Initial Study and Draft Mitigated Negative Declaration For

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					            Initial Study and
 Draft Mitigated Negative Declaration
                    For
         Chatsworth Reservoir
Wetland and Riparian Mitigation Program




              Project Applicant:
            Republic Services, Inc.
          14747 San Fernando Road
              Sylmar, CA 91342
    Contact: Kurt Bratton, General Manager
               (818) 833-6504


                  Prepared for

               City of Los Angeles
      Department of Recreation and Parks
        221 N. Figueroa Street, Suite 100
             Los Angeles, CA 90012
Contact: David Attaway, Environmental Supervisor
                 (213) 202-2660



                 Prepared by:

              Zander Associates
       4460 Redwood Hwy, Suite 16-240
            San Rafael, CA 94903
       Contact: Michael Zander, Principal
                (415) 897-8781


                October 2010
Table of Contents

Executive Summary ................................................................................................................ES-1
  ES-1 Project Overview.....................................................................................................ES-1
    Project Purpose...............................................................................................................ES-1
    Proposed Project Area ....................................................................................................ES-2
    Proposed Project Elements.............................................................................................ES-2
  ES-2 Project impact Summary........................................................................................ES-2
  ES-3 Project Implementation Schedule ...........................................................................ES-3
1.0    Introduction .......................................................................................................................1
  1.1      CEQA Process..............................................................................................................1
  1.2      Scope of the IS/MND ....................................................................................................2
  1.3      Impact Terminology ......................................................................................................2
  1.4      Organization of IS/MND ................................................................................................2
2.0    Project Description ............................................................................................................3
  2.1      Purpose of the Proposed Project..................................................................................3
  2.2      Project Location & General Characteristics ..................................................................3
  2.3      Chatsworth Reservioir Site History ...............................................................................4
  2.4      Environmental Setting and Surrounding Land Uses .....................................................5
    2.4.1       Biological Resources .............................................................................................5
    2.4.2       Hydrology ..............................................................................................................6
    2.4.3       Cultural Resources ................................................................................................8
    2.4.4       Surrounding Land Uses.........................................................................................8
  2.5      Project Elements...........................................................................................................9
    2.5.1       Concrete Channel and Berm Removal................................................................10
    2.5.2       Basin Recontouring .............................................................................................10
    2.5.3       Stream Channel Restoration ...............................................................................11
    2.5.4       Riparian Woodland Revegetation........................................................................11
    2.5.5       Enhancement of Existing Wetland.......................................................................11
  2.6      Project Approvals required .........................................................................................12
3.0    Initial Study Checklist and Environmental Impact Evaluation .........................................13
4.0    References......................................................................................................................43
5.0    List of Preparers..............................................................................................................44

                                                               TABLES

Table 1         Newly Created Wetland and Riparian Woodland Habitat........................................…9
Table 2         Summary of Construction Emission Estimates..........................................................20

                                                              FIGURES
                                                                                                                             Follows Page
Figure 1        Regional Location........................................................................................................1
Figure 2        Project Area Characteristics........................................................................................1
Figure 3        Mitigation Site and Project Area..................................................................................3
Figure 4        Locations of Groundwater Monitoring Wells…............................................................8
Figure 5        Mitigation Plan Design Components...........................................................................9
                                ATTACHMENTS

Attachment A    Chatsworth Reservoir Wetland/Riparian Mitigation Program

Attachment B    City of Los Angeles Ordinance No. 169723, Chatsworth Open Space
                Ordinance

Attachment C    Design Concepts and Hydrologic Analysis

Attachment D    A Cultural Resources Study for the Proposed Wetland Riparian
                Restoration Program at Chatsworth Reservoir, Chatsworth, Los Angeles
                County, CA

Attachment E    Estimation of Construction Emissions from Chatsworth Mitigation Project

Attachment F1   Records Search, California Natural Diversity Data Base Chatsworth
                Reservoir Mitigation Planning Area

Attachment F2   Results of Preliminary Vegetation Survey

Attachment F3   September 2007 Plant Survey

Attachment F4   July 2010 Biological Resource Reconnaissance

Attachment G    City of Los Angeles Department of Water & Power Geologic Hazards
                Information

Attachment H    Phase I & Phase II Environmental Assessment
                                CITY OF LOS ANGELES
                       CALIFORNIA ENVIRONMENTAL QUALITY ACT
                                   INITIAL STUDY
                                     (Article I---City CEQA Guidelines)



Council District: 12                                                      Date: October 14, 2010

Lead City Agency:       Department of Recreation and Parks

Project Title:          Chatsworth Reservoir Wetland/Riparian Mitigation Program


EXECUTIVE SUMMARY

This proposed Mitigated Negative Declaration (MND) provides an analysis of the potential
environmental impacts associated with implementation of a wetland/riparian mitigation program
on approximately 44 acres of lands (mitigation site) at the Chatsworth Reservoir property
currently owned and managed by the City of Los Angeles, Department of Water and Power
(DWP), and transfer of those and additional lands to the City of Los Angeles, Department of
Recreation and Parks (RAP). The mitigation program will create and restore riparian and
wetland habitat and establish a conservation easement over an approximately 44-acre area that
includes both the newly created habitats and existing adjacent wetlands and riparian areas. Up
to 140 acres of DWP property (project area), which includes the mitigation site, will be
transferred from DWP to RAP. RAP is the CEQA Lead Agency and will be the implementing
agency for the proposed project.


ES-1    PROJECT OVERVIEW

Project Purpose

The overall purpose of the project is to create, restore, enhance and preserve riparian and
wetland habitat on a portion of the Chatsworth Reservoir property in the City of Los Angeles to
mitigate for wetland and riparian habitat loss at the Sunshine Canyon Landfill near Sylmar,
California. This work is being performed by Allied Remediation Services, Inc (ARS) as a permit
requirement of Browning Ferris Industries of California, Inc. (BFI), a California corporation. BFI
and ARS are both wholly owned subsidiaries of Republic Services, Inc. and will henceforth be
referred to as “Republic” in this document. Republic will compensate DWP for use of its land
and protect the mitigation site in perpetuity through dedication of a conservation easement.
Transfer of the mitigation site and additional lands from DWP to RAP will assure appropriate
long-term open space management and maintenance.




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Proposed Project Area

The Chatsworth Reservoir property is located within the northwestern portion of the San
Fernando Valley, northeast of the intersection of Roscoe Boulevard and Valley Circle Drive in
the City of Los Angeles, Los Angeles County, California. The approximately 410-acre unused
reservoir lies within an approximately 1,323-acre property currently owned and managed by
DWP.

The 140-acre project area, which includes the 44-acre mitigation site, is located outside and
generally to the west of the perimeter levee of the former reservoir. It is located in an area of
gently rolling grasslands with a few rocky knolls, scattered oaks, a large (+35-acre) basin area,
and remnant stream channels, notably small, relatively natural reaches of Woolsey Canyon and
Box Canyon Creeks. A channelized (rip-rapped sides, soft bottom) stream section along the
western edge of the reservoir carries flows from both creeks and the reservoir’s concrete-lined
perimeter drain system through a tunnel drain and off the site via the Los Angeles County Flood
Control District’s Chatsworth Creek Channel.


Proposed Project Elements

The proposed project consists of the following elements:
    •   The detailed design, development, construction and monitoring of the Final Chatsworth
        Reservoir Wetland and Riparian Mitigation Program by Republic;
    •   Compensation from Republic to DWP for use of the approximately 44-acre proposed
        mitigation site at Chatsworth Reservoir;
    •   The establishment of a conservation easement over the approximately 44-acre
        mitigation site to preserve and protect it as permanent open space in perpetuity;
    •   The transfer of up to 140 acres of Chatsworth Reservoir property, including the
        mitigation site, from DWP to RAP;
    •   The establishment by Republic and acceptance by RAP of an interest bearing account
        for future maintenance of the mitigation site.

There are five principal components to the mitigation program design: removal of a section of
concrete perimeter drainage channel and rip-rapped berms along a channelized (soft bottom)
stream reach to create a natural stream channel; recontouring of an existing basin area to
create additional wetlands; restoration of existing stream channels associated with Woolsey
Canyon and Box Canyon Creeks; enhancement of existing wetlands; and creation of additional
riparian woodland habitat. The excess soil generated from these activities will be placed in
adjacent upland areas and will be planted with oak woodland and grassland vegetation.


ES-2    PROJECT IMPACT SUMMARY

This Mitigated Negative Declaration (MND) has determined that the proposed project may
cause potentially significant impacts in the areas of air quality, biological resources, and cultural
resources. The construction activities associated with removal of the concrete channel and
recontouring of the existing basin have the potential to impact local air quality through the
operation of gasoline and diesel powered on-road and off-road equipment (e.g. trucks, tractors,
compactors) for a period of approximately five months. Construction will also result in

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emissions of fine particulate matter and dust (PM10) from grading and earthmoving activities.
Site grading and construction activities could impact locations of Santa Susana tarplant (a
special status plant) just outside of the construction area and could cause removal or
disturbance of active migratory bird nests. The southwestern pond turtle and Sand Diego desert
woodrat could also be affected by construction activities if they are found within the construction
area. Three documented archeological sites have been identified in the vicinity of but not within
the proposed construction area.
Mitigation measures will be adopted as part of the proposed project in order to reduce impacts
to air quality, biological resources, and cultural resources to a level of less than significant. The
mitigation measures to reduce air quality impacts will include limiting the number and types of
equipment used and the hours of operation. Impacts on biological resources will be reduced to
a level of less than significant through utilizing qualified biologists to conduct preconstruction
surveys, flagging sensitive locations and establishing appropriate construction buffers, fencing
sensitive resources to avoid disturbance of these habitats, and having a qualified biologist
monitor construction activities. Mitigation measures to reduce cultural resource impacts include
utilizing a qualified cultural resource expert to monitor construction activities and to direct
installation of construction fencing to avoid any sensitive areas identified. All other resource
categories have been determined to have less than significant impacts or no impacts.


ES-3    PROJECT IMPLEMENTATION SCHEDULE

The proposed mitigation program will be implemented over the next five to six years.
Construction and restoration activities are expected to occur over a period of five months and
are anticipated to start in summer/fall 2011. A conservation easement will be established over
the mitigation site no later than December 31, 2011. Planting will begin in the fall/winter of
2011/2012 with monitoring initiated in 2012 and continuing through at least 2017.




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1.0     INTRODUCTION

In response to an application by Republic Services, Inc., this Initial Study/Mitigated Negative
Declaration (IS/MND) has been prepared for the Los Angeles Department of Recreation and
Parks (RAP) to evaluate the potential environmental consequences of implementing a
wetland/riparian mitigation program, establishing a conservation easement and transferring a
portion of the Chatsworth Reservoir property in the City of Los Angeles to RAP. The
Chatsworth Reservoir property, currently owned and managed by the Los Angeles Department
of Water and Power (DWP), is located within the northwestern portion of the San Fernando
Valley, northeast of the intersection of Roscoe Boulevard and Valley Circle Drive (Figure 1).
The areas proposed for restoration and land transfer occur at the western end of the Chatsworth
Reservoir property, just east of Valley Circle Drive (Figure 2).

As part of the project approval required by the City of Los Angeles, the proposed project is
required to undergo an environmental review pursuant to the California Environmental Quality
Act (CEQA). RAP, which will ultimately manage and maintain the project site, will serve as the
Lead Agency for the CEQA process.

One of the main objectives of CEQA is to disclose to the public and decision-makers the
potential environmental effects of the proposed activities. CEQA requires that the Lead Agency
prepare an Initial Study to determine whether an Environmental Impact Report, a Negative
Declaration, or a Mitigated Negative Declaration is needed. RAP has determined that the
proposed project will require an MND based on the results of the Initial Study.

A previous version of the IS/MND was prepared and circulated for public review in April 2008.
In response to public comments pertaining to the potential for soil and groundwater
contamination in the project area, further action on the project was stopped pending results of a
Phase I and Phase II Environmental Site Assessment (ESA) and a Human Health Screening
Evaluation (HHSE) commissioned by DWP. The IS/MND has now been revised to include the
new information and environmental analysis resulting from these studies.

1.1     CEQA PROCESS

The preparation of this IS/MND is governed by two principal sets of documents: CEQA (Public
Resources Code Section 21000, et seq.) and the State CEQA Guidelines (California Code of
Regulations Section 15000, et seq.). Specifically, the preparation of initial studies is guided by
Section 15063 of the State CEQA Guidelines, and Sections 15070–15075 of Article 6 guide the
process for the preparation of an MND. Where appropriate and supportive to an understanding
of the issues, reference will be made either to the statute, the State CEQA Guidelines, or
appropriate case law.

This IS/MND contains all of the contents required by CEQA, which includes a project
description, a description of the environmental setting, potential environmental impacts,
mitigation measures for any significant effects, consistency with plans and policies, and names
of preparers.




