addendum no. 5 (sacramento river east levee) to the ......addendum no. 5 - sacramento river east...

Addendum No. 5 (Sacramento River East Levee) to the Environmental Impact Report on the North Sacramento Streams, Sacramento River East Levee, Lower American River, and Related Flood Improvements Project

Prepared by:

Consulting

Engineers and

Scientists

Prepared for:

Sacramento Area Flood Control Agency

February 2019

State Clearinghouse No. 2014052038

sorgenk

Text Box

Exhibit A

Addendum No. 5 (Sacramento River East Levee) to the Environmental Impact Report on the

North Sacramento Streams, Sacramento River East Levee, Lower American River, and Related Flood Improvements Project

State Clearinghouse No. 2014052038

Prepared for:

Sacramento Area Flood Control Agency 1007 7th Street, 7th Floor Sacramento, CA 95814

Contact:

Pete Ghelfi, PE Director of Engineering (916) 874-7606

Prepared by:

GEI Consultants, Inc. 2868 Prospect Park Drive, Suite 400 Sacramento, CA 95670

Contact:

Drew Sutton Senior Environmental Project Manager (916) 631-4500

February 2019

Project No. 1601100

Addendum No. 5 – Sacramento River East Levee Project GEI Consultants, Inc. SAFCA i Table of Contents

Table of Contents

Abbreviations and Acronyms .................................................................................................................................. ii

1. Introduction .................................................................................................................................................. 3

2. Summary of Previous Environmental Review Process ........................................................................... 3

3. Summary of the Levee Accreditation Project ........................................................................................... 5

4. Modifications and Refinements to the Project ......................................................................................... 7 4.1 Minor Project Refinements with No Environmental Impacts Not Evaluated in Detail ...................... 7 4.2 Project Refinements Evaluated in Detail .......................................................................................... 7

4.2.1 Beach/Stone Lake Mitigation Sites ...................................................................................... 7

5. Standard for Preparation of an Addendum ............................................................................................. 11

6. Environmental Analysis ............................................................................................................................ 12 6.1 Agriculture and Forestry Resources ............................................................................................... 13 6.2 Aquatic and Terrestrial Biological Resources ................................................................................. 14 6.3 Cultural Resources ......................................................................................................................... 15 6.4 Water Quality and Groundwater Resources ................................................................................... 17

7. Conclusions ............................................................................................................................................... 17

8. References ................................................................................................................................................. 18

Figures

Figure 1: Site Overview.................................................................................................................................... 4 Figure 2. Proposed Woodland Mitigation Site B-1 ........................................................................................... 9 Figure 3. Proposed Woodland Mitigation Site B-2 ......................................................................................... 10

GEI Consultants, Inc. Addendum No. 5 – Sacramento River East Levee Project Abbreviations and Acronyms ii SAFCA

Abbreviations and Acronyms

ARCF GRR American River Common Features General Reevaluation Report

Caltrans California Department of Transportion

CEQA California Environmental Quality Act

CRHR California Register of Historic Resources

dbh diameter at breast height

EIR Environmental Impact Report

FWARG Far Western Anthropological Research Group, Inc.

IDM investigation-derived material

LAP Levee Accreditation Project

MMRP Mitigation, Monitoring and Reporting Program

NHPA National Historic Preservation Act

NEMDC Natomas East Main Drainage Canal

NRHP National Register of Historic Places

SAFCA Sacramento Area Flood Control Agency

SRCSD Sacramento Regional County Sanitation District

UAIC United Auburn Indian Community

USACE U.S. Army Corps of Engineers

Addendum No. 5 - Sacramento River East Levee Project GEI Consultants, Inc. SAFCA 3 Abbreviations and Acronyms

1. Introduction

This Addendum to the Final Environmental Impact Report for the North Sacramento Streams, Sacramento River East Levee, Lower American River, and Related Flood Improvements Project (State Clearinghouse No. 2014052038), also referred to as the Levee Accreditation Project (LAP), addresses proposed modifications and refinements to the Sacramento River East Levee improvements component of the LAP. These proposed modifications and refinements involve modifications to the timing of construction, and modifications to the size and location of woodland mitigation sites, as shown on Figure 1 and described in more detail in Section 4, below.

2. Summary of Previous Environmental Review Process

The Sacramento Area Flood Control Agency (SAFCA), as lead agency under the California Environmental Quality Act (CEQA),1 prepared a Draft Environmental Impact Report (Draft EIR) for the North Sacramento Streams, Sacramento River East Levee, Lower American River, and Related Flood Improvements Project, and distributed the Draft EIR on March 18, 2015 for a 45-day public review period. Five public meetings were held in Sacramento during the public comment period. These meetings were held jointly with the U.S. Army Corps of Engineers (USACE), Sacramento District, and included information on both the project, and also on USACE’s American River Common Features General Reevaluation Report (ARCF GRR) Project. The ARCF GRR covers a range of actions in the Sacramento region, including not only the project but also additional actions along the Lower American River, and an expansion of the Sacramento Weir and Bypass, among other improvements. The LAP is a subset, or early implementation project, of the ARCF GRR.

