Arroyo Grande City Council
July 25, 2023

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013 11 MM # Requirements of Measure Mitigation
Level
ImplementingResponsibility
MonitoringResponsibility
Compliance Standards(Note: All MitigationMeasures shall beincluded on the projectplans).

Timing Verification of
Compliance(Initials / Date /Remarks)
“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 disturbanceoperations in the area of discovery to allow evaluation of potentially
significant cultural resources inconsultation with Northern ChumashTribal Council. For significant cultural resources, a Research Design and
Data Recovery Program to mitigateimpacts shall be prepared by the consulting archaeologist and
approved by the City, then carried out
using professional archaeologicalmethods. If it can be demonstrated that a project will cause damage to a
unique archaeological resource, theCity may require reasonable efforts tobe made to permit any or all of these resources to be preserved in place or
left in an undisturbed state.”

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013 12 MM # Requirements of Measure Mitigation
Level
ImplementingResponsibility
MonitoringResponsibility
Compliance Standards(Note: All MitigationMeasures shall beincluded on the projectplans).

Timing Verification of
Compliance(Initials / Date /Remarks)
Hydrology and Water Quality9.1 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 qualityimpacts as required by the Regional Water Quality Control Board(RWQCB). At a minimum, the SWPPP and Erosion Control Plan shall
include: Designation of equipment and
supply staging and storage areasat least 100 feet from the outside edge of the creek 25‐foot setbackarea. All vehicle parking, routineequipment 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 reportingrequirements and immediate
Less thansignificantimpact
ConstructionManager
City of A.G.,CommunityDevelopment
Department
Prepare SWPPP as
indicated and implement
BMPs as required.

Prior to
issuance of
gradingpermit and
duringconstruction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013 13 MM # Requirements of Measure Mitigation
Level
ImplementingResponsibility
MonitoringResponsibility
Compliance Standards(Note: All MitigationMeasures shall beincluded on the projectplans).

Timing Verification of
Compliance(Initials / Date /Remarks)
clean up to ensure no residual soil,surface water or groundwater contamination would remain afterclean 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.

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.

Less than
significantimpact
ConstructionManager
City of A.G.,
CommunityDevelopmentDepartment
Ensure runoff andsediment control
measures are on thegrading plan and in place
prior to grading activities.

Prior to
issuance ofgradingpermit and
during
construction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013 14 MM # Requirements of Measure Mitigation
Level
ImplementingResponsibility
MonitoringResponsibility
Compliance Standards(Note: All MitigationMeasures shall beincluded on the projectplans).

Timing Verification of
Compliance(Initials / Date /Remarks)

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.

Less than
significantimpact
Coastal SanLuis ResourceConservationDistrict(CSRCD)
City of A.G.,
CommunityDevelopmentDepartment
Ensure erosion control
and bank stabilization
measures are on thegrading plan and in place
prior to grading activities.If required by CDFW, aStreambed AlterationPermit shall be approved and a copy of the permitshall be submitted to the
City.

Prior to
issuance of
gradingpermit and
duringconstruction.

9.4 All temporary fill placed during
project construction shall be removed
at project completion and the area
restored to approximate pre‐project
contours and topography.

Less than
significantimpact
ConstructionManager
City of A.G.,
CommunityDevelopmentDepartment
The grading plan shall
indicate all proposed
temporary fill areas.Removal of temporary fill
areas shall be verified
prior to final inspection.

Prior to final
inspection.

9.5 The project is located within a
regulatory floodway. The applicant
shall obtain all required permits fromregulatory agencies (City of ArroyoGrande, Regional Water Quality Control Board, US Army Corps of
Engineers, Ca. Dept. of Fish and
Wildlife, etc.) and meet any relevantFEMA requirements associated with a regulatory floodway as necessary.

Less thansignificant
impact
Coastal San
Luis ResourceConservation
District(CSRCD)
City of A.G.,
CommunityDevelopmentDepartment
A copy of all necessary
resource agency permits
shall be submitted to the
City.

Prior to
issuance of
gradingpermit.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013 15 MM # Requirements of Measure Mitigation
Level
ImplementingResponsibility
MonitoringResponsibility
Compliance Standards(Note: All MitigationMeasures shall beincluded on the projectplans).

Timing Verification of
Compliance(Initials / Date /Remarks)
Noise12.1 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.

Less than
significantimpact
ConstructionManager
City of A.G.,
CommunityDevelopmentDepartment
Ensure adherence to
construction hours.

Duringconstruction.

12.2 All construction equipment utilizing
internal combustion engines shall berequired to have mufflers that are in good condition. Stationary noise
sources shall utilize noise reducingengine housing enclosures or noise screens.

Less thansignificantimpact
ConstructionManager
City of A.G.,
CommunityDevelopmentDepartment
Ensure use of mufflers
and other attenuation
devices.

Duringconstruction.

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.

Less than
significantimpact
ConstructionManager
City of A.G.,
CommunityDevelopmentDepartment
Ensure note is on the
plans and measure isadhered to during site
inspections.

Prior to
issuance ofgrading
permit and
duringconstruction.

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
Less than
significantimpact
ConstructionManager
City of A.G.,
CommunityDevelopmentDepartment
Send notices, post sign
and designate a City staffperson to respond to anynoise concerns.

Prior to
issuance ofgradingpermit and
duringconstruction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013 16 MM # Requirements of Measure Mitigation
Level
ImplementingResponsibility
MonitoringResponsibility
Compliance Standards(Note: All MitigationMeasures shall beincluded on the projectplans).

Timing Verification of
Compliance(Initials / Date /Remarks)
shall indicate the expected dates and
duration of construction activities, aswell as provide a telephone numberthat residents can call to resolve anyconcerns about construction noise.

Corbett Creek Floodplain and Stream Restoration
Project
Addendum to the
2013 Initial Study / Mitigated Negative Declaration
SCH# 2013031045
Prepared by
Coastal San Luis Resource Conservation District
1203 Main St, Ste B, Morro Bay CA, 93442
April 2023

EXHIBIT E

Table of Contents
Table of Contents 2
Introduction 2
Previous Environmental Review 4
Corbett Creek Floodplain and Stream Restoration Project 6

1. Project Title 6

2. Lead Agency Name and Address 6

3. Contact Person and Phone Number 6

4. Project Location 6

5. Project sponsor's name and address 7

6. General Plan Designation 7

7. Zoning Designation 7

8. Description of Project 7

9. Surrounding Land Uses and Setting 9

10. Required Approvals 11

11. California Native American Tribal Consultation (AB 52) 11 Potential Impacts of Revised Project 11
Determination 14
References 14
Appendix A: 50% designs for Sediment Basin and Wetland Creation Project Appendix B: 65% designs for Stream Channel Restoration
Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

Introduction
This document is an Addendum to the 2013 Corbett Creek Floodplain and Stream Restoration Project Initial Study and Mitigated Negative Declaration (MND) prepared in compliance with the California Environmental Quality Act (CEQA) of 1970, Public Resources Code §21000, et seq., as amended, and implementing CEQA Guidelines, Title 14, Chapter 3 of the California Code of Regulations. The 2013 Corbett Creek Floodplain and Stream Restoration Project MND evaluated the acquisition of a floodplain easement on Corbett Creek as well as the restoration of approximately 900 feet of stream channel downstream of the floodplain easement.

The purpose of this Addendum is to analyze the environmental impacts of the Corbett Creek Floodplain and Stream Restoration Project, herein referred to as the “updated project.” The updated project includes more detailed engineered design plans that more accurately define project impacts. The approved project, evaluated in the 2013 MND, included 50% conceptual engineered design plans with approximate impacts. The updated project location and technical approach does not differ from the approved project. Item 7, Description of Project, of this addendum defines the revised project and describes the proposed changes in detail.

The City of Arroyo Grande assumed the role of Lead Agency for the development of the 2013 MND. Due to changes in project roles, the Coastal San Luis Resource Conservation District (CSLRCD) took over the role of Lead Agency for this project in 2023.

This Addendum has been prepared in accordance with the relevant provisions of CEQA and the CEQA Guidelines. According to Section 15164(b) of the CEQA Guidelines, an addendum to a Negative Deceleration is the appropriate environmental document in instances when “only minor technical changes or additions are necessary or none of the conditions described in Section 15261 calling for the preparation of a subsequent Negative Deceleration have occurred.” Section 15162(a) of the CEQA Guidelines states no subsequent Negative Deceleration shall be prepared for a project unless the lead agency determines, on the basis of substantial evidence in the light of the whole record, one or more of the following:

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

2. Substantial changes occur with respect to the circumstances under which the project is undertaken which will require major revisions of the previous EIR or Negative Declaration due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects; or
Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

3. New information of substantial importance, which was not known and could not have been known with the exercise of reasonable diligence at the time the previous EIR was certified as complete or the Negative Declaration was adopted, shows any of the following:

A. The project will have one or more significant effects not discussed in the previous MND, B. Significant effects previously examined will be substantially more severe than shown in the previous EIR;
C. Mitigation measures or alternatives previously found not to be feasible would in fact be feasible, and would substantially reduce one or more significant effects of the project, but the project proponents decline to adopt the mitigation measure or alternative; or D. Mitigation measures or alternatives which are considerably different from those analyzed in the previous EIR would substantially reduce one or more significant effects on the environment, but the project proponents decline to adopt the mitigation measure or alternative.

The increased detail included in the updated project are minor in the sense they would not create potentially significant environmental impacts in addition to those already identified in the 2013 MND for the approved Corbett Creek Floodplain and Stream Restoration Project. The updated project would also not substantially increase the magnitude or severity of impacts that were previously identified. This addendum includes a description of the updated project, and a discussion of the environmental impacts of the proposed project change, focusing on Air Quality, Biological Resources, Tribal Cultural Resources, Energy, Hydrology and Water Quality, and Noise.

CSLRCD Board of Directors shall consider this addendum with the 2013 Corbett Creek Floodplain and Creek Restoration Project MND prior to making a CEQA decision on the updated project. The 2013 Corbett Creek Floodplain and Creek Restoration Project MND is available for review at the CSLRCD offices, located at 1203 Main Street, suite B, in Morro Bay, 93442.

Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

Previous Environmental Review
This section provides an overview of the 2013 Corbett Creek Floodplain and Creek Restoration Project MND, to provide context for this addendum
2013 Corbett Creek Floodplain and Creek Restoration Project MND The 2013 Corbett Creek Floodplain and Creek Restoration Project MND evaluates the potential environmental effects of the acquisition of a 12.5-acre conservation easement, the design and construction of a sedimentation and flood reduction basin on the easement property, as well as an analysis of a proposed sediment removal and creek restoration project downstream along Corbett Creek intended to reduce flooding in that area. The project 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).

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 Protection Study.

The 2013 MND found that the following factors would be potentially affected by the project:

Air Quality: Analysis of project impacts determined that 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. Adopted mitigation measures MM3.1 and MM3.2 prescribe several actions to reduce emissions to less than significant.

Biological Resources: Analysis of biological resources present in the project area determined that adverse effects on sensitive species, including California red-legged frog, and riparian habitats would be less than significant with mitigation. Adopted measures include avoiding nesting and mating seasons for present sensitive species, pre-construction surveys, and appropriate regulatory permitting.

Cultural Resources: Analysis of project impacts determined that adverse change in the significance of an archaeological resource could be less than significant with mitigation. Adopted measures include suspending work and contacting appropriate authorities if resources are encountered.

Hydrology/Water Quality: Analysis of hydrology and water resources within the project area determined that project activities, including grading and filling could degrade or violate water quality and waste discharge requirements, or alter existing drainage patterns resulting in erosion or flooding. Analysis also determined that the project had the potential to impede or redirect flood flows within a 100-year flood hazard area and expose people or structures to a significant risk of loss, Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

injury, or death from flooding. 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 several mitigation measures, including adoption of a project-specific Stormwater Pollution Prevention Plan, establishment of permanent vegetation cover after project completion, installation of erosion control practices during and following construction, and compliance with any and all applicable regulation associated with floodway management.

Noise: Analysis of project impacts determined that the residents adjacent to the project area may be exposed to noise levels in excess of established standards and that the project may generate periodic or temporary increases in ambient noise levels. Noise impacts associated with short term construction are expected to be minimal, and adopted mitigation measures, including restricted work windows and engine mufflers will reduce impacts to less than significant.

Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

Corbett Creek Floodplain and Stream
Restoration Project

1. Project Title
Corbett Creek Floodplain and Stream Restoration Project

2. Lead Agency Name and Address
Coastal San Luis Resource Conservation District
1203 Main St. Suite B Morro Bay, CA 93442
(805)772-4391

3. Contact Person and Phone Number
Hallie Richard, Conservation Programs Manager
805-772-4391, [email protected]

4. Project Location

1. Floodplain Easement: APN 007-791-032 (Clark Property)

2. Stream Restoration (APNs: 007-211-013, 007-211-007, 007-211-038, 007-211-030, 007-211-029, 007-252-013) See figure 1 below.

5. Project sponsor's name and address
Coastal San Luis resource Conservation District
1203 Main St, Ste B
Morro Bay, CA 93442

6. General Plan Designation

1. Low Density Residential (LD); Conservation Open Space (C/OS)

2. Low-Medium Density Residential (LM); Conservation Open Space (C/OS)

7. Zoning Designation

1. Residential Hillside (RH); 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 for portions of properties containing the creek channel)
Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

8. Description of Project
The project scope includes the acquisition of a conservation easement and design and implementation of a sediment reduction project for the purpose of floodplain restoration, sediment capture and peak flow attenuation along specific reaches of Corbett Creek. The sediment reduction project includes two distinct components:

1. CSLRCD has acquired a conservation easement in perpetuity over 12.50 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 (Appendix A). 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. Final engineering design, permitting, implementation and monitoring are anticipated to be completed using grant funds obtained from the Department of Water Resources (DWR) through the Urban Streams Restoration Program or State Coastal Conservancy. Secured funding is contingent upon commitment from project beneficiaries (City of Arroyo Grande, SLO Co Flood Control Zones 3 and 1/1A) for long-term maintenance of the sediment basins. 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: (1) Conservation easement acquisition. (2) Sedimentation reduction through construction of active and passive sedimentation basins. (3) Long-term and regular maintenance of basins and removal of accumulated sediments.

2. Planning, design and implementation of a channel restoration project to re-establish the channel geometry of approximately two-hundred seventy feet (270’) of Corbett Creek (aka Tally Ho Creek) (Reach 3), thereby increasing flow volumes and reducing storm flow water surfaces. Beginning at the 4’ headcut at station 18+60, a rock weir will be installed, armoring the headcut and lessening the steep grade. Following upstream from the rock weir, a low flow channel would be excavated through sediment that has built up over the years along Reach 3. According to the Tally Ho Tech Memo, developed in tandem with the engineered design plans (Appendix B), a low flow channel would be cut between stations 18+60 and 20+50 (Figure 1). The thalweg will be lowered approximately 3 feet at station 18+60 and slightly less elsewhere, removing a total of approximately 120 cubic yards of material. After sediment has been removed, engineered streambed material will be placed, creating a defined and roughened channel bed along approximately 100 linear feet of stream channel.

Parallel Encapsulated Soil Lifts will be installed along approximately 75 linear feet of steam channel, creating a defined thalweg and increased storm flow capacity. The project has more Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

benefit at lower flows with less benefit at higher flows and is expected to reduce 5‐year water surfaces by 1.7 feet at Cross Section 18+60 and 10‐year water surfaces by 1.1 feet.

Implementation of the project would involve temporary dewatering of the creek channel and diversion of flows around the site, direct removal of sediment from the channel using an excavator and manual removal of riparian vegetation. Access to the work area would be through the vacant parcel at 210 Tally Ho Road. The planning and design phase is occurring between 2021 and 2023. Construction of the stream restoration is planned for September 2023 with funding from the Department of Water Resources (DWR) through the Urban Streams Restoration Program.

Figure 1. Existing conditions at Reach 3

9. Surrounding Land Uses and 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 is bounded by the Cities of Grover Beach and Pismo Beach to the southwest and west, and to the unincorporated County to the north, east and south. U.S. 101 extends northwest and southeast through the middle of the City, and Highway 227 runs east from U.S. 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.

Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

Figure 2. Location Map
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 the confluence of Arroyo Grande Creek. 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 experiences a Mediterranean climate with most precipitation occurring Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

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 project 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.

