DRAFT Environmental Impact Report

304 Pages·2014·6.49 MB·English

DRAFT
Environmental Impact Report

Orange County Water District
Prado Basin Sediment Management
Demonstration Project
State Clearinghouse No. 2013111071

Orange County Water District
18700 Ward Street
Fountain Valley, CA 92708
Contact: Daniel Bott

March 2014
Table of Contents
Section Page

SECTION 1 INTRODUCTION ........................................................................ 1-1
1.1 Purpose and Authority .............................................................................. 1-1
1.2 Public Consultation .................................................................................. 1-1
1.3 Effects Determined Not Significant ........................................................... 1-4
1.4 Effects Determined To Be Potentially Significant ..................................... 1-4
1.5 Review of the Draft EIR ............................................................................ 1-5
SECTION 2 PROJECT DESCRIPTION ......................................................... 2-1
2.1 Background .............................................................................................. 2-1
2.2 Project Area Setting ................................................................................. 2-1
2.3 Project Activities ....................................................................................... 2-2
2.4 Project Monitoring Programs .................................................................... 2-9
2.5 Construction Operations ......................................................................... 2-12
2.6 CEQA Project Objectives ....................................................................... 2-17
2.7 Permits and Approvals ........................................................................... 2-18
SECTION 3 ENVIRONMENTAL ANALYSIS ................................................. 3-1
3.1 AESTHETICS RESOURCES ................................................................... 3-2
3.1.1 Regulatory Framework ............................................................... 3-2
3.1.2 Existing Environmental Setting ................................................... 3-2
3.1.3 Thresholds of Significance ......................................................... 3-4
3.1.4 Project Impacts........................................................................... 3-4
3.2 AIR QUALITY ........................................................................................... 3-7
3.2.1 Regulatory Framework ............................................................... 3-7
3.2.2 Existing Environmental Setting ................................................. 3-10
3.2.3 Threshold of Significance ......................................................... 3-13
3.2.4 Project Impacts......................................................................... 3-13
3.3 BIOLOGICAL RESOURCES .................................................................. 3-29
3.3.1 Regulatory Framework ............................................................. 3-29
3.3.2 Existing Environmental Setting ................................................. 3-33
3.3.3 Thresholds of Significance ....................................................... 3-59
3.3.4 Project Impacts......................................................................... 3-60
3.3.5 Unavoidable Significant Impacts to Listed Sensitive Species . 3-102
3.3.6 Orange County Water District Prior Mitigation Commitments in
Prado Basin ............................................................................ 3-102
3.3.7 Proposed Mitigation Concept ................................................. 3-104
3.4 CULTURAL RESOURCES ................................................................... 3-110
3.4.1 Regulatory Framework ........................................................... 3-110
3.4.2 Existing Environmental Setting ............................................... 3-111
3.4.3 Threshold of Significance ....................................................... 3-122
3.4.4 Project Impacts....................................................................... 3-122
3.5 GEOLOGY ........................................................................................... 3-126
3.5.1 Regulatory Framework ........................................................... 3-126
3.5.2 Existing Environmental Setting ............................................... 3-127
3.5.3 Threshold of Significance ....................................................... 3-130
3.5.4 Project Impacts....................................................................... 3-130
3.6 GREENHOUSE GAS EMISSIONS ...................................................... 3-136
3.6.1 Regulatory Framework ........................................................... 3-136
3.6.2 Existing Environmental Setting ............................................... 3-137
Orange County Water District Prado Basin Sediment Management Project
Draft Environmental Impact Report i
Table of Contents
3.6.3 Threshold of Significance ....................................................... 3-139
3.6.4 Project Impacts....................................................................... 3-139
3.7 HAZARDS/HAZARDOUS MATERIALS................................................ 3-142
3.7.1 Regulatory Framework ........................................................... 3-142
3.7.2 Existing Environmental Setting ............................................... 3-144
3.7.3 Thresholds of Significance ..................................................... 3-145
3.7.4 Project Impacts....................................................................... 3-145
3.8 HYDROLOGY/WATER QUALITY ........................................................ 3-148
3.8.1 Regulatory Framework ........................................................... 3-148
3.8.2 Existing Environmental Setting ............................................... 3-152
3.8.3 Significance Criteria ............................................................... 3-172
3.8.4 Project Impacts....................................................................... 3-173
3.9 LAND USE/RELEVANT PLANNING PROGRAMS............................... 3-185
3.9.1 Regulatory Framework ........................................................... 3-185
3.9.2 Existing Environmental Setting ............................................... 3-186
3.9.3 Thresholds of Significance ..................................................... 3-187
3.9.4 Project Impacts....................................................................... 3-187
3.10 NOISE 3-192
3.10.1 Regulatory Framework ........................................................... 3-192
3.10.2 Existing Environmental Setting ............................................... 3-195
3.10.3 Thresholds of Significance ..................................................... 3-198
3.10.4 Project Impacts....................................................................... 3-198
3.11 TRANSPORTATION ............................................................................ 3-205
3.11.1 Regulatory Framework ........................................................... 3-205
3.11.2 Existing Environmental Setting ............................................... 3-206
3.11.3 Thresholds of Significance ..................................................... 3-207
3.11.4 Project Impacts....................................................................... 3-207
SECTION 4 CUMULATIVE IMPACTS ........................................................... 4-1
4.1 CEQA Analysis Requirements.................................................................. 4-1
4.2 Cumulative Analysis Methodology ............................................................ 4-1
4.3 Cumulative Impact Evaluation .................................................................. 4-7
SECTION 5 OTHER CEQA SECTIONS ........................................................ 5-1
5.1 Growth Inducing Impacts .......................................................................... 5-1
5.2 Significant Irreversible Changes ............................................................... 5-2
5.3 Summary of Project Impacts .................................................................... 5-3
SECTION 6 ALTERNATIVES TO THE PROPOSED PROJECT ................... 6-1
6.1 Purpose and Scope .................................................................................. 6-1
6.2 Project Objectives .................................................................................... 6-2
6.3 Planning Criteria ....................................................................................... 6-2
6.4 Alternatives Eliminated From Further Analysis ......................................... 6-3
6.5 Project Alternatives Considered and Evaluated ....................................... 6-5
6.5.1 Alternative 1-No Project Alternative ............................................ 6-5
6.5.2 Alternative 2- Alternative Sediment Storage Site D .................... 6-8
6.5.3 Alternative 3 - Alternative Sediment Removal Method.............. 6-13
6.6 Environmentally Superior Alternative ..................................................... 6-19
SECTION 7 LIST OF PREPARES AND REVIEWERS .................................. 7-1
SECTION 8 REFERENCES ........................................................................... 8-1

