SC 08-15-19 PacketCITY OF CUPERTINO
SUSTAINABILITY COMMISSION
AGENDA
Environmental Education Center, 22221 McClellan Road
Thursday, August 15, 2019
4:00 PM
Special Meeting
NOTICE AND CALL FOR A SPECIAL MEETING OF THE CUPERTINO
SUSTAINABILITY COMMISSION
NOTICE IS HEREBY GIVEN that a special meeting of the Sustainability Commission is hereby
called for Thursday, August 15, 2019 commencing at 4:00 p.m. in Environmental Education Center, 22221
McClellan Road, McClellan Ranch Preserve, California 95014. Said special meeting shall be for the purpose
of conducting business on the subject matters listed below under the heading, “Special Meeting."
SPECIAL MEETING
PLEDGE OF ALLEGIANCE
ROLL CALL
APPROVAL OF MINUTES
1.Subject: Minutes from July 18, 2019
Recommended Action: Approve minutes from July 18, 2019
A - Draft Minutes
POSTPONEMENTS
ORAL COMMUNICATIONS
This portion of the meeting is reserved for persons wishing to address the commission on any matter not
on the agenda. Speakers are limited to three (3) minutes. In most cases, State law will prohibit the
commission from making any decisions with respect to a matter not listed on the agenda
WRITTEN COMMUNICATIONS
OLD BUSINESS
2.Subject: Sustainability Speaker Series Subcommittee update and planning for Zero
Waste event
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Sustainability Commission Agenda August 15, 2019
NEW BUSINESS
3.Subject: Presentation from City staff and consultant on Green Stormwater
Infrastructure (GSI) and the City's Municipal Regional Permit (MRP) requirement to
adopt a long term GSI Plan
A - Cupertino Green Stormater Infrastructure Draft Plan
4.Subject: Update from Public Works staff on Household Hazardous Waste Program
5.Subject: Fall Festival tabling planning
6.Subject: Student Green Grants project planning
STAFF AND COMMISSION REPORTS
ADJOURNMENT
In compliance with the Americans with Disabilities Act (ADA), anyone who is planning to attend the
next meeting who is visually or hearing impaired or has any disability that needs special assistance
should call the City Clerk's Office at 408-777-3223, 48 hours in advance of the meeting to arrange for
assistance. Upon request, in advance, by a person with a disability, meeting agendas and writings
distributed for the meeting that are public records will be made available in the appropriate alternative
format. Also upon request, in advance, an assistive listening device can be made available for use
during the meeting.
Any writings or documents provided to a majority of the members after publication of the agenda will
be made available for public inspection. Please contact the City Clerk’s Office in City Hall located at
10300 Torre Avenue during normal business hours.
IMPORTANT NOTICE: Please be advised that pursuant to Cupertino Municipal Code 2.08.100
written communications sent to the Cupertino City Council, Commissioners or City staff concerning a
matter on the agenda are included as supplemental material to the agendized item. These written
communications are accessible to the public through the City’s website and kept in packet archives. You
are hereby admonished not to include any personal or private information in written communications to
the City that you do not wish to make public; doing so shall constitute a waiver of any privacy rights
you may have on the information provided to the City.
Members of the public are entitled to address the members concerning any item that is described in the
notice or agenda for this meeting, before or during consideration of that item. If you wish to address the
members on any other item not on the agenda, you may do so during the public comment.
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CITY OF CUPERTINO SUSTAINABILITY COMMISSION
Environmental Education Center 22221 McClellan Road
Thursday July 18, 2019 4:00 p.m.
MINUTES
PLEDGE OF ALLEGIANCE
At 4:04 p.m. Chair Weber called the meeting to order and led the Pledge of Allegiance.
ROLL CALL
Commissioners Present: Anna Weber, Gary Latshaw, Angela Chen, Meera Ramanathan, Vignesh
Swaminathan
Staff: Gilee Corral, Acting Sustainability Manager; Cheri Donnelley, Environmental Program Manager
Guests: Bruce Karney, Anne Ng, other member of the public.
1.APPROVAL OF MINUTES
Draft minutes of June 20, 2019 meeting were reviewed. Commissioner Chen moved and Commissioner
Latshaw seconded to approve the minutes. The motion carried unanimously.
POSTPONEMENTS - None.
ORAL COMMUNICATIONS
Anne Ng, Cupertino resident, introduced herself to the Commission.
WRITTEN COMMUNICATIONS - None.
Chair Weber moved and Commissioner Chen seconded to reorder the agenized items as follows: New
Business before Old Business. The motion carried unanimously.
NEW BUSINESS
6.Subject: Presentation on greenhouse gas emissions inventory metrics with consultant DNV GL
Chair Weber opened Public Comment and the following individual spoke:
Bruce Karney spoke in favor of conducing annual greenhouse gas emissions inventories and setting annual
goals, with consequences if the City fails to meet its goals.
Chair Weber closed Public Comment. Commissioners asked Karney clarifying questions and discussed the
possibility of purchasing carbon offsets as potential consequences for not meeting GHG goals.
The DNV GL consultant, Ben Butterworth, gave a presentation on GHG inventory metrics via conference call
and responded to Commissioners’s questions. Issues raised by Commissioners included: accuracy of inventory
methodology, how direct access emission factors are calculated, verification of data, setting per capita targets,
etc. The Commission discussed these issues as well as the merits and drawbacks of an annual approach to
conducting GHG inventories and potential of including consequences for not meeting GHG targets.
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OLD BUSINESS
2.Subject: Discuss Green New Deal legislative efforts on the federal and state level and consider
making a recommendation to the City Council to sign a resolution in support of H.R. 109
(Representative Ocasio-Cortez) and S. Res. 59 (Senator Markey) and AB 1276 (Assemblymember
Bonta)
Gilee Corral recommended that the Commission decide if they wished to endorse the bills to City Council or
decide to create a local Green New Deal (GND) resolution. The Commission discussed the pros and cons of
these options. Commissioner Latshaw noted potential benefits of supporting GND efforts, including: may
influence other support for the bills, possible connection to the City’s declared Climate Emergency, etc.
Commissioners expressed concerns that the GND bills covered areas outside their purview, how to implement
a local GND, and the legislative advocacy adding too much to their work load. The Commissioners agreed to
watch the GND legislation action at the federal level and see where the bill ends up in the House.
Commissioner Swaminathan moved and Vice-Chair Latshaw seconded to take up the Green New Deal
discussion at a future Commission meeting.
3.Subject: Sustainability Speaker Series planning
The Commission discussed details of the Bea Johnson / Zero Waste event and agreed to aim for a 6:30 p.m. to
8:00 p.m. timeframe with one hour talk and thirty minutes for Q&A. The Speaker Series Subcommittee will
meet with staff to plan logistics and report back at the next Commission meeting.
4.Subject: Discuss and select agenda topics for upcoming Sustainability Commission meetings
Commissioners discussed with staff the upcoming items to be scheduled, including the reach code update and
a Green Stormwater Infrastructure plan. Commissioner Latshaw passed out a handout on a recent
presentation by Silicon Valley Clean Energy (SVCE) staff on the model reach codes.
The Commission agreed to the following agenda topics and meeting dates:
August 15 Commission meeting:
-Green Stormwater Infrastructure plan update from staff
- CAP Report update from staff
-Speaker Series Subcommittee update on Bea Johnson event planning
- Fall Festival tabling
August 29 Commission meeting:
-The Commissioners agreed to add a Special Meeting on August 29 from 4:00 pm to 6:00 pm to discuss
the SVCE model reach codes and the CALGreen Tier 1 and Tier 2 options. Staff will schedule SVCE
staff and Building Division’s consultant to attend and contribute to this discussion.
-The Reach Code Subcommittee (Commissioners Swaminathan and Ramanathan) will meet and report
back at this meeting.
October 17 Commission meeting:
-Green New Deal
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Chair Weber moved and Commissioner Swaminathan seconded to approve the agenda items and dates as
agreed. The motion passed anonymously.
5. Update on Buy Clean California Act policy development and Bay Area low carbon concrete codes
initiatives
Corral gave an update on regional efforts to create model code addressing low carbon concrete requirements.
She passed out a handout on a draft version of low carbon concrete building code developed by the County of
Marin.
STAFF AND COMMISSION REPORTS
Commission updates:
-Commissioner Swaminathan gave an update on his travels and sustainable practices he observed in
Singapore. He announced that he has been elected to serve on a Citizen Advisory Board to the Santa
Clara Valley Transport Authority (VTA). He updated the Commissioners on upcoming bike-related
events: Silicon Valley Bike Coalition Summit and a pop up bikeway event on August 1st.
-Speaker Series Subcommittee members Vice-Chair Latshaw and Commissioner Chen will meet to
discuss the Bea Johnson event and possible topics for other events.
Staff updates:
- The City of Cupertino will be receiving the full Beacon Award this year. More details to follow.
- Administrative items regarding the Sustainability Commission budget and City email system.
- Sustainability Division will have a new Sustainability Manager in early August.
- Silicon Valley Clean Energy has launched its FutureFit heat pump water heater program.
ADJOURNMENT- 6:29 p.m.
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City of Cupertino
Green Stormwater Infrastructure Plan
DRAFT
Approved on: September 3, 2019
Approved by: The City Council of the City of Cupertino
Submitted by:
City of Cupertino
10300 Torre Avenue
Cupertino, CA 95014
In compliance with Provision C.3.j.i.(2) of Order R2-2015-0049
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ACKNOWLEDGEMENTS
The City of Cupertino gratefully acknowledges the following individuals and organizations that
contributed to this Green Stormwater Infrastructure Plan:
City of Cupertino
Public Works Department
•Roger Lee
•Chad Mosley, P.E.
•Cheri Donnelly
•Alex Wykoff
•Ursula Syrova
EOA, Inc.
•Jill Bicknell, P.E.
•Vishakha Atre
•Liesbeth Magna
The City would like to thank and acknowledge the City of Palo Alto and the City of San Jose for sharing
text from their Green Stormwater Infrastructure Plans.
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Table of Contents
LIST OF ACRONYMS (DRAFT) ......................................................................................................................... v
EXECUTIVE SUMMARY .................................................................................................................................. 1
1.INTRODUCTION ..................................................................................................................................... 3
Purpose and Goals of the GSI Plan ................................................................................................ 3
City Description ............................................................................................................................. 3
1.2.1 Population Size and Growth.................................................................................................. 3
1.2.2 City Characteristics ................................................................................................................ 4
1.2.3 Roadways .............................................................................................................................. 4
1.2.4 Hillsides and Water Resources .............................................................................................. 5
Regulatory Context ....................................................................................................................... 5
1.3.1 Federal and State Regulations and Initiatives ....................................................................... 5
1.3.2 Municipal Regional Stormwater Permit ................................................................................ 5
GSI Plan Development Process ..................................................................................................... 6
1.4.1 GSI Plan Development and Adoption.................................................................................... 6
1.4.2 Regional Collaboration .......................................................................................................... 7
1.4.3 Education and Outreach ....................................................................................................... 7
GSI Plan Structure and Required Elements ................................................................................... 8
2.WHAT IS GREEN STORMWATER INFRASTRUCTURE? .......................................................................... 10
Green Stormwater Infrastructure ............................................................................................... 10
Benefits of Green Stormwater Infrastructure ............................................................................. 10
Types of Green Stormwater Infrastructure Facilities.................................................................. 11
2.3.1 Biotreatment/Bioretention ................................................................................................. 11
2.3.2 Stormwater Tree Well Filters and Suspended Pavement Systems ..................................... 12
2.3.3 Pervious Pavement ............................................................................................................. 13
2.3.4 Infiltration Facilities ............................................................................................................ 13
2.3.5 Green Roofs......................................................................................................................... 14
2.3.6 Rainwater Harvesting and Use ............................................................................................ 14
Existing GSI Facilities ................................................................................................................... 14
2.4.1 Stevens Creek Corridor and Creek Restoration project ...................................................... 15
2.4.2 McClellan West Parking Lot ................................................................................................ 16
2.4.3 Apple Park ........................................................................................................................... 16
3.INTEGRATION WITH OTHER PLANNING DOCUMENTS ....................................................................... 17
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City Planning Document Review ................................................................................................. 17
3.1.1 General Plan – Community Vision 2040.............................................................................. 17
3.1.2 Pedestrian Transportation Plan .......................................................................................... 19
3.1.3 Storm Drain Master Plan ..................................................................................................... 19
3.1.4 Bicycle Transportation Plan ................................................................................................ 19
3.1.5 Climate Action Plan ............................................................................................................. 19
3.1.6 Heart of the City Specific Plan ............................................................................................. 20
3.1.7 Citywide Parks & Recreation System Master Plan (Draft) .................................................. 21
3.1.8 Workplan for Integration of GSI Language into Existing and Future City Planning
Documents .......................................................................................................................................... 21
Regional Plans ............................................................................................................................. 22
3.2.1 Santa Clara Basin Stormwater Resource Plan ..................................................................... 22
3.2.2 Santa Clara Valley Water District’s One Water Plan ........................................................... 22
3.2.3 Bay Area Integrated Regional Water Management Plan .................................................... 23
4.GSI DESIGN GUIDELINES, DETAILS, AND SPECIFICATIONS .................................................................. 24
Design Guidelines ........................................................................................................................ 24
Details and Specifications ........................................................................................................... 24
Incorporation of SCVURPPP Details and Specifications into City Standards .............................. 25
5.GSI PROJECT PRIORITIZATION AND IMPERVIOUS TARGETS ............................................................... 26
Project Types ............................................................................................................................... 26
5.1.1 Early Implementation Projects ............................................................................................ 26
5.1.2 Regulated Projects .............................................................................................................. 26
5.1.3 LID Projects ......................................................................................................................... 26
5.1.4 Regional Projects ................................................................................................................. 27
5.1.5 Green Street Projects .......................................................................................................... 27
Identification and Prioritization Process ..................................................................................... 27
5.2.1 Step 1: Stormwater Resource Plan Prioritization ............................................................... 27
5.2.2 Step 2: City-Specific Prioritization ....................................................................................... 30
Prioritization Output ................................................................................................................... 35
