PC R 13-2180' RESOLUTION NO. 13 -2180
A RESOLUTION OF THE PLANNING COMMISSION OF
THE CITY OF ARROYO GRANDE ADOPTING A
MITIGATED ,NEGATIVE DECLARATION (MND) AND
MITIGATION MONITORING AND REPORTING PROGRAM
(MMRP) AND INSTRUCTING THE CITY CLERK TO FILE A
NOTICE OF DETERMINATION FOR 'THE CORBETT
CREEK FLOODPLAIN AND STREAM RESTORATION
PROJECT (STAFF PROJECT NO. 13 -001)
WHEREAS, the 16 -acre property located between Carpenter Canyon Road and Corbett
Canyon Road (the "project site ") was identified in the 2006 "Arroyo Grande Creek Erosion,
Sedimentation and Flooding Alternatives Study" as a priority site for potential floodplain
restoration and sediment retention to remedy existing and predicted problems concerning
flood control and environmental degradation within the Arroyo Grande Creek Watershed,
particularly within and downstream of the City; and
WHEREAS; the City of Arroyo Grande participated with the Coastal San Luis Resource
Conservation District ( "RCD ") to secure a grant from the Department of Water Resources
( "DWR ") in an amount not to exceed $831,420 to fund the Corbett Creek Floodplain and
Stream Restoration Project (the "Project'); and
' WHEREAS, on November 13, 2012, the City Council of the City of Arroyo Grande
approved a Memorandum of Understanding (MOU) between the City and the RCD
regarding the Project; and
WHEREAS, the Planning Commission of the City of Arroyo Grande has considered Staff
Project No. 13 -001 to secure a 12.5 -acre conservation easement over a portion of the
project site for the purpose of designing, permitting and constructing a floodplain /sediment
detention basin for flood protection, riparian restoration and water quality protection; and
WHEREAS, the Planning Commission has held a public hearing on the Project in
accordance with City Code; and
WHEREAS, the Planning Commission finds that this project is consistent with the City's
General Plan, Development Code and the environmental documents associated therewith,
and has reviewed the draft Mitigated Negative Declaration, (MND) and Mitigation
Monitoring and Reporting Program (MMRP) under the provisions of the California.
Environmental Quality Act (CEQA); and
WHEREAS, the Planning Commission finds, after due study, deliberation and public
hearing, the following circumstances exist.
FINDINGS FOR APPROVAL:
I 1. The City of Arroyo Grande has prepared an initial study pursuant to Section 15063
of the Guidelines of the California Environmental Quality Act (CEQA), for Staff
Project No. 13 -001.
RESOLUTION NO. 13 -2180
APRIL 16, 2013
PAGE 2
2. Based, on the initial study, an MND and MMRP were prepared for,public review. .A
copy of the MND and related materials are located at City Hall in the Community
Development Department.
3. After holding a public hearing pursuant to State and City Codes, ,and. considering
the record as a whole, the Planning Commission adopts an MND and MMRP and
finds that there is no substantial evidence of any significant adverse effect, either
individually or cumulatively on wildlife resources as defined by Section 711.2 of the
Fish and Game Code or on the habitat upon which the wildlife depends as a result
of development of this project. Further, the Planning Commission finds that said
MND and MMRP reflect the City's independent judgment and analysis.
NOW, THEREFORE, BE IT RESOLVED that the Planning Commission of the City of
Arroyo Grande hereby adopts the MND and MMRP for the Project subject to the mitigation
measures set forth in Exhibits "A" and "® ", attached hereto and incorporated herein by this
reference.
On motion by Commissioner Sperow, seconded by Commissioner Barneich, and by the
following roll call vote, to wit;
AYES:
Sperow, Barneich, Keen, Martin, Ruth
NOES:
None
ABSENT:
None
the foregoing Resolution was adopted this 16th day of April 2013.
I
RESOLUTION NO. 13 -2180
APRIL 16, 2013
PAGE 3
ATTEST:
G"U" (1Q ��l ✓y Pp/1
DEBBIE,WEICHINGER
SECRETARY TO THE COMMISSION
AS TO CONTENT:
•c
TE SAM CLISH
D6FkECTOR OF COMMUNITY DEVELOPMENT
J
I
2Io Iii A,i
ELIZABETH S. RILITH, CHAIR
EXHIBIT "A"
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
®1 CITY of INITIAL STUDY/
MITIGATED NEGATIVE
/CALIFORNIA,
i� DECLARATION
Staff Project No. 13001
Corbett Creek Floodplain and,Stream Restoration Project
March 2013 '
Page 1 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
' Project: Staff,Project No. 13 -001
Corbett Creek,Floodplain and Stream Restoration Project
Lead Agency: City of Arroyo Grande
Document Availability:
City of Arroyo Grande
Community Development Department
300 East Branch Street
Arroyo Grande, CA 93420
Project Description:
The proposed project involves the acquisition by the Coastal San Luis Resource Conservation District
(RCD) of a conservation easement over the, 12.5. -acre Clark Property located between Highway 127
(Carpenter Canyon Road) and Corbett Canyon Road and the design, permitting and construction of a
floodplain /sediment detention basin on the easement property. The project also includes channel
restoration of approximately; nine hundred feet (9001of Corbett Creek located downstream of the,Clark
Property. Currently there are no ,identified implementation funds for the channel restoration
component of the project. The City will be directly involved in the project through permjttmg of the
floodplain /sediment detention basin design and implementation activities.
' Summary Document Preparation:
Pursuant to Section 21082.1 of the California Environmental Quality Act, the City of.Arroyo Grande (the
City) has °independently reviewed and analyzed the Initial Study,and Mitigated Negative Declaration for
the proposed project;and finds that these documents reflect the independent judgment of the City. The
City, as lead agency, also confirms that the project mitigation measures detailed in these documents are
feasible and will be implemented as stated in the Mitigated Negative, Declaration.
Teresa McClish, AICP Date
Community Development Director
Kelly Heffernon, AICP Date
Associate Planner
Page 2 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
Corbett Creek Floodplain and Stream Restoration Project
March 2013
Table of Contents:
,
Introduction................. .............................................................................................
..............................5
Introduction and Regulatory Guidance . ...........................::.:...::.:.............................
..............................5
LeadAgency ...............................................................................................................
..............................5
Purpose and Document Organization .........................................................................
..............................6
Summaryof Findings ....................::............................................................:.::.............
..............................6
ProjectDescription ..........................................................................................................
..............................7
Introduction.................. ...... ................ ..............................I .:..................................
............................... 7
Background'and Need for Project ............................................:...................................
...................... ........9
Other Required Public Agency Approvals ..........:.......................................................
.............................10
RelatedProtects .................... . .... ...... q.: ................. ............... . ...............................
. ............. . ........ ...: ....... 10
EnvironmentalChecklist .. ... :......... .. ...... : ........ . ..............................................
............................................. 11
ProjectInformation ..................................................................:.................................
.............................11
Environmental Factors Potentially Affected ...... ........................................
. ........................................... 13_
Determination ............... ........................................ :
---- ..... ..13
Evaluation of Environmental Impacts ......................................................................
............................... 14
Environmentallssues� .......... , .........................................................................................
............................... 15
1. Aesthetics :...........................................................................................................
.............................15
'
2. Agriculture and Forestry Resources .......................................................................
.............................16
3,.AIr' Quality .........................................................,.....,...:.........................................
...................:....:....16
4. Biological Resources .....................................:........................................................
.............................18
S. Cultural Resources .......................::.......................................................................
.............................21
6. Geology and Soils:.... .:...:.....................................................................:...........:.....
.............................23
7. Greenhouse Gas Emissions ...................................................................................
.............................25
8. Hazards and Hazardous Materials .................... ... .......... _. ... . ...... ......................................................
25
9. Hydrology and'Water. Quality ......................:.....:...................................................
.............................26
10. Land Use and Planning .........................................................................................
.............................29
11. Mineral Resources .................. ... ...................... .. ..................... ....
........................ ........................... 30
12. Noise ... :: ........... :. ....................... . ........................... .. .....................
: ................................................. 30
13. Population and Housing ......................................................................................
.............................32
14. Public Services ..................................................................................................
............................... 33
15. Recreation .................................. ......................... ......................................................
.............. , ........ 33
16. Transportation/ Traffic ........................................................................................
...:........................... 34
17. Utjlitles,and Servjce.Systems ..........................................................................
............................... 34
Page 3 of 43
Page 4 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
March�2013
Corbett Creek Floodplam and Stream Restoration Project
'
Mandatory Findings of Significance ................................................................................
.............................36
Summary of Mitigation Measures .................. ................................... ....:
.... ................ ...........................37
,References ........... .... .................. ...... ...................................... ....................
: ................ ... :: ........................... 43
Page 4 of 43
INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
Introduction
Introduction and Regulatory Guidance
The Initial Study /Mitigated Negative Declaration (IS /MIND) has been prepared by the City of Arroyo
Grande (the City) to evaluate the potential environmental effects of the proposed project. This
document has been prepared In accordance with the California Environmental Quahty.Act (CEQA), Public
Resources Code §21000 et seq., and the State CEQA Guidelines, California Code of Regulations (CCR)
§15000 et seq.
An Initial Study is conducted by a lead agency to determine if a project may have.a significant effect on
the environment [CEQA Guidelines §15063(a)]. If there is substantial evidence that a'project may have a
significant effect on the environment, an Environmental Impact Report (EIR) must be prepared, in
accordance with CEQA Guidelines §15064(a). However, if the lead agency determines that revisions In
the project plans or proposals made by or agreed to by the applicant avoid, reduce or mitigate the
'potentially significant effects to a less- than - significant level, a Mitigated Negative Declaration may be
prepared instead of an.EIR [CEQA Guidelines §15070(6)]. The lead agency prepaiesa written statement
describing the reasons ,a proposed project would not have a significant effect on the environment and,
therefore, why an EIR need not be prepared. This IS /MND conforms to the content requirements under
CEQA Guidelines §15071.
Trustee and Responsible Agencies
The following public agencies have legal responsibilities for carrying out or approving portions of the '
project. A responsible agency must actively participate in the lead agency's CEQA process, review the
lead agency's CEQA document, and use'that document when making a decision on the project. The
responsible agency must rely on the lead agency's; environmental document -to prepare and Issue its
own findings regarding the project.
• California Department of Fish and Wildlife (CDFW) — Regulatory agency
• Regional Water Quality Control Board (RWQCB) — Regulatoryagency
• US Fish and Wild life:Service (FWS) — Regulatoryagency
• US Army Corps , of'Engineers`,(U SAGE) ' — Regulatory agency
• California Coastal Conservancy (CCC) — Funder, grant contractor
• California Department of Water Resources (DWR)— Funder, grant contractor
• Coastal San Luis Resource Conservation District (RCD) — Project Manager
Lead Agency
The lead agency is the public agency with primary approval authority over the proposed project. In
accordance with CEQA Guidelines §15051(b)(1), "the lead agency will normally be an agency with
general governmental powers, such as a city or county, rather than an agency with a single or limited
purpose. "' The,lead agency for the proposed project Is the City of Arroyo Grande. The contact person for
the lead agency is:
Kelly Heffernon, AICP
Associate Planner
City.of Arroyo Grande
Arroyo Grande, CA 93420
(805) 473 -5420 .
Page.5 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
' Purpose. and.Document Organization
The purpose of this document Is to 'evaluate the potential environmental effects of the proposed
project. Mitigation measures have been identified and incorporated into the project to eliminate any
potentially significant impacts or reduce them to a less-than-significant level.
This document is organized as follows:
• Introduction
This chapter provides'an introduction to the pfojemand,describes the purpose androrganlzatlon
of this document.
• Project Description
This chapter describes�the reasons for the project, scope;ofthe project, and project objectives.