The public comment period on the Draft EIR closed on May 1, 2015. A Final EIR and the Mitigation Monitoring and Reporting Program (MMRP) were released on June 8, 2015 and sent to agencies, organizations, and individuals who had commented on the Draft EIR within the 45-day review period. The June 2015 Final EIR was subsequently updated to respond to additional comments received, and a second Final EIR was released on July 8, 2015. At its July 16, 2015 meeting, SAFCA’s Board of Directors deferred action on the EIR certification and approval of the LAP. A revised Final EIR was subsequently prepared incorporating revisions from the second Final EIR as

1 CEQA is found at California Public Resources Code, Sections 21000 et seq., and the State CEQA Guidelines are found at

California Code of Regulations, Title 14, Section 15000 et seq.

GEI Consultants, Inc. Addendum No. 5 – Sacramento River East Levee Project 4 SAFCA

Figure 1: Site Overview

Source: GEI Consultants, Inc. 2018


well as responses to comments received after July 8, 2015, and was released in June 2016. SAFCA certified the EIR, adopted the associated MMRP, and approved the LAP on July 21, 2016. The Draft and Final EIRs, MMRP, and Addenda (described below) are available at SAFCA’s offices at 1007 7th Street, 7th Floor, Sacramento, CA 95814, and online at SAFCA’s Web site (www.safca.org/protection/Environmental_Public_Review.html).

Addendum No. 1 (North Sacramento Streams) to the North Sacramento Streams, Sacramento River East Levee, Lower American River, and Related Flood Improvements Project was approved by SAFCA’s Board of Directors on December 15, 2016. Addendum No. 1 addressed modifications and refinements to the project, including the adjusted location of a staging area; two additional temporary crossings of Arcade Creek; modifications to haul truck routes to permit empty trucks to return from the Arcade Creek levees to the haul road entrance at West El Camino Avenue via Norwood Avenue and Rio Linda Boulevard; and refinements to the tree removal impacts and the mitigation approach.

Addendum No. 2 (North Sacramento Streams) to the North Sacramento Streams, Sacramento River East Levee, Lower American River, and Related Flood Improvements Project was approved by SAFCA’s Board of Directors on March 15, 2018. Addendum No. 2 addressed modifications and refinements to the project, including changes to the timing of the construction; several adjusted staging areas; and modification to haul truck routes to permit empty trucks to return from the Arcade Creek levees and Staging Area 3 via Pamela Drive and Arcade Boulevard, joining the route along Rio Linda Boulevard and El Camino Avenue approved in Addendum No. 1.

Addendum No. 3 (North Sacramento Streams) to the North Sacramento Streams, Sacramento River East Levee, Lower American River, and Related Flood Improvements Project was approved by SAFCA’s Board of Directors on May 17, 2018. Addendum No. 3 addressed modifications and refinements to the project, including modification to haul truck routes to permit on-road hauling from the 2K Borrow Site and the Twin Rivers School stockpile to the staging areas and levee improvement sites along the Arcade Creek levees. The changes analyzed in Addendum No. 3 and approved by the Board limit the use of the on-road hauling route to transportation of 9,100 cubic yards of material during May and June 2018.

Addendum No. 4 (North Sacramento Streams) to the North Sacramento Streams, Sacramento River East Levee, Lower American River, and Related Flood Improvements Project was approved by SAFCA’s Board of Directors on June 21, 2018. Addendum No. 4 addressed modifications and refinements to the project, involving dewatering a 20-foot by 40-foot area at the approach to the temporary bridge at the 2K Borrow Site. The temporary bridge was part of the project approved by the Board in 2016.

3. Summary of the Levee Accreditation Project

SAFCA is implementing improvements to the flood management system protecting portions of the City and County of Sacramento along the Lower American and Sacramento Rivers and their tributaries outside of the Natomas Basin (project area). The proposed improvements (referred to herein as the “LAP” or “project”) would reduce flood risk and bring the flood management system in the project area


into compliance with applicable engineering standards established under the National Flood Insurance Program. In addition, the project, in combination with other ongoing improvements to the flood management system along the American River, would allow the flood management system in the project area to meet the urban levee design standards established by the California Department of Water Resources in connection with the Central Valley Flood Protection Plan.