Orange County Water District Prado Basin Sediment Management Project
Draft Environmental Impact Report ii
Table of Contents
Table Page
Table 1: IS/NOP Comment Letters ...............................................................................1 -2
Table 2: Phasing Plan ................................................................................................2 -12
Table 3: Phase 1: Pre-Construction Monitoring .......................................................... 2-13
Table 4: Phase 2: Site Preparation ............................................................................. 2-13
Table 5: Phase 3 Infrastructure Construction ............................................................. 2-14
Table 6: Phase 4 Sediment Removal ......................................................................... 2-15
Table 7: Phase 5 Sediment Re-entrainment ............................................................... 2-16
Table 8: Phase 6– Monitoring and Site Restoration .................................................... 2-16
Table 9: 2010 to 2012 Air Quality Monitoring Summary .............................................. 3-11
Table 10: South Coast Air Basin Attainment Status .................................................... 3-12
Table 11: Localized Significance Analysis (Construction) ........................................... 3-19
Table 12: Regional Construction Air Pollutant Emissions ........................................... 3-22
Table 13: Mitigated Construction Air Pollutant Emissions ........................................... 3-23
Table 14: Vegetation/Land Cover (Acres) ................................................................... 3-38
Table 15: Sensitive Plant List ..................................................................................... 3-41
Table 16: List of Special Status Wildlife Species ........................................................ 3-48
Table 17: Sediment Removal Channel U.S./State Jurisdictional Area ........................ 3-59
Table 18: Fish Survey Upstream Prado Dam Point 119 May 30 2013 ........................ 3-69
Table 19: Fish Survey Upstream Prado Dam Point 119 May 30 2013 ........................ 3-69
Table 20: Fish Survey Prado Dam Approach/Outlet Channel July 1, 2, 2008 ............. 3-70
Table 21: Fish Survey Santa Ana River Green River Golf Course Reach ................... 3-71
Table 22: Native Fish Survey Santa Ana River Green River Golf Course ................... 3-71
Table 23: Native Fish Survey Santa Ana River Weir Canyon to Imperial Highway April,
November 2012 ..........................................................................................3 -72
Table 24: Summary of Soil Environmental Test Results ............................................. 3-74
Table 25: Durations to Deplete 500,000 yd³ of Sediment for Six Selected Discharges .... 3-77
Table 26: Vegetation Impacts (Acres) ........................................................................ 3-94
Table 27: Vegetation Communities at Different Elevations (Acres) ........................... 3-103
Table 28: Riparian Mitigation Sites (Acres) ............................................................... 3-105
Table 29: Coastal Sage Scrub Mitigation Site (Acres) .............................................. 3-105
Table 30: Regional Active Faults .............................................................................. 3-128
Table 31: Construction Greenhouse Gas Emissions ................................................ 3-139
Table 32: Summary of Soil Environmental Test Results ........................................... 3-144
Table 33: Summary of Water Quality Data Santa Ana River Below Prado Dam ....... 3-157
Table 34: Summary of Indicator Bacteria Water Quality Data ................................... 3-168
Table 35: Beneficial Uses ......................................................................................... 3-170
Table 36: Beneficial Uses ......................................................................................... 3-171
Table 37: Water Quality Objectives (mg/L) ............................................................... 3-172
Table 38: Impaired Water Bodies ............................................................................. 3-172
Table 39: Basin Plan Turbidity thresholds ................................................................ 3-173
Table 40: Durations to Deplete 500,000 yd³ of Sediment for Six Selected Discharges .. 3-179
Table 41: Riverside County Noise Ordinance Standards .......................................... 3-193
Table 42: City of Corona Noise Ordinance Standards .............................................. 3-194
Table 43: Noise Levels and Human Response ......................................................... 3-196
Table 44: Vibration Source Levels for Construction Equipment ................................ 3-197
Table 45: Roundtrip Traffic Trips .............................................................................. 3-207
Table 46: Vireo Territories/Breeding Pairs Prado Basin .............................................. 4-10
Table 47: Summary of Environmental Impacts ........................................................... 6-19
Orange County Water District Prado Basin Sediment Management Project
Draft Environmental Impact Report iii
Table of Contents
Figure Page