10. Required Approvals
California Department of Fish and Wildlife
Regional Water Quality Control Board
US Fish and Wildlife Service
US Army Corps of Engineers

11. California Native American Tribal Consultation (AB 52) The 2013 MND was adopted prior to the incorporation of AB 52, which assesses a project's impacts to Tribal cultural resources, into the CEQA Guidelines checklist. In the process of developing this addendum, CSLRCD has integrated an assessment of tribal cultural resources into the review process. Pursuant to AB52, CSLRCD contacted local Native American Tribes to notify them of the project. In response to notification, several Tribal representatives responded requesting formal consultation on the project. CSLRCD initiated formal consultation on April 14th, 2023. The outcomes of that consultation are detailed below in the Potential Impacts of Revised Project section.

Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

Potential Impacts of Revised Project
This addendum evaluates potential environmental impacts that could result from the updated project.

Appendix G of the CEQA Guidelines provides a checklist of environmental issues areas that are suggested as the issue areas that should be assessed in CEQA analyses. The 2013 MND for the approved project addressed 5 of the listed 24 environmental issue areas, including Biological resources, Cultural Resources, Air Quality, Hydrology and Water quality, and Noise. The City of Arroyo Grande determined that the approved project would not significantly impact the other issue areas, including Aesthetics, Agricultural Resources, Geology and Soils, Greenhouse Gas Emissions, Hazards and Hazardous Materials, Land use and Planning, Mineral resources, Population and Housing, Public Services, Recreation, Transportation and Traffic, or Utilities. This addendum tiers off the 2013 MND, addresses the environmental consequences of the updated project, focusing on Air Quality, Biological Resources, Tribal Cultural Resources, Energy, Hydrology and Water Quality, and Noise, and updates the analysis for these environmental issue areas based on current conditions, as listed below.

The potential environmental impacts of the updated project are considered in comparison with the approved project, to determine whether impacts associated with the updated project are consistent with the impact analysis provided in the 2013 MND for the approved Project, and whether additional mitigation measures are required to minimize or avoid potential impacts.

Air Quality: The 2013 MND determined that emissions associated with project construction were less than significant with mitigation. The scope of the updated project has not been modified to the extent that emissions would increase. Therefore, the updated project would not result in new or substantially more severe impacts associated with construction-related emissions when compared to the analysis of the approved Project in the 2013 MND. Prescribed mitigation measures will be implemented.

Biological Resources: The 2013 MND determined that impacts to biological resources were less than significant with mitigation due to the historical land used and modification as well as prevalence of invasive species present. It is still expected that the long term benefits of restoring the floodplain and riparian habitat will outweigh short term impacts. The increased detail in the 65% engineered design plans described construction activities more acutely, including the extent of grading, fill volumes, and number of trees removed. This increased detail indicates that the updated project will not result in new or substantially more impacts to sensitive species and habitats. Prescribed mitigation measures will be implemented, and additional opportunities for on-site habitat enhancement will be explored.

Tribal and Cultural Resources: As described above, additional Tribal Cultural Resource assessment was completed in the development of this addendum to ensure the project's potential impacts to Tribal resources was thoroughly assessed. Local Tribes were provided with a project description of Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

ground disturbing activities, engineered design plans, and a list of the avoidance and mitigation measures incorporated into the 2013 MND for the protection of archaeological resources. During formal the consultation process the following terms and conditions were agreed to:
- An approved archaeologist will conduct a California Historic Records Search for the project area and provide a memo report presenting their assessment of potential project impacts and recommendations for additional measures to protect Tribal resources - A pedestrian survey of the project area will be conducted by an approved archaeologist and Tribal representative prior to initiating any project activities. - A Tribal monitor or approved archaeologist may choose to be present during ground disturbing activities to monitor for the presence of Tribal resources. - All previously adopted measures for the protection of cultural resources will be implemented.

With the inclusion of these additional measures, the updated project will not result in new or substantially more impacts to Tribal and Cultural Resources when compared to the analysis of the approved Project in the 2013 MND.

Energy: Energy as a resource issue was not analyzed in the 2013 MND. The project occupies a relatively small footprint, utilizing an adjacent staging area and access route. Gas-powered equipment will be used to execute the construction activities, and language will be included in contracts that equipment must be maintained in good working order. Renewable energy will be utilized as available for equipment. Due to the small footprint of the project and short construction timeline, and requirements for equipment functionality, the updated project will not result in potentially significant environmental impact or conflict with or obstruct a state or local plan for renewable energy or energy efficiency when compared to the analysis of the approved Project in the 2013 MND.

Hydrology/Water Quality: The 2013 MND determined that project activities, including grading and filling, could degrade or violate water quality and waste discharge requirements, or alter existing drainage patterns resulting in erosion or flooding. Analysis also determined that the project had the potential to impede or redirect flood flows within a 100-year flood hazard area and expose people or structures to a significant risk of loss, injury, or death from flooding. The increased detail in the 2022 65% engineered design plans describe construction activities more specifically, including the extent of grading, fill volumes, and number of trees removed. Additionally, project proponents have incorporated regulatory responses on required and recommended measures and modifications to ensure the project activities are protective of water quality and will not increase flood elevations.

Approvals and permits include 401 Water Quality Certification for Small Habitat Restoration Projects from the State Water Resources Control Board and a Flood Hazard Review from the City of Arroyo Grande. Additional modeling of flood elevations via HEC-RAS modeling, indicating increased channel capacity for storm flows and increased surface water elevations has been completed and is incorporated in the 65% design plans and Tally Ho Technical Memo. Therefore, the updated project would not result in new or substantially more severe impacts associated with water quality or Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

References
Arroyo Grande Creek Erosion, Sedimentation and Flooding Alternatives Study, Swanson Hydrology & Geomorphology, January 4, 2006
Tally Ho Tech Memo, Waterways Consulting, Inc, 2012
Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

Appendix A: 50% designs for Sediment Basin
and Wetland Creation Project
Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project 17

Appendix B: 65% designs for Stream Channel
Restoration
Addendum to the MND
Corbett Creek Floodplain and Stream Restoration Project

MEMORANDUM
TO: PLANNING COMMISSION
BY: KELLY HEFFERNON, ASSOCIATE PLANNER
FROM: TERESA MCCLISH, COMMUNITY DEVELOPMENT DIRECTOR
SUBJECT: CONSIDERATION OF STAFF PROJECT 13-001; ADOPTION OF

MITIGATED NEGATIVE DECLARATION AND MITIGATION

MONITORING AND REPORTING PROGRAM FOR THE CORBETT

CREEK FLOODPLAIN AND STREAM RESTORATION PROJECT
DATE: APRIL 16, 2013
RECOMMENDATION:

It is recommended that the Planning Commission adopt the attached Resolution adopting a Mitigated Negative Declaration (MND) and Mitigation Monitoring and Reporting Program (MMRP) prepared for the Corbett Creek Floodplain and Stream Restoration Project (the “project”).

IMPACT ON FINANCIAL AND PERSONNEL RESOURCES:

The City has programmed $75,000 in the FY 2013/14 Creek Preservation Capital Improvement Project (CIP) Fund. The City’s share of the project cost is $70,000 cash and $14,000 of staff time valued at $84,000 consistent with the RCD grant application submittal to the Department of Water Resources (DWR). Funds will be dispersed as work performed is invoiced and will be funded over time from the 2013 and 2014 budgets.

BACKGROUND:

In 2007, the City received a Civil Liability Complaint Notice from the California Regional Water Quality Control Board that a violation in the form of a sewage spill had occurred in Arroyo Grande Creek, and the City was required to make restitution by expending $60,000 on supplemental environmental projects (SEP) within the City’s jurisdiction.

In partial response to the requirement, the City partnered with the RCD by providing $19,000 in initial funds toward an SEP, and later $42,000 to perform preliminary studies of the Clark Property and studies of Corbett Creek (also known as Tally Ho Creek).

Subsequently, the City also participated with the RCD in a grant application to the Department of Water Resources (DWR) for the Urban Streams Restoration Program that would provide funds for implementation of the Clark floodplain project and provide funds for design of a headcut project within the Corbett Creek. Other partners in the ATTACHMENT 4

PLANNING COMMISSION
STAFF PROJECT 13-001
APRIL 16, 2013
PAGE 2
grant application included Central Coast Salmon Enhancement, California Coastal Conservancy, and land owner Mr. Michael Clark. The grant for $831,420 was recently awarded to RCD by the DWR and part of the grant agreement is the City’s delivery of funds and staff time. The RCD will provide the administrative services for the project which includes contracting the services of subconsultants to provide design plans and reports. The City’s role is to provide funds to RCD for the subconsultant services and to provide some staff time for project review.

The City Council approved a Memorandum of Understanding between the City and the RCD in November 2012 (see Attachment 1).

Project Description and Environmental Review
The project site (Clark Property) is about 16-acres in size and located adjacent to Corbett Creek, a tributary to Arroyo Grande Creek. Corbett Creek has been impacted over the years from encroaching residential land uses, increased runoff and sedimentation. 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 our City.

Establishing a 12.5-acre conservation easement on a portion of the project site to reduce peak flows and chronic fine sediment loading at the confluence of Corbett Canyon and Carpenter Canyon Creeks will be designed to achieve multiple objectives:
 Flood protection: floodplain restoration would allow this site to detain peak flows and fine sediment before they reach the mainstem of Arroyo Grande Creek, thereby reducing stress on lower Arroyo Grande Creek where inadequate levees threaten valuable farmland and adjacent urban areas with flooding.  Restoration of riparian and floodplain habitat: the proposed project would also have the benefit of restoring riparian and floodplain habitat within the Arroyo Grande Creek watershed, a resource that has been impacted by channelization and encroachment over the last 150 years.
 Water quality protection: this project would improve and protect Arroyo Grande Creek water quality through sediment detention, and by increasing flood protection for the South San Luis Obispo Sanitation Plant. The South SLO Sanitation Plant is located immediately adjacent to the AG Creek flood control channel, and a levee breach (such as in 2001) or overtopping event could compromise operations at the Sanitation Plant. This project would help reduce peak flows in the AG Creek flood control channel by restoring Corbett Creek’s access to the historic floodplain.

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Additionally, restoring the impaired stretch of Corbett Creek will reduce future sediment loads to mainstem Arroyo Grande Creek, thereby protecting Central Coast steelhead spawning habitat, as well as improving flood protection to residents adjacent to Corbett Creek and to landowners in the Zone 1/1A Flood Control District at the downstream end of Arroyo Grande Creek.

The Initial Study/Mitigated Negative Declaration (IS/MND) prepared for the Corbett Creek Floodplain and Stream Restoration Project (Exhibit “A” of the attached Resolution) identifies several reaches of Corbett Creek (reaches 1-6). The Clark Property is known as reach 6, while reaches 1-5 encompass the numerous residential properties beginning at the East Branch Street culvert where Corbett Creek joins Arroyo Grande Creek and extends upstream approximately one mile to the Clark Property.

Improvements along reaches 1-5 are identified as the “Tally Ho project”. These improvements have not yet been designed or funded, and therefore the IS/MND contains only a brief discussion of improvements to this stretch of Corbett Creek.

However, for the Commission’s information, a brief description is provided below.

The Tally Ho project consists of arresting a large headcut (approximately 4 feet high) that is progressively moving upstream, exacerbating bank erosion, and contributing to fine sediment deposition in the main stem of Arroyo Grande Creek. The project design will include regrading of the headcut, installation of a series of grade controls, and revegetation of the site to stabilize the headcut and prevent further movement upstream and consequent release of sediment. The channel is approximately 15 feet wide. The expected reduction in sediment delivery downstream due to remediation is expected to be approximately 250 cubic yards of material over a ten year period. The Tally Ho project will be subject to additional environmental review.

ANALYSIS OF ISSUES:

The City has already expended significant funds toward the design of the floodplain project at the confluence of Corbett Canyon and Carpenter Canyon creeks and for survey of the headcut project on Corbett Creek, yet until implementation occurs, the project benefits will not exist. The main project objectives are important health and safety issues designed to alleviate flooding on Corbett Creek and reduce stress on the lower Arroyo Grande Creek, with the added benefit of restoring riparian and floodplain habitat. Staff believes these projects will take a significant step in improving management of the watershed and water quality, and are needed to improve and correct existing deficiencies.

The IS/MND and accompanying Mitigation Monitoring and Reporting Plan (MMRP) must be adopted before funding can be released for the easement acquisition, detailed design work, and permitting from the various responsible agencies. Environmental factors that are potentially affected and analyzed in the IS/MND include biological resources, cultural resources, air quality, hydrology/water quality, and noise. The sixteen (16) mitigation measures contained in the environmental document will be incorporated into the project plans as conditions. The MMRP (Exhibit “B” of the

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APRIL 16, 2013
PAGE 4
attached Resolution) ensures compliance with the adopted mitigation measures during the pre-construction, construction, and post-construction phases of the project.

ALTERNATIVES:

The following alternatives are provided for the Commission’s consideration:

1. Adopt the MND and MMRP;

2. Do not adopt the MND and MMRP; or

3. Provide direction to staff.

ADVANTAGES:

Adopting the MND and MMRP will allow the project as described above to move forward. The project will increase sediment capture on the floodplain easement, increase flood attenuation, enhance floodplain wetland for flood attenuation and habitat, and help to reduce flooding impacts downstream.

DISADVANTAGES:

No disadvantages have been identified.

ENVIRONMENTAL REVIEW:

In accordance with the California Environmental Quality Act (CEQA) Guidelines, staff has conducted an Initial Study and prepared a draft Mitigated Negative Declaration (MND) and Mitigation Monitoring and Reporting Program (MMRP) for Staff Project 13- 001. The MND and MMRP are included as Exhibits “A” and “B”, respectively, in the attached Resolution.

PUBLIC NOTIFICATION AND COMMENTS:

The agenda was posted in front of City Hall on Thursday, April 11, 2013. The Agenda and report were posted on the City’s website on Friday, April 12, 2013. Notices were sent to property owners located within 500’ of the project site. No public comments were received.

Attachment:

1. MOU between the City of Arroyo Grande and the Coastal San Luis Resource Conservation District (RCD) dated November 13, 2013

RESOLUTION NO.

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:

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.

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 “B”, attached hereto and incorporated herein by this reference.

On motion by Commissioner _____________, seconded by Commissioner __________, and by the following roll call vote, to wit:

AYES:

NOES:

ABSENT:
the foregoing Resolution was adopted this 16th day of April 2013.

RESOLUTION NO.

APRIL 16, 2013
PAGE 3
ATTEST:
______________________________ ___________________________ DEBBIE WEICHINGER ELIZABETH S. RUTH, CHAIR

SECRETARY TO THE COMMISSION
AS TO CONTENT:
_____________________________

TERESA MCCLISH

DIRECTOR OF COMMUNITY DEVELOPMENT

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

INITIAL STUDY/

MITIGATED NEGATIVE

DECLARATION
Map of Clark Property (APN 007-791-032)
Staff Project No. 13-001
Corbett Creek Floodplain and Stream Restoration Project March 2013
Exhibit "A"

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 227 (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 (900’) of 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 permitting 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

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Table of Contents:

Introduction ..................................................................................................................................................5 Introduction and Regulatory Guidance.....................................................................................................5 Lead Agency ..............................................................................................................................................5 Purpose and Document Organization.......................................................................................................6 Summary of Findings.................................................................................................................................6 Project Description........................................................................................................................................7 Introduction ..............................................................................................................................................7 Background and Need for Project.............................................................................................................9 Other Required Public Agency Approvals...............................................................................................10 Related Projects......................................................................................................................................10 Environmental Checklist .............................................................................................................................11 Project Information.................................................................................................................................11 Environmental Factors Potentially Affected...........................................................................................13 Determination.........................................................................................................................................13 Evaluation of Environmental Impacts.....................................................................................................14 Environmental Issues..................................................................................................................................15

1. Aesthetics............................................................................................................................................15

2. Agriculture and Forestry Resources....................................................................................................16

3. Air Quality ...........................................................................................................................................16

4. Biological Resources............................................................................................................................18

5. 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. Utilities and Service Systems ............................................................................................................34

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Mandatory Findings of Significance............................................................................................................36 Summary of Mitigation Measures ..............................................................................................................37 References ..................................................................................................................................................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/MND) 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 Quality 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(b)]. The lead agency prepares a 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) – Regulatory agency US Fish and Wildlife Service (FWS) – Regulatory agency
US Army Corps of Engineers (USACE) – 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

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 project and describes the purpose and organization of this document.