As described in the EIR and Addenda, SAFCA plans to implement levee accreditation improvements, a creek corridor management plan, and a mitigation and conservation strategy during the next 5–7 years, following receipt of all required environmental permits, authorizations, and permissions. Specifically, SAFCA will be implementing the following elements:

North Sacramento Streams Levee Improvements – Improve approximately 4 miles of levees along the Natomas East Main Drainage Canal (NEMDC)/Steelhead Creek East Levee and Arcade Creek North and South Levees to mitigate seepage, meet embankment and foundation stability requirements, and remove high-hazard encroachments and vegetation that threaten levee integrity to allow accreditation of the levees. In addition to levee improvements, riparian plantings associated with the Conservation Strategy would be implemented at several sites.

Sacramento River East Levee Improvements – Improve approximately 6 miles of the Sacramento River East Levee, including the Little Pocket and Pocket areas, to address seepage and meet embankment and foundation stability requirements; mitigate approximately 3,000 feet (approximately 0.6 mile) of erosion at several sites on the Sacramento River East Levee; and remove high-hazard encroachments and vegetation that threaten levee integrity to allow accreditation of the levee.

American River and Beach Lake Levees High-Hazard Levee Encroachment and Vegetation Removal – Remove high-hazard encroachments and vegetation to allow accreditation of segments of the American River North and South Levees and the Beach Lake Levee.

Natomas East Main Drainage Canal/Steelhead Creek Corridor Management Plan – Reduce channel roughness, increase floodwater conveyance capacity, and provide essential habitat for salmon and steelhead in the Dry Creek and the NEMDC/Steelhead Creek channels, and for warm-water species in the Arcade Creek channel.

The Levee Accreditation Mitigation and Conservation Strategy – Protect, avoid, minimize, reduce, and mitigate impacts on sensitive habitats and special-status species that may be temporarily or permanently affected by the LAP improvements.


4. Modifications and Refinements to the Project

4.1 Minor Project Refinements with No Environmental Impacts Not Evaluated in Detail

Changes to the year in which project-related construction would begin and end, and details as to the timing of the different types of construction would result in no new environmental impacts and would not increase the intensity or severity of impacts previously evaluated in the prior EIR because the total amount of construction would not change, and there would be no changes that would result in more intense construction activities compared to the activities previously evaluated. These changes are therefore not evaluated further in this Addendum.

4.2 Project Refinements Evaluated in Detail 4.2.1 Beach/Stone Lake Mitigation Sites In coordination with the Sacramento Regional County Sanitation District (SRCSD), SAFCA has identified portions of two parcels owned and managed by SRCSD and the Sacramento Area Sewer District, including an area within the SRCSD’s Upper Beach Lake Wildlife Area (identified as Site B-1, shown on Figure 2) and an area landside of the Sacramento River East Levee and adjacent to Morrison Creek (identified as Site B-2, shown on Figure 3) as woodland mitigation areas. A diverse assemblage of native riparian species could be planted in these areas, and establishment of such riparian woodland habitat would expand on similar habitat in the Stone Lakes National Wildlife Refuge located immediately to the south. This would enhance habitat for neotropical migrants and special-status raptor species, such as Swainson’s hawk and white-tailed kite. The areas landside of the Sacramento River East Levee (site B-2) are currently in agricultural production, but only a portion of each parcel would be planted, and the woodland planting configuration would be designed to minimize impacts on agricultural production. Up to 42 acres of woodland habitat could be planted on these areas, depending on the overall mitigation needs and efforts to minimize loss of agricultural land. Two of the planting areas would be appropriately configured to provide additional benefit as a vegetated buffer protecting the Morrison Creek Levee from wind-wave erosion during flood events.

Site B-1 (Figure 2) currently consists of native grasslands. Both ends of the site include some planted native trees and shrubs that had a low success rate, likely due to inadequate soil preparation (i.e., deep ripping) that is necessary at this site to establish deep-rooted woody vegetation. Thus, the vegetation planted at Site B-1 would both enhance existing woodland and create new woodland. Prior to implementation, the health and viability of these existing trees and shrubs would be further evaluated to determine if they would be retained or replaced. The woodland corridor would be dominated by valley oak (Quercus lobata) and interior live oak (Quercus wislizeni). Other canopy species would include scattered box elders (Acer negundo) and Oregon ash (Fraxinus latifolia). Species diversity would be limited due to the high clay content of the site soils. Understory shrubs may include California rose (Rosa californica), California blackberry (Rubus ursinus), blue elderberry (Sambucus nigra ssp. caerulea), and coyote brush (Baccharis pilularis). The herbaceous understory would be comprised of a


mix of native perennial grasses. A 50-foot-wide buffer between the levee toe and the woodland corridor would be retained to allow for levee inspection and would be comprised of a mix of native perennial grasses and forbs.