Figure 1: Regional Vicinity Map .............................................................................. 2-3
Figure 2: Proposed Project..................................................................................... 2-5
Figure 3: Sediment Removal Channel – Typical Cross-section View ..................... 2-6
Figure 4: Eligible State Scenic Highways ............................................................... 3-3
Figure 5: USGS Location ..................................................................................... 3-35
Figure 6: Sediment Removal Channel .................................................................. 3-36
Figure 7: Sediment Management Storage Site E ................................................. 3-37
Figure 8: Critical Habitat ....................................................................................... 3-56
Figure 9: Least Bell’s Vireo Locations .................................................................. 3-62
Figure 10: Southwestern Willow Flycatcher Locations ......................................... 3-63
Figure 11: Incoming Sediment Load Size ............................................................. 3-78
Figure 12: Susceptibility to Sediment Deposition ................................................. 3-79
Figure 13: Yorba Slaughter Adobe Property Mitigation Site ............................... 3-106
Figure 14: Pheasant Field Mitigation Site ........................................................... 3-107
Figure 15: Demonstration Garden Extension Mitigation Site .............................. 3-108
Figure 16: Pigeon Hill Property Mitigation Site ................................................... 3-109
Figure 17: Geological Constraints ...................................................................... 3-129
Figure 18: Mitigation Areas within Santa Ana Canyon ........................................... 4-6

Appendices Page

Appendix A-1: Initial Study/Notice of Preparation, November 2013, Orange County
Water District
Appendix A-2: Comment Letters
Appendix B: Air Quality and Greenhouse Gas Analysis Report, February 2014, First
Carbon Solutions
Appendix C-1: Biological Conditions Technical Report, July 2013, Orange County
Water District
Appendix C-2: Native Fish Relocation for ACOE Reach 9 Channel Diversions Field
Report, March 2010, Riverside-Corona Resource Conservation
District
Appendix C-3: Native Fish Relocation for ACOE Reach 9 - Phase 2 Channel
Diversions, April/May 2012, Riverside-Corona Resource
Conservation District
Appendix C-4: Native Fish Survey Lower Santa Ana River Weir Canyon to Imperial
Highway, November 2012, Orange County Water District
Appendix C-5: Fish Protection Activities Prado Dam, Corona CA, August 2008, San
Marino Environmental Associates
Appendix D-1: Assessment of Water and Sediment Patterns within Prado Basin,
November 2010, Golder Associates
Appendix D-2: HEC-RAS Sediment Transport Modeling Santa Ana River, November
2010, Golder Associates
Orange County Water District Prado Basin Sediment Management Project
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Table of Contents
Appendix D-2A
Appendix D-2B
Appendix D-2C
Appendix D-2D
Appendix D-3: Geotechnical Report for Prado Basin Sediment Management Demo
Project, November 2010, Golder Associates
Appendix D-4: Figures
Appendix E: Hazardous Waste Site Search, May 2013, Orange County Water
District