Project Description
This chapter describes the reasons for the project, scope of the project, and project objectives.

Environmental Setting, Potential Impacts 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-thansignificant level.

Mandatory Findings of Significance
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.

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 Floodplain 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 project downstream 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 impacts for Reaches 1 through 5 where they are foreseeable.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Exhibit A

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 Protection Study (see Exhibit B below for delineation of easement area).

Exhibit B
(yellow line)

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 over 12.50 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 Projects
None.

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
Number:

Kelly Heffernon, Associate Planner
(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)

2. Low-Medium Density Residential (LM); Conservation
Open Space (C/OS)
Zoning: 1. Residential Hillside (RH); 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 for portions 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 floodplain 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.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain 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 is bounded by the Cities of Grover Beach and 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.S. 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 the 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 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 active faults 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 project 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.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Environmental Factors Potentially Affected
The environmental factors checked below would be potentially affected by this project, involving at least one impact that is a "Potentially Significant Impact", as indicated by the checklist on the following pages:

Aesthetics Agricultural Resources Air Quality
Biological Resources Cultural Resources Geology/Soils
Greenhouse Gas Emissions Hazards & Hazardous Materials Hydrology/Water Quality Land Use/Planning Mineral Resources Noise
Population/Housing Public Services Recreation
Transportation/Traffic Utilities/Service Systems Mandatory Findings of Significance Determination
On the basis of this initial evaluation:

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

I find that, although the 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 previous documents.

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-thansignificant level and no further action is required. _________________________________ ________________________________ Kelly Heffernon, AICP Date
Associate Planner

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION 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 has determined that a particular physical 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.

5. Earlier analyses may be used where, pursuant to the tiering, program EIR, or other CEQA process, an effect has been adequately analyzed in an earlier EIR (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 where the 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, if any, 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.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain 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 to attenuate 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.

These improvements have not yet been designed, but there are no expected visual impacts associated with this component of the project.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
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 site and its surroundings?
d) Create a new source of substantial light or glare
which would adversely affect day or nighttime views in
the area?
Discussion
a-d: No impacts.

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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”, nor is it located near any Farmland.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No 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 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
Resources Code section 4526), or timberland zoned
Timberland Production (as defined by Government
Code section 51104(g))?
d) Result in the loss of forest land or conversion of
forest land 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 significant environmental effects, lead agencies may refer to the California Agricultural Land Evaluation and Site Assessment Model (1997), prepared by the California Department of Conservation as an optional model for use in assessing impacts on agricultural and farmland.

Discussion
a-e: No impacts.

3. Air Quality
Environmental Setting
San Luis Obispo County is in non-attainment status for ozone (O3), 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.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No 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 significant 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 depend 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 3.1: 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 (nonpotable) water when feasible.

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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 erosion control 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 prior to start of the project).

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 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 has a 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.

To determine the extent and quality of wetland habitat on the project site, and whether portions of the project area were eligible for wetland protection and restoration through the Wetland Reserve Program

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(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 identified special 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 (Scrophularia atrata), San Bernardino aster (Symphyotricham defoliatum), California red-legged frog (Rana aurora draytonii), Southwestern pond turtle (Actinemys marmorata pallid), and the Yellow Warbler (Dendroica petechia).

The U.S. Fish and Wildlife Service (USFWS) and California Department of Fish and Wildlife (CDFW) have regulatory responsibility for the 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.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No 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 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?
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?

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f) Conflict with the provisions of an adopted Habitat
Conservation Plan, Natural Community Conservation
Plan, or other approved local, regional, or state habitat conservation plan?
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 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 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. 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 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.

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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 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 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 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 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
e-f: No impacts.

5. Cultural Resources
Environmental Setting
Creeks are a 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)

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 the vicinity. Additionally, the proposed project requires a limited amount of surface excavation for the purposes of collection of fine sediment and floodplain restoration.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Cause a substantial adverse change in the
significance of a historical resource, as defined in
§15064.5?
b) Cause a substantial adverse change in the
significance of an archaeological resource, pursuant to §15064.5?
c) Disturb any human remains, including those interred
outside 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: Less than 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 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

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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 left 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

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 rains and soils with a high to very high hazard rating for water erosion led to the sedimentation 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 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.

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).

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No 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 Zoning Map, issued by the State
Geologist for the area, or based on other
substantial evidence of a known fault? (Refer to
Division of Mines 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
topsoil?
c) Be located on a geologic unit or soil that is unstable, or that would become unstable, as a result of the
project and potentially result in on- or off-site
landslide, lateral spreading, subsidence, liquefaction, or collapse?
d) Be located on expansive soil, as defined in Table 18- 1-B of the Uniform Building Code (1994), creating
substantial risks to life or property?
e) Have soils incapable of adequately supporting the
use of septic tanks or alternative waste disposal
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 deposition 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.

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 expansion of 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.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No 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 reducing the emissions of
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.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Create a significant hazard to the public or the
environment through the routine transport, use, or
disposal of hazardous materials?
b) Create a significant hazard to the public or the
environment through reasonably foreseeable upset
and/or accident conditions involving the release of
hazardous materials, substances, or waste into the
environment?

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c) Emit hazardous emissions or handle hazardous or
acutely hazardous materials, substances, or waste
within one-quarter mile of an existing or proposed
school?
d) Be located on a site which is included on a list of
hazardous materials sites, compiled pursuant to
Government Code §65962.5, and, as a result, create a
significant hazard to the public or environment?
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 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
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’s Village 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 the mitigation measures below will mitigate the impacts to less that significant.

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Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Violate any water quality standards or waste
discharge requirements?
b) Substantially deplete groundwater supplies or
interfere substantially with groundwater recharge,
such that there would be a net deficit in aquifer
volume or a lowering of the local groundwater table
level (e.g., the production rate of pre-existing nearby wells would drop to a level 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
course of a stream or river, in a manner which would
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
drainage systems or provide substantial additional
sources of polluted runoff?
f) Substantially degrade water quality?
g) Place housing within a 100-year flood hazard area,
as mapped on a federal Flood Hazard Boundary or
Flood Insurance Rate Map, or other flood hazard
delineation map?
h) Place structures that would impede or redirect flood flows within a 100-year flood hazard area?
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-thansignificant 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

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

not worsen the water quality 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 interested 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 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 SWPPP 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 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 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 Responsibility: Construction Manager
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

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 MM 9.4: All temporary fill placed during project construction shall be removed at project completion and the area restored to approximate pre-project contours and topography.

Level of Significance: Less than 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
Implementing Responsibility: Coastal San Luis Resource Conservation District Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit
b, g, j: 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 exceeds 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.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No 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
ordinance) adopted for the purpose of avoiding or
mitigating an environmental effect?
c) Conflict with any applicable habitat conservation
plan or natural community conservation plan?
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.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Result in the loss of availability of a known mineral resource that is or would be of value to the region and the residents of the state?
b) Result in the loss of availability of a locally
important mineral resource recovery site delineated
on a local general plan, specific plan, or other land use plan?
Discussion
a-b: 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.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

a) Generate or expose people to noise levels in excess
of standards established in a local general plan or
noise ordinance, or in other applicable local, state, or federal standards?
b) Generate or expose people to excessive
groundborne vibrations or groundborne 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 increase
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 public use airport? 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 longterm or operational increases to ambient noise levels.

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 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

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

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 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 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 into a conservation easement would appear to reduce the residential development potential. However, because the 12.5-acre property is located within a floodplain 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.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Induce substantial population growth in an area,
either directly (for example, by proposing new homes
and businesses) or indirectly (for example, through
extension of roads or other infrastructure)?
b) Displace substantial numbers of existing housing,
necessitating the construction of replacement housing
elsewhere?
c) Displace substantial numbers of people,
necessitating the construction of replacement housing
elsewhere?

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Discussion
a-c: No impacts.

14. Public Services
Environmental Setting
Public services to the project site are readily provided by the City of Arroyo Grande.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Result in significant environmental impacts from
construction associated with the provision of new or
physically altered governmental facilities, or the need for new or physically altered governmental facilities, to maintain acceptable service ratios, response times, or
other performance objectives for any of the public
services:

Fire protection?
Police protection?
Schools?
Parks?
Other public facilities?
Discussion
a: No impacts.

15. Recreation
Environmental Setting
The project site is a private facility with recreational uses and is not a public facility. The property owner utilizes the site primarily for corralling and grazing horses, with most of the site left in vacant open space. The project will not affect any existing private or public parks within the area, either by creating more demand for parks or diminishing the use of parks.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
a) Increase the use of existing neighborhood and
regional parks or other recreational facilities, such that substantial physical deterioration of the facility would occur or be accelerated?
b) Include recreational facilities or require the
construction or expansion of recreational facilities that might have an adverse physical effect on the
environment?

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. 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.

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No 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
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?
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.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No Impact
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
regulations as they relate to solid waste?
Discussion
a-g: No impacts.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Mandatory Findings of Significance
Would the project:

Potentially
Significant
Impact
Less Than
Significant
with
Mitigation
Less Than
Significant
Impact
No 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,
either 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.

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

Summary of Mitigation Measures
MM 3.1: 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 (nonpotable) 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 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 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 (CARB) 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, Community Development Dept.

Timing: Prior to issuance of grading permit and during construction

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 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 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 significant impact
Implementing Responsibility: 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 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. 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 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.

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 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 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 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
Monitoring Agency: City of Arroyo Grande, Community Development Dept.

Timing: Prior to issuance of grading permit

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

MM 4.4: The applicant shall 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 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: Less than 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 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 left 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

INITIAL STUDY / MITIGATED NEGATIVE 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 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 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 Responsibility: 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

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

MM 9.4: All temporary fill placed during project construction shall be removed at project completion and the area restored to approximate pre-project contours and topography.

Level of Significance: Less than 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
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 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 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

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

INITIAL STUDY / MITIGATED NEGATIVE DECLARATION March 2013 Corbett Creek Floodplain and Stream Restoration Project

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

MITIGATION MONITORING

AND REPORTING PROGRAM (MMRP)
______________________________________________
Staff Project No. 13-001
Corbett Creek Floodplain and Stream Restoration Project ADOPTED BY:

CITY OF ARROYO GRANDE

PLANNING COMMISSION
DATE:

APRIL 16, 2013
Exhibit "B"

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
2 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 impact altogether by not taking a certain action or parts of an action.

Minimizes impacts by limiting the degree or magnitude of 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 floodplain/sediment 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
3 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
Measure
The description of the mitigation measures.

Mitigation Level The level to which the impact is anticipated to be mitigated.

Implementing
Responsibility
The agency or individual that has the responsibility for implementing or performing the measure.

Monitoring
Responsibility
The public agency that has the responsibility for monitoring to ensure that the mitigation measure is effective in mitigating the impact.

Compliance
Standards
The method used to verify compliance.

Timing The appropriate points in time at which the mitigation measure is to be initiated and completed.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
4 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
Air Quality

3.1 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 (nonpotable) 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.

Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Initial site check to
ensure measures are in
place. Bi-weekly site
checks to ensure
construction area is
swept or watered
regularly.

Prior to
issuance of
grading
permit and
during
construction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
5 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
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

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
6 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
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).

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 prior to start of the
project).

Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Dept.

Project plans shall
indicate type and
horsepower of proposed
equipment used during
grading operations.

Follow up with APCD if
necessary.

Prior to
issuance of
grading
permit and
during
construction.

Biological Resources

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
Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
The Construction
Manager shall inform the
Community Development
Dept. when grading
activities are expected to
commence. If grading
must occur between
April and July, preconstruction biological
Prior to
issuance of
grading
permit.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
7 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
active nests of the Yellow Warbler
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.
surveys shall be
submitted to the City,
CSRCD, CDFW and FWS
prior to issuance of
grading permit.

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. 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
Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Pre-construction
biological surveys shall
be conducted according
to the mitigation
language and submitted
to the City, CSRCD, CDFW
and FWS prior to
issuance of grading
permit. If individuals of
special status species are
found, a biologist shall be
retained to prepare
recommendations and
provide guidance/
training for the
monitoring of the project
area during construction.

Prior to
issuance of
grading
permit and
during
construction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
8 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
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.

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 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
Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Pre-construction
botanical surveys shall be
conducted according to
the mitigation language
and submitted to the
City, CSRCD, CDFW and
FWS prior to issuance of
grading permit. If
individuals of special
status plant species are
found, a botanist shall be
retained to prepare
recommendations.

Prior to
issuance of
grading
permit.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
9 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
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.

4.4 The applicant shall acquire
appropriate resource agency permits
and undertake protection measures
as required by those agencies.

Less than
significant
impact
Coastal San
Luis Resource
Conservation
District
(CSRCD)
City of A.G.,
Community
Development
Department
CSRCD shall provide the
City with applicable
resource agency permits.

Prior to
issuance of
grading
permit.

Cultural Resources

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
Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
The mitigation measure
language shall be
included on the
construction
specifications.

During
construction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
10 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
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.

5.2 The note below shall be placed on
the grading and improvement plans
for the project:

Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Mitigation measure shall
be included on the
construction
specifications.

Prior to
issuance of
grading
permit.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
11 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
“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
left in an undisturbed state.”

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
12 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
Hydrology and Water Quality

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 SWPPP
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
Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Prepare SWPPP as
indicated and implement
BMPs as required.

Prior to
issuance of
grading
permit and
during
construction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
13 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
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 preparation and
erosion control BMPs for any work
that may need to be completed
after October 15.

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.

Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Ensure runoff and
sediment control
measures are on the
grading plan and in place
prior to grading activities.

Prior to
issuance of
grading
permit and
during
construction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
14 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)

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.

Less than
significant
impact
Coastal San
Luis Resource
Conservation
District
(CSRCD)
City of A.G.,
Community
Development
Department
Ensure erosion control
and bank stabilization
measures are on the
grading plan and in place
prior to grading activities.

If required by CDFW, a
Streambed Alteration
Permit shall be approved
and a copy of the permit
shall be submitted to the
City.

Prior to
issuance of
grading
permit and
during
construction.

9.4 All temporary fill placed during
project construction shall be removed
at project completion and the area
restored to approximate pre-project
contours and topography.

Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
The grading plan shall
indicate all proposed
temporary fill areas.

Removal of temporary fill
areas shall be verified
prior to final inspection.

Prior to final
inspection.

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.

Less than
significant
impact
Coastal San
Luis Resource
Conservation
District
(CSRCD)
City of A.G.,
Community
Development
Department
A copy of all necessary
resource agency permits
shall be submitted to the
City.

Prior to
issuance of
grading
permit.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
15 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
Noise

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.

Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Ensure adherence to
construction hours.

During
construction.

12.2 All construction equipment utilizing
internal 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.

Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Ensure use of mufflers
and other attenuation
devices.

During
construction.

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.

Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Ensure note is on the
plans and measure is
adhered to during site
inspections.

Prior to
issuance of
grading
permit and
during
construction.

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
Less than
significant
impact
Construction
Manager
City of A.G.,
Community
Development
Department
Send notices, post sign
and designate a City staff
person to respond to any
noise concerns.

Prior to
issuance of
grading
permit and
during
construction.

MMRP
Corbett Creek Floodplain and Stream Restoration Project April 2013
16 MM # Requirements of Measure Mitigation
Level
Implementing
Responsibility
Monitoring
Responsibility
Compliance Standards
(Note: All Mitigation
Measures shall be
included on the project
plans).

Timing Verification of
Compliance
(Initials / Date /
Remarks)
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.

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

Attachment 5 – Staff Report and Minutes from the June 6, 2023 Planning Commission meeting.