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                                                                                                                                               Exit                                 Flood Control Channel                                                                 Legend

                                                                                                                                                                                                                                                                                    Drainages

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                                                                                                                                                                                                                                                                                    Former Chatsworth Reservoir (Top of Levee)
                                                                                                                                                                                                                                                                                    Chatsworth Reservoir Property




       Zander Associates                                                                                                                                                                                                                               Project Area Characteristics
   Environmental Consultants                                                                                                    Date: 10/10                                                                                                               Chatsworth Reservoir                                         Figure
4460 Redwood Hwy, Suite 16-240                                                                                                  Source of Aerial Photograph: Terraserver, Flown Feb 2005                                                      Initial Study/Mitigated Negative Declaration                                2
     San Rafael, CA 94903                                                                                                                                                                                                                                 Los Angeles, California
DRAFT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION
Department of Recreation and Parks


1.2     SCOPE OF THE IS/MND

This IS/MND evaluates the proposed project’s effects on the following resource topics:

         aesthetics,                                       land use planning,
         agricultural resources,                           mineral resources,
         air quality,                                      noise,
         biological resources,                             population and housing,
         cultural resources,                               public services,
         geology and soils,                                recreation,
         hazards and hazardous materials,                  transportation/traffic, and
         hydrology and water quality,                      utilities and service systems.

1.3     IMPACT TERMINOLOGY

The following terminology is used to describe the level of significance of impacts:

             A finding of no impact is appropriate if the analysis concludes that the project would
             not affect the particular topic area in any way.
             An impact is considered less than significant if the analysis concludes that it would
             cause no substantial adverse change to the environment and requires no mitigation.
             An impact is considered less than significant with mitigation incorporated if the
             analysis concludes that it would cause no substantial adverse change to the
             environment with the inclusion of environmental commitments that have been
             agreed to by the applicant.
             An impact is considered potentially significant if the analysis concludes that it could
             have a substantial adverse effect on the environment.

1.4     ORGANIZATION OF IS/MND

The content and format of this report are designed to meet the requirements of CEQA. The
report contains the following sections:

             Section 1, Introduction, identifies the purpose and scope of the IS/MND and the
             terminology used in the report.
             Section 2, Project Description and Environmental Setting, describes the proposed
             project in detail and identifies the planning objectives, location and background of
             the project.
             Section 3, Initial Study Environmental Checklist, presents the checklist responses
             for each resource topic. This section includes a brief setting section for each
             resource topic and identifies the impacts of implementing the proposed project.



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             Section 4, References, identifies all printed references and individuals cited in this
             IS/MND.
             Section 5, List of Preparers, identifies the individuals who prepared this report, and
             their roles in the project.

2.0     PROJECT DESCRIPTION

This section provides a description of the Wetlands and Riparian Mitigation Program (proposed
project) evaluated for potential environmental impacts in Section 3.0 of this MND. The project
purpose, location, site history, environmental setting, project elements, and required approvals
are described in accordance with Section 15063 of the CEQA Guidelines.

2.1     PURPOSE OF THE PROPOSED PROJECT

The purpose of the proposed project is to mitigate for approximately 13.24 acres of riparian and
wetland habitats lost as a result of closure and extension projects at the Sunshine Canyon
Landfill, near Sylmar. Republic Services, Inc., owner of the Sunshine Canyon Landfill, obtained
regulatory permits for those projects from the U.S. Army Corps of Engineers (Corps) and the
California Department of Fish and Game (CDFG) in 2003 and 2004.1 Closure of the inactive
landfill at Sunshine Canyon began in 2003 and landfill extension to provide additional capacity
within the City limits followed thereafter.

The Corps and CDFG permits issued for those projects required the development and approval
of a mitigation plan to establish a minimum of 35 acres of riparian and wetland habitats at a
suitable mitigation site to compensate for the loss of those habitats. In addition, the permits
required the mitigation site to be dedicated through a conservation easement to protect its
biological resources in perpetuity.

Republic approached Council District 12 and the Los Angeles Department of Water and Power
(DWP) about using a portion of DWP’s Chatsworth Reservoir property to meet its mitigation
requirements. As a result, an approximately 44-acre mitigation site was identified within the
Chatsworth Reservoir property. In June 2006, Republic prepared and submitted a Final
Wetland and Riparian Mitigation and Monitoring Program for Chatsworth Reservoir (Attachment
A) in compliance with the conditions of its Corps and CDFG permits. The program, using the
44-acre Chatsworth Reservoir mitigation site, was approved by the Corps on July 17, 2006 and
by CDFG on August 14, 2006. The mitigation program would be implemented by Allied
Remediation Services, Inc (ARS), a wholly owned subsidiary of Republic Services, Inc.

2.2     PROJECT LOCATION & GENERAL CHARACTERISTICS

The 44-acre mitigation site is located within the Chatsworth Reservoir property, which
encompasses approximately 1,323 acres of land owned and managed by DWP in the
northwestern part of the San Fernando Valley, northeast of the intersection of Roscoe
Boulevard and Valley Circle Drive in the City of Los Angeles (Figures 1 & 2). The mitigation site,
which supports about seven acres of existing wetlands and riparian habitats, is situated outside
and immediately west of the former reservoir perimeter levee (Figures 2 & 3). It is located in an

1
 These permits were originally issued to Browning Ferris Industries of California, Inc (BFI), a California
corporation which is a wholly owned subsidiary of Republic Services, Inc.

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SW Drainages
DRAFT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION
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area of gently rolling grasslands with a few rocky knolls, scattered oaks, a large (+35-acre)
basin area, and remnant stream channels, notably small, relatively natural reaches of Woolsey
and Box Canyon Creeks. A channelized (rip-rapped sides, soft bottom) stream section along
the western edge of the reservoir levee carries flows from both creeks and the reservoir’s
concrete-lined perimeter drain system through a tunnel drain and off the site via the Flood
Control District’s Chatsworth Creek Channel. Existing riparian and wetland habitats within the
mitigation site will be enhanced and 37 additional acres of wetland/riparian habitat will be
created through the mitigation program. The mitigation site will be transferred from DWP to
RAP and its wetland/riparian resources will be protected in perpetuity through dedication of a
conservation easement. In addition, up to 96 acres of adjoining Chatsworth Reservoir property,
located generally to the west of the mitigation site, will also be transferred from DWP to RAP
and set aside as an open space buffer and potential future passive parkland (Figures 2 & 3).
The combined 44-acre mitigation site and 96-acre buffer area, totaling 140 acres, is referred to
as the project area in this environmental analysis.

2.3     CHATSWORTH RESERVIOIR SITE HISTORY

Chatsworth Reservoir was originally placed in service as a water supply reservoir in 1918 to
provide additional terminal storage for the Los Angeles Aqueduct and seasonal regulating
storage for the western portion of the San Fernando Valley. It was located in a natural basin at
the base of several local watersheds, including Santa Susana Creek to the east, Woolsey
Canyon and Box Canyon Creeks at the westerly end, and various other unnamed intermittent
drainages in between.

During the early years, nearly all of the water from the reservoir was used for irrigation. As land
uses in the Valley changed from agricultural to residential and commercial, more of the reservoir
supply was delivered for domestic consumption. This functional change required higher
pressure and better quality water than the reservoir could supply during the latter part of the
summer and resulted in its frequent removal from service.

As early as 1938, there were several plans to increase the storage capacity and depth of the
reservoir by raising the height of the existing dam. However, engineering for the reconstruction
of the reservoir began in earnest in the latter part of 1967. DWP prepared alternative plans to
optimize use of reservoir storage by: 1) deepening and shaping the reservoir; 2) providing a
storm water bypass; and 3) raising the high water elevation by placing a fill and parapet wall on
the crest of the dam. In 1969, a project was implemented to improve the existing perimeter
levee, build new levee sections, and intercept and bypass all storm water runoff from the
watershed (2700 acres) around the reservoir in order to prevent mud, debris and other
constituents typically found in urban runoff from entering the reservoir. The eastern portion of
the reservoir watershed was diverted into the Los Angeles County Flood Control District’s Santa
Susana Creek Channel and the remainder of the watershed was routed around the reservoir
through a perimeter drainage channel system with two large detention basins into the Flood
Control District’s Chatsworth Creek Channel.

The detention basins were constructed outside of the new levee, one along the central northern
portion of the perimeter and another to the west. The northern basin continues to collect local
runoff from the northeasterly watershed areas (with occasional supplemental municipal water in
the summer), and has developed into an aquatic and riparian habitat feature locally referred to
as the Ecology Pond (Figure 2). The west basin was designed to function as an overflow
detention basin, but has not flooded on any regular basis since the reservoir levee was

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improved. Historically, part of the mitigation site was within the high water elevation of the
original (1918) reservoir, but this changed during the reconstruction project when the mitigation
area was physically segregated from the reservoir.

As a result of the 1971 Sylmar earthquake, use of the reservoir was discontinued shortly after
the improvements were completed. Engineering studies performed by the City confirmed that
the reservoir had sustained extensive damage and was no longer viable as a key reservoir to
service the needs of the City. Since 1971, the reservoir has been dry and the site has remained
vacant and fenced along all perimeters. Furthermore, it has never been formally abandoned;
abandonment of dams in California requires official approval from the State Division of Safety of
Dams. In 1997, the City designated the Chatsworth Reservoir property (all 1,323 acres) as a
nature preserve and wildlife refuge (Attachment B).

Maintenance roads and several utility line easements (e.g., Granada Trunk Line, Los Virgenes
Conduit, sewer lines, telephone lines, etc.) exist along the northern and western perimeters of
the project area. Apart from periodic maintenance of those line and general maintenance of the
landscape and other features (e.g., mowing, drainage channel clearance, Ecology Pond
maintenance), there is very little activity within the area.

2.4      ENVIRONMENTAL SETTING AND SURROUNDING LAND USES

2.4.1    Biological Resources

Existing biological resources in the proposed project area can be divided into seven principal
habitat types as follows:

•     Riparian Wetland: This habitat is characterized by a channel-like streambed with dense,
      more or less continuous, stands of willows (Salix spp.), cottonwoods (Populus fremontii),
      sycamores (Platanus racemosa), and mugwort (Artemisia douglasiana). Both Woolsey
      Canyon Creek and Box Canyon Creek supported well-developed riparian wetland
      vegetation prior to clearing and recontouring as a result of DWP maintenance activities in
      2008. Some native riparian species are beginning to reemerge along the banks and in the
      streambed of Woolsey Canyon Creek. Riparian wetland vegetation continues to thrive in
      the channelized stream reach that courses west-northwest immediately west of the reservoir
      levee.

•     Willow/Mulefat Wetland: This habitat is characterized by a low-lying, soggy basin bottom
      that is seasonally wet and ponded, with dense to scattered stands of willows (Salix spp.),
      mulefat (Baccharis salicifolia), and tall flatsedge (Cyperus eragrostis). Some scattered
      individuals of cottonwoods (P. fremontii), salt cedar (Tamarix ramosissima), and cattails
      (Typha sp.) also occur here. The willow/mulefat wetland occurs principally in the central,
      lowest-lying area of the western basin within the broader boundary of the existing seasonal
      wetland.

•     Seasonal Wetland: This habitat is characterized by low-lying, seasonally saturated, but
      intermittently dry, basin, alkaline flats as evidenced by thick salt accretions on its surface.
      There is a dense to patchy distribution of low annual and perennial herbaceous facultative
      wetland and upland species such as saltgrass (Distichlis spicata), spikeweed (Centromadia
      sp.), brass buttons (Cotula coronopifolia), saltbush (Atriplex sp.), tall flatsedge (C.
      eragrostis), cocklebur (Xanthium strumarium), and curly dock (Rumex crispus). The

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    seasonal wetland occurs in the basin bottom area immediately surrounding the
    willow/mulefat wetland and forms a mosaic-like distributional pattern at its interface.

•   Basin Upland Habitat: This habitat is characterized by a subtle one to two foot raise in
    grade that has relatively dry, clay loam soils, but occasionally may be inundated during
    heavy precipitation. The upland basin habitat contains a number of annual introduced grass
    species (e.g. Bromus hordeaceus, B. madritensis ssp. rubens, Vulpia octoflora, Hordeum
    sp.), and other non-native species such as tocalote (Centaurea aff. melitensis), cranesbill
    (Erodium cicutarium), sow thistle (Sonchus oleraceus), mustard (Hirschfeldia incana), and
    yellow sweetclover (Melilotus officinalis). Two native species were characteristic of this
    habitat: namely, coyote brush (Baccharis pilularis ssp. consanguinea) and ragweed
    (Ambrosia psilostachya). The occurrence or ragweed often indicated a clear demarcation
    between this habitat and its interface with the seasonal wetland habitat that it surrounds. Its
    outer edge extends variably into the valley grassland habitat.

•   Valley Grassland: This habitat is extensively distributed away from the various wetland and
    basin upland sites. Its primary indicator species are annual, non-native grasses dominated
    by wild oat (Avena fatua) and barley (Hordeum sp.), among others, but there are scattered
    patches of herbaceous annuals and perennials such as the sunflower (Helianthus annuus),
    deerweed (Lotus scoparius), and telegraph weed (Heterotheca grandiflora). This area is a
    significant portion of the site that, in part, could contribute to expansion of the existing
    wetland habitats through gentle grading and species introduction.