6.GSI Implementation Plan .................................................................................................................... 38
City-wide GSI Strategy ................................................................................................................. 38
Process for Identifying and Evaluating GSI Project Opportunities ............................................. 39
Workplan to Complete Early Implementation Projects .............................................................. 39
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Legal Mechanisms for GSI Implementation ................................................................................ 40
Evaluation of Funding Options .................................................................................................... 40
6.5.1 Current Funding Sources for GSI Program Elements .......................................................... 40
6.5.2 Potential Future Funding Options ....................................................................................... 41
Impervious Area Targets ............................................................................................................. 41
6.6.1 Methodology ....................................................................................................................... 41
6.6.2 Results ................................................................................................................................. 48
Project Tracking System .............................................................................................................. 51
6.7.1 City Project Tracking System (Regulated and GSI) .............................................................. 51
6.7.2 SCVURPPP Project Tracking System .................................................................................... 51
TABLES
Table 1-2 Summary of GSI Plan Elements required by Provision C.3.j.i of the MRP. ................................... 9
Table 5-1 Screening factors for parcel-based and right-of-way project opportunities .............................. 28
Table 6-2 Potential GSI Funding Options .................................................................................................... 42
Table 6-2 Projected cumulative land area (acres) anticipated to be addressed via Green Stormwater
Infrastructure facilities via private redevelopment in the City of Cupertino by 2020, 2030, and 2040. .... 49
Table 6-3 Actual (2002-2018) and predicted (2019-2040) extent of impervious surface retrofits via GSI
implementation on privately- and publicly-owned parcels in the City of Cupertino by 2020, 2030, and
2040. ........................................................................................................................................................... 50
FIGURES
Figure 2-1 Stormwater curb extension, Southgate Neighborhood, Palo Alto (Source: EOA) ..................... 11
Figure 2-2 Stormwater planter, Hacienda Avenue, Campbell (Source: City of Campbell) ......................... 12
Figure 2-3 Stormwater tree well filter conceptual examples: modular suspended pavement system (left),
column suspended pavement system (right). (Courtesy of Philadelphia Water Department) .................. 12
Figure 2-4 Permeable interlocking concrete pavers, Mayfield Playing Fields, Palo Alto (Source: EOA) .... 13
Figure 2-5 Infiltration trench, San Jose (Source: City of San Jose) .............................................................. 13
Figure 2-6 Subsurface infiltration system (Source: Conteches.com) .......................................................... 13
Figure 2-7 Green roof at Fourth Street Apartments, San José (Source: EOA) ............................................ 14
Figure 2-8 Rainwater harvesting cistern, Environmental Innovation Center, San José (Source: City of San
Jose) ............................................................................................................................................................ 14
Figure 2-9 Subsurface vault, under construction (Source: Conteches.com) .............................................. 14
Figure 2-10 Completed green parking bays (above left) and parking bays under construction, showing
the recycled plastic geocells that support vehicle weight (above right).(Source: City of Cupertino) ........ 15
Figure 2-11 Pervious concrete bike path and walkway at Blackberry Farm. (Source: City of Cupertino) .. 15
Figure 5-1 City of Cupertino Public Parcels and Street Segments with Opportunities for GSI (Source: EOA,
and Santa Clara Basin Stormwater Resource Plan, 2018)........................................................................... 30
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Figure 5-2. City of Cupertino Special Project Areas and Priority Development Area (Source: City of
Cupertino General Plan).............................................................................................................................. 32
Figure 5-3. City of Cupertino Public Projects with Potential for GSI (Source: City of Cupertino FY 17-18
Annual Report, and 2018 Santa Clara Basin Stormwater Resource Plan) .................................................. 34
Figure 5-5 City of Cupertino GSI Overview ................................................................................................. 36
Figure 6-1 Existing and projected cumulative land area (acres) anticipated to be addressed via Green
Stormwater Infrastructure facilities installed via private redevelopment in the City of Cupertino by 2020,
2030, and 2040. .......................................................................................................................................... 48
APPENDICES
Appendix A Prioritization Metrics for Scoring GSI Project Opportunities
Appendix B Street Segments and Parcels in Cupertino with Opportunities for GSI
Appendix C GSI concept for the Mary Avenue Greenbelt and Trail Project
Appendix D Guidance for Identifying Green Infrastructure Potential in Municipal Capital Improvement
Plan Projects
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LIST OF ACRONYMS
ABAG Association of Bay Area Governments
BASMAA Bay Area Stormwater Management Agencies Association
Caltrans California Department of Transportation
CFD Community Facilities District
CIP Capital Improvement Program
DOF Department of Finance
EPA United States Environmental Protection Agency
FY Fiscal Year
GI Green Infrastructure
GIS Geographic Information System
GSI Green Stormwater Infrastructure
IRWMP Integrated Regional Water Management Plan
LID Low Impact Development
MRP Municipal Regional Stormwater NPDES Permit
MS4 Municipal Separate Storm Sewer System
NPDES National Pollutant Discharge Elimination System
NRCS National Resource Conservation Service
O&M Operation and Maintenance
PDA Priority Development Area
PICP Permeable Interlocking Concrete Pavers
PP Permeable Pavers
SCVURPPP Santa Clara Valley Urban Runoff Pollution Prevention Program
State Water Board State Water Resource Control Board
STORMS Strategy to Optimize Resource Management of Stormwater
SWRP Storm Water Resource Plan
Valley Water Santa Clara Valley Water District
Regional Water Board San Francisco Bay Regional Water Quality Control Board
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EXECUTIVE SUMMARY
Development of this Green Stormwater Infrastructure (GSI) Plan is required by the City’s Municipal
Regional Stormwater National Pollutant Discharge Elimination System (NPDES) Permit. Urban
development has traditionally involved replacing natural landscapes with solid pavements and buildings,
using underground metal-pipe storm drainage systems to carry increased amounts of stormwater runoff
and pollutants directly into local creeks, which empty into San Francisco Bay. To reduce the impact of
urban development on waterways, Bay Area municipalities are required to begin augmenting traditional
stormwater drainage systems with Green Stormwater Infrastructure (GSI) treatments.
GSI features mimic nature, and use plants, soils, and/or pervious surfaces to collect stormwater, allowing
it to soak into the ground and be filtered by the soil. This reduces the quantity of water and pollutants
flowing directly into local creeks. The City began the process of incorporating GSI into public projects in
2014, with the completion of the 18-acre Stevens Creek Corridor Park and Restoration.
The City of Cupertino has prepared this GSI Plan, specifically in accordance with its MRP requirements, to
guide the siting, implementation, tracking, and reporting of GSI projects on City-owned land, including the
public right of way, over the next several decades (2020 – 2040).
Cupertino’s GSI Plan describes the City’s approach to identifying and prioritizing potential areas for
implementing GSI, and estimating targets for the City’s area that could be addressed by GSI through 2040.
The Plan lays out the City’s GSI implementation strategy and includes maps of the City’s prioritized areas
and potential project opportunities. Key elements of the strategy include: coordination with State-
mandated GSI requirements for private development and opportunities in adjacent public rights-of-way;
identification of GSI opportunities in capital projects; and aligning GSI goals and policies with other City
planning documents to achieve multiple benefits and provide safer, sustainable, and attractive public
streetscapes. The Plan contains guidance and standards for GSI project design and construction, and
describes how the City will track and map constructed GSI projects and make the information available to
the public. Lastly, it explains existing legal mechanisms to implement the GSI Plan, and identifies potential
sources of funding for the design, construction, and maintenance of GSI projects.
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1.INTRODUCTION
Urban development has traditionally involved replacing natural landscapes with solid pavements and
buildings, and using storm drain systems to carry increased amounts of stormwater runoff and
pollutants directly into local streams. Green stormwater infrastructure (GSI), however, uses plants and
soils to mimic natural watershed processes, capture stormwater and create healthier environments. Bay
Area cities and counties are required by State and regional regulatory agencies to move from traditional
(grey) stormwater conveyance systems to GSI systems over time. This GSI Plan serves as an
implementation guide for the City of Cupertino (City) to incorporate GSI into storm drain infrastructure
on public and private lands where feasible over the next several decades.
Purpose and Goals of the GSI Plan
The purpose of the City’s GSI Plan is to demonstrate the City’s commitment to gradually transform its
traditional storm drainage infrastructure to green stormwater infrastructure. The GSI Plan will guide the
identification, implementation, tracking, and reporting of green stormwater infrastructure projects
within the City. The GSI Plan will be coordinated with other City plans, such as the General Plan, the
Climate Action Plan, the Bicycle Transportation Plan, the Pedestrian Transportation Plan, and other
specific and master plans, to achieve multiple potential benefits to the community, including improved
water and air quality, reduced local flooding, increased water supply, traffic calming, safer pedestrian
and bicycle facilities, climate resiliency, improved wildlife habitat, and a more pleasant urban
environment.
Specific goals of the GSI Plan are to:
•Align the City’s goals, policies and implementation strategies for GSI with the General Plan and
other related planning documents;
•Identify and prioritize GSI opportunities throughout the City;
•Establish targets for the extent of City area to be addressed by GSI over certain timeframes;
•Provide a workplan and legal and funding mechanisms to implement prioritized projects; and
•Establish a process for tracking, mapping, and reporting completed projects
City Description
Incorporated in 1955, the City of Cupertino is located in Santa Clara County, on the western edge of
Silicon Valley against the foothills of the Santa Cruz Mountains. It has a jurisdictional area of 7,235 acres
(11.3 square miles).
1.2.1 Population Size and Growth
According to the General Plan, “Community Vision 2040”, Cupertino’s population grew from 3,664 in
1960 to over 50,500 in 2000. Most of the population growth was from tract development during the
1970s and 1980s and annexation of unincorporated County land. Between 2000 and 2010 the City of
Cupertino’s population increased by 15.3 percent, from 50,546 (18,204 households) to 58,302 persons
(20,181 households), with a population density of 5,179 people per square mile and average household
size of 2.87. A portion of this population growth can be attributed to the City’s annexation of 168 acres
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of land between 2000 and 2008. As of 2019 according to the California Department of Finance (DOF)1,
the estimated population is 59,879. The City’s population is projected to grow to 66,110 by 2040 (Plan
Bay Area, 2013), which is approximately a 12% increase over 30 years.
1.2.2 City Characteristics
Cupertino’s land use pattern was largely built on a conventional suburban model, with predominantly
single-family residential subdivisions and distinct commercial and employment centers. This
development pattern was also heavily influenced by the topography of the area, with more intensive
growth located on the valley floor and lower design residential on the foothills. The western area by the
foothills is semi-rural with steep terrain, larger residential lots and access to open space. The pattern
becomes more suburban immediately west of Highway 85 where residential neighborhoods have a
more uniform pattern with smaller lots and older commercial and industrial areas along Stevens Creek
Boulevard and Bubb Road. The land use pattern becomes more urban east of Highway 85, with a
relatively connected street grid and commercial development along major boulevards such as Stevens
Creek, De Anza, Homestead, Stelling and Wolfe. This area also has significant amounts of multi-family
development in and around the major boulevards.
The suburban pattern is also reflected in building locations, with most of the older buildings set back
from the street with parking lots in the front. Streets have also been historically widened to
accommodate larger volumes of traffic, often to the detriment of other forms of transportation such as
walking, biking and transit. According to the 2015 General Plan Land Use Element, the City has made
strides in the last 20 years towards improving walkability and bikeability by retrofitting existing streets
to include bike lanes; creating sidewalks lined with trees along major boulevards; and encouraging
development to provide a more pedestrian-oriented frontage with active uses, gathering places and
entries lining the street.
1.2.3 Roadways
The City is defined by its four major roadways: Homestead Road, Wolfe Road, De Anza Boulevard and
Stevens Creek Boulevard. These major mixed-use corridors have been the center of retail, commercial,
office and multi-family housing in Cupertino for decades.
Common residential street widths range from 20 feet (for streets with no street parking) to 36 feet (for
those with parking on both sides). Developers are typically required to install curb, gutters, and
sidewalks. The City prefers detached sidewalks with a landscaped buffer in between the street and the
pedestrian walk to enhance community aesthetics and improve pedestrian safety.
Two state highways traverse Cupertino. The City is linked to the cities of San Francisco and San José by
Interstate Highway 280 which runs along most of the its northern border. State Route 85, which runs
from Mountain View to South San José, cuts diagonally across the City at its northwest boundary to its
southeast boundary. All state highways are owned and maintained by the California Department of
Transportation (Caltrans).
1 Source: State of California, Department of Finance, E-1 Population Estimates for Cities, Counties and the State with Annual
Percent Change — January 1, 2018 and 2011. Sacramento, California, May 2019. Online at
http://www.dof.ca.gov/Forecasting/Demographics/Estimates/E-1/.
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The City has approximately 1.5 miles of rural road in the residential hillside area.
1.2.4 Hillsides and Water Resources
Cupertino’s hillsides are an irreplaceable resource shared by the entire Santa Clara Valley. They provide
important habitat for plants and wildlife; watershed capacity to prevent flooding in downstream areas; a
wide vegetative belt that cleanses the air of pollutants; and a natural environment that provides a
contrast to the built environment. Significant water bodies and water sources within Cupertino are:
•Stevens Creek
•Permanente Creek
•Regnart Creek
•Heney Creek
•Calabazas Creek
Regulatory Context
1.3.1 Federal and State Regulations and Initiatives
The U.S. Environmental Protection Agency (EPA) has authority under the Clean Water Act to promulgate
and enforce stormwater related regulations. For the State of California, EPA has delegated the
regulatory authority to the State Water Resources Control Board (State Water Board), which in turn, has
delegated authority to the San Francisco Bay Regional Water Quality Control Board (Regional Water
Board) to issue National Pollutant Discharge Elimination System (NPDES) permits in the San Francisco
Bay Region. Stormwater NPDES permits allow stormwater discharges from municipal separate storm
sewer systems (MS4s) to local creeks, San Francisco Bay, and other water bodies as long as they do not
adversely affect the beneficial uses of or exceed any applicable water quality standards for those waters.
Since the early 2000’s, the EPA has recognized and promoted the benefits of using GSI in protecting
drinking water supplies and public health, mitigating overflows from combined and separate storm
sewers and reducing stormwater pollution, and it has encouraged the use of GSI by municipal agencies
as a prominent component of their MS4 programs.
The State and Regional Water Boards have followed suit in recognizing not only the water quality
benefits of GSI but the opportunity to augment local water supplies in response to the impacts of
drought and climate change as well. The 2014 California Water Action Plan called for multiple benefit
stormwater management solutions and more efficient permitting programs. This directive created the
State Water Board’s “Strategy to Optimize Resource Management of Stormwater” (STORMS). STORMS’
stated mission is to “lead the evolution of storm water management in California by advancing the
perspective that storm water is a valuable resource, supporting policies for collaborative watershed-
level storm water management and pollution prevention, removing obstacles to funding, developing
resources, and integrating regulatory and non-regulatory interests.”