Planning Commission Staff Report
Minutes from the June 6, 2023 Planning Commission Meeting

prepared for
Coastal San Luis Resource Conservation District
1203 Main Street, Suite B
Marrow Bay, CA 93442
prepared by
509A Swift Street
Santa Cruz, CA 95060
June 16, 2023
Tally Ho Stream Stabilization Project
Hydraulics Report
ATTACHMENT 6

Tally Ho Stream Stabilization Project – 100% Level Submittal i Hydraulic Report

TABLE OF CONTENTS
INTRODUCTION .........................................................................................................1 HYDRAULIC MODELING METHODOLOGY ...................................................................1

2.1 Peak Flow Hydrology ..................................................................................... 1

2.2 Extent of Analysis........................................................................................... 1

2.3 Boundary Conditions..................................................................................... 2

2.4 Floodway Encroachments.............................................................................. 3

2.5 Pre‐Project Conditions Model ....................................................................... 3

2.6 Revised Conditions Model ............................................................................. 3 RESULTS ....................................................................................................................3

3.1 Base Flood Elevation and floodway encroachments..................................... 3

3.2 Inundation Extents......................................................................................... 4 CONCLUSIONS ...........................................................................................................5

4.1 Water Surface Elevations .............................................................................. 5

4.2 No‐Rise Certification...................................................................................... 6 REFERENCES ..............................................................................................................7

LIST OF FIGURES
Figure 1. Hydraulic Model Overview............................................................................................. 2 Figure 2. Modeled Inundation Extents.......................................................................................... 5

LIST OF TABLES
Table 1. Manning's Roughness for Different Land Use Types....................................................... 3 Table 2. Base Flood Elevations of Existing and Proposed Conditions........................................... 4 Table 3. Encroachment Adjustments............................................................................................ 4

LIST OF APPENDICES
Appendix A – FEMA FIRM Panel
Appendix B – 100% Level Design Drawings
Appendix C – FIS Corbett Canyon Creek Flood Profile
Appendix D – HEC‐RAS Model Output Cross Sections and Tables

LIST OF ELECTRONIC ATTACHMENTS
Attachment 1 – FEMA FIS HEC‐2 Model Input and Output Data Attachment 2 – HEC‐RAS Model

Tally Ho Stream Stabilization Project – 100% Level Submittal 1 Hydraulic Report

INTRODUCTION
Waterways Consulting, Inc. (Waterways) has been retained by the Coastal San Luis Resource Conservation District to evaluate the hydraulic effects on Corbett Canyon Creek during a 100‐year base flood discharge from a proposed headcut stabilization project in Arroyo Grande, California. The Tally Ho Stream Stabilization Project site is located on Corbett Canyon Creek, approximately 0.4 miles upstream of the confluence with Arroyo Grande Creek in San Luis Obispo County. The proposed stabilization will consist of lowering the channel bed upstream of an existing headcut to reduce the drop over the headcut, stabilizing the remaining drop by installing a boulder weir, and protecting the lowered channel beds and banks upstream of the boulder weir using a combination of engineered streambed material and fabric encapsulated soil lifts.  The lowered channel will be constructed at a 2.2 percent grade extending approximately 220 feet upstream of the proposed boulder weir (see Figure 1 and Appendix B). The channel stablilization project is within a FEMA 100‐year approximate floodplain (Zone AE) with mapped floodway, as shown on the Flood Insurance Rate Map (FIRM) effective November 16, 2012 (Appendix A).

This report has been prepared to support floodplain development permitting with San Luis Obispo County for the proposed project and presents the hydraulic analysis of existing and proposed conditions for the 100‐year flood event along Corbett Canyon Creek within the vicinity of the proposed project.

This report was prepared in accordance with the Code of Federal Regulations Title 44 Section

60.3(d)(3)  ‐ Floodway Requirements, which states that a community shall “prohibit encroachments, including fill, new construction, substantial improvements and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base (100‐ year) flood discharge.” This report has been prepared in accordance with the Procedures for “No‐Rise” Certification For Proposed Developments in the Regulatory Floodway (FEMA Region X, October 2013).

The following sections summarize the methodology and results that support the Engineering No‐Rise Certification included at the end of the report.

HYDRAULIC MODELING METHODOLOGY

2.1 PEAK FLOW HYDROLOGY
The 100‐year peak flow for Corbett Canyon Creek is estimated to be 2,600 cubic feet per second (cfs) at the confluence with Arroyo Grande located downstream of the project area and 2,300 cfs upstream at the confluence with Poorman Canyon Creek, as presented in the 2017 Flood Insurance Study (FIS) for San Luis Obispo County (Table 10 of the 2017 FIS Report).  The project site is approximately halfway between the two locations where peak flows were determined, so a value of 2,450 cfs was used as the 100‐year peak flow (i.e., base flood discharge) for the modeling effort at the project area.

2.2 EXTENT OF ANALYSIS
A one‐dimensional hydraulic model of Corbett Canyon Creek extending from FEMA published Section F (River Station 1582) to FEMA published Section I (River Station 2721) (see Figure 1) was prepared using United States Army Corps of Engineers (USACE) Hydraulic Engineering Center River Analysis Software

Tally Ho Stream Stabilization Project – 100% Level Submittal 2 Hydraulic Report
(HEC‐RAS) version 6.3.1. Waterways confirmed through a FEMA Library Data request that the Current Effective Model for the creek was performed using HEC‐2 modeling software (see Attachment 1).

Figure 1. Hydraulic Model Overview
According to the Guidance for Flood Risk Analysis and Mapping (FEMA, December 2020), this data serves as the Duplicate Effective Model for this report and no Corrected Effective Model is proposed as part of this analysis.

Two modeling scenarios were developed to evaluate potential changes in the 100‐year water surface elevation (i.e. Base Flood Elevation) from the proposed project, these include the Pre‐Project Conditions Model (“PCM” is the Plan identifier in the model) and the Revised Conditions Model (“RCM” is the Plan identifier in the model). Figure 1 shows the proposed project location, cross section locations used in the hydraulic analysis, and the effective FEMA floodplain boundaries (FEMA 2012). All elevations are referenced to the NAVD88 vertical datum. Elevations shown on the design drawings in Appendix B are based on an assumed vertical datum (21.76 feet below NAVD 88 vertical datum).

2.3 BOUNDARY CONDITIONS
A known water surface elevation of 123.3 ft. (without floodway) and 124.4 ft. (with floodway) was set as the downstream boundary condition at FEMA published Section F (Table 24, Volume 2 of the 2017 FIS).  The model was run using a subcritical flow regime.

Tally Ho Stream Stabilization Project – 100% Level Submittal 3 Hydraulic Report

2.4 FLOODWAY ENCROACHMENTS
Floodway encroachments were determined for both model scenarios using Method 1, as described in the HEC‐RAS Hydraulic Reference Manual. Encroachment stations are set based on where the edge of the floodway is located (Figure 1), and then adjusted to show no more than a 1‐foot rise at each cross section. At some cross sections, it was found that the floodway did not correspond with the location of the lowest cross section elevation. At these locations, the encroachment stationing was adjusted to include these areas.

2.5 PRE‐PROJECT CONDITIONS MODEL
The pre‐project conditions model extends from FEMA published Section F (River Station 1582) to FEMA published Section I (River Station 2721).  All published cross sections and additional project specific cross sections were sampled from a terrain surface derived from topographic surveys by Waterways (11/15/2007, 1/16/2017, and 4/20/2023) and LiDAR data from FEMA (Region 9, 2018) (Note: Appendix B includes topography at the project area in an assumed coordinate system).

According to the FIS, the hydraulic roughness values (Manning’s n) for the channel and overbank areas vary between 0.025‐0.100 and 0.030‐.120, respectively. The high end of these ranges was used in the current modeling effort based on visual observations of heavy vegetation in the channel along much of the project reach, development in the floodplain, and published hydraulic roughness values (Chow, 1959), see Table 1.

Table 1. Manning's Roughness for Different Land Use Types Land Use Type Manning’s ‘n’
Channel 0.10
Overbank   0.12

2.6 REVISED CONDITIONS MODEL
The revised conditions model includes all cross sections in the existing conditions model. The existing conditions geometry was updated to include the design geometry where modifications to the channel are proposed (Appendix B). The revised conditions model Manning’s n values were not modified from the pre‐project values because it is assumed that the post‐project revegetation effort will return the vegetation roughness to pre‐project conditions.

RESULTS
Tabular and cross‐sectional results of the hydraulic modeling are presented in Appendix D.

3.1 BASE FLOOD ELEVATION AND FLOODWAY ENCROACHMENTS
Table 2 shows the resulting 1% annual chance flood (100‐year) water surface elevations with and without the floodway encroachments for the Pre‐Project Conditions Model (PCM), and the Revised Conditions Model (RCM). This table shows an equivalent or decrease in the water surface elevation at all cross sections comparing the PCM with the RCM for both the base flood and encroached channel conditions.

Tally Ho Stream Stabilization Project – 100% Level Submittal 4 Hydraulic Report
Table 3 shows how the encroachment stationing for left and right banks were changed for each cross section when compared to the FIRM. These revised stationing values were duplicated for the PCM and RCM to evaluate the effects of this project on the floodway.

3.2 INUNDATION EXTENTS
The FEMA floodway was measured, and stationing incorporated into the model with encroachment using Method 1. Initial modeling results using the FEMA floodway geometry exceeded the allowable 1‐ ft rise.  In addition, the FEMA channel does not align with the surveyed low flow channel, resulting in floodway stationing that did not encompass the low flow channel at some sections.  Stationing was moved towards the left bank in those cases to include the low flow channel, then iteratively adjusted along the left bank (where existing buildings are not present) in the Pre‐Project Conditions Model (PCM) until the allowable 1‐ft rise was met.  The identical encroachment stationing was used in the Revised Conditions Model (RCM).  Table 2 table shows an equivalent or decrease in the water surface elevation at all cross sections comparing the PCM with the RCM.

Table 2. Base Flood Elevations of Existing and Proposed Conditions Table 3. Encroachment Adjustments
PCM RCM Difference PCM RCM Difference
I 2721 131.60 131.60 0.00 132.51 132.00 ‐0.51
‐ 2605 130.48 130.47 ‐0.01 131.14 131.07 ‐0.07
‐ 2470 129.79 129.78 ‐0.01 130.75 130.71 ‐0.04
‐ 2348 129.38 129.36 ‐0.02 130.33 130.27 ‐0.06
‐ 2161 128.42 128.37 ‐0.05 129.41 129.32 ‐0.09
H 2104 127.90 127.81 ‐0.09 128.87 128.71 ‐0.16
‐ 1947 125.58 125.57 ‐0.01 126.31 126.25 ‐0.06
G 1936 125.27 125.26 ‐0.01 126.25 126.21 ‐0.04
‐ 1935 125.29 125.29 0.00 126.09 126.06 ‐0.03
‐ 1810 124.24 124.24 0.00 125.01 125.01 0.00
‐ 1696 123.64 123.64 0.00 124.56 124.56 0.00
F 1582 123.30 123.30 0.00 124.30 124.30 0.00
Cross
Section
Section ID
(River Station)
Without Encroachment With Encroachment
FEMA PCM/RCM Difference FEMA PCM/RCM Difference
2721 321.71 321.71 0.00 526.92 526.92 0.00
2605 397.98 397.98 0.00 588.93 588.93 0.00
2470 510.75 210.75 300.00 679.70 679.70 0.00 Left widened 300 ft 2348 204.09 204.09 0.00 360.61 360.61 0.00
2161 18.57 68.38 ‐49.81 243.39 243.39 0.00 Left narrowed to limit of 100yr WSE 2104 131.28 110.7 20.58 250.24 250.24 0.00 Left widened to include left bank 1947 121.03 95.9 25.13 211.10 211.10 0.00 Left widened to include left bank 1936 120.50 66.7 53.80 210.55 210.55 0.00 Left widened to include left bank plus 40 ft offset 1935 114.79 100.4 14.39 205.35 205.35 0.00 Left widened to include left bank 1810 149.74 106.5 43.24 272.35 272.35 0.00 Left widened to include left bank plus 10 ft offset 1696 101.10 60.8 40.30 252.78 252.78 0.00 Left widened to include left bank plus 20 ft offset 1582 99.50 80.4 19.10 275.61 275.61 0.00 Left widened to include left bank Notes
River Right Bank Station
Station
Left Bank Station

Tally Ho Stream Stabilization Project – 100% Level Submittal 5 Hydraulic Report

CONCLUSIONS

4.1 WATER SURFACE ELEVATIONS
The results of the hydraulic analysis indicate there will be no rise in the 100‐year water surface elevations for the Revised Conditions Model when compared to the Pre‐Project Conditions Model, for both the base flood and the encroached channel. Therefore, the proposed project satisfies the requirement of the City of Arroyo Grande Municipal Code section 16.44.050.G.7.

Figure 2. Modeled Inundation Extents

Tally Ho Stream Stabilization Project – 100% Level Submittal 6 Hydraulic Report

4.2 NO‐RISE CERTIFICATION
This is to certify that I am a duly qualified engineer licensed to practice in the State of California.

It is to further certify that the technical data summarized in this report supports the fact that the proposed Tally Ho Stream Stabilization Project will not increase the 100‐year flood elevations, floodway elevations, and floodway widths on Corbett Canyon Creek at published sections in the Flood Insurance Study for the City of Arroyo Grande, dated May 16, 2017, and will not increase the 100‐year flood elevations, floodway elevations, and floodway widths at unpublished cross‐sections in the vicinity of the proposed development.

Brent Zacharia, P.E.

Senior Engineer, Waterways Consulting, Inc.

Tally Ho Stream Stabilization Project – 100% Level Submittal 7 Hydraulic Report

REFERENCES
Chow, V.T. 1959. Open Channel Hydraulics. McGraw‐Hill, New York.

Code of Federal Regulations. 2022. Flood plain management criteria for flood‐prone area. 44 C.F.R. §

60.3. Last amended 10/1/2022.

FEMA. 2020. Guidance for Flood Risk Analysis and Mapping. MT‐2 Requests. Guidance Document 106.

December 2020.

FEMA. 2017. Flood Insurance Study Volumes 1, 2, and 3. San Luis Obispo County, California and Incorporated Areas. FIS Study No. 06079CV001C. Effective May 16, 2017.

FEMA. 2013. Procedures for “No‐Rise” Certification For Proposed Developments in the Regulatory Floodway.

FEMA. 2009. Flood Insurance Rate Map. San Luis Obispo County, California and Incorporated Areas.

Panel 1364 of 2050. Effective November 16, 2012.

City of Arroyo Grande.  Municipal Code.  Floodplain management and creek protection district, Chapter 16.44.050.

U.S. Army Corps of Engineers. Hydrologic Engineering Center. Computer Program HEC‐RAS Version

6..3.1 Davis, California. March 2019.

U.S. Army Corps of Engineers. Hydrologic Engineering Center. Hydraulic Reference Manual. Version 5.0 Davis, California. February 2016.

