Multi-Reservoir Analysis PAPILLION CREEK WATERSHED SEPTEMBER 2004 Multi-Reservoir Analysis Table of Contents EXECUTIVE SUMMARY .......................................................................................................... E-1 Evaluation of Individual Dam Sites ................................................................................................... E-1 Dam Combination Alternatives.......................................................................................................... E-2 Selection of Design Alternative.......................................................................................................... E-3 Conceptual Dam Design Summary .................................................................................................... E-4 Conclusions ........................................................................................................................................ E-7 Recommendations .............................................................................................................................. E-7 1 INTRODUCTION .......................................................................................................1-1 1.1 Project Background..................................................................................................................1-1 1.2 Project Location .......................................................................................................................1-2 1.3 Project Objectives ....................................................................................................................1-4 2 METHODOLOGIES...................................................................................................2-1 2.1 Physical Characteristics ...........................................................................................................2-1 2.1.1 Topographic Data........................................................................................................2-1 2.1.2 Soil and Stream Characteristics ..................................................................................2-1 2.1.3 Land Use Conditions...................................................................................................2-2 2.1.4 Site Reconnaissance....................................................................................................2-2 2.2 Hydrologic Modeling...............................................................................................................2-2 2.2.1 Model Background......................................................................................................2-2 2.2.2 Model Conditions and Modifications .........................................................................2-3 2.2.3 Basis of Design ...........................................................................................................2-4 2.2.4 Base Precipitation Data...............................................................................................2-5 2.2.5 Precipitation for Reservoir Routing ............................................................................2-7 2.2.6 Reservoir Routing .....................................................................................................2-10 2.3 Hydraulic Modeling ...............................................................................................................2-12 2.4 Procedures for Estimating Sediment Yield............................................................................2-12 2.4.1 Literature Review......................................................................................................2-12 2.4.2 Revised Universal Soil Loss Equation......................................................................2-13 2.4.3 Measured Data and NRCS Method...........................................................................2-15 2.4.4 Comparison of Results..............................................................................................2-16 2.4.5 Trap Efficiency .........................................................................................................2-17 2.5 Identification of Infrastructure Impacts .................................................................................2-19 2.6 Identification of Environmental Impacts ...............................................................................2-20 2.6.1 Agency Coordination................................................................................................2-21 2.6.2 Water Rights Analysis ..............................................................................................2-22 2.7 Identification of Cultural/Historical Resource Impacts .........................................................2-24 2.8 Identification of Real Estate Impacts .....................................................................................2-24 2.9 Cost Estimating Procedures ...................................................................................................2-26 3 DAM SITE 1...............................................................................................................3-1 3.1 Introduction..............................................................................................................................3-1 3.2 Conceptual Design Analysis ....................................................................................................3-1 3.2.1 HEC-HMS Model Parameters ....................................................................................3-1 3.2.2 Reservoir Routing and Design Alternatives................................................................3-2 Table of Contents i September 2004 Multi-Reservoir Analysis 3.2.3 Sediment Yield Estimates ...........................................................................................3-5 3.3 Selection of Recommended Design Alternative ......................................................................3-5 3.3.1 Operating Pool Selection ............................................................................................3-5 3.3.2 Impacts of Selected Alternative ..................................................................................3-6 3.3.3 Estimated Probable Construction Costs......................................................................3-8 3.3.4 Conclusions and Recommendations ...........................................................................3-9 3.3.5 Pertinent Dam Data.....................................................................................................3-9 4 DAM SITE 2...............................................................................................................4-1 4.1 Introduction..............................................................................................................................4-1 4.2 Conceptual Design Analysis ....................................................................................................4-1 4.2.1 HEC-HMS Model Parameters ....................................................................................4-1 4.2.2 Reservoir Routing and Design Alternatives................................................................4-2 4.2.3 Sediment Yield Estimates ...........................................................................................4-5 4.3 Selection of Recommended Design Alternative ......................................................................4-5 4.3.1 Operating Pool Selection ............................................................................................4-5 4.3.2 Impacts of Selected Alternative ..................................................................................4-6 4.3.3 Estimated Probable Construction Costs......................................................................4-8 4.3.4 Conclusions and Recommendations ...........................................................................4-9 4.3.5 Pertinent Dam Data.....................................................................................................4-9 5 DAM SITE 3...............................................................................................................5-1 5.1 Introduction..............................................................................................................................5-1 5.2 Conceptual Design Analysis ....................................................................................................5-1 5.2.1 HEC-HMS Model Parameters ....................................................................................5-1 5.2.2 Reservoir Routing and Design Alternatives................................................................5-2 5.2.3 Sediment Yield Estimates ...........................................................................................5-5 5.3 Selection of Recommended Design Alternative ......................................................................5-5 6 DAM SITE 3B ............................................................................................................6-1 6.1 Introduction..............................................................................................................................6-1 6.2 Conceptual Design Analysis ....................................................................................................6-1 6.2.1 HEC-HMS Model Parameters ....................................................................................6-1 6.2.2 Reservoir Routing