These Federal and State initiatives have influenced approaches in Bay Area municipal stormwater NPDES
permits, as described in Section 1.3.2.
1.3.2 Municipal Regional Stormwater Permit
The City is subject to the requirements of the Municipal Regional Stormwater NPDES Permit (MRP) for
Phase I municipalities and agencies in the San Francisco Bay area (Order R2-2015-0049), which became
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effective on January 1, 2016. The MRP applies to 76 municipalities and flood control agencies that
discharge stormwater to San Francisco Bay, collectively referred to as permittees.
Over the last 13 years, under Provision C.3 of the MRP and previous permits, new development and
redevelopment projects on private and public property that exceed certain size thresholds (“regulated
projects”) have been required to mitigate impacts on water quality by incorporating “Low Impact
Development” (LID) measures, including site design, pollutant source control, stormwater treatment
and flow control measures as appropriate. LID treatment measures, such as rainwater harvesting and
use, infiltration, and biotreatment, have been required on most regulated projects since December
2011.
Provision C.3.j of the 2016 MRP requires the City to develop and implement a long-term GSI Plan2 for
the inclusion of LID measures into storm drain infrastructure on public and private lands, including
streets, roads, storm drains, parking lots, building roofs, and other elements. The GSI Plan must be
completed and submitted to the Regional Water Board by September 30, 2019.
While Provision C.3.j of the MRP contains the GSI program planning and analysis requirements, other
provisions (C.11 and C.12) establish a linkage between public and private GSI features and required
reductions of pollutants in stormwater discharges. Permittees in Santa Clara County (County),
collectively, must implement GSI on public and private property to achieve specified pollutant load
reduction goals by the years 2020, 2030, and 2040. These efforts will be integrated and coordinated
countywide for the most effective and resource-efficient program. As an indication as to whether these
load reductions will be met, Permittees must include in their GSI Plans estimated “targets” for the
amounts of impervious surface to be “retrofitted” as part of public and private projects (i.e.,
redeveloped or changed such that runoff from those surfaces will be captured in a stormwater
treatment system or GSI measure) over the same timeframes (2020, 2030, and 2040).
A key part of the GSI definition in the MRP is the inclusion of GSI systems at both private and public
property locations. This has been done in order to plan, analyze, implement and credit GSI systems for
pollutant load reductions on a watershed scale, as well as recognize all GSI accomplishments within a
municipality. The focus of the GSI Plan is the integration of GSI systems into public buildings, parks,
parking lots, and rights-of-way (e.g. road or bike path). However, the GSI Plan may also establish
opportunities to include GSI facilities at private properties or in conjunction with private development,
so they can contribute to meeting the target load reductions on a county-wide level as well as
implement GSI on a larger scale.
GSI Plan Development Process
1.4.1 GSI Plan Development and Adoption
The GSI Plan development process began with the preparation of the City’s GSI Plan Framework
(Framework), a work plan describing the goals, approach, tasks, and schedule needed to complete the
GSI Plan. Development of the Framework was a regulatory requirement (Provision C.3.j.i(1) of the MRP)
2 Although the MRP uses the term green infrastructure (GI), the agencies within Santa Clara County, including the
City of Cupertino, prefer to use the term green stormwater infrastructure (GSI). Therefore, the term GSI is used in
this document.
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to demonstrate the City’s commitment to completing the GSI Plan by September 30, 2019. The City
completed the Framework and City Council approved it on April 18, 2017.
The City established a GSI Work Group, consisting of staff from the City’s Public Works and Planning
Departments. The GSI Work Group worked with a consultant team to develop the GSI Plan. Staff
attended the Sustainability Commission on March 16, 2017 where SFEI’s (San Francisco Estuary
Institute) Robin Grossinger gave a presentation on healthier landscapes for people in nature (GSI
concepts). City staff followed with an overview of the GSI Framework that City staff was in the process
of developing. More recently, an overview of the MRP requirements and summary of the proposed
Plan was presented to City Council on July 16, 2019. GSI presentations for soliciting comments and
feedback were given to the Planning Commission on August 13, 2019 and the Sustainability Commission
on August 15, 2019. The final GSI Plan was approved by the City Council on September 3, 2019.
1.4.2 Regional Collaboration
The City is a member of the Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP),
an association of thirteen cities and towns in the Santa Clara Valley, the County of Santa Clara, and the
Santa Clara Valley Water District (Valley Water) that collaborate on stormwater regulatory activities and
compliance. The City’s GSI Plan was developed in collaboration with SCVURPPP; SCVURPPP input
included technical guidance, templates, and completion of certain GSI Plan elements at the countywide
level. SCVURPPP guidance and products are discussed in more detail in relevant sections of the GSI Plan.
The City, via SCVURPPP, also coordinated with the Bay Area Stormwater Management Agencies
Association (BASMAA) on regional GSI guidance and received feedback through BASMAA from MRP
regulators on GSI expectations and approaches. BASMAA members include other countywide
stormwater programs in Alameda, Contra Costa, and San Mateo Counties, and area-wide programs in
the Vallejo and Fairfield-Suisun portions of Solano County, whose participating municipalities are
permittees under the MRP.
1.4.3 Education and Outreach
One of the first and most important steps in the development of the GSI Plan is educating a
municipality's department staff, managers, and elected officials about the purposes and goals of green
infrastructure, the required elements of the GSI Plan, and steps needed to develop and implement the
GSI Plan, and get their support and commitment to the Plan and this new approach to urban
infrastructure. Another important first step is local community and stakeholder outreach to gain public
support. The City of Cupertino began this process in FY 15-16 and FY 16-17 and completed the following
tasks:
•Convened 3-4 interdepartmental meetings with Public Works, GIS, Capital Improvement
Program (CIP), and Environmental staff and management to discuss GSI requirements and
assigned tasks.
•Discussed with appropriate department staff the MRP requirements to analyze proposed
capital projects for opportunities to incorporate GSI and completed the first list of planned
and potential GSI projects.
•Provided training to department staff on GSI requirements and strategies via presentations
and workshops.
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•Invited elected officials to a SCVURPPP Green Infrastructure presentation to raise awareness
of the goals and requirements in the MRP and the concepts, intent and multiple benefits of
GSI.
•At the suggestion of the Vice Mayor, the Sustainability Commission invited guest speaker
Robin Grossinger, a scientist from San Francisco Estuary Institute (SFEI), to give his
presentation on the vision for a resilient Silicon Valley landscape 3.
•Public Works Environmental staff participated in the Green Infrastructure Leadership
Conversation and the Regional Roundtable on Sustainable Streets
Public and stakeholder support is also essential for the successful implementation of the GSI Plan and
future GSI projects. To this end, the City has coordinated with SCVURPPP and the Watershed Education
and Outreach subgroup on a comprehensive outreach and education program. Key audiences include:
the general public (countywide, and in the neighborhood or municipality where GSI projects are
located); the development community (e.g., developers, engineers, landscape architects, and
contractors); and elected officials. The GSI outreach and education program includes a GSI website 4,
public presentations, and radio and online advertising to promote GSI features. The City of Cupertino
will conduct or continue to conduct education and outreach activities as part of development of the GSI
Plan and seek community input as specific projects are designed and constructed.
GSI Plan Structure and Required Elements
The remainder of the GSI Plan is structured as follows:
Chapter 2 describes the definition, purpose, and benefits of GSI, and describes the different types of GSI
facilities.
Chapter 3 describes the relationship of the GSI Plan to other planning documents and how those
planning documents have been updated or modified, if needed, to support and incorporate GSI
requirements. For documents whose desired updates and modifications have not been accomplished by
the completion of the GSI Plan, a work plan and schedule are laid out to complete them.
Chapter 4 outlines the materials being developed by SCVURPPP and the City to provide guidelines,
typical details, specifications and standards for municipal staff and others in the design, construction,
and operation and maintenance of GSI measures.
Chapter 5 presents information on the different types of GSI projects and the methodology and results
for identifying and prioritizing areas for potential GSI projects.
Chapter 6 outlines the City’s strategy for implementing potential GSI projects within the next ten years
and through 2040, discusses the variety of mechanisms to be employed by the City in order to
3 SFEI's recommendations for a more sustainable South Bay looks at what the City can do to integrate resilient
landscape within the reality of new and re-development. From a practical perspective, the City of Cupertino can
consider actions over the course of the next generations to improve the ecology of the area and how it can work
with larger developments to incorporate these types of principles in its planning.
4 http://www.mywatershedwatch.org/residents/green-streets/
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implement the GSI Plan, and presents the estimated targets for the amounts of impervious surface to be
“retrofitted” as part of public and private projects by 2020, 2030, and 2040.
The GSI Plan elements required by Provision C.3.j.i.(2) of the MRP and the section of the document in
which each component can be found are summarized in Table 1-2 below.
Table 1-1 Summary of GSI Plan Elements required by Provision C.3.j.i of the MRP.
MRP Provision GSI Plan Elements GSI Plan Section
C.3.j.i.(2)(a)Project Identification and Prioritization Mechanism Chapter 5
C.3.j.i.(2)(b)Prioritized Project Locations Section 5.3
C.3.j.i.(2)(c)Impervious Surface Targets Section 6.6
C.3.j.i.(2)(d)Completed Project Tracking System Section 6.7
C.3.j.i.(2)(e,f)Guidelines and Specifications Chapter 4
C.3.j.i.(2)(g)Alternative Sizing Requirements for Green Street Projects Section 4.1
C.3.j.i.(2)(h,i)Integration with Other Municipal Plans Chapter 3
C.3.j.i.(2)(i)Workplan for Integration of GSI Language into City Planning
Documents Section 3.1.8
C.3.j.i.(2)(j)Workplan to Complete C.3.j. Early Implementation Projects Section 6.3
C.3.j.i.(2)(k)Evaluation of Funding Options Section 6.5
C.3.j.i.(3)Legal and Implementation Mechanisms Section 6.4
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2.WHAT IS GREEN STORMWATER INFRASTRUCTURE?
In natural landscapes, most of the rainwater soaks into the soil or is taken up by plants and
trees. However, in urban areas, building footprints and paved surfaces such as driveways, sidewalks, and
streets prevent rain from soaking into the ground. As rainwater flows over and runs off these impervious
surfaces, this “urban runoff” or “stormwater runoff” can pick up pollutants such as motor oil, metals,
pesticides, sediment, pet waste, and litter. It then carries these pollutants into the City’s storm drains,
which flow directly to local creeks and San Francisco Bay, without any cleaning or filtering to remove
pollutants. Stormwater runoff is therefore a major contributor to water pollution in urban areas.
As urban areas develop, the increase in impervious surface also results in increases in peak flows and
volumes of stormwater runoff from rain events. Traditional “gray” stormwater infrastructure, like most
of the City’s storm drain system, is designed to convey stormwater flows quickly away from urban areas.
However, the increased peak flows and volumes can cause erosion, flooding, and habitat degradation in
downstream creeks to which stormwater is discharged, damaging habitat, property, and infrastructure.
Green Stormwater Infrastructure
A new approach to managing stormwater is to implement green stormwater infrastructure. GSI uses
vegetation, soils, and other elements and practices to capture, treat, infiltrate and slow urban runoff
and thereby restore some of the natural processes required to manage water and create healthier urban
environments. GSI facilities can also be designed to capture stormwater for uses such as irrigation and
toilet flushing.
GSI integrates building and roadway design, complete streets, drainage infrastructure, urban forestry,
soil conservation and sustainable landscaping practices to achieve multiple benefits. At the city or
county scale, GSI is a patchwork of natural areas that provides habitat, flood protection, cleaner air, and
cleaner water. At the neighborhood or site scale, GSI comprises stormwater management systems that
mimic nature and soak up and store water.5
Benefits of Green Stormwater Infrastructure
GSI can provide multiple benefits beyond just managing rainfall and runoff. These benefits include
environmental, economic, and social improvements.
GSI measures can mitigate localized flooding and reduce erosive flows and quantities of pollutants being
discharged to local creeks and the San Francisco Bay. Vegetated GSI systems can beautify public places
and help improve air quality by filtering and removing airborne contaminants from vehicle and industrial
sources. They can also reduce urban heat island effects by providing shade and absorbing heat better
than paved surfaces, and provide habitat for birds, butterflies, bees, and other local species. When GSI
facilities are integrated into traffic calming improvements such as curb extensions and bulb-outs at
intersections, they can help increase pedestrian and bicycle safety and promote active transportation,
which in turn can result in improved human health.
5 https://www.epa.gov/green-infrastructure/what-green-infrastructure
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GSI facilities designed with extra storage can capture stormwater for later use as irrigation water or non-
potable uses such as toilet flushing and cooling tower supply, thus conserving potable water supplies.
Widespread implementation of GSI potentially offers significant economic benefits, such as deferring or
eliminating the need for some gray infrastructure projects. By providing more storage within the
watershed, GSI can help reduce the costs of conveyance and pumping of stormwater. When cost-benefit
analyses are performed, GSI is often the preferred alternative due to the multiple benefits provided by
GSI as compared to conventional infrastructure.
Types of Green Stormwater Infrastructure Facilities
Integrating GSI into public spaces typically involves construction of stormwater capture and treatment
measures in public streets, parks, and parking lots or as part of public buildings. Types of GSI measures
that can be constructed in public spaces include: (1) bioretention; (2) stormwater tree well filters; (3)
pervious pavement, (4) infiltration facilities, (5) green roofs, and 6) rainwater harvesting and use
facilities. A description of these facility types is provided below.
2.3.1 Biotreatment/Bioretention
Bioretention areas are depressed landscaped
areas that consist of a ponding area, mulch
layer, plants, and a special biotreatment soil
media composed of sand and compost,
underlain by drain rock and an underdrain, if
required. Bioretention is designed to retain
stormwater runoff, filter stormwater runoff
through biotreatment soil media and plant
roots, and either infiltrate stormwater runoff
to underlying soils as allowed by site
conditions, or release treated stormwater
runoff to the storm drain system, or both.
They can be of any shape and are adaptable
for use on a building or parking lot site or in the street right-of-way.
Figure 2-1 Stormwater curb extension, Southgate Neighborhood,
Palo Alto (Source: EOA)
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Bioretention systems in the streetscape have specific names: stormwater
planters, stormwater curb extensions (or bulb-outs), and stormwater tree well
filters (described in the next section).
A stormwater curb extension (Figure 2-1) is a bioretention system that extends
into the roadway and involves modification of the curb line and gutter.
Stormwater curb extensions may be installed midblock or at an intersection.
Curb bulb-outs and curb extensions installed for pedestrian safety, traffic
calming, and other transportation benefits can also provide opportunities for
siting bioretention facilities.