Appendix A – FEMA FIRM Panel

Project Site

Appendix B – 100% Level Design Drawings

Appendix C – FIS Corbett Canyon Creek Flood Profile

80 90
100 100 110 110 120 120 130 130 140 140 150 150 160 160 170 170 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
ELEVATION IN FEET (NAVD 88)

STREAM DISTANCE IN FEET ABOVE CONFLUENCE WITH ARROYO GRANDE CREEK

FEDERAL EMERGENCY MANAGEMENT AGENCY

SAN LUIS OBISPO COUNTY, CA

AND INCORPORATED AREAS

FLOOD PROFILES

CORBETT CANYON CREEK
14P
A
B
C

D E F G

H I J K L M
(STATE HIGHWAY 227)

CONFLUENCE WITH

CONFLUENCE OF

EAST BRANCH

PRINTZ ROAD
LEGEND

0.2% ANNUAL CHANCE FLOOD1% ANNUAL CHANCE FLOOD2% ANNUAL CHANCE FLOOD10% ANNUAL CHANCE FLOODSTREAM BEDCROSS SECTION LOCATION

ARROYO GRANDE CREEK

POORMAN CANYON CREEK
STREET

CULVERT

Appendix D – HEC‐RAS Model Output Cross Sections and Tables

HEC-RAS River: CorbettCanyonCk Reach: Reach 1
Reach River Sta Profile Plan Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft)
Reach 1 2721 100-YR PCM 2450.00 126.65 131.60 131.76 0.013781 3.99 789.96 306.12 0.37 Reach 1 2721 100-YR RCM 2450.00 126.65 131.60 131.76 0.013801 3.99 789.55 306.09 0.37 Reach 1 2721 100-YR with Encr PCM 2450.00 126.65 132.51 132.73 0.014488 4.75 687.11 205.21 0.39 Reach 1 2721 100-YR with Encr RCM 2450.00 126.65 132.00 132.31 0.023808 5.62 581.58 205.21 0.49 Reach 1 2605 100-YR PCM 2450.00 125.47 130.48 130.58 0.007580 2.47 959.31 277.70 0.25 Reach 1 2605 100-YR RCM 2450.00 125.47 130.47 130.57 0.007619 2.47 957.77 277.36 0.26 Reach 1 2605 100-YR with Encr PCM 2450.00 125.47 131.14 131.32 0.010124 3.27 732.84 190.95 0.30 Reach 1 2605 100-YR with Encr RCM 2450.00 125.47 131.07 131.15 0.004951 2.26 1058.18 270.02 0.21 Reach 1 2470 100-YR PCM 2450.00 123.35 129.79 129.84 0.004003 2.84 1603.28 633.48 0.21 Reach 1 2470 100-YR RCM 2450.00 123.35 129.78 129.82 0.004081 2.86 1593.49 633.29 0.22 Reach 1 2470 100-YR with Encr PCM 2450.00 123.35 130.75 130.78 0.001879 2.17 1804.08 468.95 0.15 Reach 1 2470 100-YR with Encr RCM 2450.00 123.35 130.71 130.74 0.001948 2.20 1783.71 468.95 0.15 Reach 1 2348 100-YR PCM 2450.00 122.96 129.38 129.43 0.002902 2.54 1476.74 392.93 0.19 Reach 1 2348 100-YR RCM 2450.00 122.96 129.36 129.40 0.002960 2.56 1467.52 392.69 0.19 Reach 1 2348 100-YR with Encr PCM 2450.00 122.96 130.33 130.44 0.004280 3.41 929.18 156.52 0.23 Reach 1 2348 100-YR with Encr RCM 2450.00 122.96 130.27 130.39 0.004414 3.44 920.33 156.52 0.23 Reach 1 2161 100-YR PCM 2450.00 122.00 128.42 128.57 0.007926 3.79 940.16 328.39 0.29 Reach 1 2161 100-YR RCM 2450.00 121.99 128.37 128.52 0.008220 3.89 923.46 328.02 0.30 Reach 1 2161 100-YR with Encr PCM 2450.00 122.00 129.41 129.56 0.005202 3.45 859.78 175.01 0.25 Reach 1 2161 100-YR with Encr RCM 2450.00 121.99 129.32 129.47 0.005417 3.54 844.53 175.01 0.25 Reach 1 2104 100-YR PCM 2450.00 121.00 127.90 128.05 0.010748 4.76 896.55 318.95 0.34 Reach 1 2104 100-YR RCM 2450.00 120.76 127.81 127.98 0.011234 5.25 875.58 318.20 0.37 Reach 1 2104 100-YR with Encr PCM 2450.00 121.00 128.87 129.11 0.012571 4.80 641.62 139.54 0.32 Reach 1 2104 100-YR with Encr RCM 2450.00 120.76 128.71 129.00 0.012888 6.14 622.31 139.54 0.40 Reach 1 1947 100-YR PCM 2450.00 119.00 125.58 125.87 0.018402 5.73 621.84 208.81 0.44 Reach 1 1947 100-YR RCM 2450.00 117.29 125.57 125.86 0.016389 5.96 640.79 207.24 0.41 Reach 1 1947 100-YR with Encr PCM 2450.00 119.00 126.31 126.68 0.019325 5.81 518.92 115.20 0.41 Reach 1 1947 100-YR with Encr RCM 2450.00 117.29 126.25 126.65 0.017522 6.57 528.02 115.20 0.43 Reach 1 1936 100-YR PCM 2450.00 113.61 125.27 125.66 0.015912 7.23 694.86 271.75 0.40 Reach 1 1936 100-YR RCM 2450.00 113.61 125.26 125.66 0.014684 7.18 698.35 271.59 0.40 Reach 1 1936 100-YR with Encr PCM 2450.00 113.61 126.25 126.50 0.008441 5.60 717.28 143.85 0.30 Reach 1 1936 100-YR with Encr RCM 2450.00 113.61 126.21 126.47 0.008001 5.64 718.83 143.85 0.30 Reach 1 1935 100-YR PCM 2450.00 113.00 125.29 125.65 0.013298 6.83 727.56 274.63 0.37 Reach 1 1935 100-YR RCM 2450.00 113.00 125.29 125.65 0.013298 6.83 727.56 274.63 0.37 Reach 1 1935 100-YR with Encr PCM 2450.00 113.00 126.09 126.48 0.016540 6.24 531.61 104.95 0.33 Reach 1 1935 100-YR with Encr RCM 2450.00 113.00 126.06 126.45 0.016852 6.30 528.21 104.95 0.33 Reach 1 1810 100-YR PCM 2450.00 115.09 124.24 124.40 0.007122 4.72 1024.90 379.33 0.30 Reach 1 1810 100-YR RCM 2450.00 115.09 124.24 124.40 0.007122 4.72 1024.90 379.33 0.30 Reach 1 1810 100-YR with Encr PCM 2450.00 115.09 125.01 125.21 0.006370 4.76 799.24 165.85 0.29 Reach 1 1810 100-YR with Encr RCM 2450.00 115.09 125.01 125.20 0.006133 4.67 823.75 175.85 0.28 Reach 1 1696 100-YR PCM 2450.00 113.36 123.64 123.73 0.004643 3.86 1204.95 370.13 0.23 Reach 1 1696 100-YR RCM 2450.00 113.36 123.64 123.73 0.004643 3.86 1204.95 370.13 0.23 Reach 1 1696 100-YR with Encr PCM 2450.00 113.36 124.56 124.66 0.003422 3.55 1058.25 191.98 0.20 Reach 1 1696 100-YR with Encr RCM 2450.00 113.36 124.56 124.66 0.003422 3.55 1058.25 191.98 0.20 Reach 1 1582 100-YR PCM 2450.00 113.88 123.30 119.58 123.34 0.002457 2.75 1589.77 423.45 0.17 Reach 1 1582 100-YR RCM 2450.00 113.88 123.30 119.58 123.34 0.002457 2.75 1589.77 423.45 0.17 Reach 1 1582 100-YR with Encr PCM 2450.00 113.88 124.30 119.58 124.36 0.002003 1.92 1294.50 195.21 0.11 Reach 1 1582 100-YR with Encr RCM 2450.00 113.88 124.30 119.58 124.36 0.002003 1.92 1294.50 195.21 0.11

0 200 400 600 800
120130140150160170
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 2721
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
WS 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - RCM
EG 100-YR - PCM
EG 100-YR - RCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
1

0 200 400 600 800 1000
124126128130132134136138140142144
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 2605
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - PCM
EG 100-YR - RCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
2

0 200 400 600 800 1000 1200
122124126128130132134136138140142
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 2470
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
WS 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - RCM
EG 100-YR - PCM
EG 100-YR - RCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
3

0 100 200 300 400 500 600 700 800
120125130135140145
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 2348
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - PCM
EG 100-YR - RCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
4

0 100 200 300 400 500 600 700
120125130135140145
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 2161
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - PCM
EG 100-YR - RCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
5

0 100 200 300 400 500 600
120125130135140145150
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 2104
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - PCM
EG 100-YR - RCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
6

0 100 200 300 400 500 600 700
115120125130135140145150
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 1947
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - PCM
EG 100-YR - RCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
7

0 100 200 300 400 500 600 700
110115120125130135140145150
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 1936
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - RCM
EG 100-YR - PCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
8

0 100 200 300 400 500 600 700
110120130140150160
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 1935
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - RCM
EG 100-YR - PCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
9

0 100 200 300 400 500 600 700 800
110120130140150160
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 1810
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - RCM
EG 100-YR - PCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
10

0 100 200 300 400 500 600 700
110115120125130135140145150
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 1696
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - RCM
EG 100-YR - PCM
WS 100-YR - PCM
WS 100-YR - RCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
11

0 100 200 300 400 500 600 700
110115120125130135
07-625_TallyHo_NoRise_20230602 Plan: 1) RCM 2) PCM
RS = 1582
Station (ft)
Elevation (ft)
Legend
EG 100-YR with Encr - PCM
EG 100-YR with Encr - RCM
WS 100-YR with Encr - PCM
WS 100-YR with Encr - RCM
EG 100-YR - RCM
EG 100-YR - PCM
WS 100-YR - RCM
WS 100-YR - PCM
Crit 100-YR with Encr - PCM
Crit 100-YR with Encr - RCM
Crit 100-YR - RCM
Crit 100-YR - PCM
- PCM
Ground - PCM
Bank Sta - PCM
Encroachment - PCM
- RCM
Ground - RCM
Bank Sta - RCM
Encroachment - RCM
12

MEMORANDUM
TO: City Council
FROM: Jessica Matson, Legislative & Information Services Director/City Clerk SUBJECT: Supplemental Information
Agenda Item 10.a. – July 25, 2023 City Council Meeting
Consideration of Conditional Use Permit 23-001 and Request for Fee Waiver; Corbett Creek Floodplain and Stream Restoration ProjectCorbett Creek Between E Branch St and 379 Corbett Canyon Rd; Applicant - Coastal San Luis Resource Conservation District DATE: July 25, 2023
Attached is correspondence received for the above reference item. cc: City Manager
Assistant City Manager
Community Development Director
City Attorney
City Clerk
City Website and Public Review Binder
Enc

Cheryl Barton-Petrie
Arroyo Grande, CA 93420
July 21, 2021
Arroyo Grande City Council
Dear Council Members,
I am wri�ng to voice my support of the poten�al planned project in the Tally Ho Creek.

My husband and I were flooded out of our home on January 9th, 2023, primarily due to the overflow of the creek, which has silted up over years of neglect and restric�ons, and other issues affec�ng capacity.

There were eight inches of water and mud throughout our house, and two feet of water and mud in our guesthouse, which is in the back closer to the creek than the house. We were out of our home for three months, and we were lucky.

All the residents on Tally Ho Road from the 227 Bridge to James Way were affected nega�vely by the January 9 and March storms--either their homes were gravely damaged, or their yards were. People from at least four houses are s�ll homeless, working to get back into them.

Poten�al future damage looms large, and flooding is almost a given if something is not done. I understand the creek is a watershed that must be protected and that property lines are unclear, which complicates maters. However, with the backing of the RCD, CLC, the city and other agencies, a competent solu�on is pending—at least it is a start.

I am also aware that long-term maintenance is an issue, but I am certainly willing to consider the op�ons with the city and can be helpful in networking with neighbors.

Clearly something must be done. I believe we all will benefit from the project and its following phases.

Thank you.

Item 11.a.

MEMORANDUM
TO: City Council
FROM: Brian Pedrotti, Community Development Director
SUBJECT: Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
DATE: July 25, 2023
SUMMARY OF ACTION:

Adopt the Mitigated Negative Declaration in accordance with the applicable provisions of the California Environmental Quality Act, Public Resources Code Section 21000 et seq, and approve the Halcyon Road Complete Streets Plan. Provide direction to staff to proceed with completion of design and engineering work for the Plan, including Alternative 2 identified for the Halcyon/Fair Oaks intersection.

IMPACT ON FINANCIAL AND PERSONNEL RESOURCES:

The Halcyon Road Complete Streets Plan (“the Plan”) was originally funded with $150,000 of State Highway Account – Sustainable Communities Grant Funding, with a $19,434 local match funding. An additional $82,066 in funding was needed to complete updates to the plan due to changing traffic patterns associated with the closure of atgrade crossings on US Highway 101 and evaluations of alternatives for the intersection of Fair Oaks Avenue and South Halcyon Road, as well as environmental review. The total amount spent to date for this work is $251,500. Funding for the construction phase includes awards of $250,000 in Highway Safety Improvement Program (HSIP) funds, $100,000 in Safe Routes to School Program (SRTS) funds, $750,000 in Community Betterment grant funding through the San Luis Obispo Council of Governments (SLOCOG), and $8.1 million in Active Transportation Program (ATP) funding.

RECOMMENDATION:
1) Adopt a Resolution adopting the Initial Study and Mitigated Negative Declaration in accordance with the applicable provisions of the California Environmental, Public Resources Code Section 21000 et seq.; 2) Approve the Halcyon Road Complete Streets Plan; and 3) Direct staff to complete design and engineering for construction of the Plan, including Alternative 2 identified for the Halcyon/Fair Oaks intersection.

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

BACKGROUND:

Introduction
The City of Arroyo Grande has initiated a project to produce a "complete streets plan" for Halcyon Road, a major urban arterial that provides access within the City connecting US Highway 101 (“US 101”) and State Route 1 (“SR1”). The purpose of the Plan is to develop an improved transportation corridor that provides for safe mobility and accessibility for all users, including bicyclists, pedestrians, transit vehicles, trucks, and motorists. Presently, the Halcyon Road corridor does not provide necessary bicycle accommodations and lacks adequate pedestrian accommodations for safe multimodal transportation.

Challenges to overall safety in the corridor include: unsignalized crossings and intersections with poor visibility; lack of sidewalk connectivity; the absence of bike lanes; unclear or poorly marked lane markings; and high vehicle speeds.

The Plan proposes multimodal transportation enhancements so that all travel modes are accommodated to promote safe and convenient walking and bicycling for residents and visitors alike. This Complete Streets Plan provides a framework within which to further develop specific designs. This document is intended to guide future improvements along the corridor as funds become available.

History of the Plan
The current draft Plan has been prepared by GHD, the City’s hired transportation consultant. The Plan for a complete street for the Halcyon corridor started in 2013 when the City identified improvements that were needed and hired GHD (formerly Omni-Means) to prepare a technical memorandum for a Halcyon Road Corridor Study. This was followed in 2015 with the South Halcyon Corridor Study that identified needed improvements, including sidewalks and landscaping. In 2016, the City received a Caltrans Sustainable Communities Transportation Planning Grant Program that led to the creation of an initial draft Plan. The need for these improvements was reaffirmed in subsequent studies, such as the Circulation Element Update, the Local Road Safety Plan, and the Systemic Safety Analysis Report. A number of initial community meetings were held on the draft plan in 2017. In March 2023, the draft Plan was presented to the City Council for initial review and feedback on the proposed alternatives at the intersection of Fair Oaks Avenue, as well as direction regarding additional public outreach. Based on this direction, a second round of community meetings were held in April 2023. The proposed plan was considered by the Planning Commission on June 20, 2023 and recommended for approval to the City Council.

ANALYSIS OF ISSUES:

Project Setting
The Halcyon Road corridor is a direct regional connector with both local and pass-through traffic. The Halcyon Road corridor provides access to some very significant resources within the City of Arroyo Grande and the adjacent unincorporated areas, including the South County’s only hospital, the Arroyo Grande Community Hospital, the Arroyo Grande

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

Police Department, Harloe Elementary School, and by extension, Arroyo Grande High School located on Fair Oaks Avenue near US 101. In addition, there are numerous commercial, industrial, and residential uses along the corridor. Halcyon Road is also a key facility for transporting agricultural products and farm workers between US 101 and SR 1, serving regional traffic between the Nipomo Mesa and destinations north. Since the closure of the at-grade crossings such as El Campo Road on US 101 south of the City in 2019, Halcyon Road has experienced a significant uptick in traffic from rural Arroyo Grande and Nipomo residents heading north to connect with US 101.

Within the boundaries of the City, the Halcyon Road corridor runs generally north and south between El Camino Real and The Pike and is approximately 1.2 miles long. The character of Halcyon Road changes as it passes through three (3) distinct sections described in more detail below, from a primarily urban area at the north end, past a hospital and an elementary school, and finally through a residential neighborhood area, to the City limits.

Project Goals
 Enhance Safety for All Modes of Travel – Identify circulation improvements that enhance safety for pedestrians, cyclists, and motor vehicles to travel along and across Halcyon Road.
 Improve Multimodal Connectivity – For all age groups, improve multimodal connectivity by closing gaps to complete continuous walkways and bicycle facilities between residences, Harloe Elementary School, Arroyo Grande Community Hospital, parks, and retail destinations.
 Provide Adequate Roadway Capacity for Diverse Travel Needs – Adequate capacity on Halcyon Road needs to be provided for both local and inter-regional travel with intersection controls that promote both safe and efficient travel.  Promote Economic Vitality and Visual Character – Plan Halcyon Road in a way that promotes multimodal travel options, local visual character, vibrant civic space, social interaction and public health that fosters the local economy and creates a place one wants to be.
 Recognize and Address the Urban and Rural Interface – Embrace the diverse urban and rural communities Halcyon Road serves by recognizing the interface with a notable gateway between the two areas this road serves.  Recognize Greenhouse Gas Reduction and Air Quality Benefits – Metrics of the Plan need to include environmental benefits including, but not limited to, reduced use of motor vehicles, reduced traffic congestion and reduced greenhouse gas emissions.
 Engage the Community – Community involvement is essential so that the findings and recommendations in the Plan are drawn from public consensus and reflect the desires of the community.

