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E2: Sunnyvale East and Sunnyvale West Channels Flood Protection*

About This Project

This project is to upgrade approximately 6.4 miles of the existing Sunnyvale East Channel to provide 1% flood protection (100-year event) to 1,618 parcels and approximately three (3) miles of the existing West Channel to provide 1% flood protection for 47 acres of highly valuable industrial lands, including the Onizuka Air Force Base.

The Sunnyvale East Channel and Sunnyvale West Channel improvement projects have been combined into a single flood protection project with a single Environmental Impact Report (EIR) to reduce construction costs and improve efficiencies. Both projects decrease channel turbidity and sediment by repairing erosion sites, thereby improving water quality and reducing sediment to the San Francisco Bay.


*This project was voter approved as part of the Safe, Clean Water and Natural Flood Protection Program.

Sunnyvale West Channel_looking south at Carl Road
Start FY 2022/ Finish FY 2026
Safe, Clean Water Fund ($38.5 million)
News and UpdatesNews and Updates
Reports and DocumentsReports and Documents
Environmental and Community BenefitsEnvironmental and Community Benefits
History and BackgroundHistory and Background
News & Updates

Project design is 99% complete, awaiting receipt of regulatory permits required prior to construction advertisement. The project fact sheet is available.

To date, five (5) permanent right-of-way acquisitions, all necessary for project construction, have been acquired. Valley Water is working to acquire final leasing agreements, as well as temporary construction easements, from Santa Clara County and San Francisco Public Utilities Commission (SFPUC). All acquisitions are anticipated to be final by 2022.

In June 2017, Valley Water submitted all the required permit applications from the various state and federal regulatory agencies. The permit process is currently ongoing and permits are anticipated to be received sometime in 2023. Project construction is anticipated to begin in 2023 and to be completed by December 2026.

In October 2017, Valley Water was approached by Google, LLC with a proposal to partner on an enhancement project along approximately 1,100 linear feet of the Sunnyvale West Channel (Caribbean Drive upstream to Caspian Court) in association with their proposed development project. Valley Water staff and Google Representatives developed a Memorandum of Understanding (MOU), which the Valley Water's Board of Directors approved in April 2018. Valley Water entered into this MOU partnership to enhance existing public infrastructure, explore on-site mitigation opportunities with Google, thereby possibly accelerating receipt of the required regulatory permits, while maintaining the project objectives for the Sunnyvale East and West Channels Flood Protection Project.

Google LLC, with the City of Sunnyvale as the lead California Environmental Quality Act (CEQA) agency, released their draft CEQA documents in December 2019 for their proposed development including the West Channel Enhancement Project. 

The City of Sunnyvale certified Google's Caribbean Campus Project Environmental Impact Report on May 12, 2020. 

An agreement between Valley Water and Google to coordinate and identify the various party’s short-term and long-term responsibilities for the proposed approximate 1,100 linear foot West Channel Enhancement Project was approved by the Valley Water Board of Directors on February 22, 2022. Valley Water’s financial contribution of $2.6M is based on Valley Water’s cost to construct their proposed prior flood protection improvements for this approximate 1,100 linear foot section of the existing Sunnyvale West Channel. In addition, Valley Water will be allowed to utilize Google’s excess on-site mitigation for the proposed flood protection project.

Parties continue to engage with the various resource agencies to acquire the required regulatory permits so construction advertisement may occur on each party's respective projects.

In addition to coordination with Google on the West Sunnyvale Channel, Valley Water is continuing to collaborate with the City of Sunnyvale Water Pollution Control Plant (WPCP) on a perimeter wall around the City’s facility at the downstream end of the Sunnyvale West Channel. Valley Water and the WPCP are finalizing the design of a wall to serve both as a flood protection barrier and a secure perimeter wall for the WPCP. Construction of the WPCP perimeter wall by the City is currently scheduled to begin in 2023. A cost sharing agreement and separate operations and maintenance agreement between Valley Water and the City of Sunnyvale for the shared WPCP wall is pending the final design of the wall.