A stormwater planter is a linear bioretention facility in the public right-of-way
along the edge of the street, often in the planter strip between the street and
sidewalk. They are typically designed with vertical (concrete) sides. However, as
shown in Figure 2-2, they can also have sloped sides depending on the amount
of space that is available.
2.3.2 Stormwater Tree Well Filters and Suspended Pavement Systems
A stormwater tree well filter is a type of bioretention system consisting of an
excavated pit or vault that is filled with biotreatment soil media, planted with a tree and other
vegetation, and underlain with drain rock and an underdrain, if needed. Stormwater tree well filters can
be constructed in series and linked via a subsurface trench or underdrain. A stormwater tree well filter
can require less dedicated space than other types of bioretention areas.
Suspended pavement systems may be used to provide increased underground treatment area and soil
volume for tree well filters. These are structural systems designed to provide support for pavement while
preserving large volumes of uncompacted soil for tree roots. Suspended pavement systems may be any
engineered system of structural supports or commercially available proprietary structural systems.
Stormwater tree well filters and suspended pavements systems are especially useful in settings between
existing sidewalk elements where available space is at a premium. They can also be used in curb
extensions or bulb-outs, medians, or parking lots if surrounding grades allow for drainage to those areas.
The systems can be designed to receive runoff through curb cuts or catch basins or allow runoff to enter
through pervious pavers on top of the structural support.
Figure 2-3 Stormwater tree well filter conceptual examples: modular suspended pavement system (left), column
suspended pavement system (right). (Courtesy of Philadelphia Water Department)
Figure 2-2 Stormwater planter,
Hacienda Avenue, Campbell
(Source: City of Campbell)
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2.3.3 Pervious Pavement
Pervious pavement is hardscape that allows water to pass through its surface into a storage area filled
with gravel prior to infiltrating into underlying soils. Types of pervious pavement include permeable
interlocking concrete pavers, pervious concrete, porous asphalt, and grid pavement. Pervious pavement
is often used in parking areas or on streets where
bioretention is not feasible due to space constraints or if
there is a need to maintain parking. Pervious pavement
does not require a dedicated surface area for treatment
and allows a site to maintain its existing hardscape.
There are two types of pervious pavers: Permeable
Interlocking Concrete Pavers (PICP) and Permeable Pavers
(PP). PICP allows water to pass through the joint spacing
between solid pavers, and PP allows water to pass through
the paver itself and therefore can have tighter joints.
Porous asphalt and pervious concrete are similar to
traditional asphalt and concrete, but do not include fine
aggregates in the mixture, allowing water to pass through the surface. All types are supported by several
layers of different sizes of gravel to provide structural support and water storage.
2.3.4 Infiltration Facilities
Where soil conditions permit, infiltration facilities can be used
to capture stormwater and infiltrate it into native soils. The
two primary types are infiltration trenches and subsurface
infiltration systems.
An infiltration trench is an excavated trench backfilled with a
stone aggregate and lined with a filter fabric. Infiltration
trenches collect and detain runoff, store it in the void spaces
of the aggregate, and allow it to infiltrate into the underlying
soil. Infiltration trenches can be used along roadways,
alleyways, and the edges or medians of parking lots. An
example of an infiltration trench is shown in Figure 2-5.
Subsurface infiltration systems are another type of GSI
measure that may be used beneath parking lots or parks to
infiltrate larger quantities of runoff. These systems, also known
as infiltration galleries, are underground vaults or pipes that
store and infiltrate stormwater while preserving the uses of the
land surface above parking lots, parks and playing fields. An
example is shown in Figure 2-6. Storage can take the form of
large-diameter perforated metal or plastic pipe, or concrete
arches, concrete vaults, plastic chambers or crates with open
bottoms. Prefabricated, modular infiltration galleries are
available in a variety of shapes, sizes, and material types that are
strong enough for heavy vehicle loads.
Figure 2-4 Permeable interlocking concrete
pavers, Mayfield Playing Fields, Palo Alto
(Source: EOA)
Figure 2-6 Subsurface infiltration system
(Source: Conteches.com)
Figure 2-5 Infiltration trench, San Jose
(Source: City of San Jose)
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2.3.5 Green Roofs
Green roofs are vegetated roof systems that filter, absorb,
and retain or detain the rain that falls upon them. Green roof
systems are comprised of a layer of planting media planted
with vegetation, underlain by other structural components
including waterproof mem branes, synthetic insulation,
geofabrics, and underdrains. A green roof can be either
“extensive”, with 3 to 7 inches of lightweight planting media
and low-profile, low-maintenance plants, or “intensive”, with
a thicker (8 to 48 inches) of media, more varied plantings, and
a more garden-like appearance. Green roofs can provide high
rates of rainfall retention via plant uptake and
evapotranspiration and can decrease peak flow rates in storm
drain systems because of the storage that occurs in the planting media during rain events.
2.3.6 Rainwater Harvesting and Use
Rainwater harvesting is the process of collecting rainwater from
impervious surfaces and storing it for later use. Storage facilities that
can be used to capture stormwater include rain barrels, above-ground
or below-ground cisterns (Figure 2-8), open storage reservoirs (e.g.,
ponds), and various underground storage devices (tanks, vaults, pipes,
and proprietary storage systems)(Figure 2-9). The captured water is
then fed into irrigation systems or non-potable water plumbing
systems, either by pumping or by gravity flow. Uses of captured water
may include irrigation, vehicle washing, and indoor non-potable use
such as toilet flushing, heating and cooling, or industrial processing.
The two most common applications of rainwater harvesting are 1)
collection of roof runoff from buildings; and 2) collection of runoff from
at-grade surfaces or diversion of water from storm drains into large
underground storage facilities below parking lots or parks. Rooftop
runoff usually contains lower quantities of pollutants than at-grade
surface runoff and can be collected via gravity flow. Underground
storage systems typically include pre-treatment facilities to remove
pollutants from stormwater prior to storage and use.
Existing GSI Facilities
The City of Cupertino completed an 18-acre Stevens Creek Corridor
Park and Restoration project in July 2014. The City is also installing GSI measures at the McClellan Ranch
Preserve as part of expansion and improvements at the site, with construction expected to be
completed by September 1, 2019. GSI projects such as this, completed by the City prior to or during the
current permit term (2016-2020), are also referred to in the permit as “Early Implementation” projects
(see Section 5.1.1 of this GSI Plan). Both projects are described below. A description of the Apple Park
project, which included GSI improvements in the public right-of-way, is also described below.
Figure 2-7 Green roof at Fourth Street
Apartments, San José (Source: EOA)
Figure 2-8 Rainwater harvesting cistern,
Environmental Innovation Center, San
José (Source: City of San Jose)
Figure 2-9 Subsurface vault, under
construction (Source: Conteches.com)
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2.4.1 Stevens Creek Corridor and Creek Restoration project
The Stevens Creek Corridor and Creek Restoration project at Blackberry Farm in Cupertino consisted of
two phases.
Phase 1 of the project restored a portion of Stevens Creek, enhanced natural hydrologic processes, and
improved wildlife and habitat values. Impervious cover was reduced by 3.4 acres, including removal of
an asphalt driveway and parking lot, and concrete surfaces in the creek corridor. The former parking lot,
which drained directly into the creek, was replaced by a smaller green parking area, set back from the
creek and made entirely of permeable material. Drive aisles are made of porous concrete that is colored
to reduce heat gain. Parking bays were constructed using recycled plastic geocells to support vehicle
weight filled with special soil and planted with turf grass (see Figure 2-10). During heavy rains, excess
water flows to bioretention areas in a center median. Dozens of native trees were also planted. The
design aimed to use all rain and storm flows to water native plantings. The project site is located within
a flood plain. It was designed to accommodate being submerged during unusually high creek flows
without damage to new infrastructure, water quality or wildlife and to retain stormwater onsite. The
design enables the site’s ability to attenuate flooding, and naturally filter and return rainfall and runoff
from the site to groundwater.
Phase 2 of the Stevens Creek Corridor project included four
new bioswales and an infiltration area installed on the
adjacent golf course to capture and infiltrate runoff from
the golf course, buildings, and the parking lot that
previously flowed directly into the creek. Additionally, an
all-weather trail was installed using pervious concrete
(Figure 2-11). The trail material is compatible with
floodplain standards and protects the fishery and wildlife.
Figure 2-10 Completed green parking bays (above left) and parking bays under construction, showing the
recycled plastic geocells that support vehicle weight (above right).(Source: City of Cupertino)
Figure 2-11 Pervious concrete bike
path and walkway at Blackberry
Farm. (Source: City of Cupertino)
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2.4.2 McClellan West Parking Lot
McClellan Ranch Preserve overflow parking had historically been relegated to the 1.4 acre vacant
unimproved parcel which lies west of the Preserve and adjacent to Stevens Creek. The site experienced
poor drainage and contributed to track out of sediment during all seasons. With the construction of the
Environmental Education Center and other improvements within the Preserve, expanded community
and school use, there was need for additional parking during large events and for oversized vehicles
such as school buses. To meet the parking demand and provide habitat restoration, the project was
designed to create a “green” meadow-style parking area compatible with the existing riparian setting.
Components of this improvement include 0.53 acres of parking surface paved with permeable concrete
including a gravel overflow area, planting thirty-seven native species trees, and adding approximately
20,000 square feet of new native riparian plants which will enhance the existing native habitat along
Stevens Creek. Construction is expected to be completed by September 1, 2019.
2.4.3 Apple Park
Apple Park lies on 152 acres of land that was formerly occupied by more traditional office space with
expansive impervious parking lots and multiple office buildings. Putting parking underground and
emphasizing California native landscaping, the Apple project reduced the impervious surface from
5,085,000 square feet (117 acres) to 2,615,000 square feet (60 acres). There was an emphasis on
planting native trees, enlisting the expertise of Stanford arborist, David Muffly. The campus drains to
flow-through planter bioretention treatment before entering the Calabazas watershed and features
9,000 trees, nearly double the 4,596 trees at the pre-project site. The project exceeded regulatory
requirements by providing stormwater treatment in the public right-of-way.
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3. INTEGRATION WITH OTHER PLANNING DOCUMENTS
To ensure the success of the GSI Plan and its implementation, its goals, policies and implementation
strategies should align with the City’s General Plan and other related planning documents. The MRP
requires that municipal agencies review such documents and include in their GSI Plans a summary of any
planning documents aligned with the GSI Plan or updated or modified to appropriately incorporate GSI
requirements. The GSI Plan must also include a workplan identifying how GSI measures will be included
in future plans.
City Planning Document Review
The City completed a review of its existing planning documents to determine the extent to which GSI-
related language, concepts and policies have been incorporated. The plans that were reviewed are listed
below, with the General Plan as guiding planning document first, followed by remaining plans in order of
most recently prepared/adopted:
• General Plan – Community Vision 2040 (2015)
• Pedestrian Transportation Plan (2018)
• Storm Drain Master Plan (2018)
• Bicycle Transportation Plan (2016)
• Climate Action Plan (2015)
• Heart of the City Specific Plan (2014)
• Citywide Parks & Recreation System Master Plan (Draft)
The following sections provide a brief discussion of each plan and the extent to which it supports GSI
implementation. A prioritized workplan for the integration of GSI language into existing and future City
planning documents is provided in Section 3.1.8.
3.1.1 General Plan – Community Vision 2040
The City’s Community Vision 2040 functions as the City of Cupertino’s State-mandated General Plan and
covers a time frame of 2015–2040. Community Vision 2040 provides a framework for integrating the
aspirations of residents, businesses, property owners and public officials into a comprehensive strategy
for guiding future development and managing change. It describes long-term goals and guides decision-
making by the City Council and appointed commissions. The document was last amended in October
2015 and includes language that is very supportive of GSI. Examples of supportive language in the plan
are summarized below. No updates related to GSI are recommended at this time.
ES-3: Context, Urban Ecosystems (page ES-6):…the City is committed to enhancing the urban
ecosystem in the form of urban forestry management, integration of green infrastructure,
treatment of parks and open space, landscape and building requirements.
Strategy ES-1.1.1: Climate Action Plan (Page ES-14): Integrate multiple benefits of green
infrastructure with climate resiliency and adaptation
Goal ES-2.1.5 Urban Forest (Page ES-16): Encourage the inclusion of additional shade trees,
vegetated stormwater treatment and landscaping to reduce the “heat island effect” in
development projects.
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SE-5.1.1 Landscaping (page ES-21): Ensure that the City’s tree planting, landscaping and open
space policies enhance the urban ecosystem by encouraging medians, pedestrian crossing and
curb-extension planting that is native, drought-tolerant, treats stormwater and enhances
urban plant, aquatic and animal resources in both, private and public development.
ES-5.1.2: Built Environment (page ES-21): Ensure that sustainable landscaping design is
incorporated in the development of City facilities, parks and private projects with the inclusion
of measures such as tree protection, stormwater treatment and planting of native, drought
tolerant landscaping that is beneficial to the environment.
Policy ES-7.1 Natural Water Bodies and Drainage Systems (page ES-24): In public and private
development, use Low Impact Development (LID) principles to manage stormwater by
mimicking natural hydrology, minimizing grading and protecting or restoring natural drainage
systems.
Policy ES-7.2: Reduction of Impervious Surfaces (page ES-24): Minimize stormwater runoff
and erosion impacts resulting from development and use low impact development (LID)
designs to treat stormwater or recharge groundwater
Strategy ES-7.2.1: Lot Coverage (page ES-24): Consider updating lot coverage requirements
to include paved surfaces such as driveways and ongrade impervious patios to incentivize the
construction of pervious surfaces.
Strategy ES-7.2.2: Pervious Walkways and Driveways (page ES-24): Encourage the use of
pervious materials for walkways and driveways…
Policy ES-7.2.3: Maximize Infiltration (page ES-25): Minimize impervious surface areas, and
maximize on-site filtration and the use of on-site retention facilities.
Strategy ES-7.3.1: Development Review (Page ES-25): Require LID designs such as vegetated
stormwater treatment systems and green infrastructure to mitigate pollutant loads and flows.
Strategy ES-7.4.1 Storm Drainage Master Plan (Page ES-25): Develop and maintain a Storm
Drainage Master Plan which identifies facilities needed to prevent “10-year” event street
flooding and “100-year” event structure flooding and integrate green infrastructure to meet
water quality protection needs in a cost effective manner.
Strategy ES-7.11.5 On-site Recycled Water (Page ES-27): Encourage on-site water recycling
including rainwater harvesting and gray water use.