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

Existing Conditions/Context Zones
The draft plan includes three “Context Zones”, essentially dividing the corridor into three existing sections as follows:
 Context Zone 1: El Camino Real to East Grand Avenue
 Context Zone 2: East Grand Avenue to Fair Oaks Avenue  Context Zone 3: Fair Oaks Avenue to The Pike
Each Context Zone has its own adjacent land uses and roadway characteristics. Context Zone 1 includes the Arroyo Grande Police Station and the Arroyo Grande Cemetery and is characterized by its proximity to US 101. This zone lacks bikes lanes and continuous sidewalk infrastructure and has inconsistent lane configurations through intersections.

Context Zone 2 includes the Arroyo Grande Hospital, commercial, office, and medical offices, and is characterized by speeding, lack of accessible curb ramps, and limited visibility due to on-street parking. Context Zone 3 includes Harloe Elementary and primarily residential land uses, and is characterized by similar issues, including speeding during school hours.

Overall Concepts and Draft Plan Recommendations
Each Context Zone in the draft Plan includes recommended improvements that are tailored specifically to that section based on the existing conditions, parking, land use, and intersecting streets. Some of the terms in the draft Plan, although common in the language of transportation engineers and planners, may be unfamiliar with the general public; therefore, the draft Plan includes a definitions section for many of these terms.

Context Zone 1 improvements generally include:
 One travel lane in each direction;
 Class II buffered bike lanes; and
 All on-street parking removed except for those in front of the Arroyo Grande Police Station.

Context Zone 2 includes a more complicated mix of land uses and sections and therefore includes improvements in three general roadway segments as follows:
 A three-lane section with two travel lanes (one in each direction), a center turn lane, and buffered Class II Bike Lanes with on-street parking southbound between Grand Avenue and Dodson Way. In this section, the southbound bike lane has a buffer area on both sides between the parking for the door zone and between the travel lane.
 A brief section south of Dodson Way has a three-lane segment with a bike lane northbound, and a Class IV parking-protected bike lane southbound. Four on street parking spaces are provided southbound in front of the Arroyo Grande Optometry building at Dodson Way.

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

 The third typical cross-section is between Dodson Way and Fair Oaks Boulevard and also proposes a three-lane segment with two travel lanes, a center turn lane, and Class II Buffered Bike Lanes northbound and southbound, where achievable.

Context Zone 3 improvements generally include:
 Three lanes, with two travel lanes (one in each direction) and a center turn lane;  Class II Buffered Bike lanes where achievable;
 On-street parking along Halcyon Road northbound between Cameron Court and 130’ north of Sandalwood Avenue; and
Fair Oaks Intersection Alternatives
Although the proposed Plan is for the entire Halcyon Street corridor from US 101 to The Pike, special attention has been directed toward the intersection at Fair Oaks Avenue because of the presence of Harloe Elementary School and the Arroyo Grande Hospital on diagonal corners of the intersection. The proposed Plan presents conceptual alternatives for the Fair Oaks intersection based on long-term traffic projections. Each of the alternatives would need to be further refined through design and engineering work to complete the ultimate design of a preferred concept. Over the course of discussion with the consultant, alternatives for a modern roundabout with larger central island and Diameter and traffic signal with additional lanes were considered but ultimately deemed infeasible due to impacts to adjacent properties. In particular, these alternatives required the need to acquire significant right-of-way on at least three corners of the intersection.

Therefore, the proposed Plan includes two tailored alternatives for the intersection of Halcyon Road and Fair Oaks Avenue that recognize the unique land uses and generally stay within the footprint of the existing right-of-way; a traffic signal upgrade with road diet (Alternative 1) and a smaller, compact roundabout concept with mountable center island (Alternative 2).

Alternative 1 – Traffic Signal Upgrade with Road Diet. This concept results in a signalized intersection with the road diet, which is a technique in transportation planning whereby the number of travel lanes and/or effective width of the road is reduced in order to achieve systemic improvements. The concept provides enhanced bicycle and pedestrian facilities while minimizing impacts to existing rights-of-way. The proposed improvements to the intersection include installing green-colored Class II Bike Lanes on all approaches and delineating the bike lane through the intersection with green paint markings. Where right turn lanes are proposed, the Bike Lane would be located to the left of the right turn lane. This type of improvement reduces the risk of collisions between right-turning vehicles and bicyclists. In summary of the traffic operations analysis (page 43 of the draft Plan), the signalized intersection concept is anticipated to have very good access and comfort for bicycles and pedestrians and minimal need for additional right-ofway, but would have longer vehicles queues when compared to Alternative 2) and a Level of Service (LOS) of C/D.

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

Alternative 1 – Traffic Signal Upgrade with Road Diet
Alternative 2 – Compact Roundabout. This concept replaces the existing traffic signal at the intersection with a modern compact roundabout with single entry and exit lanes from all directions, except for the westbound Fair Oaks approach, which proposes a right turn lane and a shared thru/left lane. There would be a single circulating lane around the roundabout. Motorists at the roundabout would be required to yield the right-of-way at crossings to pedestrians and bicyclists. Based on the traffic operations analysis, the compact roundabout concept would also have very good access and comfort for bicycles and pedestrians with a higher safety rating and would result in shorter vehicles queues when compared to Alternative 1 and a Level of Service (LOS) of B/C. This concept would also have limited right-of-way needed but could require some particularly at the northeast corner (Arroyo Grande Community Hospital).

Both alternatives resulted in similar environmental impacts that include necessary mitigation to lessen these impacts to a level of insignificance, including those associated with the short-term construction phase such as dust, emissions, and hazardous materials; potential impacts to cultural resources; and stormwater impacts.

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

Alternative 2 – Compact Roundabout
Cost Estimates vs. Approved Active Transportation Program (ATP) Funding As part of the submitted application for the successful ATP funding, staff included a detailed project estimate and total project costs (see Attachment 5). While it is difficult to forecast construction costs until the project is bid for design and ultimately bid for construction in the upcoming years, several factors should be noted. First, the ATP grant application was submitted in 2022, and therefore already includes some built-in cost escalation that resulted from the recent inflation increases. Second, the grant application included a larger roundabout than the compact roundabout that is included in the revised plan, which could result in some lower costs. Third, the grant included 25% in contingency funding, which could provide some flexibility in addressing cost increases.

As noted above, the cost estimate submitted with the grant application included a roundabout which would be fully funded with the approved grant amount. The cost estimate for the upgraded traffic signal is approximately $2 million less than the roundabout, and so that alternative would also be fully funded.

One option that was supported by both the community and stakeholders (see Community Outreach below) but not factored into the original cost estimate was the addition of protected Class IV bikeways with concrete islands separating the bikeways from vehicular traffic. The original cost estimate included Class II buffered bikeways, which includes a painted separation only with no physical concrete barrier. If approved and as directed by

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

the City Council, staff could include both bikeway options in the scope of work for design and construction.

Community Outreach
During the initial planning stages in 2016 and 2017, various types of outreach and opportunities for community input were provided, including social media, printed media, pop-up workshops, community charrettes, and stakeholder meetings. A Stakeholder Advisory Group was formed to discuss the corridor and provide input on key areas of concern and potential improvements, as well as a website and online survey. Staff also met with and received additional input from residents who expressed concerns about vehicle speeds and turning movements on the Halcyon Road corridor, including a residential group identified as the Halcyon Neighborhood Group.

Following the City Council update on the draft plan on March 14, 2023, staff conducted additional outreach in the form of two public meetings. On April 26, 2023, staff and the consultant conducted a community meeting at Harloe Elementary in the multi-purpose room. Staff sent over 1,500 mailers to the owners and residents surrounding Halcyon Road, and included a flyer on the City’s social media outlets and through the school district’s Peachjar/ParentSquare parent messaging site to publicize the meeting.

The community meeting was well attended with about 30 people, with significant input and discussion. Three primary focus areas were highlighted in the meeting. For the first main focus area, left turns on to South Halcyon from Farroll Avenue, GHD prepared both a restricted left-turn and an open left-turn scenario. GHD’s original analysis showed that the number of left turns on to South Halcyon from Farroll Avenue was approximately 120 during the peak hour, and they determined that if left turns from Farroll Avenue were restricted, this number of vehicles would not be significant if spread to several other routes. However, with the understanding that there were likely neighborhood concerns with restricting left turns, GHD prepared an open left-turn scenario that they were comfortable with from an engineering and safety perspective and presented that at the meeting. This open left-turn option received overwhelming support from the attendees.

The second main focus area was regarding protected bikeways. The proposed plan includes a painted Class II buffer between the bikeways and vehicle lanes in many areas.

However, attendees were also more supportive of a more protected Class IV bikeway in the form of concrete curbs separating the bikeways from vehicular traffic.

The final main focus area was the Fair Oaks intersection with the option of a roundabout or an updated traffic signal. There was healthy discussion of the pros and cons of both, and there was generally more support for the roundabout by about a 2:1 margin. In order to ascertain support, staff had the attendees place different colored stickers representing their level of support for each option. Green stickers represented support for a particular design alternative, while yellow stickers represented community questions regarding the

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

alternative, and red stickers represented concerns or dissatisfaction regarding the design alternative. The results of the sticker exercise are shown in the image below. The majority of attendees were in favor of the proposed roundabout (16 green, 8 red, 1 yellow) over the traffic signal at Fair Oaks Avenue.

The attendees of the community meeting also highlighted that there existed a natural pedestrian route from the Bennett Avenue neighborhood for children going west to attend Ocean View Elementary. The plan was revised to include a crosswalk at the intersection of Bennett Avenue to account for this pedestrian route.

Staff also convened the Stakeholder Advisory Group for a stakeholder meeting on April 27, 2023, also at Harloe Elementary School. Those attending included Rick Ellison from Bike SLO, Jim Dececco from Lucia Mar Unified School District and Safe Routes to School, Councilmember Jim Guthrie, Architectural Review Committee Chair Glenn Martin, and Marsha Lee, a local resident. Ken Dalebout from the Arroyo Grande Hospital was invited as a stakeholder, but attended the previous night’s community meeting instead. Overall, the stakeholder group also generally endorsed an open left-turn concept at Farroll Avenue, protected bikeways, and the roundabout option at the Fair Oaks intersection.

Planning Commission
On June 20, 2023, the Planning Commission held a public hearing to consider the plan.

At that hearing, the Commission recommended to the City Council adoption of the Mitigated Negative Declaration and approval of the Halcyon Road Complete Streets Plan, with support for Alternative 2 (compact roundabout) at the Fair Oaks intersection. Their motion also included support for prioritization of pedestrian and bicycle safety, as well as an emphasis on traffic calming measures.

Funding and Next Steps
The Plan is funded with $150,000 of State Highway Account – Sustainable Communities Grant funding with a $19,434 local match. An additional $82,066 in funding was needed to complete updates to the plan due to changing traffic patterns associated with US 101 closures and evaluations of alternatives for the intersection of Fair Oaks and Halcyon Road, as well as environmental review. The total amount spent for this work is $251,500.

Funding for the construction phase includes awards of $250,000 in Highway Safety Improvement Program (HSIP) funds, $100,000 in Safe Routes to School Program (SRTS) funds, $750,000 in Community Betterment grant funding through SLOCOG, and $8.1 million in Active Transportation Program (ATP) funding. The total estimated budget for this work is $9.2 million.

If the City Council adopts the Mitigated Negative Declaration and approves the Halcyon Road Complete Streets Plan with Alternative 2 (Compact Roundabout), staff will begin the request for design proposals to ensure that the grant schedule is maintained.

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

ALTERNATIVES:

The following alternatives are provided for the Council’s consideration:

1. Adopt the Mitigated Negative Declaration and approve the proposed plan with Alternative 2 – Compact Roundabout;

2. Adopt the Mitigated Negative Declaration and approve the proposed plan with Alternative 1 – Traffic Signal with Road Diet;

3. Do not adopt the Mitigated Negative Declaration and do not approve the proposed plan; or

4. Provide other direction to staff.

ADVANTAGES:

The primary objective and benefit of the Halcyon Road Complete Streets Plan is to provide for safe mobility and accessibility throughout the Halcyon Road corridor, connecting people, schools, the hospital, and businesses by enhancing the built environment for all modes of travel including pedestrians, bicyclists, transit vehicles, trucks, and motorists. The multimodal transportation enhancements can also help to reach the State’s greenhouse gas emission reduction goals. This Plan provides the framework and tools needed to further develop specific designs and provide a complete street along Halcyon Road, ultimately filling sidewalk gaps, installing buffered bike lanes, and implementing a road diet to reduce speeds while also increasing the level of service of the road.

DISADVANTAGES:

Staff time and resources will need to be dedicated to the next steps, including requests for design proposals, right-of-way acquisition, and review of design. Upon construction of improvements associated with the proposed Plan, the acquisition of right-of-way will be needed from two property owners (Arroyo Grande Hospital and Harloe Elementary).

Furthermore, construction activities may impact adjacent businesses and residents.

ENVIRONMENTAL REVIEW:

The Community Development Department, after completion of the initial study, finds that there is substantial evidence that the project would not have a significant effect on the environment, and the preparation of an Environmental Impact Report is not necessary.

Therefore, a Mitigated Negative Declaration (pursuant to Public Resources Code Section 210000 et seq., and CA Code of Regulations Section 15000 et seq.), has been prepared for this project and was published for public review on May 24, 2023. No comments were received during the 30-day review period.

PUBLIC NOTIFICATION AND COMMENTS:

The Agenda was posted at City Hall and on the City’s website in accordance with Government Code Section 54954.2. Additionally, the City provided a courtesy e-mail notice to interested parties who provided their contact information as part of the previous outreach efforts. Staff has conducted significant public outreach on this project, including

Item 11.a.

City Council
Consideration of Approval of the Halcyon Road Complete Streets Plan and Adoption of the Mitigated Negative Declaration
July 25, 2023

workshops in 2017 and community/stakeholder meetings in April 2023. Staff sent over 1,500 mailers to the owners and residents surrounding Halcyon Road for the April 2023 meetings, and included a flyer on the City’s social media outlets and through the school district’s Peachjar/ParentSquare parent messaging site to publicize the meeting.

Attachments:

1. Proposed Resolution

2. Halcyon Road Complete Streets Plan
3 Appendices

4. Mitigated Negative Declaration

5. Cost Estimate – ATP Grant Application 2022

65501.00002\41404558.1
ATTACHMENT 1
RESOLUTION NO.

A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF

ARROYO GRANDE TO ADOPT THE INITIAL STUDY AND

MITIGATED NEGATIVE DECLARATION OF

ENVIRONMENTAL IMPACT REPORT AND APPROVE THE

HALCYON COMPLETE STREETS PLAN
WHEREAS, in 2013, the City of Arroyo Grande’s (“City”) consultant prepared a technical memorandum for a Halcyon Road Corridor Study; and WHEREAS, in 2015 the South Halcyon Corridor Study identified needed improvements to City infrastructure to create a street that can accommodate multi-modal forms of transportation; and
WHEREAS, in 2016 the City received a Caltrans Sustainable Communities Transportation Planning Grant to create a Complete Streets Plan; and WHEREAS, the phrase “Complete Streets” describes a street that is planned, designed, operated, and maintained to provide safe mobility for all users, including bicyclists, pedestrians, transit vehicles, truckers, and motorists, appropriate to the street’s function and context; and
WHEREAS, the City’s Circulation Element of the General Plan includes goals, policies, and objectives that support the Halcyon Complete Streets Plan and are consistent with AB 1358, known as “The California Complete Streets Act”; and WHEREAS, the City developed the Halcyon Road Complete Streets Plan to provide for safe mobility and accessibility for all users throughout the Halcyon Road corridor, including bicyclists, pedestrians, transit vehicles, trucks, and motorists (“Project”); and
WHEREAS, pursuant to the California Environmental Quality Act (Public Resources Code, § 21000 et seq.), the State CEQA Guidelines (California Code of Regulations, title 14, § 15000 et seq.), and the City’s Local CEQA Guidelines (collectively, “CEQA”), the City is the lead agency for the proposed Project; and WHEREAS, in April 2023, in compliance with State CEQA Guidelines section 15063, an Initial Study (IS) was prepared for the Project to analyze whether the Project may cause a potentially significant effect on the environment; and WHEREAS, based on the information contained in the Initial Study, which concluded that the Project could have potentially significant impacts but that those impacts could be reduced to less than significant levels with implementation of the proposed mitigation measures, the Planning Commission determined that a Mitigated

RESOLUTION NO.