•   Oak Savanna and Woodland: Oaks occur on the site as scattered individuals in savanna
    grassland settings rather than in dense woodlands with well-developed understory. At least
    two species of oaks, coast live oak (Quercus agrifolia) and valley oak (Q. lobata), have been
    observed but it would not be surprising to find other species (e.g. scrub and Engelmann
    oaks) onsite or in the vicinity, particularly in the rocky upland outcrops. The September
    2005 Topanga Canyon fire moved through the area and burned much of the vegetation,
    including many of the oak trees. Reintroduction of oaks that have been documented from
    the vicinity could help restore and enhance the habitat diversity of the area.

•   Coastal Sage Scrub: The rocky outcrops that occur in several nearby uplifted areas also
    provide habitat for coastal sage scrub species (e.g. Salvia shrubs and coyote brush) and
    associated animals. These areas are potential habitat for special-status species that are
    known to occur in the vicinity, such as the Santa Susana tarplant (Deinandra minthornii), the
    many-stemmed dudleya (Dudleya multicaulis), and the San Fernando Valley spineflower
    (Chorizanthe parryi var. fernandina).

2.4.2   Hydrology

Runoff from the surrounding hillsides flows into the proposed project area by way of two
relatively natural, named blue line steams (Woolsey Canyon and Box Canyon Creeks) from the
northwest, a concrete-lined drainage channel along the northern perimeter of the reservoir levee
from the east, and two small unnamed ephemeral drainages from the southwest (Figures 2 & 3).
All flows from Woolsey Canyon and Box Canyon Creeks and the perimeter concrete channel
are routed into the channelized (soft bottom) stream reach at the western toe of the reservoir
levee, conveyed to the bypass storm drain tunnel at its downstream end and then into the Flood
Control District’s Chatsworth Creek Channel south of the tunnel. The two unnamed ephemeral


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drainages on the southwest flow directly into the west basin area where they terminate in a
small wash.

Woolsey Canyon Creek drains a sub-watershed of approximately 574 acres westerly of the
project area and Box Canyon Creek carries water from an approximately 868-acre sub-
watershed to the northwest. The calculated high flows (50-year storm event) for Box Canyon
Creek and Woolsey Canyon Creek just upstream of their confluence above the channelized
stream reach are 1,955 cubic feet per second (cfs) and 1,318 cfs, respectively. Runoff from
sub-watersheds directly to the north and easterly of the former reservoir, including any overflow
from the Ecology Pond, is collected in a system of concrete-lined drainage channels. One main
channel along the northern perimeter levee of the reservoir conveys these flows into the
channelized (soft bottom) stream reach. Design flows (50 year event) at the confluence of the
northern perimeter concrete channel and the channelized stream reach were estimated at over
1,000 cfs. Flows from the two unnamed ephemeral drainages on the southwest are minimal,
coming from separate sub-watersheds of approximately 172 and 20-acres.

Mean annual precipitation in the project area is approximately 15.4 inches, based on 40 years of
records from the central Chatsworth Fire Station located 2-3 miles to the northeast.
Precipitation increases with elevation; at the top of the watershed (Chatsworth Peak, elevation
2,314 feet), mean annual precipitation is estimated to be 25 inches, based on rainfall records
from stations at similar elevations in the vicinity. None of the streams or drainages flowing into
the project area have been gauged. However, based on an analysis of other gauged streams in
the vicinity, mean annual water yield is estimated to be 0.5 area-inches but can vary widely from
year to year.

Most of the contributing watershed areas are comprised of rugged, rocky terrain. Exposed
bedrock, primarily hard sandstone with some shales and conglomerates, is common.
Weathering of the sandstone has resulted in highly permeable sandy alluvium that forms the
base of the hills and much of the topography in the project area. Although the exposed bedrock
generates rapid overland flow during storms, the sandy alluvium tends to more readily absorb
runoff. This geologic setting reduces the hydrologic response to storms in the watershed.
Intense storms, particularly early in the rainy season, generate less surface runoff in the project
area than might be expected from an area with so many visible rock exposures on the
hillslopes. Even though the rocky hills to the north produce overland flows on the rock itself, the
runoff is rapidly infiltrated into the highly permeable alluvium at the base of the slopes and within
the drainage channels.

As the water table in the lower areas, notably at the base of hills and in the west basin area,
rises in response to direct rainfall and groundwater recharge from the adjacent hills, the streams
and drainage channels become more responsive to rainfall. Nonetheless, they tend to respond
with a sizeable portion of flow appearing as “baseflow” as water from the surrounding alluvium
seeps into the channels at the base of the northern hills. All of the unlined channels entering
the project area get progressively smaller as they move away from the rocky foothills and
stream flows infiltrate the alluvium. The lack of well developed alluvial fans exiting the hills from
Woolsey Canyon and Box Canyon Creeks attests to the fact that these watersheds do not
produce large peak flows. In addition, sediment is mostly transported sand as opposed to large
materials, which tend to rapidly deposit as the drainage exits the hills.

Some of the lower areas on the mitigation site, notably the west basin area, have relatively thin
layers of alluvium over clayey subsoils and relatively high seasonal groundwater levels as a

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result. In fact, a high water table has been a constant feature in the west basin area, as
reported by DWP in geotechnical studies performed since 1928. To evaluate the nature and
extent of these groundwater levels for the purposes of potential wetland restoration, thirty-one
shallow groundwater monitoring wells were installed in the project area between September 27-
29, 2005 (Figure 4). Based on data collected at the time of installation and during weekly
monitoring conducted from February to May 2006, groundwater levels rose from what was
probably a seasonal low in September 2005 (several dry wells at depths of 10 feet) to a high on
April 10, 2006 (at least 12 wells with water levels less than one foot from the ground surface).
This correlates with the occurrence of the last significant storm of the season on April 3-6, 2006.
After that date, groundwater levels dropped from a lack of additional rainfall, and uptake in the
soil by vegetation. Data collected from the monitoring wells are discussed further in the
hydrology report included in Attachment C.

2.4.3   Cultural Resources

An archaeological records search and follow up field reconnaissance of the general project area
were conducted in September 2005 (Attachment D). The records search identified three
documented archeological sites within an approximately 150-acre study area. The subsequent
field reconnaissance confirmed the location of one historic site and one prehistoric site. The
historic site (LAN-651H) consists of a Spanish colonial era kiln that has been previously
investigated and sampled. The kiln, a well-known feature among local cultural resource
aficionados, was protected by a shed roof mounted on four corner posts until the
Chatsworth/Topanga fire of 2005 destroyed the roof. The kiln, however, appears to have
survived the fire intact. The prehistoric site that was located (LAN-652) is a milling stone feature
on a bedrock outcrop on a slope above the west basin. The second, unconfirmed prehistoric
site (LAN-653) is a midden with shell fragments reported to be on an adjacent slope. Both of
the prehistoric site locations are situated on high ground and outside of the proposed mitigation
site.

There are no records of paleontological resources or unique geological features in the project
area. The project area has been graded, excavated and otherwise disturbed over the years by
the construction of berms, levees, basins, new channels and other features associated with
operation and use of the site as a water storage reservoir. However, it is unclear whether there
was any Pleistocene ponding in the project area. Such ponding greatly increases the possibility
of encountering fossils during ground disturbance activities.

2.4.4   Surrounding Land Uses

The 1,323-acre Chatsworth reservoir property is the largest remaining undeveloped open space
area in the northwestern part of the San Fernando Valley. Residential areas surround the site
on all sides with the densest areas to the east and south and more rural residential properties to
the north and west. The Santa Susana Mountains lie to the north and the Simi Hills are located
to the west, straddling the Los Angeles/Ventura County line. The village of Chatsworth Lake
Manor is located just northeast of the mitigation site. Office park, research and development,
and other commercial uses are concentrated in an area bordering the south-central perimeter of
the DWP Chatsworth Reservoir property.




Chatsworth Reservoir Wetland/Riparian Mitigation Program                            October 14, 2010

                                                    8
                                                            Box
                                                                         Well 19
                                                            Ca
                                                                  nyo
Well 1                                                               n       Cre
                                                                                   ek




                                                                           Well 18
                                           Well 27
                                                                                                                5: 1




                                                                             ek
                                       Well 28                      Cre
                                                                yon
                                                            Can
                                                     lsey
                                                 W oo




                                                                                                                                          Ch
                             Well 29




                                                                                                                                             ann
                                                                                                                                                 eli
                                                                                                                                                    ze
                                                                                                                            Well 2




                                                                                                                                                      d
                                                                                                                                                     St
                                                                                                                                                       re
                                                                                                                                                         am
                                                                                                                                 Existing Seasonal
                                                                                                                                       Wetland

         Well 31
                                                                                                                                                              Well 1
                   Well 30

                                                                                                                                           Well 17
                                                                                                              Well 16




                                                                                                                       Well 15




                                                                                                               Well 9
                                                                                           Well 8                  Well 10
                                                                                                          Well 13

                                                                  Well 7                                                   Well 14
                                                                                                  Well 12
                                                                           Well 6
                                                                                                             Well 11


                                                                                        Well 5
                                                                                                             Well 3


                                                                                                 Well 4
DRAFT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION
Department of Recreation and Parks

2.5       PROJECT ELEMENTS

The proposed project consists of the following elements:

      •   The detailed design, development, construction and monitoring of the Final Chatsworth
          Reservoir Wetland and Riparian Mitigation Program by Republic;
      •   Compensation from Republic to DWP for use of the approximately 44-acre proposed
          mitigation site at Chatsworth Reservoir;
      •   The establishment of a conservation easement over the approximately 44-acre
          mitigation site to preserve and protect it as permanent open space in perpetuity;
      •   The transfer of up to 140 acres of Chatsworth Reservoir property, including the
          mitigation site, from DWP to RAP;
      •   The establishment by Republic and acceptance by RAP of an interest bearing account
          for future maintenance of the mitigation site.

The mitigation site and extent of lands that may be transferred from DWP to RAP (project area)
are illustrated on Figures 2 & 3. Details of the mitigation program design are described below.

There are five principal design components to the mitigation program: removal of a section of
concrete channel and rip-rap berm to create a natural channel; recontouring of an existing basin
to create additional wetlands; restoration of stream channels associated with Woolsey Canyon
and Box Canyon Creeks; enhancement of existing wetlands; and creation of additional riparian
woodland habitat. The excess soil generated from these activities will be placed in adjacent
upland areas and will be planted with oak woodland and grassland vegetation. The location and
extent of each component is illustrated on Figure 5. The new wetland and riparian habitat to be
created is summarized by project design component in Table 1. Each design component is
briefly described below.

              Table 1: Newly Created Wetland and Riparian Woodland Habitat
   Habitat                                              Square Feet        Acres
   New Riparian Wetlands from Expansion
      Removed Concrete Channel and Berm                   178.966           4.1
      Box Canyon Expansion                                  9,915           0.2
      Woolsey Canyon Expansion                             46,743           1.1
                                            Subtotal                        5.4
   New Seasonal Wetlands from Expansion                   649,884          14.9
                                            Subtotal                       14.9
           Total New Wetland Acres                                         20.3

   New Riparian Woodlands from Expansion
      Removed Concrete Channel and Berm                         87,256              2.0
      Basin Perimeter                                           533,195            12.2
      Box Canyon                                                 52,379             1.2
      Woolsey Canyon                                            44,363             1.0
                                                     Subtotal                      16.4
            Total New Riparian Woodland                                            16.4

   Total New Wetland and Riparian Woodland                                         36.7

Chatsworth Reservoir Wetland/Riparian Mitigation Program                         October 14, 2010

                                                    9
                      Box
                       Ca                                                2 Culverts
                            ny
                                 on                                    to be removed
                                          Cre
                                              ek
                                                                                           Area to be graded
                                                                                         and planted with trees
 Areas for riparian
woodland plantings
                                                                                       500' of Channel to be Removed
  Relocate road                                                    k
                                                           C   re e
                                                        on
                                                                                         Areas to be graded to
                                               a   ny                                  create expanded wetland
                                           y C
                                   o   ls e
                                 Wo



                                                                                             Berms to be removed




                                                                                        Ch
                                                                                         an
                                                                                           ne
                                                                                              liz
                                                                                                ed
                Area to be graded to




                                                                                                    St
          create expanded riparian wetland




                                                                                                      re
                                                                                                        am
            Existing seasonal wetland

                  Willow/Mulefat wetland                                                                          Area to be graded
                                                                                                                  to create new
                                                                                                                  seasonal wetland
DRAFT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION
Department of Recreation and Parks

2.5.1   Concrete Channel and Berm Removal

About 500 linear feet of concrete-lined channel outside of the northwesterly perimeter of the
reservoir levee will be removed and the area will be graded to substantially widen the
streamzone, flatten the side slopes, and create a gentle (+1%) stream gradient toward the west
(Figure 5). Expansion of the riparian area would be accomplished by removing approximately
460 feet of the existing rip-rapped berm along the channelized stream to connect this main
drainage channel to the wetland basin immediately to the west. This main drainage is the last
segment of a stormwater bypass system prior to the point where it enters a tunnel. This
connection will allow the combined flows from Woolsey Canyon Creek, Box Canyon Creek, and
the existing concrete channel entering from the east, to split between the existing channelized
stream and a new wide channel leading into the wetland basin. Grade control sills will be set at
the existing channel bottom elevation and at 0.3 feet higher on the new “overflow” channel.
Thus, low flows will continue down the existing channelized stream, but, once the depth of flow
exceeds 0.3 feet, flows will begin to split between the two channels.