Strategy ES-7.11.7 Green Business Certification and Water Conservation (Page ES-27):
Continue to support the City’s Green Business Certification goals of long-term water
conservation within City facilities, vegetated stormwater infiltration systems, parks and
medians, including installation of low-flow toilets and showers, parks, installation of
automatic shut-off valves in lavatories and sinks and water efficient outdoor irrigation.
Strategy INF-4.1.1: Stormwater Management (page INF-14): Reduce the demand on storm
drain capacity through implementation of programs that meet and even exceed on-site
drainage requirements
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3.1.2 Pedestrian Transportation Plan
Cupertino adopted its Pedestrian Transportation Plan (PTP) in 2002; an update was completed in
February 2018. The purpose of the PTP is to establish a guiding framework for the development and
maintenance of pedestrian facilities throughout Cupertino and recommend policies, programs, and
messaging to support and promote walking. Existing language in the PTP to support GSI is summarized
here:
Curb Extension Benefits (Page 38): Extended sidewalk space can be used for plantings, street
furniture, or green stormwater infrastructure.
Choker/Pinch Point Benefits (Page 41) Stormwater and greenspace elements can be
combined to calm traffic while also making the street more attractive.
3.1.3 Storm Drain Master Plan
The latest version of the City’s Storm Drain Master Plan (SDMP) dated September 2018, was accepted by
City Council Resolution on January 15, 2019. The objective of the SDMP is to provide an examination of
the flood risks within the City limits and recommend actions necessary to accomplish defined levels of
service for storm drain systems owned by the City so as to appropriately manage flood risks. The SDMP
includes a discussion of the C.3 MRP Requirements and a discussion of GSI. Existing language to support
GSI is summarized here:
Section 2.2.2 Future Land Use: The majority of future development will involve the
redevelopment of sites, such as infill projects. Future development will need to comply with
C.3 requirements of the Municipal Regional Permit (MRP) for the Bay Area. These
requirements to treat storm water runoff may result in a reduction of impervious surface…
Section 5.7 Green Infrastructure: The City should look for and evaluate opportunities to
incorporate green infrastructure and LID facilities into the design of capital projects
recommended in the master plan.
3.1.4 Bicycle Transportation Plan
The City adopted a Bicycle Transportation Plan (BTP) in 2011 that describes long-term goals with respect
to the creation of a safe, convenient, and comprehensive network of bicycle facilities throughout the
City. The BTP was updated in 2016 to identify which priority projects have already been completed and
which remain to be implemented, and to identify any new projects that should be included for
prioritization. The BTP currently does not include language to support GSI. However, all bike lane
projects will be CIP projects and therefore reviewed annually as part of the review of projects for
potential GSI opportunities (See Section 6.2).
3.1.5 Climate Action Plan
The Climate Action Plan (CAP) defines Cupertino’s path toward creating a healthy, livable, and vibrant
place for its current and future residents to live, learn, work, and play. The CAP seeks to identify
emissions reduction strategies that are informed by the goals, values, and priorities of the community.
The document was completed in January 2015. The CAP emissions reduction measures are organized
into five goals, one of which is “Expand Green Infrastructure”. Existing language in support of GSI is
summarized below.
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GHG Overarching Goals (Pages ES-14 and 66): Expand Green Infrastructure: enhance the
City’s existing urban forest and landscapes on public and private land.
Measure C-W-2 Recycled Water Irrigation Program (Page 116): As an alternative to recycled
water use…small-scale, on-site rainwater catchment systems could be installed to better
utilize natural precipitation for irrigation purposes, as opposed to use of scarce potable water
resources. The City will develop a demonstration project on municipal property …
Goal 5 – Expand Green Infrastructure (Page 127): In Cupertino, green space includes the
urban forest, parks, landscaped medians and parkways, and natural stormwater-absorbing
landscapes. Healthy and robust green infrastructure systems can mitigate the urban heat
island effect, lower building energy use, provide natural stormwater management and wildlife
habitat, improve local air quality, and increase community pride.
Measure C-G-1 Urban Forest Program (Page 128): The City should incentivize Green roofs for
their role in “protecting water resources adversely impacted by climate change by reducing
electricity usage and improving air quality.
Measure C-G-1 Action D (Page 130): Evaluate opportunities to expand current ordinances and
codes to prioritize expansion of City’s green and cool roofs, as well as pervious and cool
pavement.
Measure C-G-1 Action F (Page 130): Expand community and school gardens, and evaluate
opportunities to develop prevalent demonstration garden that incorporates water-sensitive
design and advanced irrigation control technology (if irrigation system is necessary.
Measure M-F-7 Action E. Install Graywater and Rainwater Catchment Systems in New
Construction and Major Retrofit Projects (page 186): In the absence of access to utility-
supplied recycled water in our community, Cupertino will strive to lead by example by installing
graywater and rainwater catchment systems in new municipal construction and major retrofit
projects…These projects can also serve as models for community members and businesses
seeking to achieve the same environmental and financial benefits, and should be showcased
to reconnect Cupertino’s suburban residents to their backyard gardens and the natural water
cycle.
3.1.6 Heart of the City Specific Plan
The Heart of the City Specific Plan provides specific development guidance for the most important
commercial corridor in the City of Cupertino. The purpose of the specific plan is to guide the future
development and redevelopment of the Stevens Creek Boulevard Corridor in a manner that creates a
greater sense of place and community identity in Cupertino. The Streetscape Element implements
community design goals contained in the 1993 General Plan, design concepts subsequently developed
and revised in the 1993 “Heart of the City” Design Charette, and any new policies and concepts
identified in the 2005 General Plan. The document was enacted by the City Council in December 2014
and does not include language to support GSI. However, consistent with the City’s strategy to ensure no
missed opportunities (Section 6), any development related to the Heart of the City will go through the
CIP review for identifying and evaluating GSI opportunities.
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3.1.7 Citywide Parks & Recreation System Master Plan (Draft)
The City is preparing a Citywide Parks & Recreation System Master Plan (Draft), which provides guidance
to create a park system for the future aligned with the community’s values and priorities. The Master
Plan creates a vision through the year 2040 to guide future development, renovation, management and
activation of City parks and recreation facilities. Elements of the Master Plan goals include conservation
of trees and natural areas which support wildlife and ecological functions and establish sustainable
practices in management of parks and recreation facilities. Existing language in support of GSI in the
draft plan dated January 2019 is summarized here:
Conservation Goal 1.D.v (Page 39): Embrace storm water management, incorporating
green infrastructure elements such as rain gardens, bioswales, permeable pavers and
detention ponds to help reduce flooding, filter pollutants and replenish groundwater during
storm events.
Sustainability Goal 7.C.ix (Page 73): Train staff in maintenance and stewardship of natural
areas, green infrastructure, and bioswales, so that these features thrive and the integrity of
natural resources on City property is maintained. Involve expert professional services as
needed to support informed and ongoing care for habitat areas.
Sustainability Goal 7.C.xi (Page 74): Focus on storm water management and green
infrastructure when designing or renovating City parks. For example, consider installing a
‘storm water management garden’ on City or public property to showcase green
infrastructure techniques.
Enhancements to Existing Parks, Creekside Park and Connection to Regnart Creek Trail
(page 84): Consider adding trail amenities, enhancing and protecting the riparian corridor,
and adding green infrastructure. Encourage connections between school, parks and trail.
Enhancements to Existing Parks, Saratoga Creek Trail (Page 84): Consider adding trail
amenities, enhancing and protecting the riparian corridor, and adding green infrastructure.
Encourage connections northward to Stevens Creek Blvd. and to regional destinations.
Enhancements to Existing Parks, Stevens Creek Trail (Page 84): Consider adding trail
amenities and adding green infrastructure. Encourage pedestrian and bike connections
between trail, City parks, County parks and nearby schools.
3.1.8 Workplan for Integration of GSI Language into Existing and Future City Planning
Documents
The General Plan, Climate Action Plan, Pedestrian Transportation Plan, Storm Drain Master Plan, and the
draft Citywide Parks and Recreation System Master Plan all include adequate language to support the
implementation of GSI in Cupertino. The Heart of the City Plan was last amended with the General Plan
in 2014. Unless there are development triggers, the Heart of the City Plan will be updated with GSI
language during future General Plan amendments. Consistent with the City’s strategy (See Section 6.1),
any progress on the Heart of the City will go through the CIP review and green stormwater
infrastructure will be considered as part of that review.
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When preparing new planning documents, the City will review GSI Plan requirements during the
planning process to ensure that GSI requirements and policies are incorporated. Examples of GSI related
language can be found in existing City plans, and in references such as SCVURPPP’s Model Green
Infrastructure Language for Incorporation into Municipal Plans (2016).
Regional Plans
The City is collaborating with SCVURPPP, Valley Water, and other agencies on several large-scale
planning efforts including those described below.
3.2.1 Santa Clara Basin Stormwater Resource Plan
A collaboration between SCVURPPP and Valley Water during 2017 and 2018, the Santa Clara Basin
Storm Water Resources Plan (SWRP) supports municipal GSI Plans by identifying and prioritizing
potential multi-benefit GSI opportunities on public parcels and street rights-of-way throughout the Basin
(i.e., Santa Clara Valley) and allows them to be eligible for State bond-funded implementation grants.
The SWRP includes a list of prioritized GSI opportunity locations for each SCVURPPP agency, including
Cupertino. As described in Section 5.2, the City’s GSI Plan builds on the SWRP output to further identify,
evaluate, and prioritize potential projects.
3.2.2 Santa Clara Valley Water District’s One Water Plan
Valley Water’s Watershed Division is leading an effort to develop an Integrated Water Resources Master
Plan to identify, prioritize, and implement activities at a watershed scale to maximize established water
supply, flood protection, and environmental stewardship goals and objectives. The “One Water Plan”
establishes a framework for long-term management of Santa Clara County water resources, which
eventually will be used to plan and prioritize projects that maximize multiple benefits. The One Water
Plan incorporates knowledge from past planning efforts, builds on existing and current related planning
efforts; and coordinates with relevant internal and external programs. The One Water Plan has five
goals:
1.“Valued and Respected Rain” – Manage rainwater to improve flood protection, water supply,
and ecosystem health.
2.“Healthful and Reliable Water” – Enhance the quantity and quality of water to support
beneficial uses.
3.“Ecologically Sustainable Streams and Watersheds” – Protect, enhance and sustain healthy and
resilient stream ecosystems.
4.“Resilient Baylands” – Protect, enhance and sustain healthy and resilient baylands ecosystems
and infrastructure.
5.“Community Collaboration” – Work in partnership with an engaged community to champion
wise decisions on water resources.
Tier 1 of the effort, for which a draft plan was completed in 2016 6, is a countywide overview of major
resources and key issues along with identified goals and objectives. Tier 2 (2016 to 2020) will include
greater detail on each of the County’s major watersheds. The City’s GSI Plan aligns with the goals of the
6 Santa Clara Valley Water District. 2016. One Water Plan for Santa Clara County. An Integrated Approach to Water
Resources Management. Preliminary Draft Report 2016.
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One Water Plan and may be able to coordinate with specific projects yet to be identified in the West
Valley area.
3.2.3 Bay Area Integrated Regional Water Management Plan
The Bay Area Integrated Regional Water Management Plan (IRWMP) is a comprehensive water
resources plan for the Bay region that addresses four functional areas: 1) water supply and water
quality; 2) wastewater and recycled water; 3) flood protection and stormwater management; and 4)
watershed management and habitat protection and restoration. It provides a venue for regional
collaboration and serves as a platform to secure state and federal funding. The IRWMP includes a list of
over 300 project proposals, and a methodology for ranking those projects for the purpose of submitting
a compilation of high priority projects for grant funding. The Santa Clara Basin SWRP was submitted to
the Bay Area IRWMP Coordinating Committee and incorporated into the IRWMP as an addendum. As
SWRP projects are proposed for grant funding, they will be added to the IRWMP list using established
procedures.
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4. GSI DESIGN GUIDELINES, DETAILS, AND SPECIFICATIONS
The MRP requires that the GSI Plan include general design and construction guidelines, standard
specifications and details (or references to those documents) for incorporating GSI components into
projects within the City. These guidelines and specifications should address the different street and
project types within the City, as defined by its land use and transportation characteristics, and allow
projects to provide a range of functions and benefits, such as stormwater management, bicycle and
pedestrian mobility and safety, public green space, and urban forestry.
The City, along with other SCVURPPP agencies, helped fund and provided input to the development of
countywide guidelines by SCVURPPP to address the MRP requirements and guide the implementation of
GSI Plans. The resulting SCVURPPP GSI Handbook (Handbook)7 is a comprehensive guide to planning and
implementation of GSI projects in public streetscapes, parking lots and parks. The Handbook consists of
two parts, the contents of which are described in the following sections. The City intends to use this
Handbook as a reference when creating City-specific guidelines and specifications to meet the needs of
the various departments.
Design Guidelines
Part 1 of the Handbook provides guidance on selection, integration, prioritization, sizing, construction,
and maintenance of GSI facilities. It includes sections describing the various types of GSI, their benefits,
and design considerations; how to incorporate GSI with other uses of the public right-of-way, such as
bicycle and pedestrian infrastructure and parking; and guidelines on utility coordination and landscape
design for GSI. In addition, the Handbook also provides guidance on post-construction maintenance
practices and design of GSI to facilitate maintenance.
Part 1 also contains a section on proper sizing of GSI measures. Where possible, GSI measures should be
designed to meet the same sizing requirements as Regulated Projects, which are specified in MRP
Provision C.3.d. In general, the treatment measure design standard is capture and treatment of 80% of
the annual runoff (i.e., capture and treatment of the small, frequent storm events). However, if a GSI
measure cannot be designed to meet this design standard due to constraints in the public right-of-way
or other factors, the City may still wish to construct the measure to provide some runoff reduction and
water quality benefit and achieve other benefits. For these situations, the Handbook describes (in
Section 4.2) regional guidance on alternative design approaches developed by the Bay Area Stormwater
Management Agencies Association (BASMAA) for use by MRP permittees.
Details and Specifications
Part 2 of the Handbook contains typical details and specifications that have been compiled from various
sources within California and the U.S. and modified for use in Santa Clara County. The Handbook
includes details for pervious pavement, stormwater planters, stormwater curb extensions, bioretention
in parking lots, infiltration measures, and stormwater tree wells, as well as associated components such
as edge controls, inlets, outlets, and underdrains. It also provides typical design details for GSI facilities
7 SCVURPPP (2019) Green Stormwater Infrastructure Handbook. February. Online at
http://scvurppp.org/scvurppp_2018/swrp/resource-library/
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in the public right-of-way that address utility protection measures and consideration of other
infrastructure in that space.