• Environmental Setting, Potential'lmpacts and Mitigation Measures
This chapter identifies the significance of potential environmental impacts, explains the
environmental setting for each environmental issue, and evaluates the potential impacts
Identified in the CEQA Environmental (Initial Study) Checklist, Mitigation measures are
Incorporated, where appropriate, to reduce potentially significant impacts to a less-than-
significant level.
• Mandatory Tindings,ofSignificance
' This chapter identifies and summarizes the overall significance of any potential Impacts to
natural and cultural resources, cumulative impacts, and impact to humans, as identified in the
Initial Study.
• Summary of Mitigation Measures
This chapter summarizes the mitigation measures incorporated into the project as a result of the
Initial Study.
• References
This chapter identifies the references and sources used in the preparation of this IS /MND. It also
provides a list of those Involved In the preparation of this document.
Summary of Findings
Section 3 of this document contains the Environmental (Initial Study) Checklist that identifies the
potential environmental impacts (by environmental' issue) and a brief discussion of each impact resulting
from „implementation of the proposed project.
In accordance with §15064(f) of the CEQA Guidelines, a Mitigated Negative Declaration shall be
prepared if the proposed project will not have a significant effect on the environment after the inclusion
of mitigation measures In the project. Based on the available project, information and the
environmental analysis presented in this document, there is no substantial evidence that, after the
incorporation of mitigation measures, the proposed project would have a significant effect on the
environment It Is proposed that a Mitigated Negative Declaration be adopted in accordance with the
CEQA Guidelines.
Page 6 of 43
INITIAL STUDY /,MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
Project Description
Introduction
The City of Arroyo Grande (the City) has prepared this Initial Study /Mitigated Negative Declaration
(IS /MND) to ,evaluate the potential environmental effects of the Corbett Creek Flood plain and Stream
Restoration Project (the "Project"). The Project specifically involves RCD's acquisition of a 12 ^5, acre
conservation easement, and the design and construction of a, sedimentation and flood reduction basin
on the easement property. This Initial Study also includes'an analysis of a proposed, sediment removal
and creek restoration projemclownstream along Corbett Creek intended to reduce flooding in that area.
Project Scope and Location
The project reach begins at the East Branch Street culvert and extends upstream approximately one (1)
mile to the north end of the Clark Property (APN 007- 791 -032). As indicated in Exhibit A below, the
focus of the Project area is identified as Reach 6. Additional environmental review will be performed for
Reaches 1 through 5 once a scope of work is better defined. This IS /MND addresses,lmpacts'Jor Reaches
1 through 5 where they are foreseeable.
Page '7'of 43
INITIAL STUDY/ MITIGATEDMEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
Exhibit A
LEGEND
TALLY Ho PREEN CENTERLINE
O REACH BREAKS
A HEADCDIS
FIGURE 2
Project nma ",, and reach Dve�viev.
iw Ea I.IW
- rnn.. la.aoo
WATERWAYS
CONSULTING
sema uve. CA 1 ,valway, cmo NAaM, aR
Page 8 of 43'
INITIAL STUDY /MITIGATED NEGATIVE DECLARATION March >2013,
Corbett Creek Floodplain and Stream Restoration Project
Background and Need for Project ,
A conservation easement and sedimentation reduction project is being sought,on the subject property
as a strategic location to carry out inter- related goals of the California Department of'Water Resources
Flood Protection Corridor Program and the City of Arroyo Grande's goals stated in the
Conservation /Open Space and Agricultural Element of the 2001 General Plan and 2007 Creek Resources
ProtectionStudy(see Exhibit B below.,for delineation of easement area),
Exhibit B
IN THE CITY OF ARROYO GRANDE 0 125 250 500 Feet
O'e , (yellow, line)
Page 9 of 43
INITIAL STUDY./ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
' The project consists Of two components as.follows:
1. The acquisition by RCD of a conservation easement in perpetuity over12.50 acres of the 15.79 -
acre Clark Property at the confluence of Carpenter Creek and Corbett' Creek to act as a
floodplain and thereby attenuate peak flows. The'conservation easement-area will be used to
construct a sediment basin, a, floodwater detention area,and a riparian habitat enhancement
area. These easement acquisition and construction components of the project are identified in
a technical study (Swanson Hydrology and Geomorphology, 2006) as critical to alleviating
flooding on Corbett Creek and reducing stress on lower Arroyo Grande Creek through the
reduction of peak flows and fine sediment. These,project components have also been identified
as providing an'important, location , upon which�to restore *riparian and floodplain habitat within
an urban wildlife corridor. Most of the engineering design, permitting, implementation and
monitoring will be completed using grant funds obtained from the Department of Water
Resources (DWR) through the Urban Streams Restoration Program. The, estimated 'sediment
delivery reduction provided by the site is approximately nine ,hundred (900) tons per year.
Specific,elements of the project include the following:
• Conservation easement acquisition.
• Sedimentation reduction through construction of active and passive sedimentation
basins.
• Restoration of floodplain and riparian habitat.
2. Design and permitting for a channel restoration project to re- establish the,channel geometry of
' approximately nine hundred feet (900') of Corbett-Creek (Reach 4) and thereby increasing flow
volumes'. Issues that will be considered in the design process include a four -foot (4')�high head
cut that is migrating upstream, sediment from uplands and developments that are clogging
stormwater ditches and Corbett Creek, the Increase'in wetlands and marsh plants in the creek
resulting in reduced creek flow volumes, and individual landowner's activities in the floodplain
that cause or encourage erosion. Currently °there are no identified implementation funds for
this component of the project.
Other Required Public Agency Approvals
California Department of Fish and Wildlife
Regional Water quality Control Board
US Fish and Wildlife Service
US Army Corps of Engineers
Related
None
L�
Page 10 of 43
INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
Environmental Checklist
Project Information
Project Title: Corbett Creek Floodplain and Stream Restoration Project
(Staff Project No. 13 -001)
Lead Agency Name & Address: City of Arroyo Grande
300 East Brach Street
Arroyo Grande, CA 93420
Contact Person, & Telephone Kelly Heffernon, Associate,Planner
Number: (805) 473 -5420
Project, Location: 1. APN 007 - 791 -032 (Clark Property)
2, COrbett'Creek reach,(multiple properties)
Project Sponsor Name '& Address: City of"Arroyo Grande
300 East Brach Street
Arroyo Grande, CA 93420
General Plan Designation: 1. Low Density Residential,(LD); Conservation Open'Space ?(C /OS) I
•2. Low- Medium Density Residential (LM); Conservation
Open Space (C /OS)
Zoning: 1. Residential Hillside (R H); Public Facility- (PF) (combining
designation for-the portion of the property containing,the creek
channel)
2. Residential Suburban (RS); Single Family (SF); Village Mixed Use
(VMU); Village Core Downtown (VCD); Public Facility (PF)
(combining designations forpoctions of properties containing the
creek channel)
Description of Project: Acquisition of a conservation easement and design and
implementation of a sediment reduction project for the purpose of
floodplam restoration, sediment capture and peak flow attenuation
along specific reaches of'Corbett Creek.
Surrounding Land Uses: The Clark Property contains a barn, equestrian trails, corals and
vacant open space. Properties located downstream along +the creek
channel are primarily developed with single family residences with
some commercially developed properties existing closer to the Village
Core area. Several of the properties along this stretch are vacant.
Page 11 of 43'
INITIAL STUDY/ MITIGATED NEGATIVE 'DECLARATION ,March 2013
Corbett Creek; Floodpla in and Stream, Restoration Project
' Project Setting: The City of Arroyo Grande is located in the southwestern portion of
San Luis Obispo County, and the project site is located within the
northeast section of the City of Arroyo Grande. The City is 5.45
square miles in size and isibounded „by the Cities of GroverBeachrand
Pismo Beach to the southwest and west, and to the unincorporated
County to the north, east and south. U.S. 101 extents northwest and
southeast, through the middle of the City, and Highway 227 runs east
from U'IS. 101 through the Village Area. Residential Rural and
Suburban development characterize unincorporated areas to the
north and southeast, and Agricultural uses dominate the Arroyo
Grande Valley that extends northeast and south of the City. The
project area is the reach of Corbett Creek from the northern City
border to the village Commercial -area in the center of the City,at ther
confluence of Arroyo Grande Creek. The project area includes
residential development adjacent to Corbett Creek except at the
Village Core where there are four parcels zoned Village Core /Village
Mixed Use upon which there is an existing unoccupied structure.
Plans have been approved to develop a grocery store.
The Corbett Creek reach is one of three (3) main'tributaries within the
City limits. The creek flows are generally perennial in the project
reach with higher flows in the winter and very low 'flow In the,
summer. The area enjoys a Mediterranean climate with most
precipitation occurring from November to March, Corbett Creek
stream flows remain elevated in the spring as groundwater and
subsurface flows contribute to the stream. The subwatershed is
dominated by ,agriculture and rural residential land uses. At the
protect reach the channel is not formally channelized; however,
encroachment activities by "residents over the years have effectively
channelized portions of the creek. Vegetation within the project area
includes native and exotic grasses, native and exotic brush including
blackberry and Willow trees; and ornamental landscaping on the
residential properties.
Page 12 -of 43
The topography of the City ranges from moderate and steep hillsides
to the north of U.S. 101 to relatively flat parcels toward the center of
town, to moderate slopes further south. The project area.has varying
'
topographical gradients with an approximate 2 -5% slope northeast.
Corbett Creek runs north /south to Arroyo Grande Creek. The Wilmar
Avenue fault is a potentially active fault adjacent to the City, and the
Pismo fault underlies portions of Arroyo Grande but is inactive and
poses'very low potential fault, rupture hazard'to the City. No known
active4aults- underlie the,project area.
The Corbett Creek reach is one of three (3) main'tributaries within the
City limits. The creek flows are generally perennial in the project
reach with higher flows in the winter and very low 'flow In the,
summer. The area enjoys a Mediterranean climate with most
precipitation occurring from November to March, Corbett Creek
stream flows remain elevated in the spring as groundwater and
subsurface flows contribute to the stream. The subwatershed is
dominated by ,agriculture and rural residential land uses. At the
protect reach the channel is not formally channelized; however,
encroachment activities by "residents over the years have effectively
channelized portions of the creek. Vegetation within the project area
includes native and exotic grasses, native and exotic brush including
blackberry and Willow trees; and ornamental landscaping on the
residential properties.
Page 12 -of 43
INITIAL STUDY,/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplamend Stream;Restoration Project
Environmental Factors Potentially Affected
The environmental factors checked below would be potentially affected by this project, involving at
least one impactthat is a "Potentially Significant Impact ", as Indicated by the checklist onAhe following
pages:
❑ Aesthetics
®'Biological Resources
❑Greenhouse Gas'Emissions
❑ Land Use /Planning
❑ Population /Housing
❑ Transportation /Traffic
❑ Agricultural Resources
® Cultural Resources
❑ Hazards & Hazardous Materials
❑ Mineral Resources
❑ Public Serwces
❑ Utilities /Service Systems
Determination
On the basis of this initial evaluation:
® Air Quality
❑ Geology /Soils
® Hydrology /Water Quality
® Noise
❑ Recreation
❑ Mandatory Findings of Significance
❑ 'find t-hat,the proposed project COULD'NOT have a.�significanteffect on the,environment; and a
NEGATIVE DECLARATION will "be prepared.
® I find that, although the original scope of the proposed project COULD have had a significant
effect on the environment, there WILL NOT be a significant effect because revisions /mitigations
to the project have been made by or agreed to by`the applicant: 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 or its functional equivalent will be prepared.