The grading will consist of very gentle, but varying gradients so as to both mimic the existing
topography and provide a range of soil moisture gradients. In most cases, the created slopes
will range from 5:1-7:1 around the periphery of the created wetlands but in some cases they will
be steeper in order to maximize the width of channel bottom. Below the area of berm removal,
a 120-foot wide channel will be created to convey runoff into the wetland basin. The channel
gradient is .022, which is relatively steep, although steeper gradients exist currently in Box
Canyon Creek within the project area. As a safeguard against incision, the new channel will
have a series of five loose rock grade control sills. The sills will be covered with up to 0.5 feet of
soil such that they will be not be visible. However, if there are very high flows prior to the
channel being colonized by woody riparian vegetation and some incision occurs, the cobbles
and rocks released from the sills will armor the channel surface downstream. Thus, any incision
response becomes self-limiting.

Trees, shrubs, grasses and herbaceous plant material will be introduced as seed, sprigs and
plantings into the restored stream zone areas. Approximately four acres of new stream zone
wetlands will be created by this channel work.

2.5.2   Basin Recontouring

Areas in the west basin, generally outside of the existing seasonal wetland boundary but where
groundwater level elevations are relatively high (within +3 feet of the surface), will be graded to
lower the surface elevation over a 15-acre area. This recontouring will effectively elevate
ground water levels in relation to plant root zones and provide suitable conditions for the
development of extended seasonal wetlands over time. Newly introduced flows from the
channel restoration work described above will also be directed toward these lower areas of the
basin to further increase available moisture for wetland and riparian vegetation.

The current grade control structure within the wetland basin will be improved to prevent further
headcutting that could occur as a result of additional runoff. A berm and overflow apron will be
installed to prevent any further headcutting. The elevation of the top of this grade control
structure will be set at elevation 870.7. This elevation will cause inundation of all areas within
the basin which are lower than this elevation. Although the hydrologic justification for wetlands
creation is based on a near-surface water table, allowing runoff from the watersheds to the north
could potentially result in routine, reliable inundation. It is also possible that more routine and

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extensive inundation will result through installation of the grade control simply because runoff
generated in the wetland basin’s watershed will no longer be able to freely drain out of the
basin.

Topsoil salvage within the basin will be evaluated based on the soil profile. If necessary, topsoil
will be salvaged, stockpiled and then reapplied so as to more closely replicate a natural soil
profile. This is particularly important within the transition between the existing uplands and
created wetlands, where the intent is to fully reestablish the existing upland vegetation. A
mixture of seasonal wetland plant species will be introduced as seed, sprigs or plants into these
seasonal wetland areas. Approximately 15 acres of new seasonal wetland will be created as a
result of this grading, recontouring and replanting.

2.5.3   Stream Channel Restoration

The lower reach of Woolsey Canyon Creek and a portion of Box Canyon Creek near their
confluence will be restored and expanded. The maintenance road to the south of Woolsey
Canyon Creek will be relocated to allow for channel expansion. The culverts near the
confluence will be removed allowing flows to pass through the area unimpeded. The streambed
will be widened and side slopes flattened in the confluence area to spread the active channel
(toward a braided configuration), slow velocities, and create a gently-sloped wash. The
recontoured area will be revegetated with appropriate riparian wetland species. Approximately
one acre of new stream zone and riparian wetlands would be created by this channel restoration
work.

2.5.4   Riparian Woodland Revegetation

In addition to seeding, planting and sprigging within the actively graded areas on the site, trees,
shrubs, grasses and herbaceous plant material will be introduced along the margins of the
existing creek channels and recontoured areas according to the appropriate habitat type (e.g.
riparian wetland, seasonal wetlands). This revegetation program will create an expanded
riparian woodland band adjacent to the restored and existing wetland areas. Planting patterns
will be non-geometric and the spacing and densities of the planting will follow CDFG
recommendations. All shrubs will be randomly clustered and spaced. Representative species
under consideration for the planting plan are listed in Table 4 of Attachment A. Approximately
16 acres of new riparian woodland habitat will be created as a result of this work.

2.5.5   Enhancement of Existing Wetland

An invasive plant species eradication program will be initiated in the seven acres of existing
seasonal wetland in the mitigation area. Targeted species will include saltcedar (Tamarix
ramossissima), giant reed (Arundo donax), and Mediterranean mustard (Hirschfeldia incana).
Additionally, fan palm (Washingtonia fillifera), which were planted in this area, will be removed.
Plants will be removed either manually, with equipment (e.g. backhoe), or through application of
herbicide. The appropriate eradication method will be determined based on the targeted
species. Suggested methods for conducting weed control include mechanical clearing, mowing,
and application of non-residual herbicides (Rodeo® and Roundup®). Descriptions of these
various methods are included in Attachment A.

Willow and mulefat will be sprigged in sparse clusters in the existing seasonal wetland to
provide diversity. Logs, rocks and debris piles will be placed within the seasonal wetlands to

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provide basking and loafing habitat for wildlife.

2.6     PROJECT APPROVALS REQUIRED

RAP is the lead agency pursuant to CEQA Guidelines Section 15367. The proposed project and
environmental documentation, including this MND, would require approval by the following City
of Los Angeles decision-making bodies: Board of Recreation and Park Commissioners and the
City Council. Additional anticipated approvals or permits for the proposed project include, but
are not limited to the following:
•       City of Los Angeles Department of Recreation and Parks design review
•       Board of Recreation and Park Commissioners approval of agreement with Republic
•       City of Los Angeles Department of Water and Power approval of property transfer and
        creation of the conservation easement
•       Los Angeles Regional Water Quality Control Board (RWQCB) Notice of Intent
•       City of Los Angeles permits for grading
•       City of Los Angeles Council approval of agreement, land transfer and easement




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3.0     INITIAL STUDY CHECKLIST AND ENVIRONMENTAL IMPACT EVALUATION



Project Title:                                  Chatsworth Reservoir Wetland/Riparian
                                                Mitigation Program

Lead Agency Name and Address:                   City of Los Angeles
                                                Department of Recreation and Parks
                                                221 N. Figueroa Street, Suite 100
                                                Los Angeles, CA 90012


Contact Person and Phone Number:                David Attaway, Environmental Supervisor
                                                (213) 202-2660

Project Location:                               The proposed project area comprises
                                                approximately 140 acres within the DWP
                                                Chatsworth Reservoir property. The property is
                                                located in the northwestern portion of the San
                                                Fernando Valley, northeast of the intersection
                                                of Roscoe Boulevard and Valley Circle Drive in
                                                the City of Los Angeles, Los Angeles County,
                                                California


Project Sponsor’s Name and Address: Allied Remediation Services, Inc
                                    (for) Browning Ferris Industries of California,
                                    Inc. (dba) Sunshine Canyon Landfill, a Republic
                                    Services Company
                                    14747 San Fernando Road
                                    Sylmar, California 91354

General Plan Designation:                       Open Space

Zoning:                                         [Q]OS-1XL

Description of Project:                         See Section 2, Project Description.

Surrounding Land Uses and Setting:              See Section 2, Project Description.

Other Public Agencies whose Approval California Department of Fish and Game
is Required:                         U.S. Army Corps of Engineers
                                     Los Angeles Regional Water Quality Control
                                     Board


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Environmental Factors Potentially Affected:

The environmental factors checked below would potentially be affected by this project (i.e., the
project would involve at least one impact that is a “Potentially Significant Impact”). However,
any potentially significant impacts can be mitigated to less than significant levels as indicated by
the checklist on the following pages.

    Aesthetics                              Agricultural Resources               Air Quality
    Biological Resources                    Cultural Resources                   Geology/Soils
    Hazards and Hazardous
                                            Hydrology/Water Quality              Land Use/Planning
    Materials
    Mineral Resources                       Noise                                Population/Housing
    Public Services                         Recreation                           Transportation/Traffic
    Utilities/Service Systems               Mandatory Findings of Significance

Determination:

On the basis of this initial evaluation:

    I find that the proposed project COULD NOT have a significant effect on the environment, and a
    NEGATIVE DECLARATION will be prepared.

    I find that although the proposed project could have a significant effect on the environment, there
    will not be a significant effect in this case because revisions to the project have been made by or
    agreed to by the project proponent. A MITIGATED NEGATIVE DECLARATION will be prepared.

    I find that the proposed project MAY have a significant effect on the environment, and an
    ENVIRONMENTAL IMPACT REPORT is required.

    I find that the proposed project MAY have an impact on the environment that is “potentially
    significant” or “potentially significant unless mitigated” but at least one effect (1) has been
    adequately analyzed in an earlier document pursuant to applicable legal standards and (2) has
    been addressed by mitigation measures based on the earlier analysis, as described on attached
    sheets. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects
    that remain to be addressed.

    I find that although the proposed project could have a significant effect on the environment,
    because all potentially significant effects (a) have been analyzed adequately in an earlier
    ENVIRONMENTAL IMPACT REPORT or NEGATIVE DECLARATION pursuant to applicable
    standards, and (b) have been avoided or mitigated pursuant to that earlier ENVIRONMENTAL
    IMPACT REPORT or NEGATIVE DECLARATION, including revisions or mitigation measures that
    are imposed upon the project, nothing further is required.

                                                                         October 6, 2010
                      Signature                                               Date


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Evaluation of Environmental Impacts:

1.      A brief explanation is required for all answers except “No Impact” answers that are
        adequately supported by the information sources a lead agency cites in the parentheses
        following each question. A “No Impact” answer is adequately supported if the
        referenced information sources show that the impact simply does not apply to projects
        like the one involved (e.g., the project falls outside a fault rupture zone). A “No Impact”
        answer should be explained if it is based on project-specific factors as well as general
        standards (e.g., the project will not expose sensitive receptors to pollutants, based on a
        project-specific screening analysis).

2.      All answers must take account of the whole action involved, including offsite as well as
        onsite, cumulative as well as project-level, indirect as well as direct, and construction as
        well as operational impacts.

3.      Once the lead agency has determined that a particular physical impact may occur, the
        checklist answers must indicate whether the impact is potentially significant, less than
        significant with mitigation, or less than significant. “Potentially Significant Impact” is
        appropriate if there is substantial evidence that an effect may be significant. If there are
        one or more “Potentially Significant Impact” entries when the determination is made, an
        Environmental Impact Report (EIR) is required.

4.      “Negative Declaration: Less than Significant with Mitigation Incorporated” applies when
        the incorporation of mitigation measures has reduced an effect from a “Potentially
        Significant Impact” to a “Less-than-Significant Impact”. The lead agency must describe
        the mitigation measures and briefly explain how they reduce the effect to a less-than-
        significant level. (Mitigation measures from Section XVII, “Earlier Analyses,” may be
        cross-referenced.)

5.      Earlier analyses may be used if, pursuant to tiering, program EIR, or other CEQA
        process, an effect has been adequately analyzed in an earlier EIR or negative
        declaration [Section 15063(c)(3)(D)]. In this case, a brief discussion should identify the
        following.
        (a)     Earlier Analysis Used. Identify and state where earlier analyses are available for
                review.
        (b)     Impacts Adequately Addressed. Identify which effects from the above checklist
                were within the scope of and adequately analyzed in an earlier document
                pursuant to applicable legal standards and state whether such effects were
                addressed by mitigation measures based on the earlier analysis.
        (c)     Mitigation Measures. For effects that are “Less than Significant with Mitigation
                Incorporated,” describe the mitigation measures that were incorporated or refined
                from the earlier document and the extent to which they address site-specific
                conditions for the project.

6.      Lead agencies are encouraged to incorporate into the checklist references to information
        sources for potential impacts (e.g., general plans, zoning ordinances). Reference to a
        previously prepared or outside document should, when appropriate, include a reference
        to the page or pages where the statement is substantiated.



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Department of Recreation and Parks

7.      Supporting Information Sources: A source list should be attached, and other sources
        used or individuals contacted should be cited in the discussion.

8.      This is only a suggested form, and lead agencies are free to use different formats;
        however, lead agencies should normally address the questions from this checklist that
        are relevant to a project’s environmental effects in whatever format is selected.

9.      The explanation of each issue should identify:

        (a) the significance criteria or threshold, if any, used to evaluate each question; and

        (b) the mitigation measure identified, if any, to reduce the impact to a less-than-
        significant level.




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                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                        Issues                           Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 1. AESTHETICS. Would the project:
a)   Have a substantial adverse effect on a
     scenic vista?
b)   Substantially damage scenic resources,
     including, but not limited to, trees, rock
     outcroppings, and historic buildings within
     a state scenic highway?
c)   Substantially degrade the existing visual
     character or quality of the site and its
     surroundings?
d)   Create a new source of substantial light or
     glare that would adversely affect day or
     nighttime views in the area?

Explanation (a, c): Less Than Significant Impact. The project will result in the creation of 37
acres of new wetland and riparian habitat in an undeveloped area of the Chatsworth Reservoir
property. Some of these newly created areas will be visible from adjacent residential
neighborhoods. Removal of a portion of the perimeter concrete drainage channel surrounding
the reservoir levee and establishment of native plant materials will soften views from outside the
property. Some viewers may consider that these environmental benefits will enhance the
scenic and aesthetic quality of the area, but others may initially perceive a different view as a
potential negative impact. Short-term, temporary impacts due to equipment operation, dust and
noise will occur during construction and are likely to be perceptible at the property line in some
areas (see below).