Site B-2 is currently in agricultural production (Figure 3). The northern parcel currently supports dryland crops, such as winter wheat and oats; the southern parcel is currently cultivated in alfalfa. The woodland corridor at this site would include valley oak, willows (Salix spp.), California sycamore (Platanus racemosa), box elder, Fremont cottonwood (Populus fremontii), and Oregon ash. Understory shrubs would include blue elderberry, California rose, and California blackberry. The herbaceous understory would be composed of a mix of native perennial grasses. To avoid shade impacts to crop production, approximately 10–20 feet at the southern and eastern edges of the corridor would be planted only with shrubs and understory vegetation.

A 50-foot-wide buffer adjacent to the levee would be retained at Site B-2 to allow for levee inspection and would be comprised of a mix of native perennial grasses and forbs. There is an existing agricultural irrigation ditch (approximately 20 feet wide at top-of-bank) located at the northern boundary of Site B-2. Within the ditch is a standpipe that could be used for future irrigation of the agricultural fields. The standpipe is connected to an existing, but currently non-operational, slant pump waterside of the Sacramento River East Levee that is located directly west of the B-2 mitigation site. To facilitate continued agriculture at Site B-2, access to the irrigation standpipe and an existing access road from the northern levee would be retained.

The sites would be accessed using existing agricultural roads, and staging would be restricted to previously disturbed, adjacent areas. The limit of work boundaries would be clearly demarcated to prevent disturbance to outside areas. Trees and/or shrubs at Site B-1, including any existing trees greater than 6 inches diameter at breast height (dbh) and multi-trunk trees greater than 10 inches dbh would be preserved or transplanted on-site. Soil preparation would avoid impact to the root zone of trees to be retained. Poor performing trees would be removed to facilitate proper soil preparation. Prior to planting, soil preparation at Site B-1 would include deep ripping to depths of up to 6 feet using a single shank attached to a bulldozer. Soil preparation at Site B-2 may also include ripping to depths of 3–4 feet. All planting areas would be disked to a depth of 6–12 inches. Following soil preparation, planting holes would be augered. It is anticipated that container planting would be accomplished manually. All disturbed areas would be seeded by drill or broadcast seeding method.

Once planting is complete, all equipment, trash and debris, would be transported off‐site. To facilitate establishment, periodic manual or mechanical removal of invasive species, herbicide application, and irrigation would be conducted. A temporary drip irrigation system would be installed to water the woody vegetation at both sites during a 3- to 5-year establishment period. The irrigation system connection for Site B-1 would be from an existing well located approximately 0.5-mile to the south of the site. Water used for establishing the plantings on Site B-2 would be obtained from a new agricultural well planned to be installed.


Figure 2. Proposed Woodland Mitigation Site B-1



Figure 3. Proposed Woodland Mitigation Site B-2



5. Standard for Preparation of an Addendum

If, after adoption of an EIR, altered conditions or changes or additions to a project are proposed, the State CEQA Guidelines provide three ways to address these changes: a Subsequent EIR (Section 15162), a Supplemental EIR (Section 15163), or an Addendum (Section 15164).

State CEQA Guidelines Section 151622 describes the conditions when preparing a Subsequent EIR is required.3 A Subsequent EIR is appropriate if the lead agency determines, on the basis of substantial evidence in light of the whole record, that one or more of the following conditions is met:

Substantial changes are proposed in the project which will require major revisions of the previous EIR due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects;

Substantial changes occur with respect to the circumstances under which the project is undertaken which will require major revisions of the previous EIR due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects; or

New information of substantial importance, which was not known and could not have been known with the exercise of reasonable diligence at the time the previous EIR was certified, shows any of the following:

The project will have one or more significant effects not discussed in the previous EIR;

Significant effects previously examined will be substantially more severe than shown in the previous EIR;

Mitigation measures or alternatives previously found not to be feasible would in fact be feasible, and would substantially reduce one or more significant effects of the project, but the project proponents decline to adopt the mitigation measure or alternative; or

Mitigation measures or alternatives which are considerably different from those analyzed in the previous EIR would substantially reduce one or more significant effects on the environment, but the project proponents decline to adopt the mitigation measure or alternative.

2 See State CEQA Guidelines, Section 15162(a)(1)-(3). 3 A Supplemental EIR is required if any of the conditions described in Section 15162 would require preparation of a

Subsequent EIR, but only minor additions or changes would be necessary to make the previous EIR adequate. State CEQA Guidelines, Section 15163(a)(1)-(2).