❑ I find that the proposed project MAY have a "potentially significant impact" 'or "potentially
significant unless mitigated impact" on the environment, However, at least one impact has
been adequately analyzed in an earlier document, pursuant to applicable legal standards, and
has been addressed by mitigation measures based on the earlier analysis, as described in the
,report's attachments. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze
only the;impacts not sufficiently addressed'in previousdocuments.
❑ I find that, although the proposed project could have had a significant effect on the
environment, because all potentially significant effects have been adequately analyzed in an
earlier EIR or Negative Declaration, pursuant to applicable standards, and have been avoided or
mitigated, pursuant to an earlier EIR; including revisions or mitigation measures that are
imposed upon the proposed project,.all impacts have been avoided'or mitigated,to a less -than-
significant level and no further action is required.
Kelly Heffernon, AICP
Associate Planner
Date
Page 13 of 43
I
INITIAL STUDY'/ MITIGATED NEGATIVEDECLARATI ON March 2013
Corbett Creek Floodplain and Stream Restoration Project
' Evaluation of Environmental Impacts
1. A brief explanation is required for all answers, except "No Impact'.', 'that are adequately
supported by "the information sources cited. A "No Impact" answer is adequately supported if
the referenced information sources show that the impact does not apply to the project being
evaluated (e g.,, the ' project falls outside a fault rupture zone). .A "No Impact" answer should be
explained where it is based on general or project- specific factors (e.g., the project will not
expose sensitive receptors to pollutants, based on a project - specific screening analysis).
2. All answers must consider the whole of the project - related effects, both direct and indirect,
including off -site, cumulative, construction, and operational impacts.
3. Once the lead agency haskdeterminedrthat a,pariicularphysical impact may occur,,,the checklist
answers must Indicate whether that impact is potentially significant, less'than significant with
mitigation, or less than significant. "Potentially Significant Impact" is appropriate when there is
sufficient evidence that a substantial or potentially substantial adverse change may occur in any
of the physical conditions within the area affected by the ,project that cannot be mitigated
below a level.of significance. If there are one or more "Potentially Significant Impact" entries, an
Environmental Impact Report (EIR) is required.
4. A "Mitigated Negative Declaration" (Negative Declaration: Less Than Significant with Mitigation
Incorporated) applies where the incorporation of "mitigation measures, prior to declaration of
project approval, has reduced an effect from "Potentially Significant Impact" to a "Less Than
Significant Impact with Mitigation." The lead agency must describe the mitigation measures and
briefly explain how they reduce the effect to a less than significant level.
S. Earlier analyses may be used where, pursuant to the tiering, program EIR, or other CEQA
' process, an,'effect has been adequately analyzeG'n an earlier 6R, (including a General;Plan) or
Negative Declaration [CCR, Guidelines for the Implementation of CEQA, § 15063(c)(3)(D)).
References to an earlier analysis should:
a) Identify the earlier analysis and state where it is available for review.
b) Indicate which effects; from the environmental checklist were adequately analyzed in the
earlier document, pursuant to applicable legal standards, and whether these effects were
adequately addressed by mitigation measures included in that analysis.
c) Describe the mitigation measures in this document that were incorporated or refined from
the earlier document and indicate, to what extent they address site - specific conditions for
this project.
6. Lead agencies are encouraged to incorporate references to Information sources for potential
impacts into the checklist or appendix (e.g., general plans, zoning ordinances, biological
assessments). Reference to a previously prepared or outside document should include an
Indication of the page or pages.wheresthe statement is substantiated.
7. A source list should be appended to this document. Sources used or individuals contacted
should be listed in the source list and cited in the discussion.
8. Explanation(s) of each issue should identify:
a), the criteria or threshold, ifany„used,to evaluate'the significance of the impact addressed by
each question and
b) the mitigation measures, if any, prescribed to reduce the impact below the level of
significance.
Page 14 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodpla n and Stream Restoration Project
Environmental Issues
1. Aesthetics
Environmental Setting
The Clark Property is about 16 acres in size and is located adjacent to Corbett Creek, a tributary to
Arroyo Grande Creek near the confluence of Carpenter and Corbett Creeks. The portion of the property
to be encumbered with the proposed conservation easement consists primarily of open space, the creek
and riparian corridor, and several small isolated wetlands: An outbuilding and a series of fenced
pastures currently occupy most of the property, with approximately six (6) acres of land in seasonal
pasture. The conservation easement will encompass a portion of the fenced pasture area, but does not
include any structures. The project would utilize approximately 12.5 acres for a conservation easement
for the purpose of restoring a historic floodplain. The project would create a sedimentation basin,
expand a wetland area, construct an earthen berm around the detention area to impound additional
runoff, and install control structures. These Improvements; would help toaattenuate peak storm flows,
thereby increasing flood protection`to urban and agricultural areas downstream: The proposed project
would enhance the rural setting by placing existing open space in a perpetual conservation easement
and by adding riparian vegetation. There are no visual impacts anticipated.
Project 'Improvements downstream along the Corbett Creek `reach include channel restoration at
strategic locations. Improvements include removing a four foot (4') high head -cut that is migrating
upstream, removal of sediment, and strategic removal of vegetation to increase conveyance capacity. I
These improvements have, not yet been designed, but there are no expected visual impacts associated
with this component of the'project.
Discussion
a -d: No ^impacts.
Page 15 of 43
Potentially
Less Than
Less Than
Significant
Significant
Significant
No Impact
Impact
with
Impact
Would the project:
Mitigation
a) Have:a substantial',adverse, affect 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 slteand itsssurroundings?
d) Create a new source of substantial light of, glare
which would adversely affect day or nighttime views in
❑
❑
❑
the area?
Discussion
a -d: No ^impacts.
Page 15 of 43
” In determining whether impacts to agricultural resources, are sigmf,cont environmental effects„leod agencies may refer to the
California Agricultural ,Land Evaluation and Site Assessment' Model (19971 prepared by 'the, California Deportment of
Conservation as an optional,modelfor use iii, assessing impacts on,agriculturol and farmland.
Discussion
a -e: No impacts.
3._ Air Quality
Environmental Setting
San.Luis Obispo County is in non - attainment status for ozone (Oa), respireable particulate matter (PM10)
and vinyl chloride under the California Air Resource Board (CARB) standards. The County is in
attainment status for all other applicable CARB standards.
Page 16 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
March 2013
Corbett Creek Floodoanand Stream Restoration Project,
2. Agriculture and Forestry Resources
Environmental Setting
The project area is not 'Prime Farmland, Unique Farmland,
or
Farmland of
Statewide Importance
'(Farmland), as "shown on the maps prepared' pursuant
to the
Farmland Mapping
and Monitoring
Program of the California Resources Agency', noris it located near any Farmland.
Potentially
Less Than
Significant
Less Than
Significant
with
Significant No Impact
Would the project:
Impact
Mitigation
Impact
a) Convert Prime Farmland, Unique Farmland, or
Farmland of Statewide Importance (Farmland), as
shown on the maps prepared pursuant to the
❑
❑
❑
Farmland Mapping and Monitoring Program of the
California Resources Agency „to non- agricultural,use?
b) Conflict with existing zoning for agricultural use:or a
❑
❑
El
Williamson Act contract?
c) Conflict with existing zoning for, or cause rezoning
of, forest land (as defined in Public Resources Code
section 12220)g)), timberland (as defined by Public
El
El
El
Resources Code section 4526); or timberland zoned
Timberland Production (as defined by Government
'
Code section 51104(8))?
d) Result in the loss of forest land or conversion of
El
El
❑
forestland to non - forest use?
e). Involve other changes in the existing environment
which, due to their location or nature, could result In
❑
❑
❑
conversion of Farmland to non - agricultural use?
” In determining whether impacts to agricultural resources, are sigmf,cont environmental effects„leod agencies may refer to the
California Agricultural ,Land Evaluation and Site Assessment' Model (19971 prepared by 'the, California Deportment of
Conservation as an optional,modelfor use iii, assessing impacts on,agriculturol and farmland.
Discussion
a -e: No impacts.
3._ Air Quality
Environmental Setting
San.Luis Obispo County is in non - attainment status for ozone (Oa), respireable particulate matter (PM10)
and vinyl chloride under the California Air Resource Board (CARB) standards. The County is in
attainment status for all other applicable CARB standards.
Page 16 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
Corbett Creek Eloodplain and Stream Restoration Project
_
March 2013
Potentially
Less Than
an
�Signitican[,
,Significant
with
Significant
No Impact
Would the project:
Impact,
Mitigation
Impact
a) Conflict with or obstruct Implementation of the
❑
❑
❑
applicable air quality plan?
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 in
non - attainment under an applicable federal or state
❑
®
❑
❑
ambient air quality standard (Including releasing
emissions which exceed quantitative thresholds for
ozone precursors)?
d) Expose sensitive receptors to substantial pollutant
❑
❑
❑
concentrations?
e) Create objectionable odors affecting a substantial
❑
❑
❑
number of people?
Discussion
a: No impacts
b -c: The San Luis Obispo County Air Pollution Control District (APCD) has developed the CEQA Air. ,
Quality Handbook to evaluate project specific impacts and determine if air quality mitigation measures
are needed, or if potentially significani, impacts could result. The City refers to this Handbook for all
projects subject to CEQA. Although the construction phase of the project-'is below the thresholds for
significance, some mitigation is recommended. Construction for this project includes grading to expand
the wetland area and to create the sedimentation basin. The "operation" phase of this project would
include periodic maintenance of the sedimentation basin and is considered insignificant. It is
anticipated that sedimentation removal might occur every five (5) to ten (10) years, and would largely
depen&on the severity of =storm conditions.
According to the general operational screening criteria in the APCD Handbook, the grading associated
with the proposed project is not expected to generate potentially significant air quality Impacts.
However, emissions associated with project construction could affect adjacent properties and would
add to the cumulatively significant effect that results -in basin -wide exceedance ^of air,quality standards.
These temporary fugitive dust and combustion emissions can impact local air quality. Implementation
of the following mitigation measures will reduce air quality impacts to,a less than significant level:
MM 3A The following conditions shall be included on all project plans and adhered to for all
grading - related permits:
• Reduce'the,amount of disturbed area where possible.
• Use water trucks or sprinkler systems in sufficient quantities to prevent airborne dust
from leaving the site. Increase watering frequency when wind speeds exceed 15 MPH.
Reclaimed (non - potable) water shall be used whenever possible.
• All dirt stockpile areas should be sprayed daily or as needed using reclaimed (non- ,
potable) water when feasible.
Page 17 of 43
INITIAL STUDY "l MITIGATEDNEGATIVEAECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
' Exposed ground areas that are planned to be reworked more than one (1) month after
initial grading should be sown with a fast - germinating native,grass seed 'and watered
until vegetation is established.
• All areas to be paved (i.e. access _road to the sediment basin) should be completed as
soon as possible.
• All trucks hauling dirt, sand, soil or other loose materials) are to be covered or shall
maintain at least .two ,(2) feet of freeboard (minimum vertical distance between top of
load and top of trailer) in accordance with CVC Section 23114.
• Streets shall be swept- at the end of each day if visible soil material is carried onto
adjacent paved roads. Water sweepers with reclaimed (non - potable) water should be
used where feasible.
• Diesel idling'shall not be permitted.
• Signs that specify the no idling requirement shall be posted and enforced at the
construction site.
• Use of alternative- fueled equipment -is recommended whenever possible.
• The contractor shall designate a person or persons to monitor and implement these
measures as necessary to minimize dust complaints, reduce visible emissions below 20%
opacity and to prevent,the transport of dust off -site. The name and telephone number
of such persons shall be provided to the Air Pollution, Control District (APCD) prior to the
start of any grading: related activities:, (See MM 9.1 for erosicimcontrol measures).
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit and during,construction
MM 3.2: All portable equipment (50 horsepower or greater) used during grading operations
must be issued a permit by either the California Air Resources Board (CARB) or, the APCD.
