.U.D. NO. 1 481578 RICHMOND, CITY OF 480231 ORCHARD, CITY OF 481655 ROSENBERG, CITY OF 480232 SIMONTON, CITY OF 481564 STAFFORD, CITY OF 480233 SUGAR LAND, CITY OF 480234 THOMPSONS, TOWN OF 481642 WESTON LAKES, CITY OF 481197 WEST KEEGANS BAYOU I.D. 481602 WILLOW FORK DRAINAGE DISTRICT 481603 Revised: April 2, 2014 Federal Emergency Management Agency FLOOD INSURANCE STUDY NUMBER 48157CV000A 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 may not contain all data available within the repository. It is advisable to contact the community repository for any additional data. Part or all of this Flood Insurance Study may be revised and republished at any time. In addition, part of this Flood Insurance Study may be revised by the Letter of Map Revision process, which does not involve republication or redistribution of the Flood Insurance Study. It is, therefore, the responsibility of the user to consult with community officials and to check the community repository to obtain the most current Flood Insurance Study components. Initial Countywide Flood Insurance Study Date Effective Date: September 30, 1992 First Revised Countywide Flood Insurance Study Date: January 3, 1997 Second Revised Countywide Flood Insurance Study Date: April 20, 2000 Third Revised Countywide Flood Insurance Study Date: November 7, 2001 Fourth Revised Countywide Flood Insurance Study Date: April 2, 2014 TABLE OF CONTENTS Page 1.0 INTRODUCTION ......................................................................................................................... 1 1.1 Purpose of Study ................................................................................................................. 1 1.2 Authority and Acknowledgments ....................................................................................... 1 1.3 Coordination ....................................................................................................................... 4 2.0 AREA STUDIED ........................................................................................................................... 4 2.1 Scope of Study .................................................................................................................... 4 2.2 Community Description ...................................................................................................... 9 2.3 Principal Flood Problems .................................................................................................. 10 2.4 Flood Protection Measures ............................................................................................ ...10 3.0 ENGINEERING METHODS .................................................................................................... .12 3.1 Hydrologic Analyses ......................................................................................................... 13 3.1.1 New Detailed Study Streams ............................................................................................ 13 3.1.2 Redelineated Detailed Study Streams .............................................................................. 14 3.1.3 Enhanced Approximate Study Streams ............................................................................. 24 3.2 Hydraulic Analyses ........................................................................................................... 25 3.2.1 New Detailed Study Streams ............................................................................................ 25 3.2.2 Redelineated Detailed Study Streams ............................................................................... 26 3.2.3 Enhanced Approximate Study Streams ............................................................................. 28 3.3 Vertical Datum .................................................................................................................. 29 3.4 Land Subsidence ............................................................................................................... 29 4.0 FLOODPLAIN MANAGEMENT APPLICATION ................................................................. 34 4.1 Floodplain Boundaries ...................................................................................................... 34 4.2 Floodways ......................................................................................................................... 35 5.0 INSURANCE APPLICATION ................................................................................................... 59 6.0 FLOOD INSURANCE RATE MAP .......................................................................................... 59 7.0 OTHER STUDIES ....................................................................................................................... 64 8.0 LOCATION OF DATA ............................................................................................................... 64 9.0 BIBLIOGRAPHY AND REFERENCES ................................................................................... 64 i TABLE OF CONTENTS (Cont’d) Page FIGURES Figure 1 – NGS-HGCSD Benchmarks ....................................................................................................... 31 Figure 2 – Fort Bend Subsidence Adjustment Values from 1973 to 2000 ................................................. 31 Figure 3 – Land Subsidence Schematic ...................................................................................................... 33 Figure 4 – Floodway Schematic.................................................................................................................. 35 TABLES Table 1 – Scope of Study .............................................................................................................................. 5 Table 2 – Letters of Map Revision ................................................................................................................ 7 Table 3 – Levees in the Brazos River ........................................................................................................ 12 Table 4 – Redelineated Detailed Study Streams ......................................................................................... 14 Table 5 – Summary of Discharges .............................................................................................................. 16 Table 6 – Summary of Stillwater Elevations .............................................................................................. 23 Table 7 – Enhanced Approximate Study Streams ...................................................................................... 24 Table 8 – Subsidence Adjustment Values for Redelineated Streams ......................................................... 26 Table 9 – Manning’s “n” Values................................................................................................................. 28 Table 10 – Floodway Data Table ................................................................................................................ 37 Table 11 – Community Map History .......................................................................................................... 60 EXHIBITS Exhibit 1 – Flood Profiles Alcorn Bayou Panel 01P Brazos River Panels 02P-20P Cane Island Branch Panel 21P Clear Creek Panel 22P Clodine Ditch/Long Point Slough Panel 23P Coon Creek Panels 24P-26P Cow Creek Panels 27P-28P Dry Creek Panels 29P-33P Keegans Bayou Panels 34P-35P Little Prong Buffalo Bayou - Panel Removed Panel 36P Little Prong Buffalo Bayou Side Channel Panel 37P Long Point Creek Panel 38P Long Point Creek East Fork Panel 39P Lower Oyster Creek Panels 40P-41P Mustang Bayou Panels 42P-43P Mustang Bayou Diversion Channel Panel 44P North Branch Dry Creek Panel 45P ii Oyster Creek Panels 46P-52P Red Gully Panels 53P-54P San Bernard River Panels 55P-56P Seabourne Creek Panels 57P-59P Snake Creek Panel 60P Snake Slough Panel 61P Stafford Run Panels 62P-63P Steep Bank Creek Panel 64P Tributary 20.25 to Sims Bayou Panel 64 (a)P Willow Fork Buffalo Bayou Panels 65P-67P Willow Fork Diversion Channel Panel 68P Exhibit 2 – Flood Insurance Rate Map Index Flood Insurance Rate Maps iii FLOOD INSURANCE STUDY FORT BEND COUNTY, TEXAS AND INCORPORATED AREAS 1.0 INTRODUCTION 1.1 Purpose of Study This Flood