State CEQA Guidelines Section 15164 states that a lead agency may prepare an Addendum to a certified EIR if some changes or additions are necessary, but none of the conditions described above in Sections 15162 or 15163 calling for the preparation of a Subsequent or Supplemental EIR have occurred.

As explained in the analysis in Section 3, below, the proposed modifications and refinements to the project would not:

result in any new significant or potentially significant environmental effects, or

result in a substantial increase in the severity of previously identified significant or potentially significant effects.

In addition, no new information of substantial importance has arisen that shows that:

the project would have new significant or potentially significant effects,

the project would have substantially more severe effects,

mitigation measures previously found to be infeasible would in fact be feasible, or

mitigation measures that are considerably different from those analyzed in the EIR would substantially reduce one or more significant or potentially significant effects on the physical environment.

Because none of the conditions described in Section 15162 of the State CEQA Guidelines calling for preparation of a Subsequent EIR have occurred, an Addendum to the EIR, consistent with Section 15164 of the State CEQA Guidelines, is the appropriate CEQA document to evaluate the proposed modifications and refinements to the project and substantiate that none of the conditions described in Section 15162 have occurred.

6. Environmental Analysis

This section of the Addendum analyzes the potential effects on the physical environment from implementation of the proposed modifications and refinements to the project. This analysis has been prepared to determine whether any of the conditions in State CEQA Guidelines Section 15162 (described in Section 1.4) would occur as a result of the proposed modifications and refinements.

The proposed project modifications and refinements (i.e., modifications to the timing of construction, and modifications to the size and location of woodland mitigation sites) would not cause any new significant or potentially significant impacts or a substantial increase in the intensity or severity of the impacts analyzed and disclosed in the prior EIR for the following topic areas, because the activities associated with the proposed modifications and refinements would result in negligible additional impacts that would not substantially increase the magnitude from the prior EIR:


Aesthetics Air Quality Geology and Soils Geomorphology Greenhouse Gas Emissions Hazards and Hazardous Materials Land Use and Planning Mineral Resources Noise Paleontological Resources Recreation Transportation and Traffic Utilities and Service Systems

Although the proposed Beach/Stone Lakes Mitigation Sites have shifted from the footprints analyzed in the prior EIR, similar or larger mitigation sites with overlapping footprints were analyzed in the prior EIR. The modified footprint for Site B-1 is a modification of the “potential riparian woodland habitat site in the Upper Beach Lake Wildlife Area” identified on Exhibit 3-26 of the prior EIR. Site B-2 is a modification of the site identified as a “potential riparian woodland habitat site near Stone Lakes National Wildlife Refuge” in Exhibit 3-23 of the prior EIR.

The following topic areas may be affected by the proposed modifications and refinements to the project and, therefore, are analyzed below.

6.1 Agriculture and Forestry Resources The modifications at Site B-2 would result in a total of 25 acres of land being removed from agricultural use and permanently established as woodland habitat. This total acreage is less than the 75 acres of impact which were disclosed in the prior EIR, and less than the 50-acre Sacramento County conversion threshold identified in the prior EIR, which was identified as a significant impact related to loss of Important Farmland. The planting of 25 acres of riparian habitat on Site B-2 would thus, not result in new or substantially more severe impacts related to agriculture than what was already disclosed. Furthermore, the proposed installation of a new groundwater well at Site B-2 would improve the productivity of the remaining farmland on the parcel. Implementation of Mitigation Measure AG-1 (Avoid Disruption of Existing Agricultural Operations During Construction Activities and Minimize Important Farmland Conversion to the Extent Feasible), which was previously adopted and incorporated into the LAP, would reduce the significant impact associated with the conversion of Important Farmland to non-agricultural uses, but not to a less-than-significant level, because no new farmland would be made available and the productivity of existing farmland would not be improved. Consequently, full compensation for loss of Important Farmland would not be achieved and a net loss of Important Farmland would still occur. Therefore, as with the impact described in the prior EIR, this impact would remain significant and unavoidable. No further mitigation beyond that included in the prior EIR and previously adopted is required.

The riparian plantings at Site B-1 would enhance and expand existing degraded woodland adjacent to that site, resulting in an overall benefit to forestry resources, consistent with the beneficial impact described in the prior EIR. The modifications at Site B-1 would, therefore, not result in new or


substantially more intense, severe, or greater impacts related to forestry resources than what was already disclosed.

6.2 Aquatic and Terrestrial Biological Resources GEI Consultants, Inc. (GEI) conducted a wetland delineation at woodland Sites B-1 and B-2 on April 20, 2018. One agricultural irrigation ditch was identified along the northern edge of the agricultural field on Site B-1, outside of the disturbance footprint. One feature that meets the definition of a “waters of the United States” is present at the southwestern end of Site B-2. Planting would not occur within areas that meet the regulatory definition of a water or wetland and no permanent fill would occur in these areas. Therefore, no impacts to sensitive aquatic habitats would occur with implementation of woodland mitigation Sites B-1 and B-2.