(Contact the APCD Engineering Division at (805) 781 -5912 for specific information regarding
permitting requirements,prlor to'start of the Project).
Level of Significance:
Less than significant impact
Implementing Responsibility:
ConstructionVanager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit and during construction
d -e: No impacts.
4. Biological Resources
Environmental Setting
The project area includes the confluence of Corbett Creek and Carpenter Canyon Creek as well as the
confluence of Corbett Creek and Arroyo Grande Creek. Corbett Creek:is a perennial creek that carries
flow except in drought years: The property hash long history of livestock grazing, and there has been
some modification of natural hydrology by re- alignment of the creeks and construction of a berm.
I To determine the extent and quality of wetland habitat,on the project site, and whether portions of the
,project arearwere eligible,for' wetland protection and restoration'through the Wetland Reserve Program,
Page 18 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodpla'n and Stream Restoration Project
(WRP), a report was conducted by'the Natural Resources Conservation Service (NRCS) in December '
2006. According to the report, the Clark Property does not contain any land'that would be eligible for
the Wetland Reserve Program. The site contains small areas of natural wetlands in four (4) delineations
and the remaining land subject.to the conservation easement is considered non- wetland.
The project site contains a variety of non - native and native plant species, with willows. being the
dominant native tree species. The prevailing understory species present - include German ivy, poison
hemlock, California blackberry, hoary nettle, poison oak, and, morning glories (Denise Duffy and
Associates, 2003). According to the Tally Ho Creek Planning Project Technical Memo Appendices
prepared by Waterways Consulting, Inc. (June 2010), there are several identifiedispecial status plant and
wildlife species that are likely present, although were not observed during the site inventory. These
,include Hoover's bent grass (Agrostis hooveri), black - flowered figwort (Scrophulario atrato), San
Bernardino aster (Symphyotrichom defoliotum), California red - legged frog (Rana aurora draytonii),
Southwestern pond turtle (Actinemys marmorota pallid), and the Yellow Warbler (Dendroico petechia).
The U.S. Fish and Wildlife Service (USFWS) and California Department of Fish and Wildlife (CDFW) have
regulatory responsibility forthe� protection of special status plant and wildlife species. "Special status'
species are selected for protection because they are rare and/or subject to population and habitat
declines. Special status is a general term for species that are afforded varying levels of regulatory
protection_
preservation policy or ordinance? I
Page 19, of, 43
Potentially Less Than Less Than
iSignificant
Significant with Significant No Impact
Would the project:
Impact Mitigation Impact
a) Have a substantial adverse effect, either directly or
'
through habitat.modification, on any species identified
as a sensitive, candidate, or special status species irr
El ❑ ❑ .
local or regional plans, policies, or regulations, or by
the California Department of Fish and Wildlife or,the
U.S. Fish and Wildlife,Service?
b) Have a substantial adverse effect on 'any riparian
habitat or other sensitive natural community identified
in local or regional plans, policies, or regulations, or`by
❑ ® ❑ ❑
the California Department of Fish and Wildlife or the
U.S. Fish and Wildlife Service?
c) Have a substantial adverse effect on federally
protected wetlands, as defined by §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? I
Page 19, of, 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplainand Stream, Restoration Project
f) Conflict with the provisions of an adopted Habitat
Conservation Plan, Natural Community Conservation
Plan, or other approved local, regional, or state habitat El El El 0
conservation. plan?
Discussion
a -d: With the mitigation measures identified below, it is not anticipated that the project will have a
significant impact on biological resources due to the historic equestrian use of the site and the short
duration of construction /grading activities. The site is dominated by non - native plants except for
willows. The purpose of creating the sedimentation basin and enhancing the floodplain area is to first
impede flooding downstream, and second to enhance the native habitat. It is expected that the long
term benefits of restoring the floodplain and riparian habitat will outweigh ,short term impacts.
Although, the project will incorporate requirements for any necessary permits from the California
Department of Fish and Wildlife (CDFW) and United States Fish and Wildlife Service ( USFWS), several
mitigation measures are included to offset any potential short term impacts. The following measures
are primarily designed to promote habitat avoidance.
MM 4.1: Construction /grading shall take place after the,breeding,season for the Yellow Warbler
(April — July) to limit noise impacts. If construction /grading must start during this time period,
surveys of nesting birds within the project vicinity shall be completed by a qualified wildlife
biologist. If the surveys identify active nests of the, Yellow Warbler within the,project vicinity, all
earthmoving;acLVitiesrshall cease until the chicks have fledged. The biologist shall provide the
lead agency and responsible.agencies with a written report of survey findings, and shall specify
when the project work may safely commence.
Level of,5ignificance:
Less than significant Impact
Implementing Responsibility:
Construction Manager (in consultation with the,U:S. Fish,and
Wildlife SerVICe(USFWS) prior to proceeding with work)
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit
MM 4.2: A qualified wildlife biologist shall complete and submit to the lead agency and
responsible agencies a pre- construction survey for California red - legged frogs and Southwestern
pond turtles. The survey shall be conducted during the time period when these species are
known to be active. If no individuals are found, construction may proceed. If Individuals are
found during the initial investigation, the biologist shall conduct clearance surveys for these
species approximately one (1) week prior to construction Individual's found within the
construction area will either be relocated to similar, adjacent habitats at least fifty (50) yards
outside of the project area, or held in captivity until, construction is complete. The project area
shall be monitored during construction and appropriate measures taken to ensure that the
Individuals, of relocated species do not move into the construction area. The decision of
whether to relocate the animals shall be made by the biologist, although all mitigation activities
would have to occur within the framework of any permits issued by the USFWS and CDFG.
Page'20 of;43
INITIAL STUDY,/ MITIGATED NEGATIVE DECLARATION March 2013
'Corbett Creek Noodplain and'Stream Restoration Project
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager (in consultation with the U.S. Fish and
Wildlife Service (USFWS) prior to proceeding with work)
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing'.
Prior to issuance of;gradin&permit and during construction
MM 4.3: A qualified botanist shall conduct,an initial site,survey to map occurrence of Hoover's
bent grass, San Bernardino aster and black - flowered figwort. If sensitive plant species are found
on site and determined to be potentially impacted, the botanist shall prepare procedures that
ensure no net lossxof plants. These include, but are not limited to, designating avoidance areas,
transplanting the plant populations to an equivalent location on site, ot,replaced in -kind with
new plants at a ratio of two (2) plantsyreplaced for each one (1) lost or at a ratio acceptable to
the botanist. The transplanted or replaced plants shall be monitored over a five (5) year period.
Any plants lost during this time period shall be replaced. The botanist shall prepare a planting,
irrigation and maintenance plan that includes these provisions. If the botanist concludes that
avoidance is a viable option, locations determined to be potentially impacted will be flagged
against inadvertent or unintentional damage.
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager (in consultation with the U.S. Fish and
Wildlife Service (USFWS) prior to proceeding with work) _
Monitoring Agency.,
City of Arroyo Grande „Community Development Dept.
Timing:
Prior to issuance of grading permit
MM 4.4: The applicant shall acquire appropriate resource agency permits and undertake
protection measures,as required by'those,agencles.
Level of Significance::
Less than'significant.impact
Implementing Responsibility:
Coastal San Luis Resource Conservation District
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit
e -f: Noimpacts.
S. Cultural Resources
Environmental Setting
Creeks area focal area of concern for the purposes of cultural resource,sensitivity due to the pre- history
and historical activity that occurred along and extending'from� creeks. The,Central Coastal Information
Center under contract to the State Office of Historic Preservation (OHP) helps implement the California
Historical Resources Information System (CHRIS). It integrates information on new resources and known
resources into CHRIS, supplies information on resources and surveys to governments and supplies lists
of consultants qualified to conduct historic preservation fieldwork within the area. The California
Archaeological Site Inventory is =the collection of Site Records, which has been acquired and managed by
the Information Centers and the OHP since 1975. According to these records,.�no known cultural site is
located in the immediate project vicinity. Of the nineteen (19) site investigations conducted within a
half mile radius of the project site, four (4) of which were on adjoining properties, there was only one (1) '
Page 22 of 43
J
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and stream Restoration Project
site that revealed any positive results for archaeological resources, which was located :about 0.4 mile .
south of the project site near Paulding Middle School.
By virtue of the project area including the confluence of two (2) creeks, there may be a likelihood of
prehistoric or early historic occupation or use of the site even though there are no known sites' in tFie
vicinity. ,Additionally; the proposed project requires a limited amount of surface excavation for the
purposes of collection of fine sediment and floodplain restoration.
MM '5.1: In the event that prehistoric cultural materials or historic cultural materials are
encountered, work in the immediate vicinity of the finds shall be suspended until reviewed by
an archaeologist, and the City shall be notified immediately should such resources be
discovered. The archaeologist shall work as quickly as possible to permit resumption of
construction activities. It is preferred that location data of finds be ,recorded using a hand -held
global positioning system:(GPS) receiver.
If human remains are encountered and determined to be Native American In origin, the•San Luis
Obispo County coroner will notify the Native American Heritage Commission (NAHC) within 24
hours of the find. The NAHC'shall identify, the person or persons it believes to be,the most likely
descendent 'of the deceased Native American. The most likely descendent may make
recommendations for means of treating or disposing of the human remains and any associated
grave goods as provided in Public Resources Code Section 5097.98.
Level of Significance:
Potentially
Less Than
Less Than
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Significant
Significant
Significant
No Impact
Would the project:
Impact
with
Mitigation
Impact
a) Cause a substantial adverse change in the
significance of a historical resource, as defined in
❑
❑
0.
❑
§15064.5?
b) Cause a substantial adverse change yin the
significance of an archaeological resource, pursuant to
❑
®
❑
❑
§15064.5?
c) Disturb any human remains, including those interred
El
®
1:1
El
of formal cemeteries?
Discussion
a -c: Although it is not anticipated that there are any impacts to
archaeological /cultural
resources,
implementation of the mitigation measures below -will ensure
that no impacts will
occur.
MM '5.1: In the event that prehistoric cultural materials or historic cultural materials are
encountered, work in the immediate vicinity of the finds shall be suspended until reviewed by
an archaeologist, and the City shall be notified immediately should such resources be
discovered. The archaeologist shall work as quickly as possible to permit resumption of
construction activities. It is preferred that location data of finds be ,recorded using a hand -held
global positioning system:(GPS) receiver.
If human remains are encountered and determined to be Native American In origin, the•San Luis
Obispo County coroner will notify the Native American Heritage Commission (NAHC) within 24
hours of the find. The NAHC'shall identify, the person or persons it believes to be,the most likely
descendent 'of the deceased Native American. The most likely descendent may make
recommendations for means of treating or disposing of the human remains and any associated
grave goods as provided in Public Resources Code Section 5097.98.
Level of Significance:
LessShan significant_Impact
Implementing' Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
During construction
.MM 5.2: The note below shall -be placed'on the gradmgiand improvement plans,forthe project:
"If human remains (burials) are encountered, the County Coroner shall be contacted
immediately (805 -781- 4513). In the event that previously unidentified potentially
significant cultural resources are discovered, an archaeologist shall have the authority to
Page 22 of 43
INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
divert or temporarily `halt ground disturbance operations in the area of discovery to allow '
evaluation of ,potentially significant- cultural' resources in consultation with Northern
Chumash Tribal Council. For significant cultural resources, a Research Design and Data
Recovery Program to mitigate impacts shall be prepared by the consulting archaeologist
and approved by the City, then carried out using professional archaeological methods. If
it can be demonstrated that a project will cause damage to a unique archaeological
resource, the City, may require, reasonable efforts to be made to,permit any or all of
these resources to be preserved'in plac& or left.inranundisturbed state."