Incorporation of SCVURPPP Details and Specifications into City Standards
The City plans to reference the SCVURPPP GSI Guidelines and Specifications for design of GSI projects.
The City will review these for consistency with its own local standards, and revise existing guidelines,
standard specifications, design details, and department procedures as needed. The City will also
reference details and build on its experience from design and construction of the Stevens Creek Corridor
and Creek Restoration Project (Section 2.4.1).
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5. GSI PROJECT PRIORITIZATION AND IMPERVIOUS TARGETS
To meet the requirements of the MRP, the City’s GSI Plan must contain a mechanism to prioritize and
map areas for potential and planned projects, both public and private, for implementation over the
2020, 2030, and 2040 milestones. The mechanism must include the criteria for prioritization and outputs
that can be incorporated into the City’s long-term planning and capital improvement processes.
This chapter describes different GSI project categories considered within the City, followed by a
description of the process employed by the City to identify public lands that offer opportunities to
implement GSI and prioritize those opportunities, and the results of the process.
Project Types
GSI project types that have been or may be implemented in the City fall into the following categories:
Early Implementation Projects, C3 Regulated Projects, Green Streets, LID Retrofits, and Regional
Projects. Green Streets, LID Retrofits, and Regional Projects are types of GSI capital projects that the
City may implement to meet the water quality goals in the MRP and multi-benefit objectives defined in
the GSI Plan. GSI capital projects are typically not regulated projects (although they must conform to the
sizing and design requirements contained in Provision C.3, except under certain circumstances) and they
are primarily public projects under control of the City. These three project types are the focus of the
prioritization process described in Section 5.2, but all five GSI project types are considered as part of the
City wide GSI strategy presented in Chapter 6. Several factors, such as change in scope of work, funding,
site conditions, etc. determine the ability of the City to implement GSI capital projects.
5.1.1 Early Implementation Projects
Early Implementation Projects are GSI projects that have already been implemented by the City or are
already scheduled and funded for implementation during the permit term (i.e., through December
2020). The City has already implemented one GSI projects, as discussed in Section 2.4. The City has
identified an additional Early Implementation project through a review of its Capital Improvement
Program (CIP), as discussed in Section 5.2.2 below.
5.1.2 Regulated Projects
C3 Regulated Projects are those implemented as part of new and redevelopment within the City, both
private and public, that must meet the post-construction stormwater treatment requirements per
Provision C.3 of the MRP. Regulated projects include private development or redevelopment projects,
such as multi-family residential buildings, commercial office buildings, or shopping plazas, as well as
public projects, such as libraries, police stations, and parking lots, exceeding the impervious surface
thresholds. The “Apple Park” project, a 176-acre site that replaced the former Hewlett Packard industrial
campus and includes LID measures, is an example of a regulated project.
5.1.3 LID Projects
LID projects mitigate stormwater impacts by reducing runoff through capture and/or infiltration and
treating stormwater on-site before it enters the storm drain system. LID projects may include
bioretention facilities, infiltration trenches, detention and retention areas in landscaping, pervious
pavement, green roofs, and systems for stormwater capture and use. For the purposes of the GSI Plan,
LID projects are GSI facilities that treat runoff generated from a publicly-owned parcel on that parcel.
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5.1.4 Regional Projects
Regional projects capture and treat stormwater runoff from on-site and off-site sources, including
surface runoff and diversions from storm drains. Benefits of regional stormwater capture projects can
include flood risk reduction, stormwater treatment and use, and groundwater recharge. These projects
may take a variety of forms such as detention and retention basins and subsurface vaults and infiltration
galleries. The site characteristics will determine what types of regional projects are feasible, e.g.,
whether a project is on-line or off-line from the storm drain network, whether it is desirable to change
the functionality of the site, whether the project is above ground or underground, and the size of the
project.
5.1.5 Green Street Projects
Green street projects are GSI opportunities in the public right-of-way that capture runoff from the street
and adjacent areas that drain to the street. The technologies used for green streets are similar to those
used in LID projects but are limited to designs that can be used in the right-of-way. Green street projects
may include bioretention (e.g., stormwater planters, stormwater curb extensions or stormwater tree
filters), pervious pavement, and/or infiltration trenches. Green street GSI features can be incorporated
into other improvements in the right-of-way, including complete streets designs and improvements for
pedestrian and cyclist safety.
Identification and Prioritization Process
The City of Cupertino GSI opportunity identification and prioritization process involved two steps. The
first step was the screening and prioritization methodology used in the Santa Clara Basin SWRP (see
Section 3.2.1) to identify and prioritize GSI opportunities on public parcels and street segments within
the region. The second step in the process involved overlaying City-specific priorities, planning areas,
and upcoming City projects onto the regional prioritization results to align the results of the SWRP
prioritization process with the City’s priorities. These steps are described in detail below.
City projects in areas associated with a project opportunity identified in the SWRP can qualify for State
bonded-funded stormwater capture project implementation grants (e.g., Proposition 1). Opportunities
for GSI implementation that arise in areas that are not adjacent to a prioritized project opportunity
identified in the SWRP may be considered on a case by case basis for feasibility, cost effectiveness, and
availability of funding.
5.2.1 Step 1: Stormwater Resource Plan Prioritization
Building on existing documents that describe the characteristics and water quality and quantity issues
within the Santa Clara Basin (i.e., the portion of Santa Clara County that drains to San Francisco Bay), the
SWRP identified and prioritized multi-benefit GSI opportunities throughout the Basin, using a metrics-
based approach for quantifying project benefits such as volume of stormwater infiltrated and/or
treated, and quantity of pollutants removed. The metrics-based analysis was conducted using
hydrologic/ hydraulic and water quality models coupled with Geographic Information System (GIS)
resources and other tools. The products of these analyses were a map of opportunity areas for GSI
projects throughout the watershed, an initial prioritized list of potential project opportunities, and
strategies for implementation of these and future projects.
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The process began by identifying and screening public parcels and public rights-of-way 8 that can support
GSI. Project opportunities were split into the three categories described above – LID, regional, and green
streets projects -- because of fundamental differences in GSI measures used, project scale, and
measures of treatment efficiency. Screening factors are presented in Table 5-1.
After the identification of feasible GSI opportunity locations, screened streets and parcels were
prioritized to aid in the selection of project opportunities that would be the most effective and provide
the greatest number of benefits. In addition to physical characteristics, several special considerations
were included in the prioritization methodology to consider coordination with currently planned
projects provided by agencies, as well as consideration of additional benefits that projects could
provide. A discussion of the screening and prioritization process for each project category is presented
in the subsequent sections. Figure 5-1 presents the results of the various steps.
LID and Regional Stormwater Capture Project Opportunities
The screening criteria for LID and regional projects were ownership (focusing only on public parcels),
land use, and site slope. As shown in Table 5-1, parcel size was used to determine whether a location
could support a regional or LID project.
Parcels that met the screening criteria were prioritized based on physical characteristics such as soil
group, slope, and percent impervious area, proximity to storm drains, proximity to flood-prone creeks
and areas, proximity to potential pollutant sources (e.g., PCBs 9), whether they were in a priority
development area (PDA), whether they were within a defined proximity to a planned project, and
whether the project was expected to have other benefits such as augmenting water supply, providing
water quality source control, re-establishing natural hydrology, creating or enhancing habitat, and
enhancing the community. Prioritization metrics for LID project scoring and regional project scoring are
shown in separate tables in Appendix A. The result of the parcel prioritization was a list and map of
potential project locations based on the above criteria. This subset of projects from the SWRP was
carried over into Step 2 City-Specific Prioritization (Section 5.2.2).
Table 5-1 Screening factors for parcel-based and right-of-way project opportunities
Screening
Factor Characteristic Criteria Reason
Parcel-based
Public
Parcels Ownership
County, City, Town,
Valley Water, State,
Open Space
Agencies
Identify all public parcels for regional
stormwater capture projects or onsite LID
retrofits
8 Public parcels can include those not owned by the City, such as public school grounds, County, State, and Federal properties,
and property owned by the Water District.
9 Polychlorinated biphenyls – manmade chemicals which resist extreme temps, and were used in electrical equipment such as
transformers and capacitors; and building materials such as caulking, adhesives, mastics etc. primarily from 1950s through
1981. PCBs pose developmental or neurological risks to fetuses, babies, and children, and have been shown to cause cancer in
animals and evidence supports cancer causing effect in PCB workers.
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Screening
Factor Characteristic Criteria Reason
Parcel-based
Land Use Park, School, Other
(e.g., Golf Course)
Suitability
Parcel Size
≥ 0.25 acres Opportunity for regional stormwater capture
project
< 0.25 acres Opportunity for on-site LID project
Site Slope < 10 % Steeper grades present additional design
challenges
Right-of-Way
Selection Ownership Public Potential projects are focused on public right-
of-way opportunities
Suitability
Surface Paved Only roads with paved surfaces are considered
suitable. Dirt roads were not considered.
Slope < 5% Steep grades present additional design
challenges; reduced capture opportunity due
to increased runoff velocity
Speed ≤ 45mph Excludes higher speed roads such as major
arterials and highways
Green Street Project Opportunities
The screening criteria for green streets projects in the public right-of-way were ownership, surface
material, slope, and speed limit (Table 5-1). The screened public right-of-way street segments were then
prioritized based on physical characteristics, proximity to storm drains, proximity to flood-prone creeks
and areas, proximity to potential pollutant sources (e.g., PCBs 10), whether they were in a priority
development area, whether they were in proximity to a planned project, and whether the project was
expected to have other benefits (similar to LID and regional projects). Prioritization metrics for green
streets projects are shown in Appendix A.
The initial prioritization process resulted in a large number of potential green streets project
opportunities within the Santa Clara Basin. In order to identify the optimal locations for green street
projects, the street segments in each municipality’s jurisdiction with scores in the top 10 percent of
ranked green street opportunities were identified and mapped.
10 Polychlorinated biphenyls – manmade chemicals which resist extreme temps, and were used in electrical equipment such as
transformers and capacitors; and building materials such as caulking, adhesives, mastics etc. primarily from 1950s through
1981. PCBs pose developmental or neurological risks to fetuses, babies, and children, and have been shown to cause cancer in
animals and evidence supports cancer causing effect in PCB workers.
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5.2.2 Step 2: City-Specific Prioritization
The City reviewed the results from the SWRP prioritization (Section 5.2.1) and refined the list of parcels
and street segments based on current knowledge of City plans and project opportunities. The resulting
parcel-based and green street opportunities for the City of Cupertino are presented in Figure 5-1. The
City’s list of parcel-based and green street opportunities is provided in tabular format in Appendix B.
Next, as discussed in the remainder of this section, the City-specific prioritization incorporated local
priorities for GSI project implementation, which include: 1) opportunities to implement GSI projects in
conjunction with anticipated areas of private development and 2) upcoming capital improvement
projects that can potentially be combined with GSI projects.
Figure 5-1 City of Cupertino Public Parcels and Street Segments with Opportunities for GSI (Source: EOA, and
Santa Clara Basin Stormwater Resource Plan, 2018).
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Priority Development Areas
Priority Development Areas, commonly known as PDAs, are areas within existing communities that local
city or county governments have identified and approved for future growth. These areas typically are
accessible by one or more transit services; and they are often located near established job centers,
shopping districts and other services. PDAs are expected to accommodate 78% of new housing
production (over 500,000 units) and 62% of employment growth (almost 700,000 jobs) in the Bay Area
through the year 204011. As PDAs are developed, they offer good opportunities to construct GSI
facilities.
Cupertino’s PDA area includes properties within a quarter mile of Stevens Creek Boulevard from
Highway 85 to its eastern border and a portion of North and South De Anza Boulevards. The boundary of
the PDA is shown in Figure 5-2.
Special Areas
The City’s General Plan identifies nine Special Areas within Cupertino:
•Heart of the City
•Vallco Shopping District
•North Vallco Park
•South De Anza
•North De Anza
•Homestead
•Bubb Road
•Monta Vista Village
•Other Non-Residential/ Mixed-Use Special Areas
Each Special Area is located along one of the four major mixed-use corridors in the city, which represent
key areas within Cupertino where future development and reinvestment will be focused. Goals for these
areas include more bicycle- and pedestrian-friendly streets and improved walkable, bikeable
connectivity to adjacent areas and services. Because these Special Areas are where the most
development is expected to occur, they will likely have the best opportunities to construct GSI facilities.
The GSI projects could be part of private redevelopment projects or public improvement projects.
The location of the Special Areas are shown on Figure 2-2, with the exception of the Other Non-
Residential/ Mixed-Use Special Areas. These Other Non- Residential/Mixed-Use Special Areas are
located throughout Cupertino and include the following: west side of Stevens Canyon Road across from
McClellan Road; intersection of Foothill Boulevard and Stevens Creek Boulevard; Homestead Road near
Foothill Boulevard; northwest corner of Bollinger Road and Blaney Avenue; and all other non-residential
properties not referenced in an identified commercial area.
11 From Table 4.2 and Table 4.3 of the Association of Bay Area Governments and Metropolitan Transportation Commission
“Plan Bay Area 2040” Report, adopted July 26, 2017.
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Figure 5-2. City of Cupertino Special Project Areas and Priority Development Area (Source: City of Cupertino
General Plan)
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Capital Improvement Projects
As required by the MRP, the City reviews its CIP project list annually to identify opportunities for GSI.
Based on this review, the City prepares and maintains a list of any public GSI projects that are planned
for implementation during the permit term and a list of public projects that have potential for GSI
measures.
As discussed in Section 2.4.2, the City has completed one public GSI project (Stevens Creek Corridor and
Creek Restoration Project). The second public GSI project (McClellan Ranch West Parking Lot
Improvement) is under construction and expected to be completed in September 2019. The project
locations are shown on the map in Figure 5-4.
In addition, through its CIP project review, the City identified the following projects as having potential
to include GSI:
•South Foothill Blvd and N. Foothill Blvd. Green Street: Reconstruct the medians to reduce
runoff and better infiltrate stormwater, and consider bioretention areas along the outer edges
of the boulevard
•Union Pacific Railroad Trail Feasibility Study: Incorporate bioretention areas and pervious trails,
if the study results in a project. Currently this is just a study.