All native oaks and other trees located on public lands that are greater than 6 inches dbh and multi-trunked trees greater than 10 inches dbh that are growing on public lands are subject to the Sacramento County Tree Ordinance (Chapter 19.12, Tree Preservation and Protection). A tree removal permit is required to remove or prune trees protected by the Sacramento County Tree Ordinance. Removal of saplings––including oaks, that are less than 6 inches dbh, or that are multi-trunked, but measure less than 10 inches dbh––may occur at Site B-1 to increase the planting area available and improve soil conditions. Removal would be restricted to saplings that are under the County Tree Ordinance threshold of protection and, therefore, would not result in the need for a tree permit, or result in an impact to a sensitive habitat. No mitigation is required.

Elderberry shrubs, which provide habitat for the Federally threatened valley elderberry longhorn beetle, are present within Site B-1. Activities associated with soil preparation, including deep ripping and disking would encroach within 20 feet of elderberry shrubs at Site B-1, but temporary fencing would be established around each shrub to protect from mechanical damage. Elderberry shrubs are located adjacent to, but not within the planting areas of Site B-2. Elderberry shrubs would not be removed at either site. Implementation of Mitigation Measure BIO-3 (Implement Conservation Strategy Measures to Avoid, Minimize, and Compensate for Direct and Indirect Effects to Valley Elderberry Longhorn Beetle Habitat), which were previously adopted and incorporated into the LAP, would ensure that the impacts to valley elderberry longhorn beetle, and its habitat are less-than-significant. No further mitigation is required.

The EIR identified up to 75 acres of suitable Swainson’s hawk foraging habitat could be converted to woodland at Site B-2, resulting in a loss of foraging habitat and a potentially significant impact to the species. The planting area has been reduced from 75 acres, as identified in the prior EIR, to approximately 25 acres. Therefore, the proposed project modifications would not result in any new or substantially more severe impacts related to loss of Swainson’s hawk foraging habitat. Implementation of Mitigation Measure BIO-7b (Minimize Adverse Impact of Swainson’s Hawk Foraging Habitat Loss and Compensate for Substantial Loss), which was previously adopted and incorporated into the LAP, would ensure that the impacts to Swainson’s hawk, and its habitat are less-than-significant. No further mitigation beyond that included in the prior EIR and previously adopted is required.

Implementation of the project modifications during the nesting season (generally considered February 1 to August 15), could adversely affect Swainson’s hawk, raptors, and other birds protected by the Migratory Bird Treaty Act or California Fish and Game Codes 3503 and 3503.5, if active nests are located within Sites B-1 and B-2, or proximity of disturbance. Removal of saplings could result in the loss of nests of common songbirds, and soil preparation could result in the loss of nests of ground-


nesting species, if conducted during the nesting season. Vegetation removal, including the removal of trees, and clearing and grubbing was evaluated in the prior EIR. The scope of this project modification is consistent with the severity of effect previously analyzed. Implementation of BIO-7a (Implement Conservation Strategy Measures to Avoid and Minimize Effects to Nesting Swainson’s Hawks) and BIO-8 (Implement Conservation Strategy Measures to Avoid and Minimize Effects to Nesting Special-status Birds, Common Raptor Species, and Colonial-nesting Egrets and Herons), which were previously adopted and incorporated into the LAP, would reduce the potential for the loss of active nests to a less-than-significant level. No further mitigation is required.

Implementing Mitigation Measures BIO-3 (Implement Conservation Strategy Measures to Avoid, Minimize, and Compensate for Direct and Indirect Effects to Valley Elderberry Longhorn Beetle Habitat), BIO-7a (Implement Conservation Strategy Measures to Avoid and Minimize Effects to Nesting Swainson’s Hawks), BIO-7b (Minimize Adverse Impact of Swainson’s Hawk Foraging Habitat Loss and Compensate for Substantial Loss), BIO-8 (Implement Conservation Strategy Measures to Avoid and Minimize Effects to Nesting Special-status Birds, Common Raptor Species, and Colonial-nesting Egrets and Herons), BIO-10 (Implement Conservation Strategy Measures to Avoid, Minimize, and Mitigate for Unavoidable Impacts on Sensitive Habitats on a No-Net-Loss Basis), and BIO-12 (Implement Conservation Strategy Measures to Avoid and Mitigate for Adverse Effects on Protected Trees), which were previously adopted and incorporated into the LAP, would reduce these impacts to a less-than-significant level. No further mitigation is required.