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring,Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuanceof gradin&permit
6. Geology -and Soils
Environmental Setting
The site has varying topographical gradients but generally consist of a 2,-5% northeasterly slope. The
soils on the-Corbett Creek watershed are derived from soft, highly erodible sandstones. High levels of
sediment in the creek have come from several locations of erosion and flooding events. The highest
profile erosion sources came from the clearing and grading, of an upslope property on James Way for a
housing development. In 2001, a combination of heavy ^rams °and soils, with a high to very high hazard
rating for water erosion led to the:sedlmentation of the James Way stormwater ditch and Corbett Creek;
in turn causing flooding to adjacent homes. Homes along Corbett Creek in some cases are as little as
twenty feet (20') from the creek and are not elevated. The sediment was deposited in Corbett Creek,
raising the streambed. Sediment, accumulation has created marsh -like wetland areas that alter the form
and function of the creek, diminishing,the ; in- stream habitat and the conveyance;of water and sediment.
In addition,to erosion, expansion of the urban fringe, road development and increases in impervious
surfaces have resulted in changes in the timing and magnitude of peak flows in the creek. There are
small berms in some localized areas along the north side of the active, channel built by landowners.
Another factor affecting stream function is a four foot (4') high head -cut In,the creek (as of 2007). If the
head -cut was to progress upstream 2,700 feet, approximately 7,000 cubic yards ofuediment would
mobilize. (Swanson Hydrology & Geomorphology, 2008) and be transported downstream to Arroyo
Grande Creek, impacting steelhead habitat and increasing flooding challenges in the Zone 1 /1A flood
control channel.
No active faulting, is known to exist on or close to the subject property. The 'project is not within a
known area containing serpentine or ultramafic rock or soils (i.e. low risk of naturally occurring'
asbestos).
Page 23 of 43
a: No impacts.
b. The project is intended to alleviate risks from increasing head -cuts and depositic m•of sediment. The
project does not alter geotechnical requirements or permit additional construction in geologically
sensitive or hazardous areas. The project description integrates development and implementation of
both short and long term Best Management Practices (BMPs) to address construction and long term
maintenance of the sedimentation basins on the Clark, Property, design of the head -cut remediation and
BMPs for landowners on'the',project :area.
c -e: No impacts.
Page 24 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
Corbett Creek Floodplain and Stream Restoration Project
March 2013
Less
Than Less Than
Potentially
Significant
Significant with Significant No Impact
Would the project:
Impact Mitigation Impact
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 on the most recent Alquist- Priolo
Earthquake Fault,Zonin&Map, issued bythe;State
Geologist for the area, or based on other
El ❑ El
evidence of a known fault? (Refer to
Division of Mines and Geology Special Publication
42.)
ii) Strong seismic; ground shaking?
iii) Seismic- related ground failure, Including
liquefaction?
iv) Landslides?
b) Result in substantial soil erosion or the loss of
El ❑. ® ❑
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',
orcollapse?
d) Be located on expansive soil, as defined in Table 18-
1-8 of the Uniform Building Code (1994), creating
❑ ❑ ❑
substantial risks to life or property?
e) Have soils incapablenof adequately supporting the
use of septic tanks or alternative waste disposal
F-1 El El
systems, where sewers are not available for the
disposal of waste water?
Discussion
a: No impacts.
b. The project is intended to alleviate risks from increasing head -cuts and depositic m•of sediment. The
project does not alter geotechnical requirements or permit additional construction in geologically
sensitive or hazardous areas. The project description integrates development and implementation of
both short and long term Best Management Practices (BMPs) to address construction and long term
maintenance of the sedimentation basins on the Clark, Property, design of the head -cut remediation and
BMPs for landowners on'the',project :area.
c -e: No impacts.
Page 24 of 43
INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
7. Greenhouse Gas (GHG) Emissions ,
Environmental Setting'
The project area includes residential development adjacent to Corbett Creek except at the Village Core
where there are four parcels zoned Village Core /Village Mixed Use. The Clark Property is mostly
undeveloped and contains a.barn, equestrian trails and corals. Project construction is limited to creation
of a sedimentation basin and,expansiomof,the floodplain within defined areas. Short,term greenhouse
gas (GHG) emissions would be generated from equipment used for grading operations and are
considered less than significant. There, is not an operational phase to this project except for periodic
(every 5 -10 years) maintenance of the sedimentation basin. Therefore, GHG emissions cease once the
initial construction is complete.
Potentially 'Less Than Less Than
Significant Significant Significant No Impact
with
Would the project: Impact Mitigation Impact
a) Generate greenhouse gas emissions, either directly
or Indirectly, that may have a significant effect on the ❑ ❑ ® ❑
environment?
b) Conflict with an applicable plan, policy or regulation
adopted for the purpose of reducingthe emissions of ❑ ❑ ❑ IK
greenhouse gases?
Discussion
a: The amount of GHG emissions from construction activities • do - not exceed the cumulative impact '
thresholds established by the San Luis Obispo County Air Pollution Control District,(APCD). It,should be
noted that Mitigation Measures 3.1 and 3.2 address equipment and idling requirements that have the
dual benefit of reducing GHG emissions.
b: No impacts.
8. Hazards and Hazardous Materials
Environmental Setting
There are no known hazards or hazardous materials associated with'the project site.
Page 25 of 43
Potentially
Less Than
Less Than
Significant
Significant
with
Significant
No Impact
Would the'project:
Impact
Mitigation
Impact
a) Create a significant hazard to the public or the
environment through Lthe. routine transport„ use, or
❑
❑
❑
disposal of hazardous materials?
b) Create a significant hazard to the public or the
environment through reasonably foreseeable upset
and /or accident conditions involving' the release of
❑
❑
®
❑
hazardous materials, substances, or ,waste' into the
environment?
Page 25 of 43
Environmental ^,Setting
The project area includes the confluence of Corbett and Carpenter Canyon Creeks as well as the
confluence of Corbett and Arroyo Grande Creeks. Except for drought years, Corbett Creek maintains
perennial flow and meanders from the City limits near Highway 227 to Arroyo Grande Creek in the
commercial core.of the City'sNillage area. It has an active low flow channel /bank full morphology that
narrows to approximately two -four feet (2' -4;) wide near Arroyo Grande Creek. The creek travels
through the backyards of residences on Tally Ho Road where there is persistent flooding: There Is a four
foot (4') high head -cut in the creek that was initially observed by field crews in 2007. If the head -cut
were to progress upstream 2,700 feet, approximately 7,000 cubic yards of sediment would mobilize
(Swanson Hydrology.& Geomorphology,.2008) and be transported downstream,to Arroyo.Grande Creek,
impacting steelhead habitat and increasing flooding challenges in the Zone 1 /1A flood control channel.
The project is intended to restore the riparian habitat and provide flood protection.
Construction /grading activities and exposed soil could cause temporary erosion; however,
' implementation of Best Management Practices (BMPS) that are integrated into the project description
and themnitigatlon'measures'!below will mitigate the impacts to less thaYSignificant.
Page 26 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
March 2013
Corbett Creek Floodplain and Stream Restoration Project
c) Emit hazardous emissions or handle hazardous or
acutely hazardous materials, substances, or waste
El El El
within one - quarter mile of an existing or proposed
school?
d) Be located on a site which isriocluded on, a list of
hazardous materials sites, compiled pursuant to
❑ El El
Government Code §65962.5, and, as a result, create a
significant hazard to the public or environment?
e) Be located,within.an airport use,plan or, where
such a'plan has not been adopted, within 'twoL miles of
a public airport or public use airport? If so, would the
❑ ❑ ❑
project result in a_safety hazard for people residing or
working In the project area?
f) Be located in the vicinity of a private airstrip? If so,
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?
h) Expose people or structures -to a significant risk of
loss, injury, or death from wildland fires, including
❑ 11 El
areas where wildlands are adjacent to urbanized,areas
or where residences are intermixed, with wildlands?
'
Discussion
b: The project as proposed does not pose a significant
hazard to the public or the environment.
However, in the unlikely event that there is an equipment
malfunction producing an oil or gas spill,
procedures shall be followed as outlined under MM
9.1 (preparation of a Storm Water Pollution
Prevention Plan).
a, c- h: No impacts.
9. Hydrology and Water Quality
Environmental ^,Setting
The project area includes the confluence of Corbett and Carpenter Canyon Creeks as well as the
confluence of Corbett and Arroyo Grande Creeks. Except for drought years, Corbett Creek maintains
perennial flow and meanders from the City limits near Highway 227 to Arroyo Grande Creek in the
commercial core.of the City'sNillage area. It has an active low flow channel /bank full morphology that
narrows to approximately two -four feet (2' -4;) wide near Arroyo Grande Creek. The creek travels
through the backyards of residences on Tally Ho Road where there is persistent flooding: There Is a four
foot (4') high head -cut in the creek that was initially observed by field crews in 2007. If the head -cut
were to progress upstream 2,700 feet, approximately 7,000 cubic yards of sediment would mobilize
(Swanson Hydrology.& Geomorphology,.2008) and be transported downstream,to Arroyo.Grande Creek,
impacting steelhead habitat and increasing flooding challenges in the Zone 1 /1A flood control channel.
The project is intended to restore the riparian habitat and provide flood protection.
Construction /grading activities and exposed soil could cause temporary erosion; however,
' implementation of Best Management Practices (BMPS) that are integrated into the project description
and themnitigatlon'measures'!below will mitigate the impacts to less thaYSignificant.
Page 26 of 43
INITIAL STUDY /- MITIGATED,NEGATIVE DECLARATION
Corbett Creek Floodplain and Stream Restoration Project
March ,2013
Less,Than
.Potentially Significant Less Than
Significant
with Significant
'NO Impact
Impact - �
Would the project: Mitigation Impact
a) Violate any water quality standards or waste El ® El
El
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
El 1-1 El level (e.g., the production rate of pre- existing nearby
wells would drop to a level that 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 alteration of the ❑
of a stream or river, in a manner which would ® E)
El
result In substantial on- or off -site erosion or siltation?
d) Substantially alter the existing drainage pattern of
the site or area, including through 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 on- or off -site flooding?
e) Create or contribute runoff water which would
exceed the capacity of existing or planned stormwater
'
El ® El
drainage systems or provide substantial additional
❑
sources of polluted runoff?
f) Substantially degrade water quality? El ® El
g) Place housing within a'100 -year flood,hazard.area,
as mapped on a federal Flood Hazard Boundary or ❑
❑ El Flood Insurance Rate Map, or other flood hazard
delineation map?
h) Place structures that would,impede or redirect flood
El ®
flows within a- 100 -,year flood hazard area?
E)
I) Expose people or structures to a significant risk of
loss, injury, or death from flooding, including flooding ❑ ® ❑
❑
resulting from the failure of a levee or dam?
j) Result In inundation by seiche, tsunami, or, mudflow? ❑ ❑ []
Discussion'
a, c -f, h -I: Potentially significant impacts from soil erosion and an increase in sediment and turbidity
to
Arroyo Grande Creek could result from project grading and construction. Potentially significant
impacts
on hydrology and water quality from construction related activities can be reduced to a
less-
than-significant level with implementation of the mitigation measures listed - below.
The project' site is within a floodway where waters, flood onto horse ,pastures , and therefore water
quality impacts from equestrian use and manure accumulation may also be a concern. The project
may
bring surface water more frequently in contact with pastures and manure. However, the project
would
,
Page,27 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
not worsen the water quali ty situation since no more horses would'be added'to'the:site, and °some of
the area currently used for'horse corrals and pasture would be allocated to floodwater detention and
riparian habitat enhancement. It is unknown at this time what the water quality impacts from nitrogen
or bacteria will be from the project. Water quality monitoring will be carried out as required by the
Storm Water Pollution Prevention Plan. The property owner Is'jnterested in.BMPs to manage manure
through composting. These BMPs would reduce potential bacteria pollutant loading, and would be
implemented separately from this project. The continued equestrian use is not considered a potentially
significant impact.
