[House Document 105-145]
[From the U.S. Government Publishing Office]
105th Congress, 1st Session - - - - - - - - - - House Document 105-145
NORCO BLUFFS, RIVERSIDE COUNTY, CALIFORNIA
__________
COMMUNICATION
from
THE ACTING ASSISTANT SECRETARY (CIVIL WORKS), THE DEPARTMENT OF THE
ARMY
transmitting
A REPORT ON THE PROJECT FOR RIVER BANK EROSION CONTROL AND BLUFF
STABILIZATION AT NORCO BLUFFS, RIVERSIDE COUNTY, CALIFORNIA, PURSUANT
TO SECTION 101(b)(4) OF THE WATER RESOURCES DEVELOPMENT ACT OF 1996
October 6, 1997.--Referred to the Committee on Transportation and
Infrastructure and ordered to be printed
C O N T E N T S
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Page
Letter of transmittal............................................ vii
Comments of the Office of Management and Budget.................. ix
Comments of the State of California.............................. x
Comments of the Department of the Interior....................... xi
Comments of the Federal Emergency Management Agency.............. xii
Report of the Chief of Engineers, Department of the Army......... 1
Report of the District Engineer:
Syllabus..................................................... 7
I. Study Authority.................. 9
Authority.................... 9
Local Sponsorship............ 9
II. Study Purpose and Scope.......... 10
III. Prior Studies and Reports........ 11
Existing Water Projects...... 12
IV. Plan Formulation................. 13
Location and Extent of Study 13
Area.
Location of the Study 13
Area.
Drainage Basin 13
Description.
Physical Setting......... 14
Urban Setting............ 15
Problems and Opportunities... 15
Problems................. 15
Opportunities............ 18
Planning Objectives and 18
Constraints.
Planning Objectives...... 18
Planning Constraints..... 19
Without-Project Conditions... 19
Hydrology................ 20
Hydraulics............... 20
Geotechnical............. 24
Economics................ 25
Environmental............ 28
Recreation............... 34
Formulation of Alternative 35
Plans.
Evaluation of Alternative 42
Plans.
Alternatives Carried 42
Forward.
With-Project Impact 44
Evaluation.
Plan Selection............... 51
Benefits................. 52
Costs.................... 56
Benefits/Cost Analysis... 58
System of Accounts....... 59
Additional Evaluation 65
Criteria.
V. Description of the Selected Plan. 66
NED Plan..................... 66
Downstream Impacts....... 68
Real Estate and 69
Construction Easements.
Operation and Maintenance 69
Mitigation Plans......... 70
Recreation Plans......... 71
Locally Preferred Plan....... 71
Downstream Impacts....... 72
Real Estate and 73
Construction Easements.
Operation and Maintenance 73
Mitigation Plans......... 74
Report of the District Engineer--Continued
Recreation Plans......... 75
Plan Selection............... 76
VI. Plan Implementation.............. 77
Study Recommendation......... 77
Cost Allocation.............. 77
Institutional Requirements... 77
Environmental Requirements... 78
Views of the Non-Federal 78
Sponsor.
VII. Summary of Coordination, Public 79
Views, and Comments.
VIII. Conclusions and Recommendation... 81
Conclusions.................. 81
Additional Study Needs....... 82
Recommendation............... 82
IX. References....................... 83
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Exhibits:
1. Regional Map............................................. 85
2. Erosion Zones............................................ 86
3. Norco Bluffs and Santa Ana River Drainage................ 87
4. Urban Area............................................... 88
5. Chronological Sequence of Bluff Retreat.................. 89
6. Alternative 1a: Buttress Fill (Imported)................. 90
7. Alternative 1b: Buttress Fill (Cut and Fill)............. 91
8. Alternative 1c: Hilfiker................................. 92
9. Alternative 1d: Crib Wall/Earthlock...................... 93
10. Alternative 1h: Reinforced Earth......................... 94
11. Alternative 1i: Concrete Retaining Wall.................. 95
12. Alternative 2b: Soil Cement.............................. 96
13. Alternative 2f: Groins................................... 97
14. Alternative 5 (Combined 1A & 2B): Locally-Preferred Plan. 98
15. Alternative 2b: Soil Cement Toe Protection Alternative,
Plan View.................................................. 99
16. GAlternative 5: Combination of Slope Stabilization and
Toe Protection Alternative, Plan View...................... 100
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Photos 1 Through 13 Follow Exhibits.............................. 101
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Environmental Impact Statement................................... 109
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APPENDICES ACCOMPANYING THE REPORT OF THE DISTRICT ENGINEER
(Only Appendices F and G are printed)
Appendix A Written Comments on NOI/NOP
Appendix B Habitat Evaluation Procedure Analysis
Appendix C Background Information on Noise Analysis
Appendix D Fish and Wildlife Reports and Documentation
Appendix E Endangered Species Act Coordination and Biological
Assessment
Appendix F 404b(1) Analysis...................................... 240
Appendix G Finalizing Addendum................................... 245