PAGE 2
Negative Declaration (“MND”) should be prepared for the Project, and a MND was prepared pursuant to CEQA; and
WHEREAS, on June 27, 2023, the Planning Commission conducted a duly noticed public hearing to consider the staff report, recommendations by staff, and public testimony concerning the Halcyon Road Complete Streets Plan. Following the public hearing, the Planning Commission voted to forward the Halcyon Road Complete Streets Plan to the City Council with a recommendation in favor of its adoption; and WHEREAS, on July 25, 2023, the City Council conducted a duly noticed public hearing to consider the Halcyon Road Complete Streets Plan, including: (1) the public testimony and agenda reports prepared in connection with the Halcyon Road Complete Streets Plan; (2) the policy considerations discussed therein; and (3) the consideration and recommendation of the Planning Commission; and
WHEREAS, the City Council of the City of Arroyo Grande, at its regularly scheduled public meeting on July 25, 2023 adopted the Mitigated Negative Declaration and approved the Halcyon Road Complete Streets Plan; and NOW, THEREFORE, BE IT RESOLVED that the City Council of the City of Arroyo Grande hereby adopts a Resolution to adopt the Initial Study and Mitigated Negative Declaration of Environmental Impact Report and approve the Halcyon Road Complete Streets Plan as attached hereto as Exhibit “A” and incorporated herein by this reference.

On motion by Council Member ________, seconded by Council Member _______, and by the following roll call vote, to wit:

AYES:

NOES:

ABSENT:
the foregoing Resolution was adopted this 25
th day of July, 2023.

RESOLUTION NO.

PAGE 3
________________________________

CAREN RAY RUSSOM, MAYOR
ATTEST:

JESSICA MATSON, CITY CLERK
APPROVED AS TO CONTENT:
_________________________________

WHITNEY MCDONALD, CITY MANAGER
APPROVED AS TO FORM:
_________________________________

ISAAC ROSEN, CITY ATTORNEY

COMPLETE STREET PLAN
Made Possible Through Caltrans Sustainable Communi
Ɵes Transporta
Ɵon Planning Grant Program
Final
‐ June 20, 2023
ATTACHMENT 2

THIS PAGE IS INTENTIONALLY LEFT BLANK

page i

TABLE OF CONTENTS

ACKNOWLEDGEMENTS

CITY COUNCIL
Caren Ray Russom, Mayor
Kristen Barneich, Mayor Pro Tem
Lan George
Jim Guthrie
Kate Secrest

PLANNING COMMISSION
Jamie Maraviglia
Bruce Berlin
Cathy Sackrison
Kevin Buchanan
Virginia Roof

CITY STAFF
Whitney McDonald, City Manager
Bill Robeson, Assistant City Manager/Director of Public Works Brian Pedrotti, Community Development Director
Andrew Perez, Planning Manager
Jill McPeek, CIP Manager

TABLE OF CONTENTS
EXECUTIVE SUMMARY................................................................................................................1

1. INTRODUCTION ......................................................................................................................2 Project Setting.....................................................................................................................3 Project Challenges...............................................................................................................3 Project Goals.......................................................................................................................3 Current Policy and Planning Documents.............................................................................4

2. EXISTING CONDITIONS............................................................................................................5 Speeds.................................................................................................................................5 Context Zones.....................................................................................................................5 Environmental Conditions and Potential Constraints..........................................................9 Existing Traffic Characteristics.............................................................................................9 Existing Traffic Conditions & Analysis..................................................................................9 Existing Conditions Analysis Summary .............................................................................. 18

3. COMMUNITY PARTICIPATION............................................................................................... 19 Public Outreach Participation Plan.................................................................................... 19 Stakeholder Participation.................................................................................................. 19 Pop-Up Outreach Survey................................................................................................... 20 Community Charrettes...................................................................................................... 20 Social Media and Online Engagement............................................................................... 22 2022 Outreach: Neighborhood Group .............................................................................. 24

4. COMPLETE STREETS ELEMENTS............................................................................................. 25 Type of Complete Streets Elements ................................................................................. 25

5. ALTERNATIVES ANALYSIS & PLAN RECOMMENDATIONS ....................................................... 29 CONTEXT ZONE 1: URBAN (EL CAMINO REAL TO E. GRAND AVENUE.)............................. 30 CONTEXT ZONE 2: URBAN TRANSITION (E. GRAND AVENUE. TO FAIR OAKS AVENUE.) ... 32 CONTEXT ZONE 3: NEIGHBORHOOD (FAIR OAKS AVENUE. TO THE PIKE)......................... 34 PARKING............................................................................................................................ 36 FUTURE TRAFFIC OPERATIONS ANALYSIS & ALTERNATIVES COMPARISON...................... 37 TRAFFIC OPERATIONS ANALYSIS ....................................................................................... 42 PROTECTED BIKEWAY OPTION.......................................................................................... 44 BICYCLE LTS ANALYSIS....................................................................................................... 46 LIFE-CYCLE BENEFIT/COST ANALYSIS................................................................................. 47 ALTERNATIVES ANALYSIS SUMMARY ................................................................................ 48

6. COSTS & FUNDING OPPORTUNITIES ..................................................................................... 50 Phasing Potential............................................................................................................... 50 Funding Opportunities...................................................................................................... 50 Federal Funding Programs ................................................................................................ 50 State Funding Programs.................................................................................................... 51 Developer In-Kind Contributions....................................................................................... 52 Additional Grant Programs................................................................................................ 52 APPENDIX A – CURRENT POLICY & PLANNING DOCUMENTS
APPENDIX B – POTENTIAL ENVIRONMENTAL CONSTRAINTS
APPENDIX C— ENVIRONMENTAL CONSTRAINTS (UPDATED)
APPENDIX D—EXISTING CONDITIONS ANALYSIS MEMORANDUM
APPENDIX E— BICYCLE LTS ANALYSIS
APPENDIX F— OUTREACH MEMORANDUM
APPENDIX G—COST ESTIMATES
Made Possible Through Sustainable Communities Transportation Planning Grant Program (Caltrans)

THIS PAGE IS INTENTIONALLY LEFT BLANK

Complete Streets Plan Page 1

EXECUTIVE SUMMARY
Executive Summary
Local and State transportation policy has progressed from planning and designing almost solely for the movement of motorized vehicles, to a collective focus on the movement of people and goods. Complete streets policy and design exemplifies this paradigm shift by recognizing that not all people travel by car, and that land use affects how the street is used and how the street should function as a whole.

The objective of the Halcyon Road Complete Streets Plan is to provide for safe mobility and accessibility, throughout the Halcyon Road corridor, connecting people, schools, the hospital, and businesses by enhancing the built environment for all modes of travel including pedestrians, bicyclists, transit vehicles, trucks, and motorists. This objective is parallel to the mission of the California Department of Transportation (Caltrans):

Provide a safe, sustainable, integrated and efficient transportation system to enhance California’s economy and livability.

The Plan proposes multimodal transportation enhancements so that all travel modes are accommodated, and will promote safe and convenient walking and bicycling for residents and visitors alike. The multimodal transportation enhancements can also help to reach the State’s greenhouse gas emission reduction goals. This Plan provides the framework and tools needed to further develop specific designs and provide a complete street along Halcyon Road.

Table ES-1 describes the issues that are currently present and the proposed multimodal improvements detailed in this Plan, for each of the three Context Zones.

In addition to filling in the sidewalk gaps, installing buffered bike lanes or separated bikeways where feasible, and implementing a road diet, the Plan evaluates two alternative improvements at Halcyon Road and Fair Oaks Avenue: an upgraded traffic signal with enhanced bicycle facilities, or a roundabout. These enhancements are projected to provide safer travel for all travel modes at both the intersections and the adjacent roadway segments.

The roundabout will provide adequate capacity for the diverse travel needs of the corridor, and improve intersection efficiency, which will in turn discourage cut-through traffic on Todd and Olive Streets. The upgraded traffic signal will also greatly enhance pedestrian and bicycle access and safety through the intersection. Either the upgraded traffic signal or the roundabout will significantly enhance safety and improve multimodal connectivity for all roadway users while maintaining the urban/suburban interface.

Context Zone
(see page 9 Figure) Existing Conditions and Issues Proposed Multimodal Improvements 1: Urban (El
Camino Real to
East Grand
Avenue)
 Lack of continuous and adequate
sidewalks,
 Difficulty in effectively accessing transit
and park and ride facilities,
 Proximity to US 101,
 Inconsistent lane configurations
through intersections, and
 Poor traffic signal timing.
 Class II Buffered Bike Lanes on both sides (except southbound approaching E. Grand Avenue will be a Bike Route),
 Bike Box for left turning cyclists at El Camino Real,  Green Pavement treatment in conflict zones,
 Complete sidewalk connectivity on northbound side, and  Install curb ramps at Bennett Avenue.
2: Urban
Transition (East
Grand Avenue to
Fair Oaks
Avenue)
 Poor traffic signal timings,
 Speeding,
 Lack of accessible curb ramps,
 Poor crosswalk visibility,
 Narrow and degraded sidewalks,
 Limited visibility caused by on-street
parking, and
 Inconsistent or confusing lane
configurations
 No bicycle facilities are available
 A brief four-lane section with striped Class II Bike Lanes between E. Grand Avenue and 150’ south of Park Way,
 Transitions to a three-lane segment with two travel lanes and a center turn lane,  A Class II Buffered Bike Lane northbound, a striped Class II Bike Lane southbound, and onstreet parking southbound,  Four on-street parking spaces are provided southbound in front of the Arroyo Grande Optometry building at Dodson Way,
 Class IV Separated Bikeway is provided from Dodson Way to approximately 130’ feet south, in between the sidewalk and the parking zone, via a separated landscaped median,  Class IV Separated Bikeway is provided northbound, with a separated landscaped median, from the main hospital driveway to approximately 120’ north,  Green pavement treatment provided in the conflict zones,  Marked Crosswalk on north side of intersection at Dodson Way, and  Curb extensions are proposed at all corners of the Dodson Way intersection, and  Additional improvements to Farroll Avenue and Halcyon Road 3: Neighborhood
(Fair Oaks
Avenue to The
Pike)
 Speeding, especially during school
hours,
 Lack of continuous sidewalk and
accessible curb ramps,
 Limited visibility caused by on-street
parking, inconsistent or confusing lane
configurations, and
 Poor crosswalk visibility
 No bicycle facilities are available
 At Halcyon Road and Fair Oaks Avenue, either upgrade the traffic signal with enhanced bike facilities, a leading pedestrian interval, and signal timing and lane configuration adjustments, or install a single-lane modern roundabout with a dedicated right turn lane westbound. The proposed roundabout will provide bike ramps for all approaches leading to a multi-use path, for both pedestrians and bicyclists to navigate the roundabout, as well as shared lane markings for cyclists within the roundabout, improving safety for all.  Three-lane cross-section with two travel lanes, a center turn lane,  On-street parking is provided along Halcyon Road northbound between Cameron Court and 130’ north of Sandalwood Avenue,
 Install all-way stop control at Halcyon Road and The Pike,  Class II Buffered Bike Lanes are proposed for both sides of Halcyon Road between Fair Oaks Avenue and Olive Street, and between Sandalwood Avenue and The Pike,  Northbound, a Class IV Separated Bikeway from Farroll Avenue to 130 feet north,  Southbound, a dedicated Bike Lane between the through lane and the right turn lane at Farroll Avenue. Green pavement treatment provided in the conflict zones,  A new two-stage crossing on the north side of Sycamore Drive, with a refuge island,  A continuous 6-foot wide sidewalk on the east side of Halcyon Road from The Pike to Willow Lane, and a 7-foot wide sidewalk from Willow Lane to Cameron Court, and  Curb Extensions and new curb ramps at various locations.

Table ES-1: Summary of Issues and Improvements by Context Zone

1. INTRODUCTION
Complete Streets Plan
The concepts and recommendations within the Plan are
based on community input obtained from multiple
workshops, extensive in-person and online surveys,
comprehensive meetings with stakeholders, as well as
from the review of existing plans, policies and programs that support walking, biking, driving, and overall
community livability and sustainability.

The Plan:
 Evaluates existing and forecasted vehicular and
multimodal operations,
 Uses available Geographic Information System (GIS)
data, right of way data and aerial imagery mapping,
and
 May require comprehensive topographic, boundary
surveys, and operational analysis to implement
specific improvements.

1. INTRODUCTION
The City of Arroyo Grande has initiated a project to
produce a "Complete Streets Plan" (Plan) for Halcyon
Road. Halcyon Road serves as a major urban arterial for the City providing access between US Route 101 (US
101) and State Route (SR) 1. Halcyon Road connects the
urbanized City of Arroyo Grande to the unincorporated
rural Nipomo Mesa. The Halcyon Road corridor runs
generally north-south and is approximately 1.7 miles
long. The character of Halcyon Road changes as it
passes through three (3) distinct Context Zones, from a primarily urban area at the north end, past a hospital
and an elementary school, and finally through a
neighborhood area, to the City limits. This project is
funded in large part by the Caltrans Sustainable
Communities Transportation Planning Grant Program.

Presently, the Halcyon Road corridor does not provide
necessary bicycle accommodations and lacks adequate
pedestrian accommodations. Unsignalized crossings and
intersections with poor visibility, lack of sidewalk
connectivity, the absence of bike lanes, unclear or
poorly marked lane markings, and high vehicle speeds
present challenges to overall corridor safety.

THE PIKE

FAIR OAKS AVENUE
The purpose of the Plan is to develop an improved
transportation corridor that provides for safe mobility and accessibility for all users, including bicyclists,
pedestrians, transit vehicles, trucks, and motorists.

The Plan proposes transportation enhancements so
that all travel modes are accommodated, and will
promote safe and convenient walking and bicycling for
residents and visitors alike.

This Complete Streets Plan provides a framework
within which to further develop specific designs. This
document is intended to guide future improvements
along the corridor as funds become available.

HALCYON ROAD HALCYON ROAD
Arroyo Grande
Community Hospital
Arroyo Grande
Police Department
Harloe Elementary
School
Arroyo Grande
High School

Complete Streets Plan Page 3

1. INTRODUCTION
Project Goals
Recognizing the unique and diverse character and needs of the Halcyon Road corridor, the following specific Project Goals have been identified as follows:
 Enhance Safety for All Modes of Travel - Identify circulation improvements that enhance safety for pedestrians, cyclists, and motor vehicles to travel along and across Halcyon Road.  Improve Multimodal Connectivity - For all age groups, improve multimodal connectivity by closing gaps to complete continuous walkways and bicycle facilities between residences, Harloe Elementary School, Arroyo Grande Community Hospital, parks and retail destinations.
 Provide Adequate Roadway Capacity for Diverse Travel Needs - Adequate capacity on Halcyon Road needs to be provided for both local and inter-regional travel with intersection controls that promote both safe and efficient travel.
 Promote Economic Vitality and Visual Character - Plan Halcyon Road in a way that promotes multimodal travel options, local visual character, vibrant civic space, social interaction and public health that fosters the local economy and creates a place one wants to be.  Recognize and Address the Urban and Rural Interface - Embrace the Project Challenges
Given its importance to the City and region, Halcyon Road remains disjointed and dated in terms of the transportation utility it provides.

Halcyon Road currently has an assortment of travel lane and on-street parking configurations. There are no dedicated bike lanes within the corridor and cyclists compete with motorists for the traveled way. With only three signalized intersections in the corridor, pedestrians have a difficult time navigating safely across the facility, and the public has expressed concerns about the excessive speeds of the motorized vehicles using the corridor. In addition to the crossing difficulties, an incomplete sidewalk system makes walking along the corridor an uncomfortable and unattractive alternative.

It is critical to bring the Halcyon Road corridor up to a standard that will encourage Harloe Elementary school children, Arroyo Grande High School students, hospital employees, and residents to walk, ride their bikes, or take transit; ultimately improving the local economy and the overall livability of the corridor while maintaining the special rural town site of old Halcyon. Distinctive transitions will remain between the adjacent land uses along Halcyon Road, and "Gateway" treatments could be utilized to give all users a sense of entering a special place regardless of the direction they are traveling on Halcyon Road.