There is a potential for berm failure that could impact downstream properties. This potential will be
addressed through the design process, and applicable design standards will be used.
MM 9.1: The applicant shall prepare a Storm Water Pollution Prevention Plan ( SWPPP) and
Erosion Control Plan that specifies the Implementationof Best Management Practices (BMP,.$) to
avoid and minimize water quality impacts as required by the Regional Water Quality Control
Level of Significance:
Board (RWQCB). At a minimum, the SWPPP and Erosion Control Plan shall include:
Implementing Responsibility: ,
• Designation of equipment and supply staging and storage areas at least 100 feet
Monitoring Agency:
from the outside; edge of the creek 25 -foot setback area. All vehicle parking,
Timing:
,routine equipment maintenance, fueling, minor repair, etc:, and soil and
material stockpile, shall be done only in the designated staging area.
• Major vehicle /equipment maintenance, repair, and equipment washing shall be
performed off site.
'
. A wet and dry spill cleanup plan that specifies reporting requirements and
Immediate clean up to ensure no residual soil, surface water or groundwater
contamination would remain after clean up.
• Designating concrete mixer washout areas at least 100 feet from outside edge
of the creek,25- foot'setback with the use of appropriate containment or'reuse
practices.
• A temporary and excess fill stockpile and disposal plan that ensures that no
detrimental' affects to receiving waters would result.
• Required site;preparatiomand erosion control BMPs`for'any work that may need
to be, completed after October 15.
Level of Significance:
Less than significant impact
Implementing Responsibility: ,
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit and during construction
MM 9.2:- To reduce erosion hazards due to construction activities, grading shall be
minimized; 'and project contractors shall use runoff and sediment control structures, and /or
establish a permanent plant cover on side slopes following construction.
Level of Significance:
Less than sign ificant'impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept,
Page 28 of 43
INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
Timing: Priontoiissuance of grading permit and:durmg construction ,
MM 9.3: Erosion control and bank stabilization measures shall be implemented for any
work that requires access to the creek, subject to CDFW approval through a Streambed
Alteration Permit. These measures shall be clearly indicated on the grading plan.
Level of.Significance:
Less than.significant, impact
Implementing Responsibility:
Coastal San Luis Resource Conservation District
Monitoring Agency:
City of Arroyo Grande, Community Development Dept
Timing:
Prior to issuanceiof grading permit and during construction
MM 9.4: All temporary' fill placed dunng.project construction shall';be removed at project
completion and the area restored to approximate pre - project contours and topography.
Level of Significance:
Lessthan significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande; Community Development Dept.
Timing:
Prior to final inspection
MM 9.5: The project is-located within[a, regulatory floodway. The applicant shall obtain
all required permits from regulatory agencies (City of Arroyo Grande, Regional Water ^Quality
Control Board, US Army Corps of Engineers, Ca. Dept. of Fish and Wildlife; etc.) and meet any
relevant FEMA requirements associated with a regulatory floodway as necessary.
Level of Significance:
Less than significant impact
Implementin0esponsibility.
Coastal San Luis Resource Conservation District
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit
b, g, i:, No impacts.
10. Land Use and Planning
Environmental Setting
Surrounding uses are identified on Page 10 of the Initial Study. The proposed project was reviewed for
consistency with policy and /or regulatory documents and appropriate land use (Land Use Element,
Development Code, and Zoning Map). Outside the channel of Corbett Creek, the Clark Property is zoned
for low density residential development at a density of 0.67 dwelling units /acre (a total of up to ten
units). This project includes a conservation easement in perpetuity for 12.5 acres leaving „a potential
residential density of up to two (2) dwelling units: There are several antiquated lots'in the project area
that have been developed over time and the built density along Corbett Creek•exceecis that of the low
density residential designation. City policy C /OS 2 states that the City is to "safeguard important
environmental and sensitive biological resources contribution to healthy, functioning ecosystems ".
Conserving, land for the purposes of localized and downstream flood protection and habitat restoration
is consistent with'the,City's General Plan.
Page '29,of 43
Environmental Setting
The project site is primarily located within a'low to medium density residential area. Existing ambient
noise in the vicinity of the project is primarily,generated by vehicular traffic. The Noise Element of the
2001 General Plan includes goals and implementation measures designed to reduce noise impacts on new
development, and the City's; Noise Ordinance, is the primary implementing tool of the Noise Element
'through specific, noise standards.
Potentially Less Than Less Than
Significant Significant
with Significant No Impact
Impact
Would the project: Mitigation Impact,
Page 30 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
Corbett Creek Floodplain and Stream Restoration Project
March 2013
Potentially
Less Than
Less Than
Significant
Significant
with
Significant
No Impact
Would the project:
P 1
Impact
Imp t
Mitigation
Impact
a) Physically divide an established community?
❑
❑
❑
b) Conflict with the applicable land use,plan, policy, or
regulation of any agency with jurisdiction over the
project (including, but not limited to, a general plan,
specific plan, local coastal program, or zoning
El
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ordinance) adopted for the purpose of avoiding or
mitigatingian environmental effect?
c) Conflict with any applicable habitat conservation
plan or natural community conservation plan?
El
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El
Discussion
a -c: No impacts.
11. Mineral Resources
Environmental Setting
The project site is not located within an area known to contain
mineral resources-
The
site is not
designated in the 2001 General Plan or Identified in
the Integrated
Program
EIR prepared for the
General Plan as having locally- important mineral resources. There are no permitted
mining
operations
located within the City limits of Arroyo Grande.
Potentially
Less,Than
Less Than
'Significant
,Significant
with
Significant
No Impact
Would the project:
Impact
Mitigation
Impact
a) Result in the loss of availability of a known mineral
resource that is or would b&of value to the region and
❑
❑
❑
the,residents ofaheatate?
b) Result in the loss of availability of a locally
important mineral resource recovery site delineated
El
El
❑
on a local general plan, specific plan, or other land use
plan?
Discussion
a -lb: No impacts.
12. Noise
Environmental Setting
The project site is primarily located within a'low to medium density residential area. Existing ambient
noise in the vicinity of the project is primarily,generated by vehicular traffic. The Noise Element of the
2001 General Plan includes goals and implementation measures designed to reduce noise impacts on new
development, and the City's; Noise Ordinance, is the primary implementing tool of the Noise Element
'through specific, noise standards.
Potentially Less Than Less Than
Significant Significant
with Significant No Impact
Impact
Would the project: Mitigation Impact,
Page 30 of 43
INITIAL STUDY./ MITIGATED NEGATIVE DECLARATION March;2013
Corbett Creek Floodplain and Stream Restoration Project
a) Generate or expose people to noise levels in excess
Less.than significant impact
of standards established in a local general plan or
® ❑ ❑
noise ordinance, or'in other applicable local, state, or
City of Arroyo Grande, Community Development Dept.
federal standards?
During construction
b) Generate or expose people to excessive'
❑ ❑ ❑
groundborne vibrations orgroundborne noise levels?
c) Create a substantial permanent increase in ambient
noise levels in the vicinity of the project (above levels
❑ ❑ ❑
without the project)?
d)•Create "a substantial temporary or periodic'incre"ase
In ambient noise, levels in the vicinity of the project, in
❑ ® ❑ ❑
excess of noise levels existing without the project?
e) Be located within an airport land use plan or, where
such a plan has not been adopted, within two miles of
a, public :airport or'publicusegairport? If so, would the
❑ ❑ ❑
project expose people residing or working in the
project area to excessive noise levels?
f) Be in the vicinity of a private airstrip? If so, would
the project expose people residing or working in the
❑ ❑ ❑
project area to excessive noise levels?
Discussion
a, d: Noise impacts associated with short term construction'are.expected to be minimal due to the need for
limited surface excavation. Existing ambient noise In the vicinity of the project site is generated by vehicular
traffic on Highway 227. The average sound levels during construction could exceed the threshold criteria
when equipment is operating. This is considered a potentially significant impact that can be mitigated to a
less- than - significant level with implementation' of the below mitigation measures. There are no; long -
term'or operational increases to ambient noise;Jevels.
MM 12.1: Construction activities shall be restricted to the hours of 8:00 AM to 5:00 PM Monday
through Friday. On -site equipment maintenance and servicing shall be confined to the same
hours.
Level of Significance:
Less.than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
During construction
MM 12.2 All construction'equipment utilizing internal ,combustiomengines shall.be required to
have mufflers that are In good condition. Stationary noise,.sources shall utilize noise reducing
engine housing enclosures or noise screens.
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of'Arroyo Grande, Community Development Dept.
Timing:
During construction
Page 31 of 43
1
INITIAL STUDY/ MITIGATED.NEGATIVE DECLARATION March 2013
Corbett Creek Floodplam and Stream Restoration Protect
MM 12.3: A note shall be placed on the construction plans that no more than two (2) pieces of
major earth moving equipment' shall be allowed to operate simultaneously.
Level of Significance:
Less than significant impact, _
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permitand during construction
MM 12.4: All residential units located within five, hundred feet (500') of the construction site
shall be sent a notice,regarding� the construction schedule of the project. A clearly.'legible sign
shall also be posted at the project site. All notices and the signs shall indicate the expected
dates and duration of construction activities, as well as provide a telephone number that
residents can call to resolve any concerns about construction noise.
Level of Significance:
Less'than significant Impact
Irriplementing,Responsibility:
Construction Manager
Monitoring Agency:
City of.Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit and during construction -
b -c, e -f: No Impacts.
13. Population and'Housing
Environmental Setting
The project'site is located within an established low and medium density residential area. Placing 12.5
acres of'the roughly 16 -acre Clark, Property 'mto , a conservation easement would appearto reduce the
residential development, potential. However, 'because the 12.5 -acre property is located within' a
floodplam area, it is unlikely that housing opportunities are lost. With 3.5 acres remaining of the 16 acre
site, two (2) homes could be constructed at a density of 0.67 dwelling units per acre 'under the
Residential Hillside (RH) zoning district. Downstream along the Corbett Creel reach, the only properties
with development potential (i.e. vacant) are zoned Village Mixed Use (VMU) and Village Core (VC).
These zoning, designations allow commercial and residential development. The proposed, project would
not impede development of these properties.
Page 32 of 43
Potentially
ess Than
Less Than
Significant
Significant
ith
Significant
No Impact
Would the project:
Impact
Mitiwgation
Impact
a) Induce substantial population ,growth in an area,
either directly (for example, by proposing new homes
El
El
and businesses) or indirectly (for example, through
extension of roads or other infrastructure)?
b) Displace substantial numbers of existing housing,
necessitating_ the constructiomof replacement housing
❑
❑
❑
'elsewhere?
c) Displace substantial numbers of people,
necessitating the construction of replacement housing
❑
❑
❑
elsewhere?
Page 32 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION. March 2013
Corbett Creek Roodplam and Stream Restoration Protect
Discussion
a -c. No impacts.
14. Public Services
Environmental Setting
,Public services to'the „project site are readdy,pfovided by the,Cityof,Arroyo,Grande,
Fire protection? El C1
Potentially
Less Than
Less Than
Schools? 0 ❑
Significant
Significant
Significant Nog m pact
Would the project:
Impact
with
Mitigation
Impact
a) Result�in significant environmental Impacts from
Impact
15: Recreation
a) Increase the use of existing neighborhood and
construction associated wlth'the provision of new or
The project site is a private facility,with recreational uses and,ls,not'a public.facllity.