Explanation (b): No Impact. Some trees may be removed for restoration of the concrete-lined
channel but this removal will not adversely affect the scenic vista. A substantial number of new
trees will be planted within the proposed mitigation site. No rock outcroppings will be affected
by the project. There are no historical buildings or scenic highways in the project area.

Explanation (d): No Impact. There are no elements of the project that would create a new
source of substantial light or glare either during the day or night.

The project will not cause significant long-term impacts to visual and aesthetic resources.




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                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                        Issues                           Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 2. AGRICULTURAL RESOURCES. In
    determining whether impacts to agricultural
    resources are significant environmental
    effects, lead agencies may refer to the
    California Agricultural Land Evaluation and
    Site Assessment Model (1997) prepared by
    the California Department of Conservation
    as an optional model to use in assessing
    impacts on agriculture and farmland.
    Would the project:
a)   Convert Prime Farmland, Unique
     Farmland, or Farmland of Statewide
     Importance (Farmland), as shown on the
     maps prepared pursuant to the Farmland
     Mapping & Monitoring Program of the
     California Resources Agency, to non-
     agricultural uses?
b)   Conflict with existing zoning for agricultural
     use, or a Williamson Act contract?
c)   Involve other changes in the existing
     environment which, due to their location or
     nature, could result in conversion of
     Farmland to non-agricultural use?

Explanation (a-c): No Impact. The proposed project would occur in and adjacent to a former
water supply reservoir as described above and would not affect any farmland, agricultural uses
or lands subject to Williamson Act contracts. There will be no impact to agricultural resources.


 3. AIR QUALITY. Where available, the
    significance criteria established by the
    applicable air quality management or air
    pollution control district may be relied upon
    to make the following determinations.
    Would the project:
a)   Conflict with or obstruct implementation of
     the applicable air quality plan?




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3. AIR QUALITY (cont.)
                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                        Issues                           Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

b)   Violate any air quality standard or
     contribute substantially to an existing or
     projected air quality violation?
c)   Result in a cumulatively considerable net
     increase of any criteria pollutant for which
     the project region is non-attainment under
     an applicable federal or state ambient air
     quality standard (including releasing
     emissions that exceed quantitative
     thresholds for ozone precursors)?
d)   Expose sensitive receptors to substantial
     pollutant concentrations?
e)   Create objectionable odors affecting a
     substantial number of people?

Explanation (a): Less Than Significant Impact. All new development is subject to the “clean
air” requirements of the U.S. Environmental Protection Agency (EPA), the California Air
Resources Board, and the South Coast Air Quality Management District (SCAQMD). A project
is deemed inconsistent with air quality plans when it results in population and/or employment
growth that exceeds growth estimated in the Air Quality Management Plan. The project
includes construction of new wetland and riparian areas, which would not cause growth in
population or employment. Additionally, the site is currently designated as Open Space under
the City of Los Angeles’ General Plan and is zoned OS (Open Space) in the City’s Zoning
Ordinance, anticipating future development of the site for recreational purposes. Therefore, the
project is consistent with the Air Quality Management Plan and impacts would be less than
significant.

Explanation (b): Less Than Significant Impact With Mitigation Incorporated. The
construction activities will involve the use of gasoline and diesel powered on-road and off-road
equipment (e.g. trucks, tractors, compactors) for a period of approximately five months. Such
equipment will emit air pollutants. Construction also will result in emissions of PM10 from
grading and earthmoving activities. Construction activities will be subject to Rule 403 – Fugitive
Dust of the South Coast Air Quality Management District (SCAQMD), which requires persons
engaging in earthmoving and construction activities to employ best available control measures
to minimize fugitive dust emissions. The exhaust emissions from the construction equipment
that will be used for the project and the PM10 emissions resulting from construction have been
quantified and are below the thresholds of significance for construction emissions set forth in the
SCAQMD CEQA Handbook, assuming that the number and types of equipment and hours of
operation are implemented as described in the January 28, 2008 report prepared by ENVIRON
(Attachment E). A summary of the construction emissions estimates is provided in Table 2.


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       Table 2: Summary of Construction Emission Estimates

                                                                   Total Construction Emissions (tons)

                                                            CO         ROC         NOx         SOx       PM10

                   Total Emissions                         0.40        0.13        1.1       1.1E-03     0.36
       SCAQMD CEQA Significance Thresholds                 24.75       2.5         2.5         6.75      6.75
                 Exceeds Threshold?                         No         No          No          No        No


To reduce potential impacts to a level of less than significant, the following mitigation measures
will be incorporated into the proposed project:

Mitigation Measures:

MM 3-1. To assure that construction emissions remain less than significant, Republic will limit
the equipment used to the number and types of equipment and the hours of operation as
described in the January 28, 2008 report from ENVIRON (Attachment E).

MM 3-2. The project will comply with the rules of the SCAQMD pertaining to emissions from
grading and earthmoving operations. Operation in compliance with these rules is consistent
with the applicable air quality plan.

Explanation (c): Less Than Significant Impact. Once construction activities are complete,
there will be no further need for mobile construction equipment and there will be no construction
equipment at the project site. Accordingly, there will be no net increase of any criteria pollutant.
There are no projects within approximately one mile that would cause related impacts resulting
in a cumulatively considerable net increase of any criteria pollutant.

Explanation (d): Less Than Significant Impact. Due to the limited duration of construction
activities, the distance to sensitive receptors (nearest residence), and the fact that project
emissions are less than the SCAQMD significance levels for construction emissions, the
mitigation project is not expected to expose sensitive receptors to substantial pollutant
concentrations.

Explanation (e): Less Than Significant Impact. There will be diesel exhaust emissions
associated with grading and construction, but given the distance to the nearest residences, such
emissions are not expected to result in objectionable odors.




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                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                        Issues                           Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 4. BIOLOGICAL RESOURCES. Would the
    project:
a)   Have a substantial adverse effect, either
     directly or through habitat modifications,
     on any species identified as a candidate,
     sensitive, or special status species in local
     or regional plans, policies, or regulations,
     or by the DFG or USFWS?
b)   Have a substantial adverse effect on any
     riparian habitat or other sensitive natural
     community identified in local or regional
     plans, policies, regulations or by the DFG
     or USFWS?
c)   Have a substantial adverse effect on
     federally protected wetlands as defined by
     Section 404 of the Clean Water Act
     (including, but not limited to, marsh, vernal
     pool, coastal, etc.) through direct removal,
     filling, hydrological interruption or other
     means?
d)   Interfere substantially with the movement
     of any native resident or migratory fish or
     wildlife species or with established native
     resident or migratory wildlife corridors, or
     impede the use of native wildlife nursery
     sites?
e)   Conflict with any local policies or
     ordinances protecting biological resources,
     such as a tree preservation policy or
     ordinance?
f)   Conflict with the provisions of an adopted
     Habitat Conservation Plan, Natural
     Community Conservation Plan, or other
     approved local, regional, or state habitat
     conservation plan?


Explanation (a): Less Than Significant With Mitigation Incorporated. A query of the
California Natural Diversity Database (CNDDB) (Simi Valley East, Canoga Park, Oat Mountain
and Calabasas 7.5-minute USGS quadrangles) was conducted initially in 2005 and again in

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2007 and 2010 for recorded occurrences of special-status species in the vicinity. The California
Native Plant Society's On-line Inventory (CNPS 2010) was also consulted for information on
special-status plants known to occur in Los Angeles and Ventura Counties. A target list of
special status plant and animal species was developed and evaluated for their potential to occur
within the project area (Attachment F1). CNDDB occurrences of special status species within a
five mile radius of the project area were plotted on a quad sheet base (Attachment F1). All
special-status species recorded within a five mile radius of the site were evaluated for their
potential to occur in the project area. Several plant species including the Santa Susana tarplant
(Deinandra minthornii), the many-stemmed dudleya (Dudleya multicaulis), Blochman’s dudleya
(Dudleya blochmaniae ssp. blochmaniae) and the San Fernando Valley spineflower
(Chorizanthe parryi var. fernandina) have been recorded or potentially occur in coastal scrub
habitats in the project vicinity. Special-status animal species recorded within a five mile radius
of the project area include the tricolored blackbird (Agelaius tricolor), burrowing owl (Athene
cunicularia), arroyo toad (Bufo californicus), two-striped garter snake (Thamnophis hammondii),
San Diego desert woodrat (Neotoma lepida intermedia), coast (San Diego) horned lizard
(Phrynosoma coronatum) and western spadefoot (Spea hammondii).

None of the targeted special-status plants were observed in the proposed project area during
reconnaissance-level surveys conducted in summer 2005 as part of the initial site
characterization work associated with mitigation plan development (Attachment F2). However,
most of the project area burned during the September 2005 Chatsworth/Topanga fire. A
systematic plant survey was conducted on September 7, 2007 to identify late season blooming
species that might occur in the area. During those surveys, several locations of Santa Susana
tarplant were identified in the Chatsworth Reservoir property but none of these are within the
proposed project area (Attachment F3). A follow-up biological resource reconnaissance of the
area was conducted in July 2010 (Attachment F4). Apart from clearing and recontouring work in
Woolsey Canyon and Box Canyon Creeks as a result of DWP maintenance activities in 2008,
conditions in the project area have not changed substantially since 2007. The locations of
Santa Susana tarplant observed in 2007 were reconfirmed during the July 2010
reconnaissance.

No focused surveys for special-status animals have occurred in the project area, but members
of the Southwestern Herpetologists Society have conducted regular monitoring of fixed
coverboard locations, primarily focused on reptiles, over a period of several years on the
Chatsworth Reservoir property. Those surveys identified four special status animals on the
Chatsworth Reservoir property: western spadefoot, coast horned lizard, two-striped garter
snake and tri-colored blackbird. Other special-status animals with potential to occur in the
project vicinity include southwestern pond turtle, San Diego desert woodrat, and several birds
considered species of special concern. An historical occurrence of arroyo toad was reported
from Chatsworth drain below Chatsworth Reservoir in 1970. The CNDDB states that this
occurrence is thought to be extirpated. Members of the Southwestern Herpetologists Society
have not observed the arroyo toad during any surveys of the area and they do not expect it to
occur due to lack of suitable habitat and presence of the California toad.

Site grading and construction activities are not expected to directly impact any special status
plant species; none have been observed in the proposed project area over a period of several
years of assessment. However, seasonally-timed spring surveys have not been conducted in
the area since the Chatsworth/Topanga fire and there is a possibility for new species (especially
annuals) to have become established following the fire. Locations of Santa Susana tarplant
occur just outside of the project area that could be indirectly affected by equipment during

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construction and planting activities. Depending on the extent of disturbance, these activities
could adversely affect the local population of Santa Susana tarplant. Individual southwestern
pond turtles, San Diego desert woodrats and nesting birds could be impacted during
construction activities if they are found within the work area. Loss of individual pond turtles or
San Diego woodrats is not likely to have a substantial adverse effect on the species but
minimization measures could reduce the extent of this potential effect. Active nests of birds-of-
prey and other migratory birds are protected under the Migratory Bird Treaty Act and under
Section 3503.5 of the Fish and Game Code. Removal or disturbance of an active migratory bird
nest during construction activities is therefore considered a potentially significant impact. Since
the resulting restoration project is expected to have a net benefit on native plant and wildlife
species, there should be long-term favorable effects on special status species.

To reduce potential impacts to a level of less than significant, the following mitigation measures
will be incorporated into the proposed project:

Mitigation Measures:

MM 4-1. Republic will contract with a qualified botanist to conduct appropriately-timed floristic
surveys during the spring of the year of construction to confirm that no new special-status plant
species have become established in the project area (possibly as a result of the
Chatsworth/Topanga fire). In the unlikely event that new special-status plants are identified,
they will be flagged and avoided during construction. If avoidance is infeasible, plant material
will be salvaged, propagated and reintroduced into appropriate habitats following site
restoration.

MM 4-2. Prior to initiation of construction, Republic will ensure that the populations of Santa
Susana tarplant located near the construction area are delimited with orange construction
fencing. The exact location of the fence shall be determined by a qualified biologist based on
appropriately-timed (July-September) pre-construction surveys for the species.

MM 4-3. Republic will contract with a qualified biologist to conduct preconstruction surveys for
the southwestern pond turtle, San Diego desert woodrat and nesting birds within the
construction area. The surveys will be conducted by a qualified biologist within 30 days prior to
initiation of construction. Surveys for nesting birds will be expanded up to 300 feet beyond the
construction area if determined necessary by the biologist to ensure that construction activities
will not cause abandonment of an active nest. If any woodrat nests, pond turtles, or active bird
nests are observed within the proposed work area, the biologist will consult with CDFG on
measures to avoid or minimize disturbance to these animals. It may be possible to move
woodrats and/or turtles out of harm’s way. If active bird nests are discovered, a buffer zone
may be required around the nest to minimize disturbance until such time that the young have
fledged. Once the biologist determines the nest is no longer active, construction activities can
resume within the established buffer zone.

MM 4-4. Republic will contract with a qualified biologist to be on-site during construction to
monitor effects on local wildlife, ensure protection measures (e.g. fences) are maintained,
recommend minimization measures as needed, and generally oversee implementation of the
mitigation program.