Orange County Water District Prado Basin Sediment Management Project
Draft Environmental Impact Report v
Executive Summary
EXECUTIVE SUMMARY
Proposed Project
The Orange County Water District (OCWD) is proposing a sediment
management demonstration project within the Prado Basin that will remove
between 250,000 and 500,000 cubic yards of materials from the Prado Basin and
re-entrain it into the lower Santa Ana River. OCWD is the Lead Agency for the
proposed project.
Project Overview
The purpose of the Prado Basin Sediment Management Demonstration Project
(Project) is to explore practical and beneficial methods to remove approximately
250,000 to 500,000 cubic yards of sediment from Prado Basin and re-entrain the
sediment into the lower Santa Ana River, below Prado Dam to help restore
sediment migration to habitats and beaches downstream and to help maintain
water conservation storage behind Prado Dam. The demonstration project will be
implemented over a five year period and involves the following three activities; 1)
construction and operation of a sediment removal channel, 2) construction and
operation of sediment storage and handling area and a green waste processing
area and 3) sediment re-entrainment activities.
Sediment Removal Channel
The sediment removed from the Prado Basin for re-entrainment will be removed
from a sediment removal channel. The sediment removal channel will parallel the
alignment of the Santa Ana River in the southeast portion of Prado Basin. The
western end of the channel will be located approximately 1,700 feet from the
Prado Dam outlet works. The sediment removal channel will have a length of
6,000 feet, a width of 200 feet and a depth of 12 feet. A 30 foot access road will
be provided along both sides of the channel alignment. A 300 buffer area is
proposed around the perimeter of the sediment channel. The intent of the buffer
area is to allow for modifications to the alignment during the detail design phase
to minimize impacts to sensitive areas.
In order to construct the sediment removal channel all vegetation within the
channel will have to be removed. The alignment of the channel to the maximum
extent possible will extend through areas that contain arundo or other non-native
vegetation. The vegetation removal will occur outside of nesting season. The
removed vegetation will be trucked to a green waste area where it will be
processed and converted to mulch and/or firewood.
The sediment will be removed from the sediment removal channel with hydraulic
dredge operating in the wetted channel. A dredging barge will travel up and down
the sediment removal channel by anchoring spuds into the ground. The collected
Orange County Water District Prado Basin Sediment Management Project
Draft Environmental Impact Report ES-1
Executive Summary
sediment slurry will be conveyed by booster pumps to a sediment storage site
through a temporary above ground discharge pipeline.
Sediment Storage and Handling Area/Green Waste Processing Area
The project includes sediment storage and handling area and green waste area
to process the vegetation removed from the site and to prepare the sediment for
re-entrainment. The vegetation removed from the sediment removal channel and
sediment storage site will be processed at the green waste area.
In order to remove and re-entrain sediments back into the Santa Ana River to
achieve an adequate sediment concentration, the sediment will need to be re-
entrained under flow conditions of 500 cfs and greater. Therefore, it will be
necessary to store the removed sediments for a period of time until adequate
releases are occurring from Prado Dam. The slurry collected from the hydraulic
dredging will be processed at a sediment storage site to prepare it for re-
entrainment back into the river. Once the slurry is processed it will be pumped
into the first de-watering basin to begin the drying process. Once the sediment is
dry it will be temporarily stockpiled for re-entrainment.
Sediment Re-entrainment
When Santa Ana River flows are at a sufficient rate, the sediment will be re-
mixed into a slurry using water from the Santa Ana River and then pumped
through an above ground temporary discharge pipeline to a sediment re-
entrainment area. A crane will be positioned on the levee to secure the discharge
end of the re-entrainment pipeline to insure even distribution of sediment into the
river.
Project Objectives
The following project objectives have been established for the Prado Basin
Sediment Management Demonstration Project to assist public agencies and
decision makers in their review of potential impacts associated with the Project
and Project Alternatives.
• Remove between 250,000 and 500,000 cubic yards of sediment material
from Prado Basin to prevent further loss of storage capacity and to
enhance water storage conservation capabilities.