The property owner
physlcally:altered governmental facilities, or the need
space. The project will not affect anyexlsting private or public parks within the area, either by "creating
more demand for parks or diminishing the use.of parks.
for new or physically altered governmental facilitiesyto
substantial physical deterioration of the facility would
❑
❑
❑
E)
E)
ED
maintain acceptable service ratios, response times, or
”
b) Include recreational facilities or ,require the
other performance objectives for any of the public
services:
'
Fire protection? El C1
El
Police protection? ❑ ❑
❑
Schools? 0 ❑
❑
Parks? ❑ ❑
❑
Other'public facilities? ❑ ❑
❑ E
Discussion
'
a: No impacts.
Impact
15: Recreation
a) Increase the use of existing neighborhood and
Environmental Setting
The project site is a private facility,with recreational uses and,ls,not'a public.facllity.
The property owner
utilizes the site primarily "for corralling and grazing horses, with most of the 'site left in vacantropen
space. The project will not affect anyexlsting private or public parks within the area, either by "creating
more demand for parks or diminishing the use.of parks.
Page 33 of 43
Potentially
Less Than
Less Than
Significant
'Significant
with
Significant
No Impact
Would the project:
Impact
Mitigation
Impact
a) Increase the use of existing neighborhood and
regional parks or other recreational•facilitles, such that
substantial physical deterioration of the facility would
❑
❑
❑
occur or be.accelerated?
b) Include recreational facilities or ,require the
constructiomor expansion,of,recreationa("fac lines that
might have an adverse physical effect on the
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environment?
Page 33 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
Discussion
a: No impacts.
b: The site will continue to serve as an equestrian recreational use. The existing - facilities will remain,
with some reduction in corral and grazing areas (see Exhibit B above under Background and Need for
Project).
16.1 Transportation /Traffic
Environmental Setting
The project site is located within an established low and medium density residential area with access
from Highway 227 /Carpenter Canyon Road, Corbett Canyon Road, and Tally Ho Road where street
parking is available and level of service Is acceptable (LOS�C or better). The project does not generate
any trips that would impact the surrounding street network LOS or the backbone,circulation system of
the City.
Page 34 of 43
Potentially
Less Than
Significant
Less Than
'Significant
Significant
with
No Impact
Would the project:
Impact
Mitigation
Impact
a) Cause a substantial Increase in traffic, in relation to
existing traffic and the capacity of the street system
_
(i.e., a ,substantial increase in either the number of
❑
❑
❑
vehicle trips, the volume to capacity'ratio on roads, or
congestion at intersections)?
'
b) Exceed, individually or cumulatively, the level of
service standards established by the county congestion
❑
❑
El
management agency for designated roads or
highways?
c) Cause 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) Contain a design feature (e.g., sharp curves or a
dangerous Intersection) or incompatible uses (e.g.,
❑
❑
❑
farm equipment) that would substantially increase
hazards?
e) Result,in inadequate emergency access?
❑
❑
❑
ED
f) Result in inadequate parking capacity?
❑
❑
❑
g) Conflict with adopted policies, plans, or programs
supporting alternative transportation (e.g., bus
❑
❑
❑
turnouts, bicycle racks)?
Discussion
a -g: No impacts.
17. Utilities and Service Systems
Environmental Setting
The project site. is located within the. incorporated City
Limits of Arroyo
Grande.
Utilities are available
from both the City and other regional entities.
Page 34 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
Would the project:
a) Exceed wastewater treatment restrictions or
standards 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?
Would the construction of these facilities cause
significant environmental,effects?
c) Require or result in the construction of new storm
water drainage facilities or expansion of existing
facilities?
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 that serves or may serve the
project, that It has adequate capacity to - service the
project's anticipated 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
regulationsas' they relatehojsolid waste?
Discussion
a -g: No Impacts.
❑
Less,Thcm
❑
Potentially
❑
Less Than
Significant
Significant
Significant No Impact
Impact
with
Impact
Mitigation
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑,
❑
❑ ❑ ❑
❑ ❑ ❑ ® '
❑ ❑ ❑
Page 3Sbf 43
Discussion
a, c -d: The project is located within an established low and medium density residential area. The
purpose of the project is to reduce flooding downstream and will enhance a wetland habitat area.
Isolated prehistoric materials may be present on the project site; however, the site does not serve as an
example of a, major period.of California history or prehistory. The project will not cumulatively increase
traffic or the demand for public services and utilities. With implementation of the proposed mitigation
measures, the project will not cause substantial adverse effects on human beings or special status plant
or animal species, either directly or indirectly.
b: No impacts.
Page 36 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
Corbett Creek Floodplaimand Stream Restoration Project
March 2013
'
Mandatory Findings of Significance
Potentially Less Than Less Than
Significant Significant Significant No Impact
with
Would the project:
Impact Mitigation Impact
a) Substantially 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;, substantially
❑ ❑ ® ❑
reduce the number or restrict the range of an
endangered, rare or threatened species; or eliminate
examples of the major periods of California history or
prehistory?
b) Have the potential to achieve short -term
environmental goals to the disadvantage of long -term
❑ ❑ ❑
environmental goals?
c) Have possible environmental effects that are
Individually limited but cumulatively considerable?
"Cumulatively considerable" means that the
Incremental effects of an individual project are
❑ ❑ ® ❑
significant when viewed''in connection, with the effects
of past projects, the effects +of other current projects,
'
and the effects of possible future projects.
d) Cause substantial adverse effects on human beings,
El ❑ ® El
directly or Indirectly?
Discussion
a, c -d: The project is located within an established low and medium density residential area. The
purpose of the project is to reduce flooding downstream and will enhance a wetland habitat area.
Isolated prehistoric materials may be present on the project site; however, the site does not serve as an
example of a, major period.of California history or prehistory. The project will not cumulatively increase
traffic or the demand for public services and utilities. With implementation of the proposed mitigation
measures, the project will not cause substantial adverse effects on human beings or special status plant
or animal species, either directly or indirectly.
b: No impacts.
Page 36 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION
Corbett Creek Floodplain and Stream Restoration Project
March 2013
Summary of Mitigation Measures
Construction Manager
MM 3.'1: The following conditions shall'be included on all project plans and adhered:toJcn1all
grading - related permits:
• Reduce the amount of disturbed area where possible.
• Use water trucks or sprinkler systems in sufficient quantities to prevent airborne dust
from leaving the site. Increase watering frequency when wind speeds exceed 15 MPH.
Reclaimed (non - potable) water shall be used,whenever possible:
• All dirt stockpile areas should be sprayed daily or as needed using, reclaimed (non -
potable) water when feasible.
Exposed ground areas that are planned to be, reworked more than one (1) month after
initial grading should be sown with a fast - germinating native grass seed and watered
until vegetation, is established.
• All areas to be paved, (i.e. _access road to the sediment basin) should be completed as
soon as possible.
• All trucks hauling dirt, sand, soil or other Those materials are to be covered or shall
maintain at least two (2) feet of freeboard (minimum vertical distance between top of
load and top of trailer) in accordance with CVC Section 23114.
• Streets shall be swept at the end of each day if visible soil material is carried onto
adjacent paved roads. Water,sweepersrwith reclaimed (non' - potable) water should be
used where feasible.
• Diesel idling shall not be permitted.
•. Signs that specify the no idling requirement shall be posted and enforced at the '
construction site.
Use of'alt_ernative- fueled equipment is recommended whenever possible.
• The contractor shall designate a person or persons, to monitor and implement these
measures as necessary to minimize dust complaints, reduce visible emissions below 20%
opacity and to prevent the transport of dust off -site. The name and telephone number
of such persons shall be provided to the Air Pollution Control District (APCD) prior to the
start of any grading- related activities. (See,MM 9.1 for erosion control measures).
Level of Significance:
Less than significant' impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
During construction
MM 3:2: All portable equipment (50 horsepower or greater) used during grading operations
must be issued a 'permit by either the California Air Resources Board (CARE) or the APCD.
(Contact the APCD Engineering Division at (805) 781 -5912 for specific information regarding
permitting requirements prior to start of the project).
Level of Significance:
Less than significant impact
Implementing;Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, CommunityDevelopment,Dept.
Timing:
Prior to issuance of grading permit and during construction
Page 37 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
MM 4.1: Construction /grading shall take place after the breeding season for the Yellow Warbler
(April — July) to lim it' noise, impacts. If construction /grading must stawduring thlsi time period,
surveys of nesting birds within the project vicinity shall be completed by a qualified wildlife
biologist. If the surveys Identify active nests of the Yellow Warbles within the project vicinity, all
earthmoving activities. shall cease until the chicks have fledged. The biologist shall provide the
lead agency and responsible agencies with a written report of survey findings, and shall specify
when the project work may safely commence.
Level of Significance:
Less than.signlficant impact
l6iplementingAesponsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit
MM 4.2: A qualified wildlife biologist shall complete and submit to the lead agency and
responsible agencies a pre- construction surveyfor California red - legged frogs and Southwestern
pond turtles, The survey shall be conducted during the time period when these species are
known to be active- If4no{Individuals are found, construction may proceed. If individuals are
found during the initial Investigation, the biologist shall conduct clearance surveys for these
species approximately one (1) week prior to construction. Individuals found within the
construction area will either be relocated to similar, adjacent habitats at least fifty (50) yards
outside of the project area, or held in captivity until construction is complete. The project, area
shall be monitored during construction and appropriate measures taken to ensure that the
' individuals of relocated species do not move 'into the construction area. The decision of
whether,to relocateitRe,animalsshall be made by the biologlst,although; all mitigation activities
would have to occur within the framework of any permits issued,by the USFWS and CDFG:
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to Issuance of,grading; permit and during construction
MM 4.3: A qualified botanistlshall conduct an initial site survey to map occurrence of Hoover's
bentgrass, San Bernardino aster and black - flowered figwort. If sensitive plant species are found
on site and determined to be potentially impacted, the botanist shall prepare procedures' that
ensure no net loss of plants. These include, but are not limited to, designating avoidance areas,
transplanting the plant populations to an equivalent location on site, or replaced in -kind with
new plants at a ratio of two (2) plants replaced for each one (1) lost or at a ratio acceptable to
the,botanist. The transplanted or replaced plants,shall be monitored, over a,,five (5) year period.
Any plants,lost during this time period shall,be replaced. The botanisyshall prepare a- planting,
irrigation and maintenance plan that includes these provisions. If the botanist' concludes that
avoidance is a viable option, locations determined to be potentially impacted will be flagged
against inadvertent or unintentional damage.
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City ofArroyo Grande, Community,Development :Dept
Timing:
Prior to Issuance of grading permit
Page 38 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2M
Corbett Creek Floodplain and Stream Restoration Project
MM 4.4: Thegapplicantshall .acquire.appropriate.resource agency permits and undertake ,
protection measures;as required by those agencies.
Level of Significance:
Less than significant impact
Implementing Responsibility:
Coastal San Luis Resource Conservation District
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit
MM 5.1: In the event that prehistoric cultural .materials or historic cultural m_ aterials are
encountered, work in the immediate vicinity of'the finds shall be suspended until reviewed by
an archaeologist, and the City shall be notified immediately should such resources be
discovered. The archaeologist shall work as quickly as possible to permit resumption of
construction activities. It is preferred that location data of finds be recorded using a hand -held
global positioning system (GPS) receiver.
If „human remain'' are,•encountered and determined to be Native American in origin, the San Luis
Obispo County coronerwill notify the Native American Heritage Commission (NAHC) within 24
hours of the find. The NAHC shall identify the'person or persons it believes to be.the rriost, likely
descendent of the deceased Native American. The most likely descendent may make
recommendations for means of treating or disposing of the human remains and any,associated
grave goods as provided in Public Resources Code Section 5097.95.