MM 4-5. Republic will install orange construction fencing around the perimeter of the existing
wetland to ensure that heavy equipment and other construction vehicles do not impact the

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habitat during construction. The onsite biologist will determine if additional exclusion techniques
(e.g. drift fencing) are warranted to protect local wildlife during construction.

Explanation (b) Less Than Significant With Mitigation Incorporated. The overall purpose of
the project is to enhance and restore riparian, wetland and woodland habitats. Plans have been
formulated to avoid direct disturbance of existing riparian wetland and woodland areas during
project grading and construction to the extent feasible. The previously cleared reaches of
Woolsey Canyon and Box Canyon Creeks allow grading and enhancement activities to proceed
in those areas with minimal effect on riparian habitats. However, riparian vegetation has
become established in the section of concrete channel proposed for removal and also in the
channelized reach of the western drainage that will be realigned as part of the project. Some of
this colonizing riparian vegetation will be removed or disturbed during project construction.

To reduce potential impacts to a level of less than significant, the following mitigation measures
will be incorporated into the proposed project:

Mitigation Measures:

MM 4-6. Native plant materials will be salvaged from on-site sources and used for revegetation
of the restoration areas as well as areas temporarily disturbed during construction. Republic will
ensure success of the wetland/riparian mitigation program by obtaining written confirmation from
the Corps and CDFG that the required success criteria have been met and wetland and riparian
habitat has been created.

Explanation (c-d): Less Than Significant Impact. The overall purpose of the project is to
compensate for the loss of federally-regulated wetlands as defined by Section 404 of the federal
Clean Water Act. Thus, it will have a net positive effect on such resources by design. Existing
wetlands in the project area have been delineated and will be avoided during construction to the
extent feasible. Following construction, these wetlands will remain and be enhanced as part of
the restoration effort. No wetlands will be permanently removed, filled, hydrologically isolated or
otherwise adversely affected in the long term by this project.

The project will create new movement corridors and provide new opportunities for a diversity of
habitats to support the various life stages of wildlife species. Temporary disturbance of
corridors may result from construction activities. But, these activities are not expected to
interfere substantially with the movement of any native, resident or migratory fish and wildlife
species, with established corridors, or with the use of native wildlife nursery sites.

Explanation (e-f): Less Than Significant Impact. The City of Los Angeles has an Oak Tree
Ordinance (Sec. 46.00 LAMC; Ord. 153,478) that protects not only oak trees, but also Southern
California black walnuts, western sycamores, and California bays with trunk diameters greater
than four (4) inches. No trees meeting these specifications will be removed for construction of
the project. The Department of Recreation and Parks also has a Tree Preservation Policy,
which protects trees by the abovementioned ordinance, as well as designated Heritage Trees,
Special Value Trees and Other Common Park Trees. Besides the trees protected by ordinance,
the Special Value trees, including box elder (Acer negundo ‘Californica’), big leaf maple (Acer
macrophyllum), Californian walnuts (Juglans californica and J. hindsii), toyon (Heteromeles
arbutifolia), native cherry trees (Prunus ilicifolia, P. lyonii), cottonwood (Populus fremontii, P.
trichocarpa), and native willow trees (Salix hindsiana, S. laevigata, S. lasiandra, S. lasiolepis)
are the only category of trees that may be affected by the project. Some willow and cottonwood

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trees occur in the channelized sections of the drainages to be restored and therefore will be
removed during construction. However, the project will be creating up to 16 acres of new
riparian habitat that will adequately offset the minor amount of tree loss anticipated during
construction.

There is no adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other
approved local, regional, or state habitat conservation plan for the Chatsworth Reservoir area.
The site has been designated as a nature preserve by the City of Los Angeles. The project will
be consistent with that designation.


                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                        Issues                           Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 5. CULTURAL RESOURCES. Would the
    project:
a)   Cause a substantial adverse change in the
     significance of a historical resource as
     defined in §15064.5?
b)   Cause a substantial adverse change in the
     significance of an archaeological resource
     pursuant to §15064.5?
c)   Directly or indirectly destroy a unique
     paleontological resource or site or unique
     geologic feature?
d)   Disturb any human remains, including
     those interred outside of formal
     cemeteries?

Explanation (a-d): Less Than Significant With Mitigation Incorporated. A focused cultural
resources investigation was undertaken for the general project area by John Minch and
Associates, Inc. (Attachment D). The investigation included an archaeological records search
and follow up field surveys in September 2005. The records search identified three documented
archeological sites within the study area. The subsequent field reconnaissance confirmed the
location of one historic site and one prehistoric site. The historic site (LAN-651H) consists of a
Spanish colonial era kiln that has been previously investigated and sampled. The kiln, a well-
known feature among local cultural resource aficionados, was protected by a shed roof mounted
on four corner posts until the Chatsworth/Topanga fire of 2005 destroyed the roof. The kiln,
however, appears to have survived the fire intact. The site is located well outside of the
proposed impact area and can be completely avoided. The prehistoric site that was located
(LAN-652) is a milling stone feature on a bedrock outcrop on a slope above the west basin. The
second, unconfirmed prehistoric site (LAN-653) is a midden with shell fragments reported to be
on an adjacent slope. Both of the prehistoric site locations are situated on high ground outside
of the proposed mitigation site and will not be affected during construction activities.



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There are no records of paleontological resources or unique geological features in the project
area. The project area has been graded, excavated and otherwise disturbed over the years by
the construction of berms, levees, basins, new channels and other features associated with
operation and use of the site as a water storage reservoir. However, it is unclear whether there
was any Pleistocene ponding in the project area. Such ponding greatly increases the possibility
of encountering fossils during ground disturbance activities.

The project area is situated primarily on low ground that was periodically inundated when it was
used as a water storage reservoir. In subsequent years, the ground was graded, excavated and
otherwise disturbed by the construction of berms, levees, basins, new channels and other
features associated with reservoir improvements. Native American burial areas are typically
located on higher ground; no discovery of human remains has been reported from the years of
reservoir operation and improvement and none is expected as a result of this project.

Mitigation Measures:
MM 5-1. A qualified cultural resource expert will be on site to inform construction crews about
the site’s significance and the need to avoid any of the sensitive areas identified.

MM 5-2. A perimeter construction fence will be installed a suitable distance away from the
archeological sites to insure that the areas are not affected during construction activities.

MM 5-3. A qualified monitor will remain available during construction in the event that
paleontological resources, archaeological resources, unique geological features, or human
remains are discovered; work will cease until appropriate measures are determined.


                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                        Issues                           Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 6. GEOLOGY and SOILS. Would the
    project:
a)   Expose people or structures to potential
     substantial adverse effects, including the
     risk of loss, injury, or death involving:
         i) Rupture of a known earthquake
         fault, as delineated in the most recent
         Alquist-Priolo Earthquake Fault Zoning
         Map issued by the State Geologist for
         the area or based on other substantial
         evidence of a known fault? Refer to
         Division of Mines & Geology Special
         Publication 42.




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6. GEOLOGY and SOILS (cont.)
                                                                         Less Than
                                                                         Significant
                                                         Potentially        With       Less Than
                        Issues                           Significant      Mitigation   Significant
                                                           Impact       Incorporated     Impact      No Impact

         ii) Strong seismic ground shaking?
         iii) Seismic-related ground failure,
         including liquefaction?
         iv) Landslides?
b)   Result in substantial soil erosion or the
     loss of topsoil?
c)   Be located on a geologic unit or soil that is
     unstable, or that would become unstable
     as a result of the project, and potentially
     result in on- or off-site landslide, lateral
     spreading, subsidence, liquefaction, or
     collapse?
d)   Be located on expansive soils, as defined
     in Table 18-1-B of the Uniform Building
     Code (1994), creating substantial risks to
     life or property?
e)   Have soils incapable of adequately
     supporting the use of septic tanks or
     alternate wastewater disposal systems
     where sewers are not available for the
     disposal of wastewater?

Explanation (a): Less Than Significant Impact. No people or structures are at risk from any
geological hazards in the project area, as further described below:

(i) The proposed project area is not located in an Alquist Priolo Earthquake Fault Hazard Zone.
However, it is located approximately 0.5 mile from the potentially active Chatsworth Fault (see
Figure 1 in Attachment G). The Chatsworth Fault is a reverse fault which juxtaposes Cretaceous
Chatsworth Formation (formerly called Chico Formation) and Paleocene Martinez Formation
over Miocene Modelo Formation. The fault trends southwesterly across the reservoir and
passes through the right abutment of Dam No. 2 and the left abutment of Dam No. 3. There are
no known traces of this fault in the proposed project area.

(ii) In addition to the Chatsworth Fault, which is considered inactive at this time, the two major
active faults closest to the project area are (see Figure 2 in Attachment G):

        Fault Name                       Distance (km)                 Moment Magnitude (Mw)

        Santa Susana Fault                       10.6                         6.6
        Northridge Fault                         14.5                         6.9

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Based on probabilistic analyses using two different seismic hazards risk assessment methods
(see Attachment G), strong seismic shaking could be expected in the event of a major
earthquake on active faults close to the site. However, since the area is proposed to be a
wetland, not occupied by humans or inhabited structures, it is anticipated that damage would be
minimal.

(iii) The project area is located in a State-designated potential, seismically-induced liquefaction
zone (see Fig. 5 in Attachment G). However, if liquefaction occurs, it would not expose people
or structures to potential substantial adverse effects, including the risk of loss, injury, or death
since the project area will be open space that is not occupied by humans or inhabited
structures.

(iv) The project area is not located in a State-designated potential, seismically induced landslide
zone and there are no known landslide risks at the site, which is located on gently sloping
ground (see Fig. 5 in Attachment G). Therefore, the risk of landslides would be insignificant.

Explanation (b): Less Than Significant Impact. Since the purpose of the project is to create
additional wetlands and restore earthen channels, it is expected that the velocity of the water
entering the project area will be decreased thereby allowing sediment to be deposited rather
than eroding the project area and adding sediment downstream. There may be some erosion at
outlet structures from the wetlands, but it would be minimal. Erosion during construction would
be minimized through the use of appropriate Best Management Practices (BMPs) as identified
in the Storm Water Pollution Prevention Plan (SWPPP) that is required for the project and
additional measures as described in Section 8 (a).

Explanation (c): Less Than Significant Impact. The project area is not located in a
designated landslide zone and there are no known landslide risks at the site, which is located on
gently sloping ground. The risk of landslides, therefore, would be insignificant. The project area
is located in a designated liquefaction zone. However, if liquefaction, subsidence, lateral
spreading or collapse occurs, damage from any of these phenomena is expected to be less
than significant since no people or structures will be at risk in the project area.

Explanation (d): Less Than Significant Impact. Trenching in the project area indicated clay
layers at relatively shallow depths (2.5 to 9 feet below the ground surface) (see Attachment G).
Further tests would be required to determine if the clay is expansive but even if it were, any
damage resulting from expansive clay is expected to be of minimal concern since the proposed
project involves restoration and expansion of wetlands that will not be occupied by humans or
inhabited structures.

Explanation (e): No Impact. No septic tanks or alternate wastewater disposal systems are
proposed as part of this project; therefore, there will be no impact to soils from wastewater
percolation.




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                                                                         Less Than
                                                                         Significant
                                                          Potentially       With       Less Than
                       Issues                             Significant     Mitigation   Significant
                                                            Impact      Incorporated     Impact      No Impact
 7. HAZARDS AND HAZARDOUS
 MATERIALS. Would the project:
a)   Create a significant hazard to the public
     or the environment through the routine
     transport, use, or disposal of hazardous
     materials?
b)   Create a significant hazard to the public
     or the environment through reasonably
     foreseeable upset and accident
     conditions involving the release of
     hazardous materials into the
     environment?
c)   Emit hazardous emissions or handle
     hazardous or acutely hazardous
     materials, substances, or waste within ¼
     mile of an existing or proposed school?
d)   Be located on a site which is included on
     a list of hazardous materials sites
     compiled pursuant to Government Code
     §65962.5 and, as a result, would it create
     a significant hazard to the public or to the
     environment?
e)   For a project located within an airport
     land use plan or, where such a plan has
     not been adopted, within two miles of a
     public airport or a public use airport,
     would the project result in a safety hazard
     for people residing or working in the
     project area?
f)   For a project within the vicinity of a
     private airstrip, would the project result in
     a safety hazard for people residing or
     working in the project area?
g)   Impair implementation of or physically
     interfere with an adopted emergency
     response plan or emergency evacuation
     plan?




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7. HAZARDS AND HAZARDOUS MATERIALS (cont.)
                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                       Issues                            Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

h)   Expose people or structures to a
     significant risk of loss, injury, or death
     involving wildland fires, including where
     wildlands are adjacent to urbanized areas
     or where residences are intermixed with
     wildlands?