6.3 Cultural Resources GEI conducted a cultural resources investigation of woodland Sites B-1 and B-2. The investigation included a cultural resources records search and pedestrian survey. The cultural resources records search was conducted in October 2016 at the North Central Information Center of the California Historical Resources Information System. In addition to Information Center resource and inventory maps, the records search included the following sources:

National Register of Historic Places (NRHP)-listed properties (National Park Service 1996) and updates;

California Inventory of Historic Resources (State of California 1976 and updates); California Points of Historical Interest (State of California 1992 and updates); California Department of Transportation (Caltrans) Bridge Inventory (Caltrans 1989, 2000, and 2004); Historic Maps; California Historical Landmarks (State of California 1996 and updates); Directory of Properties in the Historic Resources Inventory (State of California 2006); Gold Districts of California (Clark 1970); California Gold Camps (Gudde 1975); California Place Names (Gudde 1969); and Historic Spots in California (Hoover et al. 1966 and 1990).

The records search identified two previously known cultural resources in the study area for Sites B-1 and B-2: Morrison Creek Levee Segments and archaeological site CA-SAC-48.

In addition, GEI conducted an intensive pedestrian archaeological survey (survey transects spaced no more than 10 meters apart) of Sites B-1 and B-2 on November 7–11, 2016. Most of the survey area consisted of agricultural fields. The archaeological survey was conducted by three GEI archaeologists under the direct supervision of Jesse Martinez, MA, RPA, who meets the Secretary of the Interior’s


Professional Qualifications Standards for Archaeology. The GEI survey crew was accompanied by a United Auburn Indian Community (UAIC) monitor.

Morrison Creek Levee Segments

Two segments of the Morrison Creek Levee are located directly adjacent to both Sites B-1 and B-2, immediately east and west of Interstate 5. The segments are not part of a USACE project levee system and are part of a levee system that was previously determined not eligible for the National Register of Historic Places (NRHP) and the California Register of Historical Resources (CRHR). The portions of this levee adjacent Sites B-1 and B-2 were constructed after 1975 and have been modified since that period through realignment. In 2002, JRP Historical Consulting, LLC evaluated a section of the levee system (located northeast of Sites B-1 and B-2) and recommended that it was not eligible for the NRHP or the CRHR because of a lack of historical integrity. The State Historic Preservation Officer has concurred with the finding of not eligible for this resource. Since that time additional segments of the drainage and levee system have been recorded and found to not change the previous eligibility findings. Because the subject levee segments are of more recent construction and part of a larger levee system that was previously determined not eligible, they do not meet NRHP or CRHR criteria and no further analysis or mitigation is required.

Archaeological Site CA-SAC-48

Resource CA-SAC-48 (P-34-000075), also known as the Azevedo Mound, is a prehistoric site that has been heavily affected by earth movement and removal of the original soil. The recorded site location is situated at an existing access corridor to Site B-2. The site was first reported by Heizer in 1934 who described it as a mound approximately 50 yards in diameter. Heizer stated that the mound had been scraped off and formed a foundation for a barn. Far Western Anthropological Research Group (FWARG) revisited the site in 2007. FWARG noted the 1934 barn was gone and no evidence of the site could be found. A GEI archaeologist and UAIC monitors went to the recorded site location for this project modification and could find no evidence of the site, but noted that a gravel road runs through the center of the plotted site location.

Although CA-SAC-48 appears to have been demolished and no evidence of the site is visible, it is possible that unobserved site constituents could be present. The existing gravel road would be used as an access road for the project. Use of the existing road for the project would have no effect on previously recorded site because the resource does not appear to still exist.

The Sacramento River East Levee project vicinity is known to have contained documented significant prehistoric archaeological sites, including sites with human burials. Based on the intensity of documented prehistoric use, known early Native American occupation of the project area, and the presence of human remains in previously identified sites in the project vicinity, it is possible that Native American human remains and archaeological resources could be encountered during construction associated with Sites B-1 and B-2. Although no human remains or intact archaeological resources were identified during the investigations of Sites B-1 and B-2, it is possible that presently unknown human remains or archaeological resources could be encountered during site preparation or planting activities. Therefore, the prior EIR determined that the LAP could have a potentially significant impact. Implementing Mitigation Measures CR-3 (Implement Procedures for Inadvertent Discovery of Cultural Resources) and CR-4aPrepare and Implement a Native American Burial Discovery and Treatment Plan, and Mitigation Measure CR-4b: (Implement Procedures for Inadvertent Discovery of Human Remains), which were previously adopted and incorporated into the LAP, would reduce the potentially significant


impact on cultural resources to a less-than-significant level. These mitigation measures apply to all ground-disturbing activities, including the project modifications described in this Addendum. Therefore, for all of the reasons discussed above, the proposed project modifications would not result in any new or substantially more intense, severe, or greater impacts related to cultural resources. No further mitigation is required.