•Mary Avenue Greenbelt and Trail Project: Create a wide bioretention-enhanced green belt on
the west side of Mary Avenue. Include a pervious multi-use pathway to accommodate bicyclists,
pedestrians, strollers, and joggers. Install bioretention tree wells at optimal intervals on the east
side of the street to treat stormwater, and on the west side of the street where feasible to
create a future tree canopy over Mary Ave.
•Junipero Serra Trail Extension: Incorporate bioretention areas and pervious trails where
feasible.
•Memorial Park Renovation: Look for an opportunity to construct an infiltration basin at the park
to treat runoff from Stevens Creek Blvd.
•Regnart Creek Trail: Incorporate bioretention areas and pervious trails where feasible.
•Lawrence Mitty Park: Pending the City acquiring the land, look for opportunities to incorporate
GSI features to treat runoff from the adjacent expressway.
•Stelling Road Potential Future Storm Drain and Street Upgrades: Incorporate bioretention
areas to treat street runoff where feasible.
•Rainbow Drive Storm Drain Pipeline Rehabilitation: Incorporate bioretention areas to treat
street runoff where feasible.
•Bike Boulevard Projects: Cupertino is planning a network of bicycle-friendly routes along
residential streets throughout the City in order to encourage bicycling. Traffic circles and bulb
outs will be considered and designed, where feasible, to include GSI features.
•Citywide Parks and Recreation Master Plan: Install GSI at Linda Vista, Memorial, Monte Vista,
Wilson, and Portal Parks where feasible.
These potential CIP project locations are shown on the map in Figure 5-3. A GSI concept for the Mary
Avenue Greenbelt and Trail Project was completed for the SWRP. The project is currently unfunded, and
the concept design is intended to assist with the grant application process should the City decide to
pursue funding via Proposition 1 or other State bond-funded grant program.
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Figure 5-3. City of Cupertino Public Projects with Potential for GSI (Source: City of Cupertino FY 17-18 Annual
Report, and 2018 Santa Clara Basin Stormwater Resource Plan)
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Prioritization Output
The map in Figure 5-4 presents a compilation of the factors used to identify and prioritize the City’s
opportunities for GSI projects: the City’s list of parcel-based and green street project opportunities,
overlaid with the City’s PDA, Special Areas, and CIP projects that may have potential to include GSI. The
locations of the City’s completed GSI projects, including the McClellan Ranch West Parking Lot project
which is under construction and expected to be completed by September 2019, are also shown. As
shown in Figure 5-4, a large number of the green street opportunities identified in the SWRP are located
within the City’s PDA and Special Areas. This indicates a strong correlation between the areas identified
as having potential for GSI and the City’s construction and redevelopment plans.
The City’s list of parcel-based and green street opportunities is provided in tabular format in Appendix B.
The list includes additional information for each parcel and green street opportunity, including general
information such as APN, landowner and land use or street name, the SWRP prioritization score for each
project opportunity, and co-location with a City criteria for prioritization (CIP project, PDA or Special
Area).
An implementation plan is described in Section 6 to guide the development, design, and construction of
GSI projects.
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Figure 5-4 City of Cupertino GSI Overview
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6.GSI Implementation Plan
This chapter provides an overall strategy and steps for implementing GSI within the City of Cupertino
over the long term. The implementation plan has the following components: (1) the Citywide GSI
strategy; (2) a process for identifying and evaluating GSI opportunities, (3) a workplan to complete Early
Implementation Projects, (4) the legal and funding mechanisms that enable implementation, (5)
estimated targets for the amounts of impervious surface to be “retrofitted” (i.e., redeveloped with GSI
facilities to treat runoff from impervious surfaces), and (5) the technical tools that ensure the tracking of
implemented projects.
City-wide GSI Strategy
The City of Cupertino’s approach to GSI planning will be consistent with the City’s Community Vision
2040 (See Section 3.1.1), which has as guiding principle to:
“Preserve Cupertino’s environment by enhancing or restoring creeks and hillsides to their
natural state, limiting urban uses to existing urbanized areas, encouraging environmental
protection, promoting sustainable design concepts, improving sustainable municipal
operations, adapting to climate change, conserving energy resources and minimizing
waste.”
The City’s approach will also be guided by various other existing plans that support the implementation
of GSI, such as the Climate Action Plan, and the Storm Drain Master Plan. Cupertino has already
completed one project, the Stevens Creek Corridor and Restoration Project (Section 2.1.4), which
incorporated GSI and preserved an 18-acre site and restored creek habitat in the City to maintain
biodiversity and ecological integrity of local natural systems. As the City seeks to achieve sustainability
and community health objectives, future growth and retrofitting of existing infrastructure will create
mixed-use, commercial, employment and neighborhood centers; pedestrian-oriented and walkable
spaces for the community to gather; and distinct and connected neighborhoods with easy walkable and
bikeable access to services, including schools, parks and shopping.
The City of Cupertino’s GSI implementation strategy consists of the following:
•Priority Development Areas - The City will focus future change within the Special Areas that are
located on Cupertino’s major mixed-use corridors. These areas already have a mix of
commercial, office, hotel and residential uses, and are located along roadways that will be
enhanced with “Complete Streets” features, improved landscaping and expanded public spaces
(e.g., parks and plazas). Complete Streets can be enhanced with GSI features to become green
“Sustainable Streets”.
•Evaluation of CIP Projects for Opportunities – The City will continue to review its CIP list annually
for opportunities to incorporate GSI into CIP projects and evaluate the feasibility of such
projects. The City has established a process for CIP review to avoid missing GSI opportunities
(see Section 6.2).
•Evaluation of Opportunities Identified in the Stormwater Resource Plan – The public parcels and
street segments identified in the SWRP (See Section 5.1 of this report) are opportunity areas for
GSI projects. The City will use the SWRP list to help identify potential project locations for GSI
implementation, as described in Section 6.2.
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•Evaluation of Non-CIP Project Opportunities - As awareness of GSI increases, municipal staff or
local community members may also identify and recommend GSI projects opportunities. These
projects will be considered using the methodology described in Section 6.2.
•Coordination with Private Development – The City of Cupertino will explore working with private
property developers to install green infrastructure facilities in public rights-of-way near the
properties they are developing, such as along street frontages.
•Community Outreach and Engagement – The City will provide outreach to the Sustainability
Commission, the Bike and Pedestrian Commission, the local community, and other stakeholders
to get input and support for the implementation of the GSI Plan. The City will also continue to
engage with San Francisco Estuary Institute (SFEI) and/or other potential partners that offer a
regional perspective for enhancing sustainable natural landscaping with multi-faceted benefits.
The City will also continue to require future development projects to comply with C.3 requirements of
the Municipal Regional Permit (MRP), and include site design, source control, treatment control, and
hydromodification management measures as applicable.
Process for Identifying and Evaluating GSI Project Opportunities
The City will use the various mechanisms described in its strategy (Section 6.1) to identify GSI
opportunities in public projects.
The City will use the guidance developed by BASMAA12 (see Appendix D) and the SWRP prioritization
criteria to evaluate public projects to determine the potential for the inclusion of GSI measures at the
project planning level. The evaluation may include site reconnaissance, drainage area delineation, and
cost analysis. If not already on the CIP list, projects identified through this process will be added to the
CIP list when it is updated. Projects with a GSI component may be included in the CIP as funded or
unfunded projects. An unfunded project’s inclusion in the CIP demonstrates that it is a City priority
pending adequate funding. The City prepares the CIP Budget biennially. The next Biennial CIP Budget will
be prepared in 2020 covering FY 2020-21 and FY 2021-22.
The City will map all potential GSI project opportunities to determine their proximity to green street or
parcel-based project opportunities identified in the SWRP (Section 5.2.1). Potential GSI projects that are
adjacent to SWRP opportunity areas may be eligible for state bond funding. Projects with opportunities
for GSI measures may be submitted to the SWRP during the SWRP update process if they are not already
included in the SWRP. This will allow those projects to be eligible for future state bond funding. The
SWRP will likely be updated in the 2022-2023 timeframe. At this time, SCVURPPP will reach out to all
member agencies to provide their project lists for prioritization and inclusion in the updated SWRP.
Workplan to Complete Early Implementation Projects
As discussed in Section 5.2.2 of this GSI Plan, Provision C.3.j. of the MRP requires that the City identify,
prepare, and maintain a list of GSI projects that are planned for implementation during the permit term
(i.e., through December 2020), and infrastructure projects that have potential for GSI measures. The list
12 BASMAA Development Committee (2016) Guidance for Identifying Green Infrastructure Potential in Municipal
Capital Improvement Program Projects. May.
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is submitted with each Annual Report to the Regional Water Board. Projects with GSI that are scheduled
and funded for implementation during the permit term are considered “Early Implementation Projects”.
The City has already identified and completed one early implementation project (Stevens Creek Corridor
and Creek Restoration Project), with a second project (McClellan West Parking Lot) currently under
construction and expected to be completed by September, 2019(see Section 2.4).
The City will continue to review its CIP list annually, using the SWRP prioritization and the guidance
developed by BASMAA for identifying opportunities to incorporate GSI into CIP projects. A copy of the
BASMAA Guidance is provided in Appendix D.
Legal Mechanisms for GSI Implementation
Provision C.3.j.i.(3) of the MRP requires permittees to “Adopt policies, ordinances, and/or other
appropriate legal mechanisms to ensure implementation of the Green Infrastructure Plan in accordance
with the requirements of this provision.”
As described in Section 1.3.2, the City of Cupertino and other municipalities subject to Provision C.3 of the
MRP must require post-construction stormwater control measures on regulated development projects.
Post-construction stormwater controls reduce pollutants from flowing to streams, creeks, and the Bay
and reduce the risk of flooding by managing peak flows. Section 9.18.100 (Permanent Stormwater
Measures Required for Development and Redevelopment Projects) of the City’s Municipal Code provides
legal authority for the City to require regulated private development projects to comply with MRP
requirements.
GSI projects are typically not regulated projects (although they must conform to the sizing and design
requirements contained in Provision C.3 except under certain circumstances) and they are primarily
public projects under control of the City. As part of the GSI Plan process, the City reviewed its existing
policies, ordinances, and other legal mechanisms related to the implementation of stormwater NPDES
permit requirements and found that it has sufficient legal authority to implement the GSI Plan. Adoption
of the GSI Plan by the City Council will further strengthen the authority.
Evaluation of Funding Options
The GSI Plan prioritizes specific projects for near-term integration into CIPs and long-term integration into
City planning efforts. Implementation of these projects is contingent upon the City identifying funding
sources for GSI planning, design, construction, and maintenance.
The total cost of GSI includes costs for planning, capital (design, engineering, construction) and ongoing
expenditures, including operations and maintenance (O&M), utility relocation, and feature replacement.
It is likely that no single source of revenue will be adequate to fund implementation of GSI, and a
portfolio of funding sources will be needed. There are a variety of approaches available to help fund up-
front and long-term investments. This section discusses the City’s current stormwater management
funding sources and then describes additional funding strategies available to implement GSI that are
being considered by the City for future funding.
6.5.1 Current Funding Sources for GSI Program Elements
The City of Cupertino currently uses a combination the City’s General Fund and Federal, State, and other
applicable grants to fund construction of projects in its capital improvement program (CIP) and other
projects. The General Fund, and when applicable, CalRecycle grants, are used for public street, parking
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lot and building maintenance; maintenance of stormwater control measures installed at public projects;
and maintenance of other landscaped areas (e.g., parks, medians, public plazas, etc.)
6.5.2 Potential Future Funding Options
As required by the MRP, the City analyzed possible funding options to raise additional revenue for
design, construction, and long-term operation and maintenance (O&M) of GSI projects. The City used
the guidance on stormwater funding options developed by SCVURPPP (2018) as a reference for
conducting its analysis. Table 6-1 summarizes the funding options that will be considered by the City as
the Plan is implemented. For each type of funding mechanism, the table provides a brief overview and
specifics related to GSI, pros and cons, and applicability to funding planning, capital, and/or long-term
O&M costs.
Impervious Area Targets
As mentioned in Section 1.3.2, the focus of the GSI Plan is the integration of GSI systems into public
rights-of-way. However, the MRP (Provisions C.11 and C.12) establishes a linkage between public and
private GSI features and required reductions of pollutants in stormwater discharges. To help estimate
the pollutant load reductions that can be achieved by GSI during the 2020, 2030, and 2040 timeframes,
the MRP requires that Permittees include in their GSI Plans estimated targets for the amounts of
impervious surface to be “retrofitted” (i.e. redeveloped with GSI facilities to treat runoff from
impervious surfaces) as part of public and private projects during the same timeframes.
The City worked with SCVURPPP staff to develop a methodology to predict the extent and location of
privately- and publicly-owned land areas that will be redeveloped in their jurisdictions and whose
stormwater runoff will be addressed via GSI facilities, and to derive impervious surface targets for GSI
retrofits associated with these redevelopment projects. The methodology and results are described in
Sections 6.6.1 and 6.6.2 below.
6.6.1 Methodology
The first step in the process used historic development trends and City staff’s knowledge of
planned/projected redevelopment in the City to estimate the acres of redevelopment that will occur in
the City by 2020, 2030, and 2040 via redevelopment of privately- and publicly-owned parcels that would
trigger C.3 requirements under the current MRP (i.e. C.3 regulated projects). Stormwater runoff
associated with these parcels will be addressed via GSI facilities, as required by the permit.
The second step was to estimate the acres of impervious surface associated with future redevelopment
of these private and public parcels. To do this, it was necessary to predict the likely locations and types
of land areas that are anticipated to be addressed by GSI in the future. Growth patterns and time
horizons for development, along with algorithms to identify which parcels are likely to redevelop,
resulted in preliminary estimates of the land area that is predicted to be addressed by GSI facilities in
the City of Cupertino by 2020, 2030, and 2040. Using the current land uses of the predicted locations of
GSI implementation and associated impervious surface coefficients for each land use type, estimates of
the amount of impervious surface that would be retrofitted with GSI on privately-owned parcels were
developed.
The methodology focused on parcel-based redevelopment as the location and timing of projects in the
public right-of-way is uncertain and the contribution of these projects to overall impervious surface area
treated by GSI expected to be minor relative to the acreage projected to be treated by C.3 projects.
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Table 6-1 Potential GSI Funding Options
Section/Overview GSI Specifics Pros Cons Type of Funding
Parcel Taxes: revenue
stream through taxing
property or other
system.
Can be used to set up,
fund and maintain a
stormwater program
and MRP compliance.
•Well understood tax
•Stable revenue stream
over many years
•Legally reliable
•Can also be done by
mail.
•High political threshold
•Vulnerable to competition with other
measures on the ballot.
•Considerable effort and resources
required with uncertain odds of
success.