Project Setting
Halcyon Road is located in the southern part of the City of Arroyo Grande, which is approximately 15 miles south of the City of San Luis Obispo. The Halcyon Road corridor is a direct regional connector with a varied user base of local and through traffic. The Halcyon Road corridor provides access to some very significant resources within the City of Arroyo Grande and the adjacent unincorporated areas. It serves as primary access to the South County's only hospital, the Arroyo Grande Community Hospital, that averages over 2,000 patients monthly. In addition to providing patient care, the hospital is the major job center for the community. Halcyon Road provides primary access to Harloe Elementary School, and by extension, the high school located on Fair Oaks Avenue near US 101. In addition to these major traffic generators, there are numerous commercial, industrial, and residential uses along the corridor. Halcyon Road is also a key facility for transporting a vast array of agricultural products and farm workers between US 101 and SR 1, serving regional traffic between the Nipomo Mesa and destinations north. The corridor has evolved over several decades in an attempt to perform many functions. Based on US Census Bureau data, population within Arroyo Grande has increased from 17,252 in 2010, to 18,441 in 2020 (0.69% per year). This growth is consistent with San Luis Obispo County’s population growth of 0.53% per year between 2010 and 2019.

Project Location
Halcyon Road provides access to schools, the hospital, and commercial uses Halcyon Road

1. INTRODUCTION
Complete Streets Plan
diverse urban and rural communities Halcyon Road serves by recognizing the interface with a notable gateway between the two areas this road serves.
 Recognize Greenhouse Gas Reduction and Air Quality BenefitsMetrics of the Plan need to include environmental benefits including, but not limited to, reduced use of motor vehicles, reduced traffic congestion and reduced greenhouse gases.
 Engage the Community – Community involvement is essential so that the findings and recommendations in the Plan are drawn from public consensus and reflect the desires of the community.

In addition to these project specific goals, this effort also recognizes and strives to achieve both the State Transportation Planning Goals and the Federal Transportation Planning Goals as required by the Caltrans Sustainable Transportation Planning Grant Program, which has been a large funding source for this effort.

Current Policy and Planning Documents
This section lists current policies and planning documents that guide or regulate transportation planning decisions related to Complete Streets.

The Plan aims to align its recommendations with these available documents. Descriptions for each of the documents are provided in Appendix A. To the extent feasible, the following documents were referenced for this study:
 South Halcyon Road Corridor Study
 City of Arroyo Grande Circulation Element (updated 2021)  City of Arroyo Grande Multimodal Traffic Impact Study Guidelines (updated 2021)
 County of San Luis Obispo General Plan
 2015/16 County Bikeways Plan
 SLOCOG Regional Transportation Plan (RTP)/Sustainable Communities Strategy (SCS): Connecting Communities
 City of Arroyo Grande Climate Action Plan
 California AB 1358 - Complete Streets Act
 City of Arroyo Grande Bicycle and Trails Master Plan
 Urban Bikeways Design Guide, 2nd Edition, NACTO
 Urban Streets Design Guide, NACTO
 California AB 32
 Main Street, California: A Guide for Improving Community and Transportation Vitality, 2003
 Complete Streets Implementation Action Plan 2.0 (CSIAP 2.0), June 2014 - June 2017
 Safe Routes to School
 City of Arroyo Grande 2018 Citywide Engineering and Traffic Survey

Complete Streets Plan Page 5

2. EXISTING CONDITIONS

2. EXISTING CONDITIONS
This section summarizes the existing multimodal transportation conditions for the Halcyon Road corridor and identifies deficiencies in relation to Complete Streets and multimodal circulation priorities. Multimodal refers to all modes of transportation including vehicular, pedestrian, bicycle, and transit.

Speeds
At the junction of US 101/El Camino Real, the speed limit on Halcyon Road is 35 mph. It increases to 40 mph south of Dodson Way with a school zone speed limit of 25 mph beginning just north of Fair Oaks Avenue and ending just north of Sandalwood Avenue.

Context Zones
For the purposes of this Plan, the study corridor is divided into three (3) distinct Context Zones to illustrate the changes in adjacent land uses and roadway characteristics along the corridor.

This Plan will evaluate the Halcyon Road corridor relative to each segment’s context. The three distinct Context Zones of the study corridor are discussed in detail.

Halcyon Road Context Zones
 Context Zone 1: Urban
 US 101/El Camino Real to East Grand Avenue
 Context Zone 2: Urban Transition
 East Grand Avenue to Fair Oaks Avenue
 Context Zone 3: Neighborhood
 Fair Oaks Avenue to The Pike

2. EXISTING CONDITIONS
Complete Streets Plan
Context Zone 1: El Camino Real to East Grand Avenue
Halcyon Road through Context Zone 1 is approximately 0.3 miles long and passes through a primarily urban area. This urban Context Zone is predominantly developed with urban uses oriented toward El Camino Real and East Grand Avenue, both of which provide critical access to important commercial and retail areas of the City of Arroyo Grande. City of Arroyo Grande (City) land use and zoning designations within this zone include:
 General Plan Land Use Designations
 Community Facilities
 Mixed Use
 Single-Family Residential - Medium Density
 Zoning Designations
 Public Facility
 Highway Mixed Use
 Fair Oaks Mixed Use
 Single-Family
Existing uses include commercial, residential, retail, and notable public facilities, including churches, the Arroyo Grande Cemetery, and the Arroyo Grande Police Department. The urban Context Zone also includes mature trees and landscaping adjacent to the existing roadway, as well as existing overhead utility lines, signage, street lighting, fencing, and other infrastructure.

The City and Caltrans are currently considering modifications to the Brisco -Halcyon Road/US 101 Interchange within this Context Zone to provide congestion relief, alleviate queuing, and improve the traffic operations of the regional and local street system in the vicinity of US 101 in Arroyo Grande. Modifications proposed within the urban Context Zone boundary include re-striping and lane reconfiguration at the Brisco Road/US 101 undercrossing, the Brisco Road/El Camino Real intersection, and along the eastbound and westbound El Camino Real approaches to the Brisco Road/ El Camino Real intersection. There is also an existing Park and Ride lot immediately adjacent to the urban Context Zone, approximately 200 feet east of the Halcyon Road/El Camino Real/US 101 southbound ramps intersection.

Speeds and Right-of-Way
The posted speed limit is 35 miles per hour (mph). The right of way in this zone is approximately 60 feet with a street width varying from 38 to 48.5 feet. There is one travel lane in each direction with on-street parking allowed on approximately 25% of the curb face, and 20 access points.

No designated bike lanes are provided. Sidewalk varying from 5 to 10 feet in width exists on both sides of the street; sidewalk is continuous southbound, however, there are gaps in the connectivity in the northbound direction.

Issues in Context Zone 1 include:
 Lack of continuous and adequate sidewalks,
 Difficulty in effectively accessing transit and park and ride facilities,  Proximity to US 101,
 Inconsistent lane configurations through intersections, and  Poor traffic signal timing.

Due to the adjacent Arroyo Grande Cemetery along much of the northern part of the street in this Context Zone, expansion of the right of way to accommodate additional modal improvements is limited.

Context Zone 1: No Bicycle Facility Designations
Context Zone 1: Gaps in Continuous Sidewalks

Complete Streets Plan Page 7

2. EXISTING CONDITIONS
Context Zone 2: East Grand Avenue to Fair Oaks Avenue
Halcyon Road through Context Zone 2 is approximately 0.4 miles long and transitions from an urban area to a residential area. This urban transition Context Zone is predominantly developed with urban uses with few residential driveways having direct access to Halcyon Road, with direct access to parking lots for local commercial, office, and medical businesses.

City land use and zoning designations within this zone include:
 General Plan Land Use Designations
 Mixed Use
 Office Professional
 Single-Family Residential - Medium Density
 Multi-Family Residential - High Density
 Multi-Family Residential - Very High Density
 Zoning Designations
 Fair Oaks Mixed Use
 Office Mixed Use
 Single-Family
 Multi-Family
Existing uses include commercial, residential, retail, and public facilities, and notable land uses within this zone include the Arroyo Grande Community Hospital and other medical offices. The urban transition Context Zone also includes mature trees and landscaping adjacent to the existing roadway, as well as existing overhead utility lines, signage, street lighting, fencing, and other infrastructure.

A marked pedestrian crossing is located at the side-street stop-controlled intersection of Halcyon Road and Dodson Way.

Speeds and Right-of-Way
Consistent with the recommended speed noted in the 2018 Citywide Engineering and Traffic Survey, the posted speed limit is 35 mph south of East Grand Avenue and transitions to 40 mph south of Dodson Way, with a school zone speed limit of 25 mph in the vicinity of Harloe Elementary School, which extends north of Fair Oaks Avenue.

The right of way in this zone is approximately 80 feet with a street width varying from 63 to 64.5 feet. Two lanes in each direction are provided, with a center Two-Way Left-Turn Lane (TWLTL) from approximately 350 feet south of Dodson Way to Fair Oaks Avenue where it becomes an exclusive southbound left-turn lane. On-street parking is allowed on the west side of Halcyon Road north of the end of the TWLTL to Dodson Way, and then on both sides of the street north of Dodson Way. North of Park Way, on-street parking is allowed on the west side of the street only.

No bike lanes are provided. Continuous sidewalks exist on both sides of the street, which vary in width from 5 to 7 feet.

Issues in Context Zone 2 include:
 Poor traffic signal timings,
 Speeding,
 Lack of accessible curb ramps,
 Poor crosswalk visibility,
 Narrow and degraded sidewalks,
 Limited visibility caused by on-street parking, and
 Inconsistent or confusing lane configurations
Context Zone 2: No Current Room for Bicycles
Context Zone 2: Crosswalk at East Grand Avenue

2. EXISTING CONDITIONS
Complete Streets Plan
Context Zone 3: Fair Oaks Avenue to The Pike
Halcyon Road in Context Zone 3 is approximately 0.44 miles long and passes through a neighborhood area. This neighborhood Context Zone is predominantly developed with single-Family residences between Fair Oaks Drive and the southern City limits. This Context Zone also includes a small area of existing mobile homes within a portion of unincorporated San Luis Obispo County, at the northeast corner of Halcyon Road and the southern City limits of Arroyo Grande (i.e., The Pike). City and County of San Luis Obispo (County) land use designations and City zoning designations within this zone are listed below.
 General Plan Land Use Designations
 Community Facilities
 Single-Family Residential - Medium Density
 Zoning Designations
 Public Facility
 Single-Family
 San Luis Obispo County Land Use Designations
 Residential Multi-Family
Notable land uses within this zone include Harloe Elementary School and the school fields at the northern end of the zone. The neighborhood Context Zone also includes mature trees and landscaping adjacent to the existing roadway, as well as existing utility lines, signage, street lighting, fencing, and other infrastructure.

Speeds and Right-of-Way
Consistent with the recommended speed noted in the 2018 Citywide Engineering and Traffic Survey, the posted speed limit is 40 mph with a school zone speed limit of 25 mph in the vicinity of Harloe Elementary School. A marked yellow pedestrian crossing with rectangular rapid flashing beacons is located at the side-street stop-controlled intersection of Halcyon Road and Sandalwood Avenue, south of the elementary school.

The right of way in this zone is approximately 80 feet with a street width varying from 52 (South of Cameron Court) to 64 feet (North of Cameron Court). There are two travel lanes in each direction with a TWLTL until just south of Olive Street and then the street transitions to one travel lane in each direction with a TWLTL. No designated bike lanes are provided. A continuous sidewalk of width varying from 5 to 7 feet is provided on both sides of the street except between The Pike and Cameron Court where no sidewalk exists on the east side of the street.

Issues in Context Zone 3 include:
 Speeding, especially during school hours,
 Lack of continuous sidewalk and accessible curb ramps,  Limited visibility caused by on-street parking, inconsistent or confusing lane configurations, and
 Poor crosswalk visibility
Context Zone 3: Wide Road with Long School Crosswalk
Context Zone 3: No Current Room for Bicycles
Context Zone 3: Speeding is a Concern
Halcyon Road

Complete Streets Plan Page 9

2. EXISTING CONDITIONS
Environmental Conditions and Potential
Constraints
Potential environmental constraints associated with project development are summarized in Appendix B based on a memorandum by SWCA Environmental Consultants dated September 7, 2016 and updated on [CITY TO PROVIDE DATE] (provided in Appendix C).

Existing Traffic Characteristics
Table 1 presents the existing mode of travel split, based on the 2015-2019 American Community Survey five-year estimates for Means of Transportation to Work by Selected Characteristics, and compares the commuting patterns of Arroyo Grande to the adjacent cities of Grover Beach and Oceano, San Luis Obispo County, California statewide, and nationwide. The commuting patterns within Arroyo Grande present how residents currently travel to work. Although commute patterns may also be correlated to commute times and distances to work, travel between non-work related trips will vary by mode.

As shown in Table 1 and the Chart to the right, the City of Arroyo Grande’s commute patterns reflect similar commute patterns to the adjacent cities and San Luis Obispo County, but with a lower amount of people carpooling to work or using public transportation. Statistics for the bicycle mode were grouped with taxicab, motorcycle, or other means of travel.

Overall, these statistics indicate a consistent trend of a large percentage of commuters driving alone and more people working at home than using other modes of transportation besides car, truck, or van. The average travel time to work is also relatively consistent with the adjacent cities and San Luis Obispo County. The travel times between Arroyo Grande and the City of San Luis Obispo are typically 20-30 minutes in the PM peak period during the weekday via US 101. This same route would take approximately one hour via public transit (San Luis Obispo Regional Transit Authority).

Existing Traffic Conditions & Analysis
An analysis of the existing traffic conditions was performed for the corridor to evaluate traffic volumes, existing capacity and deficiencies, LOS, and collision history. Along the Halcyon Road corridor, 11 key intersections, three of which are signalized intersections, and eight roadway segments were selected for the analysis. The technical parameters, methodologies, and results detailing existing multimodal intersection analysis including LOS tables are contained in the Existing Conditions Analysis Memorandum, included in Appendix D. An updated analysis is also provided separately, in the Existing Conditions Background Report (November 2020, GHD), prepared during the update of the City Circulation Element.

Existing weekday AM and PM peak hour traffic volume counts were collected for the corridor in September 2014, September 2016, and November 2019. The AM peak hour is defined between 7:00 am and 9:00 am while the PM peak hour is defined between 4:00 pm and 6:00 pm on a typical weekday with school in session. The following eight intersections were analyzed under existing weekday AM and PM peak hour conditions:
 Halcyon Road/El Camino Real
 Halcyon Road/Bennett Avenue
 Halcyon Road/East Grand Avenue
 Halcyon Road/Dodson Way
 Halcyon Road/Farroll Avenue
 Halcyon Road/Fair Oaks Avenue
 Halcyon Road/Sycamore Drive
 Halcyon Road/The Pike
In addition, Average Daily Traffic (ADT) volumes were collected for the eight study segments along the corridor. The following eight study roadway segments were analyzed under existing daily conditions:
 Between El Camino Real and Bennett Avenue
 Between Bennett Avenue and East Grand Avenue
 Between East Grand Avenue and Dodson Way
 Between Dodson Way and Fair Oaks Avenue
 Between Fair Oaks Avenue and Farroll Avenue
 Between Farroll Avenue and Sycamore Drive
Existing Mode of Travel Split
2019 Means of
Transportation to
Work
Arroyo Grande
Grover Beach
Oceano
San Luis Obispo
County
California
United States
Car, Truck, or Van 88.4% 85.0% 92.4% 84.7% 84.0% 85.5%
Drove Alone 74.5% 69.9% 81.5% 74.0% 73.7% 76.4%
Carpooled 14.0% 15.1% 10.9% 10.7% 10.3% 9.1%
Public Transportation 0.7% 2.0% 1.3% 1.2% 5.1% 5.0%
Walked 2.1% 3.7% 2.4% 4.3% 2.7% 2.7%
Bicycle, Taxicab,
Motorcycle, or Other 1.8% 2.5% 3.7% 3.0% 2.6% 1.8%
Worked from Home 7.1% 6.7% 0.3% 6.7% 5.7% 4.9%
Total Workers 16
years+:
8,529 6,768 3,458 128,339 17,904,213 150,571,044
Travel time to work
(minutes): 22.7 20.5 23.4 22.2 29.3 26.6
Source: U.S. Census American Community Survey 5-year estimates 2015-2019 Table 1: Existing Modal Split