Level of significance:
Less than significant impact
Implementing'Responsibility;
Construction Manager
Monitoring Agency:
Cityof Arroyo Grande, Community Development'Dept.
Timing:
During construction
MM 5.2: The note below shall be placed on the grading,and improvement plans for the project:
"If human remains (burials) are encountered, the County Coroner shall be contacted
immediately (805 - 781 - 4513). In the event that previously unidentified potentially
significant cultural resources are discovered, an archaeologist shall have, the authority to
divert or temporarily halt ground, disturbance operations in the °area of discovery %to allow
evaluation of potentially significant cultural resources in consultation with Northern
Chumash Tribal Council. For significant, cultural resources, a Research Design and Data
Recovery Program to mitigate impacts shall be prepared by the consulting archaeologist
and approved by the City, then carried out using professional archaeological methods. If
it can be demonstrated that a project will cause damage to a unique archaeological
resource, the City may require reasonable efforts to be made to permit any or all of
these resources to be preserved' in,place,or,lett in an,undisturbed state.”
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit
Page 39 of 43
INITIAL STUDY-/ MITIGATEDAEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
MM 9.1: The applicant shall prepare a Storm Water Pollution Prevention Plan (SWPPP) and
Erosion Control Plan that specifies the implementation of Best Management Practices (BMPs) to
avoid and minimize�water,quality impacts as required by the Regional Water Quality Control
Board (RWQCB). At a minimum, the SWPP'and Erosion Control Plan shall include:
• Designation of equipment and supply staging and storage areas at least 100 feet
from the outside edge of the creek 25 -foot setback area. All vehicle parking,
routine equipment maintenance, fueling, minor repair, etc., and soil and
material stockpile, shall be,done only in the designated staging area.
• Major vehicle/equipment maintenance,.repair, and equipment washing shall be
performed off site.
• A wet and dry spill cleanup plan that specifies reporting requirements and
immediate clean up to ensure no residual soil, surface water or groundwater
contamination would,remajmafter clean up.
• Designating. concrete, mixer, washout areas at least 100'feet from outside edge
of the creek 25 -foot setback with the use of• appropriate containment or reuse
practices.
• A temporary and excess fill stockpile and disposal plan that ensures that no
detrimental affects to receiving waters would result.
• Required site, preparation'and erosion control BMPs for any work that.may need
to be completed after October 15.
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:,
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading, permit and during construction
MM 9.2: To reduce erosion hazards due to construction activities, grading shall be
minimized, and project contractors shall use runoff and sediment control structures, and /or
establish a permanent plant cover on side slopes following construction.
Level of Significance:
Less than significant impact
Implementing.Responsibilityr
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit and during construction
MM 9.3: Erosion control and bank stabilization measures shall be implemented for any
work that requires access to the creek, subject to CDFW approval through a Streambed,
Alteration Permit, These measures shall be clearly indicated on the,grading,plan.
Level of Significance:
Less than significant impact
Implementing Responsibility:
Coastal San Luis Resource Conservation District
Monitoring Agency:
City,of Arroyo Grande, Community Development Dept.
Timing:
Prior to Issuance of grading permit,and during, construction,
Page 40 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
MM 9:4: All temporaryifill placed during projectconstruction shall be removed at project I
completion and the area restored to approxinnate; pre- project contours-and topography.
Level of Significance:
Less than significant impact
Implementing Responsibility:
I Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Prior to final inspection
MM 9.5: The project Is located within a regulatory. flopdway. The applicant- shall.obtain
all required permits from regulatory agencies (City of Arroyo Grande, Regional Water Quality
Control Board, US Army Corps of Engineers, Ca. Dept. of Fish and Wildlife; etc.) and meet any
relevant FEMA requirements associated with a regulatory floodway as necessary.
Level of. Significance:,
Less thaWslgnificant impact
Implementing Responsibility:
CoastaBan Luis, Resource,Conservation District,
Monitoring Agency:
City of Arroyo Grande, Community Development Dept.
Timing:
Priorto issuance of grading permit
MM 12.1: Construction activities shall be restricted to the hours of 8:00 AM to 5:00 PM Monday
through Friday. On -site equipment maintenance and servicing shall be confined to the same
hours.
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of Arroyo Grande, Community Development Dept,
Timing:
During,construction
MM,, 12.2: All construction equipment utilizingInternal,combustion engines shall be, required to
have mufflers that are in good condition. , Stationary noise sources shall utilize noise reducing
engine housing enclosures or noise screens.
Level of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City of,Arroyo�Grande, Community Development,Dept.
Timing:,
During construction
MM 12.3: A note shall be placed on the construction plans that no more than two (2) pieces of
major earth moving equipment shall be allowed to operate, simultaneously.
Level of significance.
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring Agency:
City,of'Arroyo Grande, Community Development Dept,
Timing:
Prior to issuance of grading permit and during construction
Page 41 of 43
INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION March 2013
Corbett Creek Floodplain and Stream Restoration Project
' MM'.12.4: All residential units located within'five hundred feet (500',) of the construction site
shall be-sent a notice regarding the construction schedule of the project. A, clearly legible sign
shall also be posted at the project site. All notices and the signs shall indicate the expected
dates and duration of construction activities, as well as provide a telephone number that
residents can call to resolve any concerns,about construction noise.
Level,of Significance:
Less than significant impact
Implementing Responsibility:
Construction Manager
Monitoring, Agency:
City of.Arroyo Grande, Community Development Dept.
Timing:
Prior to issuance of grading permit and during construction
Page 42 of 43
INITIAL STUDY / MITIGATED NEGATIVE DECLARATION, March 2013
Corbett Creek Floodialain and Stream Restoration Protect
References ,
Documents & Maps
1. Arroyo Grande General Plan
2. Arroyo Grande Municipal Code
3. Arroyo Grande Zoning Map
4. Arroyo Grande Existing Settings Report & Draft Arroyo Grande Existing Settings Report (2010)
5. Arroyo Grande Urban Water Management Plan
6. Arroyo Grande'Stormwater Management Plan
7. San Luis Obispo Important Farmland Map (California Department of Conservation,,2006)
8. CEQA &'.Climate Change, White Paper (CAPCOA,' +2008)
9. Air Quality Handbook (SLO APCD, 2009)
10. Project Plans — Swanson Hydrology & Geomorphology
11. Site Inspection
12. Arroyo Grande Creek Erosion, Sedimentation and Flooding Alternatives Study, Swanson
Hydrology & Geomorphology, January 4, 2006
13. Letter from,the Natural Resources Conservation Service regarding,land eligibility report for Clark
WRO Offering, dated December,19, 2006
Page 43 of 43
EXHIBIT "B"
O.CITY OF
fCALIFOFNIA .�)
MITIGATION MONITORING
AND REPORTING PROGRAM (MMRP)
Staff Project No. 13 -001
Corbett Creek Floodpiain and Stream Restoration Project
ADOPTED BY:
CITY OF ARROYO GRANDE
PLANNING COMMISSION
' DATE:,
APRIL, 16, 2013
MMRP
Corbett Creek Floodplain and Stream Restoration, Project
April 2013.
Introduction
A Mitigated Negative Declaration (MND) was prepared to comply with the California
Environmental Quality Act (CEQA) for the Corbett Creek Floodplain and Stream
Restoration Project (the "Project "). The MND identified potential environmental impacts
as well as mitigation measures to reduce the impacts, where feasible.
CEQA requires that mitigation measures identified in environmental review documents
are implemented after a project is approved. Therefore, this Mitigation Monitoring and
Reporting Program (MMRP) has been prepared to ensure compliance with the adopted
mitigation measures during the pre- construction, construction, and post - construction
phases of the Project. The mitigation measures listed herein, will be adopted by the
Arroyo Grande Planning Commission as part,of the overall project approval.
Per Public Resources Code Section 21081.6 the measures listed in the table below
constitute the mitigation monitoring and /or reporting program that will reduce potentially
significant impacts to less than significant levels. These measures will become
conditions of approval (COAs) upon adoption of the MND. The Lead Agency (City of
Arroyo Grande) or other Responsible Agencies, as specified', in the following measures,
are responsible to verify compliance with these COAs
Mitigation is defined by the California Environmental Quality Act (CEQA) as a measure
which: '
• Avoids the impacYalfogether by not taking a certain action or parts of an action.
• Minimizes impacts by limiting the degree or magnitude cf�the action and,its
implementation.
• Rectifies the Impact by repairing, rehabilitating, or restoring the impacted
environment.
• Reduces or eliminates the impact over time by preservation and maintenance
operations during the life of'the Project.
• Compensates for the impact by replacing or providing substitute resources,or
environments.
The mitigation measures discussed in the table below have been identified as feasible
and effective in mitigating Project - related environmental impacts.
Project Location
The project reach begins at the Highway 227 Bridge over Tally Ho Creek and extends
upstream to the east end of the Clark property (APN 007- 791 -032).
Project Description
The, proposed project involves the, acquisition by the Coastal San Luis Resource
Conservation District (RCD) of a conservation easement over the 12.5 -acre; Clark
Property located between Highway 227 (Carpenter Canyon Road) and Corbett Canyon
Road and the design, permitting and construction of a flood plaih/sedi ment detention
basin on the easement property- The project also includes channel restoration of '
approximately nine hundred feet (900') of Corbett Creek located downstream of the
MMRP
Corbett Creek.Floodplain and'Stream Restoration Project
' April 2013
Clark Property- Currently there are no identified implementation funds for the channel
restoration component of the project., The City will be directly involved in the project
through permitting of the floodplain /sediment detention basin design and
implementation activities
The Project'goals are
1. Increase sediment capture on floodplain easement
2. Increase flood attenuation on floodplain easement
3. Enhance floodplain wetland for flood attenuation and habitat.
The Project will construct a sediment, basin and enhance a floodplain wetland resulting
in an estimated 524 tons of sediment per year settled into a basin, reduced peak flows
in storms with recurrence intervals of ten (10) years or greater, and three (3) acres of
floodplain wetland enhanced.
Program Implementation and Monitoring,
Each mitigation measure is described in the following format:
Requirements of The description of the mitigation measures.
' Measure
Mitigation Level The level to which the impact is anticipated to be mitigated._
Implementing The agency or individual that has the responsibility for
Responsibility implementing or performing the measure.
Monitoring The public agency that has the responsibility for monitoring to
Responsibility_ ensure that the mitigation measure, is effective in mitigating the
impact.
Compliance The method used to verify compliance.
Standards
Timing The appropriate, points in time at,which the mitigation measure is
to be initiated and completed
Q
MMRP
Corbett.Creek Floodplain and Stream Restoration Project
j April 2013
Clark Property. Currently there. are no ' identified implementation funds for the channel
restoration component, of'the project, The City will be directly involved in the project
through permitting of the: floodplain /sediment detention basin design and
implementation activities.
The Project goals are:
1 Increase sediment capture on floodplain easement
2. Increase flood attenuation on floodplain easement
3. Enhance floodplain wetland for flood attenuation and habitat
Thee Project will construct a, sediment basin and enhance.a floodplain wetland resulting
in an estimated 524 tons of sediment per year settled into a basin, reduced peak flows
in storms with recurrence intervals of ten (10) years or greater, and three (3) acres of
floodplain wetland enhanced.
Program Implementation and Monitoring
Each mitigation measure is described in the following format:
Requirements of
The description of the,mitigation measures:
— Measure
Mitigation Level
The level to which the impact is anticipated to be mitigated.
Implementing
The agency or individual that has the responsibility for
Responsibility
implementing or performing the measure.
Monitoring
The public agency that.has the responsibility for monitoring to
Responsibility
ensure that the mitigation measure is effective in mitigating the
impact.
Compliance
The method used to verify compliance.
Standards
Timing
The appropriate points in time at which the mitigation measure is
to be initiated and completed.
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