•Planning
•Capital
•O&M
Property-related Fees:
fees on real property.
•Fee on property
contributing
stormwater
runoff to MS4.
•Can be used to
set up, fund and
maintain a
stormwater
program and MRP
compliance.
•Most-commonly used
mechanism for funding
stormwater programs.
•Easier to pass with 50%
threshold and mailing
process.
•Property-based fees must use a
standardized methodology for
calculating the fee.
•Considerable effort and resources
required with uncertain odds of
success.
•Approval process is more time
consuming and expensive for staff.
•Schools may have large fees and public
schools may be exempt from fees
depending on the agency’s specific
ordinance.
•Planning
•Capital
•O&M
General Obligation
Bonds
•Tax on property
owners through
debt obligation
taken on by
municipality.
•Long term
payback period
typically 10-30
years.
•Typically a lower
interest rate than what
is available from
commercial banks.
•Allows funds to be used
in the near term and
paid back over the long
term.
•Interest rate variable depending on
financial markets
•Some risk to general fund for
municipality if payments cannot be
made.
•Can only be used for capital costs –
not O&M
•Planning
•Capital
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Section/Overview GSI Specifics Pros Cons Type of Funding
Development Impact
Fees: paid by an
applicant seeking
approval of a
development project.
Could potentially be
used to fund retrofits
of adjacent public
right-of-way areas
with GSI as part of
development or
redevelopment
projects.
Cost for retrofitting streets
can be leveraged through
development activities.
If a fee is found to not relate to the impact
created by the development project, or to
exceed the reasonable cost of providing
the public service, then the fee may be
declared a “special tax” subject to approval
by a two-thirds majority of voters.
•Planning
•Capital
Grants: one time funds
that require an
application from a
funding agency.
Could be used to plan,
design and/or build
GSI.
Can fund programs or
systems that would
otherwise take up significant
general fund revenues.
•Usually a one-time source of funding
only.
•May need to create new programs and
systems for each grant.
•Usually have strings attached for
matching funds and other
requirements.
•Little control over timing of
applications and payment can lead to
difficulties in coordination with other
programs and grants.
•Can be very competitive and resource
intensive to apply.
•No guarantee of success.
•Post-project O&M costs must be
borne by the agency.
•Planning
•Capital
Benefit Assessment and
Community Facility
Districts
Typically used to build
and/or maintain
facilities such as GSI
improvements and/or
services.
Can be used to fund
maintenance and
operations.
Requires property owners and/or
businesses to agree that the need is
present and that they should be (at least
partially) responsible for funding it.
•Capital
•O&M
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Section/Overview GSI Specifics Pros Cons Type of Funding
Business Improvement
Districts
Businesses and
property owners tax
themselves and
manage the funds to
build or maintain GSI
assets.
Can provide sense of
ownership and pride in the
neighborhood when results
are visible.
Can burden businesses, property owners
and others to the extent that they are
unwilling to approve other funding
measures.
•Planning
•Capital
•O&M
Infrastructure Financing
Districts
Captures increase in
ad valorum tax
increases (similar to
redevelopment
agencies) for
infrastructure
improvements such
as GSI
Can be jointly done with
multiple cities.
Cannot capture any of the local school
district’s portion of tax increment.
•Planning
•Capital
•O&M
Motor Vehicle License
Fees: fees on each motor
vehicle that is registered.
Could be used to plan,
design and/or build
GSI.
Can be flexible in purpose
and can supply a long-term
stable revenue source.
•If the total number of new annual
motor vehicle registrations decline
over time (as may happen with car-
sharing, transit increases, biking and
walking and the rollout of automated
vehicles) revenues will decline.
•Difficult to achieve the 2/3 majority
needed to pass due to Prop 26.
•Only for activities that are deemed to
help mitigate impacts from motor
vehicles.
•Planning
•Capital
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Section/Overview GSI Specifics Pros Cons Type of Funding
Realignment of
Municipal Services:
municipalities shift costs
to programs where
revenue can be increased
such as sewer, water and
trash.
Could be used to plan,
design, build and/or
maintain GSI where
there is a nexus
between the two
programs.
A means of leveraging
existing or new resources
funded by non-balloted fee
structures.
•Bureaucratic issues can be difficult to
overcome.
•Sewer, trash and water may be
controlled by different agencies that
may not be able to coordinate or
share resources.
•There may be political restrictions to
significant increases in rates.
•Planning
•Capital
•O&M
Integration with
Transportation Projects:
transportation funding is
leveraged to cost-
effectively include
stormwater quality
elements.
Installation and
maintenance of GSI
facilities as part of
integrated roadway
programs.
•Roadway projects have
more funding than
stormwater programs
and are generally more
popular with the public.
•Complete and green
streets may be more
popular with the public
than traditional car-
focused streets.
•Green streets may be
less expensive than
traditional streets based
on a life cycle cost
analysis.
•Roadways have been designed in
certain ways with expectations of
costs and purposes for decades.
•Many roadways are in poor condition
and there is not enough funding to fix
them all.
•GSI is perceived as an “added” cost
which, could reduce the number of
roadways that can be maintained.
•Transportation funding is often
restricted to certain roadway
construction elements.
•Planning
•Capital
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Section/Overview GSI Specifics Pros Cons Type of Funding
Alternative Compliance:
Allows developers the
flexibility to build, or
fund through payment of
an in-lieu fee, off-site
stormwater treatment
systems for regulated
projects or set up credit
trading programs.
Leveraging
development activities
to build and maintain
GSI systems. In lieu
fees can be used by
developers who would
rather make a lump
sum payment and
quickly complete their
compliance
requirements. Credit
trading programs can
incentivize non-
regulated properties
to retrofit impervious
surfaces.
• Gives flexibility to site
GI systems in locations
that optimize pollutant
loading reduction and
other benefits to the
community.
• Allows for off-site
stormwater treatment
when stormwater
management
requirements can’t be
met within a regulated
project site.
• An in-lieu fee and/or
credit trading system
can be used to achieve
additional retrofits and
installation of GSI.
• Can be difficult to come up with viable
alternative locations for GSI
installations.
• Can be difficult to quantify how much
a developer should pay upfront for
long-term maintenance costs that the
municipality will bear.
• May require agencies to modify the
stormwater sections of their municipal
codes to allow for the creation and/or
use of the desired options/programs.
• Planning
• Capital
• O&M
Existing Permittee
Resources: Utilize
general funds for GSI.
Could be used to plan,
design, build and/or
maintain GSI.
Voter approval or new
revenue sources not
required.
• GSI must compete with many other
municipal priorities and essential
services.
• Normally not a viable option for
substantial GI implementation.
• Planning
• Capital
• O&M
Long Term Debt: borrow
money up-front against a
dedicated stream of
revenue projected over
the life of the program.
Can borrow money
from future revenues
to construct GSI
systems in the
present.
• Well understood
process of raising funds.
• Allows acceleration of
improvements to
compliance deadlines
• Need a dedicated stream of revenue
to pay off debt.
• If the general fund is used, can put the
general fund at risk if jurisdiction
cannot make the payments, credit
rating will be downgraded jeopardizing
other programs.
• Planning
• Capital
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Section/Overview GSI Specifics Pros Cons Type of Funding
Public-Private
Partnerships (P3s):
agreements or contracts
between a municipality
and a private company to
perform specific tasks.
Can provide for the
design, construction
and maintenance of
GSI systems over a
long period.
•Leverages public funds
while minimizing
impacts to a
municipality’s debt
capacity.
•Access to advanced
technologies.
•Improved asset
management.
•Draws on private sector
expertise and financing.
•Benefits local economic
development and
“green jobs.”
•Relieves pressure on
internal local
government resources.
•Stormwater fee or other source of
stable revenue over the life of the P3
contract is required.
•Contracts out to the private sector the
construction and maintenance of GSI
systems, possibly removing some
municipal control.
•Planning
•Capital
•O&M
Volunteer Programs:
provide community-
based volunteer labor for
specific tasks.
Use volunteer
programs to help build
or maintain GSI
facilities.
•A low-cost source of
labor.
•Educational program for
community.
•Can build support for a
stormwater fee or other
funding source.
•Can be time intensive for staff to set
up and administer.
•May not be dependable in the long
run
•May result in loss of municipal control
depending on program specifics.
•Planning
•Capital
•O&M
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6.6.2 Results
Using the methodology described above, a predicted redevelopment rate of 15 acres per year was
calculated for the City of Cupertino. “Best” estimates of the magnitude of land areas that is predicted to
be addressed by future GSI facilities by the 2020, 2030, and 2040 milestones were calculated using the
rate. “High” (i.e., 50% > “best”) and “Low” (i.e., 50% < “best”) estimates of future GSI implementation
were also calculated to provide a range of potential redevelopment levels and account for uncertainty in
the “Best” estimate. Figure 6-1 and Table 6-2 present the outputs of the analysis and represent the total
acreage known to be addressed by GSI in Cupertino through 2018, and the best estimate of the
cumulative land area that will be addressed in 2020 (363 acres), 2030 (513 acres), and 2040 (663 acres)
by GSI on privately- and publicly-owned parcels in the City of Cupertino.
1High estimate – projected from 150% of “Best Estimate; 2Best estimate – rate of redevelopment based on 10-year average
(2008-2017); and 3Low estimate – projected from 50% of “Best Estimate”. The large increase in GSI in 2017-2018 was due to
the completion of the Apple Park Campus and surrounding buildings.
Figure 6-1 Existing and projected cumulative land area (acres) anticipated to be addressed via Green
Stormwater Infrastructure facilities installed via private redevelopment in the City of Cupertino by 2020,
2030, and 2040.
0
100
200
300
400
500
600
700
800
900
Area (acres) Addressed by GSIProjectedReported
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Table 6-2 Projected cumulative land area (acres) anticipated to be addressed via Green Stormwater
Infrastructure facilities via private redevelopment in the City of Cupertino by 2020, 2030, and 2040.
Year Low1 Best2 High3
Existing GSI4 - 333 -
2020 348 363 378
2030 423 513 603
2040 498 663 828
1Low estimate – projected from 50% of “Best Estimate”; 2Best estimate – rate of redevelopment based on 10-year average (2009-2018); and
3High estimate – projected from 150% of “Best Estimate”; 4Total area addressed by parcel-based redevelopment projects with GSI completed
through 2018 (excludes non-jurisdictional and green street and regional projects).
Table 6-3 lists the impervious surface percentage for each land use class, based on impervious surface
coefficients typically utilized, and the estimated impervious surfaces that are predicted to be retrofitted
by 2020, 2030, and 2040 in the City via GSI implementation on private and public parcels: 275 acres by
2020, 431 acres by 2030 and 557 acres by 2040. Note that these predictions do not include impervious
surface that may be addressed by projects in the public right-of-way, and that these predictions have a
high level of uncertainty because future redevelopment rates may increase or decrease relative to the
historic development trends and staff knowledge that the rate for Cupertino was based on. Therefore,
actual impervious surface addressed by GSI by the various milestones may increase or decrease relative
to what is presented in Table 6-3.
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Table 6-3 Actual (2002-2018) and predicted (2019-2040) extent of impervious surface retrofits via GSI implementation on privately- and publicly-owned parcels in the
City of Cupertino by 2020, 2030, and 2040.
Previous Land Use % of Area
Impervious a
Retrofits via GSI Implementation
2002-2018 2019-2020 2021-2030 2031-2040 Total (2002-2040)
Total
Area
(acres)
Impervious
Area
(acres)
Total
Area
(acres)c
Impervious
Area
(acres)
Total
Area
(acres)
Impervious
Area
(acres)
Total
Area
(acres)
Impervious
Area (acres)
Total
Area
(acres)
Impervious
Area (acres)
Commercial 83% 26 22 1 0 45 37 99 83 171 142
Industrial 91% 189 172 0 0 25 23 4 4 219 199
Residential - High Density 82% 26 21 0 0 24 20 16 13 66 54
Residential - Low Density 47% 4 2 0 0 0 0 0 0 4 2
Retail 96% 58 55 3 2 78 75 27 26 166 159
Urban Parks 20% 0 0 0 0 0 0 3 1 3 1
Open Spaceb 1% 30 0 1 0 3 0 0 0 34 0
Totals 333 272 4 3 176 155 150 126
662 557
Cumulative d 333 272 337 275 512 431 662 557
a Source: Existing Land Use in 2005: Data for Bay Area Counties, Association of Bay Area Governments (ABAG), January 2006
b Development totals from 2002-2018 may include new development of open space and vacant properties.
c The total area for 2019-2020 is based on facilities that are currently under construction or planned to occur prior to 2020 and not the Phase I redevelopment rate and may therefore deviate from the “Best”
acres presented for 2020 in Table 6-2.
d Totals in this table differ slightly from predictions presented in Table 6-2 due to the inclusion of entire parcels in this table, as opposed to more generic “land areas” projections presented in Table 6-2.
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Project Tracking System
A required component of the GSI Plan is to develop a process for tracking and mapping completed
public and private GSI projects and making the information available to the public. The City will continue
to implement existing internal tracking procedures for processing public and private projects with GSI,
meeting MRP reporting requirements, and managing inspections of stormwater treatment facilities. In
addition, the City will provide data to SCVURPPP for countywide tracking of completed public and
private GSI projects. This countywide tracking tool can be used to document a project’s pollutant
reduction performance as well as overall total progress toward city or county-level stormwater goals
6.7.1 City Project Tracking System (Regulated and GSI)
The City currently utilizes an internal tracking system to manage information about installed stormwater
treatment measures (including GSI), operation and maintenance (O&M) of public facilities, O&M
verification program inspections, and enforcement actions. The tracking system consists of a site specific
GIS layer for installed stormwater treatment measures, an internal database (CityWorks) for O&M of
public facilities, and a spreadsheet for installed LID O&M and enforcement actions on private property.
6.7.2 SCVURPPP Project Tracking System
SCVURPPP has developed a centralized, web-based data management system, with a connection to GIS
platforms, for tracking and mapping all GSI projects in the Santa Clara Valley. The GSI Database provides
a centralized, accessible platform for municipal staff to efficiently and securely collect, upload, and store
GSI project data, and enhances SCVURPPP’s ability to efficiently and accurately calculate and report
water quality benefits associated with GSI projects. It also allows portions of the GSI project information
to be made publicly available.
City staff will collect and manage information on GSI projects locally using the data management
systems described above. City staff will directly enter project data into the SCVURPPP GSI Database on
an annual basis through a web-based data entry portal for individual projects or upload data for multiple
projects in batch using standardized formats.
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