Explanation (a): Less Than Significant Impact. There will be no routine transport, use, or
disposal of hazardous materials. Earthwork in the project area will involve grading (cut and fill),
movement and placement of onsite soils to recontour the stream channels and basin area. A
Phase II Environmental Site Assessment (ESA) and Human Health Screening Evaluation
(HHSE) for the project area conducted by Kleinfelder West, Inc. in 2010 on behalf of DWP
(Attachment H) analyzed 150 soil samples for metals, volatile organic compounds, and
radionuclides. The likelihood of adverse health effects was assessed by comparison of
maximum and 95% upper confidence limit (95UCL) of the mean concentrations to health-based
screening levels developed by Cal/EPA and federal EPA. Although the ESA concluded that
three metals (arsenic, cadmium and vanadium) and two radionuclides (strontium-90 and
potassium-40) were present in site soils at concentrations that exceeded health-based
screening levels, these constituents were not considered to pose a health hazard for the
following reasons:
     • Arsenic—concentrations reported were within the range expected for naturally-occurring
        background in California;
     • Cadmium—generally within the range of naturally-occurring background concentrations
        in California and the median concentration is less than the Cal/EPA screening level;
     • Vanadium—only one sample contained vanadium at a concentration greater than
        screening levels;
     • Strontium-90—maximum activity was well below the occupational screening level
        consistent with proposed future land use;
     • Potassium-40—reported concentrations are within the range of naturally-occurring
        background concentrations.

Explanation (b): Less Than Significant Impact. During construction, there is a slight
possibility of a fuel spill from construction equipment. In the unlikely event that such a spill
occurs, appropriate best management practices as required in the project SWPPP (MM 8-1)
would be employed to isolate the spilled fuel, prevent it from entering any sensitive area, and to
remove and properly dispose of the spilled fuel. If such a spill were to occur, it would not create
a significant hazard to the public since the public does not have access to the site. Any hazard
to the environment would be addressed through the best management practices.

Explanation (c-g): No Impact. There will be no use of hazardous or acutely hazardous
materials or substances either during construction or following development of the project. The
project area is not located within a quarter mile of a school. The project is not located on a
listed hazardous materials site compiled pursuant to Government Code 65962.5. The project is

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not located within an airport land use plan or within two miles of an airport. The project is not
located within the vicinity of a private airstrip. Since there is no public access to the project site,
the development of the project will not impair implementation or physically interfere with an
adopted emergency response plan or emergency evacuation plan.

Explanation (h): Less Than Significant Impact. The Chatsworth Reservoir currently is
undeveloped open space surrounded by residential communities and is designated a Very High
Fire Hazard Severity Zone in the Safety Element of the City of Los Angeles' General Plan.
Portions of the project area were burned in a 2005 wildfire that began outside of the reservoir.
Development of the riparian wetlands mitigation program will result in the introduction of
grasses, herbaceous material and shrubs into the area, but these plant materials are primarily
associated with wetlands and moist areas and should not increase (and may even reduce) the
risk of wildland fires in the project area.

                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                       Issues                            Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 8. HYDROLOGY & WATER QUALITY.
    Would the project:
a)   Violate any water quality standards or
     waste discharge requirements?
b)   Substantially deplete groundwater
     supplies or interfere substantially with
     groundwater recharge such that there
     would be a net deficit in aquifer volume or
     a lowering of the local groundwater table
     level (e.g., the production rate of pre-
     existing nearby wells would drop to a
     level which would not support existing
     land uses or planned uses for which
     permits have been granted)?
c)   Substantially alter the existing drainage
     pattern of the site or area, including
     through the alteration of the course of a
     stream or river, in a manner which would
     result in substantial erosion or siltation
     on- or offsite?
d)   Substantially alter the existing drainage
     pattern of the site or area, including
     through the alteration of the course of a
     stream or river, or substantially increase
     the rate or amount of surface runoff in a
     manner which would result in flooding on-
     or off-site?



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8. HYDROLOGY & WATER QUALITY (cont.)
                                                                         Less Than
                                                                         Significant
                                                          Potentially       With       Less Than
                       Issues                             Significant     Mitigation   Significant
                                                            Impact      Incorporated     Impact      No Impact

e)   Create or contribute runoff water which
     would exceed the capacity of existing or
     planned stormwater drainage systems or
     provide substantial additional sources of
     polluted runoff?


f)   Otherwise substantially degrade water
     quality?
g)   Place housing within a 100-yr. flood
     hazard area as mapped on a federal
     Flood Hazard Boundary or Flood
     Insurance Rate Map or other flood
     hazard delineation map?
h)   Place within a 100-year flood hazard area
     structures which would impeded or
     redirect flood flows?
i)   Expose people or structures to a
     significant risk of loss, injury, or death
     involving flooding as a result of the failure
     of a dam or levee?
j)   Inundation by seiche, tsunami, or
     mudflow?


Explanation (a): Less Than Significant With Mitigation Incorporated. The project will result
in ground disturbance associated with the grading, some of which will occur within and adjacent
to channels. Erosion from the project area has the potential to enter the surface drainages.
However, all of the potentially affected channels are ephemeral and flow only in response to
periods of sustained rainfall or very intense storms. The receiving water body, the Chatsworth
Creek Flood Control Channel, is a large concrete-lined storm drain that accepts untreated urban
runoff from the San Fernando Valley. Runoff from the site is eventually tributary to the Los
Angeles River. Erosion potential from the site is low since most of the grading would occur on
nearly level terrain and during the dry season.

To reduce potential impacts to a level of less than significant, the following mitigation measures
will be incorporated into the proposed project:

Mitigation Measures:

MM 8-1. Project construction will generally be limited to the non-rainy season (typically April


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through October) but may extend into the rainy season if appropriate measures to contain
sediment are implemented. Since the project entails construction over a site greater than 6
acres, a NPDES construction permit will be obtained from the Los Angeles Regional Water
Quality Control Board. The permit requires the preparation of a Storm Water Pollution
Prevention Plan (SWPPP), which specifies the Best Management Practices (BMPs) to be
utilized during construction of the project, to prevent erosion and protect surface water against
nonpoint source pollution.

MM 8-2. Topsoil will be salvaged and reapplied, which will serve to rapidly provide groundcover
of the endemic species during the rainy season following construction, thereby minimizing the
risk of erosion. Additional BMPs may be specified within the SWPPP.

Explanation (b): Less Than Significant Impact. The project area has a shallow water table
that rises to within the rooting zone during years of normal or above-normal precipitation. This
water table is part of a small aquifer bounded on the north and south by bedrock hills. The
aquifer typically discharges seasonally into the principal drainage below the confluence of
Woolsey Canyon Creek and Box Canyon Creek, and probably through bedrock fractures.
There are no known wells that withdraw water from this aquifer. The project is expected to
increase the consumption of groundwater to a negligible degree through increased transpiration
associated with expansion of riparian habitat. However, flows entering the expanded seasonal
wetland area will be subject to infiltration. This will serve as a new source of recharge to the
aquifer, which is a beneficial effect of the project. Expansion of seasonal wetlands will not affect
groundwater levels as the seasonal wetland vegetation will tend to transpire less water than the
existing annual grassland vegetation that it is replacing.

Explanation (c): Less Than Significant Impact. Since the project is to create additional
wetlands and restore earthen channels, it is expected that the velocity of the water entering the
project area will be decreased thereby allowing sediment to be deposited rather than eroding
the project area and adding sediment downstream. There may be some erosion at outlet
structures from the wetlands, but it would be minimal. Erosion potential during construction will
be minimized through the use of appropriate BMPs as identified in the SWPPP that is required
for the project and additional measures as described in Section 8 (a) above. Therefore, the
project will not cause substantial erosion or siltation either on- or off-site.

Explanation (d): Less Than Significant Impact. The project will result in an expansion of
portions of the existing constructed storm water channels and a small expansion in the terminus
of the Woolsey Canyon Creek channel. The affected constructed channels were built to route
storm flow around the now abandoned Chatsworth Reservoir. The project will result in the
removal of 500 lineal feet of impervious concrete-lined channels, allowing for greater opportunity
for storm water infiltration. Routing portions of higher flows into the expanded seasonal wetland
area will subject it to infrequent flooding but also tend to further decrease most peak flows from
the project area and allow for additional infiltration. The project will not result in off-site flooding
and will not increase peak flows off site. Rather, the project will tend to increase infiltration and
decrease peak flows through infiltration and detention storage, both of which are beneficial
effects of the project.

Explanation (e): No Impact. The project will not generate additional runoff that would be
directed into storm water drainage systems off-site. Under existing conditions, large storm
events result in spill over into the west basin area from the downstream end of the channelized
stream when the water surface elevation in the main channel exceeds 877 feet. The project

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would provide increased detention storage in the west (new wetland) basin at lower flows as a
result of diversion at the upstream end of the channelized stream. Thus, the project could
actually decrease runoff into the off-site storm water drainage system at lower flows. However,
during very high flows, there would be no change from existing conditions; the west basin area
would continue to fill and equilibrate with the water surface elevation in the main channel with or
without the project. Also, since the project does not result in the construction of structures or in
a fundamental change in land use, it will not substantially increase sources of polluted runoff.

Explanation (f): Less Than Significant Impact. Since the project does not result in the
construction of structures or in a fundamental change in land use there is no potential for water
quality degradation other than that associated with sediment. As discussed above (a),
appropriate measures to reduce erosion and sedimentation will be included in SWPPP. BMPs
to guard against surface or groundwater pollution associated with the operation and refueling of
heavy equipment will also be required as part of the SWPPP.

Explanation (g): Less Than Significant Impact. The Chatsworth Reservoir is a designated
100-year floodplain according to the Safety Element of the City of Los Angeles’ General Plan.
However, no housing is proposed in this floodplain as part of the project, therefore, the impact is
less than significant.

Explanation (h): Less Than Significant Impact. No structures will be placed within the
designated 100-year floodplain that would impede or redirect flood flows. The project will result
in the removal of 500 lineal feet of impervious concrete-lined channel, allowing for greater
opportunity for storm water infiltration.

Explanation (i): Less Than Significant Impact. The project does not alter any of the dam or
levee structures at the reservoir, and therefore, does not pose any greater risk of loss, injury, or
death to people or structures as a result of dam or levee failure.

Explanation (j): No Impact. Given its position significantly inland, the project is not subject to
damage by a tsunami. Similarly, there is no potential for impact from a seiche, since the
wetland basin would inundate only about 40 acres at a maximum, and is shallow, infrequently
flooded, and removed from commercial and residential areas. The surrounding terrain is gentle
and not subject to mudflows.


                                                                        Less Than
                                                                        Significant
                        Issues                           Potentially       With       Less Than
                                                         Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 9. LAND USE AND PLANNING. Would the
    project:
a)   Physically divide an established
     community?




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9. LAND USE AND PLANNING (cont.)
b)   Conflict with any applicable land use plan,
     policy, or regulation of an agency with
     jurisdiction over the project (including, but
     not limited to, the general plan, specific
     plan, local coastal program, or zoning
     ordinance) adopted for the purpose of
     avoiding or mitigating an environmental
     effect?
c)   Conflict with any applicable habitat
     conservation plan or natural community
     conservation plan?

Explanation (a): No Impact. The project will be located within the existing Chatsworth
Reservoir property and the proposed project area currently consists of undeveloped open space
surrounded by residential communities. The creation of additional wetland/riparian habitat will
not change the existing nature of the property, but rather will enhance and benefit its current use
as open space. The project will not divide the surrounding residential communities.

Explanation (b): Less Than Significant Impact. The City of Los Angeles General Plan
designates the project area as Open Space. In 1997, the City of Los Angeles designated the
Chatsworth Reservoir as a nature preserve and wildlife refuge (Attachment B). The proposed
project will increase the extent of wetland and riparian habitat in the area and therefore will not
conflict with the Open Space or nature preserve designations.

Explanation (c): No Impact. There is no adopted Habitat Conservation Plan or Natural
Community Conservation Plan that includes the Chatsworth Reservoir area.


                                                                         Less Than
                                                                         Significant
                                                          Potentially       With       Less Than
                        Issues                            Significant     Mitigation   Significant
                                                            Impact      Incorporated     Impact      No Impact

 10. MINERAL RESOURCES. Would the
 project:
a)   Result in the loss of availability of a known
     mineral resource that would be of value to
     the region and the residents of the State?
b)   Result in the loss of availability of a locally-
     important mineral resource recovery site
     delineated on a local general plan, specific
     plan, or other land use plan?

Explanation (a–b): No Impact. There are no mineral resources identified in the project area
that are of value to the region or residents of the State. There are no locally-important mineral
resource recovery sites in the project area delineated on any general plans, specific plans, or

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other local land use plans. The DWP conducted exploratory investigations to evaluate the
availability of clay within the Chatsworth Reservoir property and determined that there were
suitable clay resources in the central portion of the former reservoir area but not within the
proposed project area.


                                                                        Less Than
                                                                        Significant
                                                         Potentially                  Less Than
                        Issues                                             With
                                                         Significant                  Significant
                                                                         Mitigation                 No Impact
                                                           Impact                       Impact
                                                                       Incorporated

 11. NOISE. Would the project result in:
a)   Exposure of persons to, or generation of,
     noise levels in excess of standards
     established in the local general plan or
     noise ordinance, or applicable standards
     of other agencies?
b)   Exposure of persons to, or generation of,
     excessive groundborne vibration or
     groundborne noise levels?
c)   A substantial permanent increase in
     ambient noise levels in the project vicinity
     above levels existing without the project?
d)   A substantial temporary or periodic
     increase in ambient noise levels in the
     project vicinity above levels existing
     without the project?
e)   For a project located within an airport land
     use plan or, where such a plan has not
     been adopted, within two miles of a public
     airport or public use airport, would the
     project expose people residing in or
     working in the project area to excessive
     noise levels?
f)   For a project within the vicinity of a private
     airstrip, would the project expose people
     residing in or working in the project area to
     excessive noise levels?