• Prevent further degradation of the Santa Ana River due to sediment-
starved stream flows.
• Allow operation of Prado Dam to take place to maximize water diversion
and infiltration between Imperial Highway and the 22 Freeway.
Orange County Water District Prado Basin Sediment Management Project
Draft Environmental Impact Report ES-2
Executive Summary
• Enhance and restore habitat in the Santa Ana River by preventing further
degradation of certain areas of the river through sediment transport
processes.
• Increase recharge rates in the Santa Ana River by reducing the armoring
and incising of the river bed.
• Reduce coastal erosion processes by providing sediment to the Santa
Ana River that will reach the Pacific Ocean.
• Enhance and restore high value habitat in Prado basin by preventing
further accumulation of sediments in Prado basin.
• Minimize impacts to native vegetation within the Prado Basin.
• Collect data and monitor project effects.
Significant Unavoidable Adverse Impacts
• The Project will have the potential to generate temporary construction
noise impacts that could disrupt the breeding patterns of the Federal and
State Listed Least Bells Vireo if it occurs within construction activity noise
impact area.
• The Project will have the potential for native fish to occur within the project
area and require physical relocation.
• The Project will have the potential to generate temporary construction
noise impacts that could disrupt breeding patterns of nesting migratory
birds.
• The Project during sediment re-entrainment activities could temporary
exceeds the Regional Water Quality Control Board Basin Plan threshold
for turbidity.
Environmental Issues Not Considered
The following environmental issues were determined to be less than significant in
the Initial Study/Notice of Preparation prepared for the Prado Basin Sediment
Management Demonstration Project. The Initial Study/Notice of Preparation is
presented in Appendix A. In accordance with section 15063(C) of the CEQA
Guidelines these issues do not require further evaluation in the Draft EIR.
Agriculture/Forest Resources
• Mineral Resources
• Population/Housing
• Public Services
• Utilities/Service Systems
Orange County Water District Prado Basin Sediment Management Project
Draft Environmental Impact Report ES-3
Executive Summary
Project Impacts
Table ES-1 provides a summary of project impacts and mitigation measures and
a determination on the level of project impacts after the incorporation of
mitigation measures.
Summary of Project Alternatives
The Draft EIR evaluates three alternatives to the Project.
Alternative 1 – No Project Alternative
Under the No Project Alternative, the proposed sediment management
demonstration project will not be implemented. No activities will occur to remove
between 250,000 and 500,000 cubic yards of material from Prado Basin. There
will be no change to the existing conditions at the Prado Basin, sediment will
continue to build up in the Prado Basin reducing storage for water conservation
and continuing to degrade existing riparian habitat in Prado Basin. The lower
Santa Ana River will continue to be starved of sediment.
Alternative 2 Sediment Storage Site/Green Waste Site Alternative Location
Under Alternative 2, between 250,000 and 500,000 cubic yards of sediment will
be dredged and removed from the sediment removal channel. . The sediment will
be removed from the sediment removal channel by a hydraulic dredging method.
Under Alternative 2 the sediment would be removed and conveyed to the
sediment storage site with the same method as the Project and will require same
mix of construction equipment. However, under Alternative 2 the green waste
processing and sediment storage and handling activities will occur at an
alternative sediment storage site and green waste site. At the sediment storage
site the sediment will be re-mixed with water into slurry and conveyed by an
above ground discharge pipeline to the sediment re-entrainment area,
downstream of the highway 71 crossing.
Alternative 3 Alternative Sediment Removal Method
Under Alternative 3 the sediment removal channel will be excavated along the
alignment of the Santa Ana River. Between 250,000 and 500,000 cubic yards of
sediment will be removed from the channel with heavy construction equipment.
The removed sediment will be transported by heavy equipment to an alternative
sediment storage site. The sediment will be re-mixed into slurry and conveyed by
an above ground discharge pipeline to the sediment with water re-entrainment
area.
Environmentally Superior Alternative
The Project will result in the least amount of significant adverse impacts to the
environment and will better achieve the project objective of minimizing impacts to
Orange County Water District Prado Basin Sediment Management Project
Draft Environmental Impact Report ES-4