6.4 Water Quality and Groundwater Resources Installing a groundwater well on Site B-2 is one option under consideration to provide water to new plantings. The prior EIR did not analyze impacts related to installation and use of a groundwater well.

The well would be installed within the South American Subbasin, which is under the jurisdiction of the Sacramento Central Groundwater Authority. The subbasin is not on the California Department of Water Resources’ current list of critically overdrafted basins. The well would provide up to 700 acre-feet per year of water for agricultural use. The groundwater basin and the subbasin has historically operated below its sustainable yield of 273,000 acre-feet per year, and use of up to 700 acre-feet per year of groundwater for agricultural purposes in the vicinity of Site B-2 would not deplete groundwater supplies or substantially interfere with groundwater recharge. As required by Sacramento County Code, well construction permits would be obtained for each well. This impact would be less than significant. No mitigation is required.

Possible temporary and short-term significant impacts on water quality could occur at Sites B-1 and B-2, from stormwater runoff, sediment erosion, and spills of bentonite, fuels, lubricants, hydraulic fluids, and coolants, all of which could directly and indirectly affect the water quality of Morrison Creek and downstream waterbodies. Such water quality impacts and can be toxic to fish and other aquatic organisms. However, the project modifications discussed in this Addendum would not substantially increase the severity of the water quality impacts already identified in the prior EIR, including Impact WQ-1 (Possible Temporary and Short-term Impacts on Water Quality from Stormwater Runoff, Erosion, and Spills Associated with Construction) and Impact WQ-3 (Possible Temporary Effects on Groundwater or Surface Water Quality Resulting from Contact with the Water Table during Construction). Implementing Mitigation Measures GEO-1 (Acquire Appropriate Regulatory Permits and Prepare and Implement a Storm Water Pollution Prevention Plan and Associated Best Management Practices), GM-1 (Implement Conservation Strategy Measures to Reduce Erosion and Sediment Transport), HAZ-1 (Implement Conservation Strategy Measures such as a Spill Prevention and Control Plan to Reduce the Potential for Environmental Contamination during Construction Activities), and WQ-3 (Obtain Appropriate Discharge and Dewatering Permit and Implement Provisions for Dewatering), which were previously adopted and incorporated into the LAP, would reduce these impacts to a less-than-significant level. No further mitigation is required.

7. Conclusions

As described in the preceding sections, the proposed modifications and refinements to the project do not require any revisions to the prior EIR because new or substantially more severe significant


environmental impacts or potentially significant environmental impacts would result from the proposed modification and refinements to the project. Section 15162 thresholds would not be triggered.

Based on the analysis in Section 3, “Environmental Analysis,” the proposed modifications and refinements to the project as described in this Addendum would not result in any of the conditions described in Section 15162 of the State CEQA Guidelines calling for preparation of a Subsequent EIR or Supplemental EIR. In summary, the proposed modifications and refinements to the project would not:

o result in any new significant or potentially significant environmental effects,

o substantially increase the severity of previously identified effects,

o new information that mitigation measures or alternatives previously found to be infeasible that would substantially reduce one or more significant or potentially significant effects on the physical environment would in fact be feasible, or

o new information showing that mitigation measures or alternatives that are considerably different from those analyzed in the prior EIR that would substantially reduce one or more significant or potentially significant effects on the physical environment.

These conclusions confirm that a Subsequent or Supplemental EIR is not warranted, and this Addendum to the prior EIR pursuant to State CEQA Guidelines Section 15164 is the appropriate CEQA document to evaluate and document the modifications and refinements (i.e., modifications to the timing of construction, and modifications to the size and location of woodland mitigation sites) to the project, and resulting impacts thereof. No changes are needed to the certified EIR or the adopted MMRP for the project.

8. References

California Department of Transportation. 1989, 2000, and 2004. Caltrans Bridge Inventory.

Caltrans. See California Department of Transportation.

Clark, W. B. 1970. Gold Districts of California. California Division of Mines and Geology Bulletin 193.

Gudde, E. G. 1969. California Place Names. Berkeley: University of California Press.

———. 1975. California Gold Camps. Berkeley: University of California Press.

Hoover, M.B., H. E. Rensch, E. G. Rensch, and W. N. Abeloe. 1966 and 1990. Historic Spots in California. Stanford University Press.


National Park Service. 1996. National Register of Historic Places. List of properties.

State of California. 1976. California Inventory of Historic Resources.

———. 1992. California Points of Historical Interest.

———. 1996. California Historical Landmarks.

———. 2006. Directory of Properties in the Historic Resources Inventory.

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