Explanation (a-b): Less Than Significant Impact. During development of the project there
will be noise impacts from construction equipment and grading operations. Following
development of the wetlands, project noise levels will return to natural ambient conditions and
will not exceed any City standards. Construction is not expected to expose persons to
groundborne vibrations or noise levels.

Explanation (c): No Impact. Following development of the wetlands, project noise levels will

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return to natural ambient conditions and will not exceed any City standards.

Explanation (d): Less Than Significant Impact. While there will be an increase in ambient
noise levels during construction, they will be temporary (4-6 months) and will not exceed City
standards. Once grading activities are completed, noise levels will return to pre-construction
conditions and no periodic increases are anticipated.

Explanation (e-f): No Impact. The project area is not located within an airport land use plan
or within two miles of an airport. The project area is not located within the vicinity of a private
airstrip.


                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                        Issues                           Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 12. POPULATION AND HOUSING. Would
    the project:
a)   Induce substantial population growth in an
     area either directly (e.g., by proposing new
     homes and businesses) or indirectly (e.g.,
     through extension of roads or other
     infrastructure)?
b)   Displace substantial numbers of existing
     housing, necessitating the construction of
     replacement housing elsewhere?
c)   Displace substantial numbers of people,
     necessitating the construction of
     replacement housing elsewhere?

Explanation (a-c): No Impact. The proposed project does not involve the construction of any
new homes, businesses, roads or infrastructure and is not growth inducing. There is no housing
at the Chatsworth Reservoir. No one will be displaced by the development of the project.


 13. PUBLIC SERVICES
 a) Would the project result in substantial
    adverse physical impacts associated with
    the provision of new or physically altered
    governmental facilities, the construction of
    which could cause significant
    environmental impacts, in order to maintain
    acceptable service rations, response times
    or other performance objectives for any of
    the public services:


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13. PUBLIC SERVICES
                                                                        Less Than
                                                                        Significant
                                                         Potentially                  Less Than
                        Issues                                             With
                                                         Significant                  Significant
                                                                         Mitigation                 No Impact
                                                           Impact                       Impact
                                                                       Incorporated

         Fire protection?
         Police protection?
        Schools?
        Parks?
        Other public facilities?

Explanation (a): No Impact. The purpose of the project is to create additional wetland and
riparian habitat that will enhance existing open space within the Chatsworth Reservoir and is
consistent with its designation of as a nature preserve. The Chatsworth Reservoir is currently
not open to the public, and will remain so as part of the proposed project. Accordingly, there is
no need for the provision of public services associated with public use of the project area or the
construction of new facilities that might cause a physical impact. As part of the project, an
endowment will be established for long-term maintenance of the mitigation site that will
eventually be transferred to RAP.


 14. RECREATION.
a)   Would the project increase the use of
     existing neighborhood and regional parks
     or other recreational facilities such that
     substantial physical deterioration of the
     facility would occur or be accelerated?
b)   Does the project include recreational
     facilities or require the construction or
     expansion of recreational facilities that
     might have an adverse physical effect on
     the environment?

Explanation (a-b): No Impact. The proposed project will have no effect on the use of existing
parks or recreational facilities. The project will not include recreational facilities and will not be
open to the public. In the event that RAP develops a plan for future public use of the area,
separate environmental review and approvals would be required.




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                                                                           Less Than
                                                                           Significant
                                                            Potentially                  Less Than
                        Issues                                                With
                                                            Significant                  Significant
                                                                            Mitigation                 No Impact
                                                              Impact                       Impact
                                                                          Incorporated

 15. TRANSPORTATION / CIRCULATION.
    Would the project:
a)   Cause an increase in traffic that is
     substantial in relation to the existing traffic
     load and capacity of the street system
     (i.e., result in a substantial increase in
     either the number of vehicle trips, the
     volume-to-capacity ratio on roads, or
     congestion at intersections)?
b)   Exceed, either individually or cumulatively,
     a level-of-service standard established by
     the county congestion management
     agency for designated roads or highways?
c)   Result in a change in air traffic patterns,
     including either an increase in traffic levels
     or a change in location that results in
     substantial safety risks?
d)   Substantially increase hazards due to a
     design feature (e.g., sharp curves or
     dangerous intersections) or incompatible
     uses (e.g., farm equipment)?
e)   Result in inadequate emergency access?
f)   Result in inadequate parking capacity?
g)   Conflict with adopted policies supporting
     alternative transportation (e.g., bus
     turnouts, bicycle racks)?

Explanation (a-g): No Impact. During construction activities, there will be a temporary
increase in traffic due to the delivery of construction equipment to the site and worker
commutes. There will be approximately ten pieces of construction equipment that will be used
for site preparation and development. It is anticipated that there will be approximately 15
construction workers at the site for a period of up to 5 months. The workers will drive to the site
in their own cars. Once the project is developed, there will be no traffic other than periodic
(quarterly or annual) inspections and maintenance activities during the project monitoring
period.

The project does not involve any changes to roadways either inside or outside of the
Chatsworth Reservoir. Construction equipment will be used exclusively within the fenced area
of the Chatsworth Reservoir and will not travel on public streets or leave the site until the project


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is completed. The project will not affect emergency access to any surrounding land uses. The
Chatsworth Reservoir is not open to the public and so parking is not provided or required. The
wetlands mitigation project will not result in a change in status. Additional trips will occur only
during project construction. Therefore, there will be no long-term impacts on the level-of-service
standards established by the county congestion management agency for designated roads or
highways. After completion of the project, there will be no regular trips to the project area and,
therefore, no conflict with adopted policies supporting alternative transportation. The project will
not result in a change in air traffic patterns.

                                                                           Less Than
                                                                           Significant
                                                            Potentially                  Less Than
                        Issues                                                With
                                                            Significant                  Significant
                                                                            Mitigation                 No Impact
                                                              Impact                       Impact
                                                                          Incorporated

 16. UTILITIES AND SERVICE SYSTEMS.
    Would the project:
a)   Exceed wastewater treatment
     requirements of the applicable Regional
     Water Quality Control Board?
b)   Require or result in the construction of
     new water or wastewater treatment
     facilities or expansion of existing facilities,
     the construction of which could cause
     significant environmental impacts?
c)   Require or result in the construction of
     new storm water drainage facilities or
     expansion of existing facilities, the
     construction of which could cause
     significant environmental impacts?
d)   Have sufficient water supplies available to
     serve the project from existing
     entitlements and resources, or are new or
     expanded entitlements needed?
e)   Result in a determination by the
     wastewater treatment provider which
     serves or may serve the project that it has
     adequate capacity to serve the project’s
     projected demand in addition to the
     provider’s existing commitments?
f)   Be served by a landfill with sufficient
     permitted capacity to accommodate the
     project’s solid waste disposal needs?
g)   Comply with federal, state, and local
     statutes and regulations related to solid
     waste?


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Explanation (a, c, e-g): No Impact. There will be no wastewater discharges from the project.
The project will be modifying an existing storm water drainage system by returning portions of
the system to natural conditions. The modified system will be designed to handle at least the
current storm water flows. See discussion at 8 (e). No soil will be removed from the project
area during grading or other construction activities. Any solid waste removed during
development of the project will be transported to the Sunshine Canyon Landfill, which has
adequate capacity to accommodate the project’s solid waste disposal needs. All green waste
will be used on-site as mulch or recycled. Once the project is established, it is not expected that
any waste will need to be transported off-site. The project will comply with all federal, state and
local statutes and regulations related to solid waste.

Explanation (b): Less Than Significant Impact. Due to its limited water usage and lack of
waste water discharges, the project will not require the construction of new water or waste water
treatment facilities or the expansion of existing facilities.

Explanation (d): Less Than Significant Impact. The project will require minimal water for
irrigation during the time the vegetation is becoming established (approximately 3-5 years after
planting). Once the vegetation is established, irrigation will cease. DWP will provide the
irrigation water and no new or expanded entitlements are needed.




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                                                                        Less Than
                                                                        Significant
                                                         Potentially       With       Less Than
                        Issues                           Significant     Mitigation   Significant
                                                           Impact      Incorporated     Impact      No Impact

 17. MANDATORY FINDINGS OF
     SIGNIFICANCE.
a)   Does the project have the potential to
     degrade the quality of the environment,
     substantially reduce the habitat of a fish or
     wildlife species, cause a fish or wildlife
     population to drop below self-sustaining
     levels, threaten to eliminate a plant or
     animal community, reduce the number or
     restrict the range of a rare or endangered
     plant or animal or eliminate important
     examples of the major periods of
     California history or prehistory?
b)   Does the project have impacts that are
     individually limited, but cumulatively
     considerable? ("Cumulatively
     considerable" means that the incremental
     effects of a project are considerable when
     viewed in connection with the effects of
     past projects, the effects of other current
     projects, and the effects of probable future
     projects)
c)   Does the project have environmental
     effects which will cause substantial
     adverse effects on human beings, either
     directly or indirectly?

Explanation (a): Less Than Significant Impact With Mitigation Incorporated. As discussed
in the preceding sections, the project would not substantially degrade the quality of the
environment. Mitigation measures have been incorporated into the project to protect air quality,
hydrology and water quality, biological resources, and cultural resources.

Explanation (b-c): Less Than Significant Impact. The project will not result in potentially
significant individual or cumulative direct or indirect impacts on the environment. The project
will have a net benefit to the environment through the expansion of wetland and riparian
vegetation and enhancement of wildlife habitat.

The project consists of the construction and monitoring of new wetland and riparian areas,
establishment of a conservation easement, transfer of property, and creation of an interest-
bearing account to fund long-term maintenance. There are no similar projects ongoing or
planned within the Chatsworth Reservoir and surrounding area that would result in considerable
cumulative impacts.

Chatsworth Reservoir Wetland/Riparian Mitigation Program                                      October 14, 2010

                                                    42
DRAFT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION
Department of Recreation and Parks



4.0     REFERENCES

California Department of Fish & Game 2002. “Streambed Alteration Agreement #R5-2002-0163,
     Sunshine Canyon Landfill Closure/Post Closure Maintenance project.”       Sylmar,CA:
     California Department of Fish and Game, September 12, 2002.

___________.2004. “Streambed Alteration Agreement #R5-2003-0005, Sunshine Canyon
    Landfill Expansion project.” Los Angeles County, CA: California Department of Fish and
    Game, March 11, 2004.

__________, 2010. California Natural Diversity Data Base. CDFG Natural Heritage Division,
      Rancho Cordova, CA

California Native Plant Society (CNPS). 2010. Electronic Inventory of Rare and Endangered
        Vascular Plants of California. CNPS, Sacramento, California. Online publication;
        http://cnps.web.aplus.net/cgi-bin/inv/inventory.cgi.

California Regional Water Quality Control Board. Los Angeles Region. 2002. Conditional
        Certification for Proposed Sunshine Canyon Landfill Closure Project (Corps Project No.
        2002-00802-AOA), Bull Creek, Tributary to Los Angeles River, City of Sylmar, Los
        Angeles County. File No. 02-064. September 18, 2002.

___________. 2004. Conditional Certification for Proposed Sunshine Canyon City Landfill
      Expansion Project (Corps Project No. 2003-00408-AOA), Bull Creek, City of Los
      Angeles, Los Angeles County. File No. 03-001. February 11, 2004.

Essentia, 2004, Site Investigation Report – Final: Soil Suitability Evaluation, Chatsworth
       Reservoir, Chatsworth, California, report by K. Floom, PE, and E. Rogan, PE, REAII,
       submitted to G. Faeustle, LADWP.

Los Angeles Department of Water and Power, 1969, Chatsworth Reservoir Improvements
      Hydrology Report: Bypass Storm Drainage System, Water Engineering Design Division,
      Dams, Geology and Materials Section.

Los Angeles Department of Water and Power, 1969, Chatsworth Reservoir Improvements 1968
      Core Hole Investigation, Water Engineering Design Division, Dams, Geology and
      Materials Section, Geology Group.

Los Angeles Department of Water and Power, undated, Chatsworth Reservoir and Dams
      Geology Report.

U.S. Army Corps of Engineers. 2003. Permit 2002-00802-AOA. Sunshine Canyon City Landfill
       Closure. Issued to Browning Ferris Industries of California. February 12, 2003.

____________. 2004. Permit 2003-00408-AOA. Sunshine Canyon City Landfill Extension.
      Issued to Browning Ferris Industries of California. February 26, 2004.

U.S. Geological Survey, 1977, Magnitude and Frequency of Floods in California, Water-
      Resources Investigations 77-21.

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DRAFT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION
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5.0     LIST OF PREPARERS

Environmental Management Section
Planning and Development Division
Department of Recreation and Parks

        David Attaway, Environmental Supervisor II
        Paul Davis, Environmental Compliance Specialist


Zander Associates
Environmental Consultants

        Leslie Zander, Principal
        Michael Zander, Principal
        Sandra Meyers, CAD Technician




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