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01042 Norman Cover 11X17.Indd An employee-owned company Document No. 080238 PBS&J Job No. 441941 FINAL REPORT STORM WATER MASTER PLAN NORMAN, OKLAHOMA Prepared for: City of Norman, Oklahoma 201 West Gray Building A Norman, Oklahoma 73070 Prepared by: in association with: PBS&J PBS&J Halff Associates, Inc. Vieux, Inc. 6504 Bridge Point Parkway 350 David L. Boren Blvd. 4030 West Braker Lane 350 David L. Boren Blvd. Suite 200 Suite 1510 Suite 450 Suite 2500 Austin, Texas 78730 Norman, Oklahoma 73072 Austin, Texas 78759-5356 Norman, Oklahoma 73072-7267 October 2009 Contents Page Page List of Figures................................................................................................................................................iv 4.2.2 Hydraulic Modeling for Level 3 and 4 Streams..............................................................4-27 List of Tables.................................................................................................................................................iv 4.2.2.1 RFD Inputs and Outputs..........................................................................4-27 List of Exhibits ............................................................................................................................................... v 4.2.2.2 RFD Processing .......................................................................................4-28 Acronyms and Abbreviations ........................................................................................................................vi 4.2.2.3 RFD Application for Level 3 and 4 Streams............................................4-28 4.2.3 Hydraulics for Local Drainage Issues ............................................................................4-28 Acknowledgements ......................................................................................................................................vii 4.3 HYDROLOGIC AND HYDRAULIC MODELING FOR SOLUTIONS ...........................................4-28 Executive Summary ................................................................................................................................ ES-1 4.3.1 Hydrologic Modeling General Approach........................................................................4-29 1.0 INTRODUCTION.......................................................................................................................................... 1-1 4.3.2 Hydraulic Modeling General Approach..........................................................................4-29 1.1 GOALS............................................................................................................................................... 1-1 4.3.3 Specific Modeling Considerations for Study Watersheds.............................................4-30 1.2 GENERAL STUDY AREA CHARACTERISTICS ........................................................................... 1-1 4.3.3.1 Imhoff Creek .............................................................................................4-30 1.3 APPROACH....................................................................................................................................... 1-1 4.3.3.2 Merkle Creek ............................................................................................4-31 1.4 REPORT ORGANIZATION.............................................................................................................. 1-3 4.4 FLOODPLAIN MAPPING................................................................................................................4-32 2.0 DATA SOURCES AND COLLECTION ..................................................................................................... 2-1 4.4.1 Level 1 Streams ..............................................................................................................4-32 4.4.2 Level 2 Streams ..............................................................................................................4-32 2.1 WATERSHED/STREAM ASSESSMENTS, AND STREAM FLOODING, AND LOCAL DRAINAGE PROBLEMS.................................................................................................................. 2-1 4.4.3 Level 3 and 4 Streams....................................................................................................4-32 2.2 WATER QUALITY............................................................................................................................. 2-1 5.0 STORM WATER PROBLEMS....................................................................................................................5-1 3.0 WATERSHED AND STREAM ASSESSMENTS...................................................................................... 3-1 5.1 SUMMARY OF PROBLEMS ............................................................................................................5-1 3.1 ASSESSMENT SUMMARIES.......................................................................................................... 3-1 5.2 PROBLEM IDENTIFICATION METHODOLOGY..........................................................................5-15 5.2.1 Stream Flooding..............................................................................................................5-15 3.2 METHODS......................................................................................................................................... 3-3 5.2.2 Stream Erosion................................................................................................................5-15 3.2.1 Primary Data Sources ...................................................................................................... 3-3 5.2.3 Water Quality...................................................................................................................5-15 3.2.2 Watersheds and Subareas .............................................................................................. 3-3 5.2.4 Local Drainage ................................................................................................................5-18 3.2.3 Stream Reaches............................................................................................................... 3-4 4.0 HYDROLOGIC AND HYDRAULIC ANALYSES ...................................................................................... 4-1 6.0 STORM WATER SOLUTIONS....................................................................................................................6-1 6.1 SUMMARY OF SOLUTIONS............................................................................................................6-1 4.1 HYDROLOGIC ANALYSIS............................................................................................................... 4-1 4.1.1 Detailed Hydrologic Modeling for Level 1 and 2 Streams.............................................. 4-1 6.2 SOLUTIONS DEVELOPMENT METHODOLOGY .......................................................................6-70 4.1.1.1 Hydrologic Modeling Methodology ........................................................... 4-1 6.2.1 Stream Flooding, Stream Erosion, and Local Drainage ...............................................6-82 4.1.1.2 Summary of Hydrologic Modeling for Level 1 Watersheds................... 4-11 6.2.1.1 Capital Improvements Program...............................................................6-85 4.1.1.3 Summary of Hydrologic Modeling for Level 2 Watersheds................... 4-12 6.2.2 Water Quality...................................................................................................................6-86 4.1.2 Hydrologic Modeling for Level 3 and 4 Streams........................................................... 4-14 7.0 KEY ISSUES.................................................................................................................................................7-1 4.1.2.1 Methodology – Rapid Floodplain Delineation (RFD) Tool..................... 4-14 7.1 STREAM PLANNING CORRIDORS................................................................................................7-1 4.1.2.2 USGS Regression Equations ................................................................. 4-15 7.1.1 Key Questions, Options, and Recommended Actions....................................................7-2 4.1.2.3 Development of Discharge Grid (Q-Grid) for RFD Tool ........................ 4-16 7.2 STRUCTURAL AND NONSTRUCTURAL STORM WATER QUALITY CONTROLS .................7-4 4.1.3 Hydrology for Local Drainage Issues ............................................................................ 4-16 7.2.1 Key Questions, Options, and Recommended Actions....................................................7-4 4.1.4 Hydrologic Modeling Results ......................................................................................... 4-16 7.3 ACQUISITION OF DRAINAGE EASEMENTS AND RIGHTS-OF-WAY.....................................7-11 4.2 HYDRAULIC ANALYSIS ................................................................................................................ 4-22 7.3.1 Key Questions, Options, and Recommended Actions..................................................7-12 4.2.1 Detailed Hydraulic Modeling for Level 1 and 2 Streams .............................................. 4-22 7.4 ENHANCED MAINTENANCE OF CREEKS AND STORM WATER DETENTION 4.2.1.1 Field Reconnaissance............................................................................. 4-24 FACILITIES ......................................................................................................................................7-14
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