In 2016, a joint use agreement and a cost sharing agreement were executed by Valley Water and the City of Sunnyvale to establish public trails along the East Channel and West Channel, upon completion of the Valley Water Flood Protection Project.  In addition, in 2020 a trail agreement was executed by Valley Water and Google LLC to provide cost sharing for trail surfacing along the lower West Channel and the lower East Channel where the project coincides with the existing San Francisco Bay Trail. 

Updated April 2022

For more information: 


Reports & Documents

Project Fact Sheets

Pursuant to the California Environmental Quality Act, the Santa Clara Valley Water District, as the lead agency for the proposed project, prepared a Draft Environmental Impact Report and a Final Environmental Impact Report to evaluate environmental impacts of the proposed flood protection project. Below is a summary of the environmental reports and documents. 

Final Environmental Impact Report

The Final EIR responds to public comment received on the Draft EIR during the public review period, as well as reflects changes to the Draft EIR made to address comments received during public circulation. The Final EIR was certified on September 9, 2014 by the District's Board of Directors.

Response Letters

Draft Environmental Impact Report 

The Draft EIR identified potentially significant environmental impacts associated with aesthetics, air quality, biological resources, cultural resources, geology/soils, greenhouse gas emissions, hazardous materials, hydrology/water resources, noise and vibration, land use, public utilities, recreation, and traffic. The majority of impacts were determined to be less than significant after the implementation of mitigation measures proposed. Construction impacts related to violation of applicable air quality and noise/vibration standards were determined to be significant and unavoidable even after implementation of air quality and vibration mitigation measures.

The Draft EIR was published and circulated between November 1, 2013 and December 15, 2013. The public review period was extended to February 21, 2014 to accommodate additional review time by the public agencies.

Environmental & Community Benefits

FY22-36 Key Performance Indicator for the Safe, Clean Water Program

  1. Provide 1% (100-year) flood protection for 1,618 properties and 47 acres (11 parcels) of industrial land, while improving stream water quality and working with other agencies to incorporate recreational opportunities.


  • Provides 1% flood capacity for approximately 6.4 miles of channel along Sunnyvale East and approximately three (3)
    miles of channel along Sunnyvale West within the City of Sunnyvale, protecting 1,618 properties (Sunnyvale East)
    and 47 acres (11 properties) of industrial land (Sunnyvale West)

  • Improves channel water quality by providing erosion control measures to decrease sediment and turbidity

  • Identifies recreational opportunities that can be integrated by the City of Sunnyvale and others as appropriate

  • Addresses climate change

Geographic Area of Benefit


History & Background

Flooding History and Project Background 

The Sunnyvale East and West Channels were constructed by the Santa Clara Valley Water District in the 1960’s and 1970’s to alleviate the storm drain systems of Sunnyvale and Cupertino during a 10-year storm by directing the overflow through the channels to San Francisco Bay. Since construction of the channels, the project area has experienced flooding during major storm events in 1963, 1968, 1983, 1986 and 1998.

Each winter, thousands of households, businesses and schools in Sunnyvale are susceptible to flooding from the Sunnyvale East and West channels during a major storm. The Sunnyvale East and West Channels were identified initially as separate projects in the Clean, Safe Creeks Plan approved by voters in November 2000. In order to improve efficiency, the two projects were combined and will move forward as a single effort. In November 2012, the project was transitioned to the Safe, Clean Water and Natural Flood Protection Program.

In 2018, Valley Water entered into a Memorandum of Understanding with Google, LLC (Google) to incorporate Google’s proposed enhancement effort along 1,100 linear feet of the Sunnyvale West Channel into the project. This portion of the project will also be part of Google’s Caribbean Campus Project. Valley Water has completed 100% design and has submitted all required permit applications for the project. Once all permits are received, Valley Water will begin construction.

About the Safe, Clean Water and Natural Flood Protection Program

In November 2020, voters in Santa Clara County overwhelmingly approved Measure S, a renewal of Valley Water’s Safe, Clean Water and Natural Flood Protection Program.

The program was first passed by voters in 2000 as the Clean, Safe Creeks and Natural Flood Protection Plan, then again in 2012 as the Safe, Clean Water and Natural Flood Protection Program. The renewal of the Safe, Clean Water Program will continue to provide approximately $47 million annually for local projects that deliver safe, clean water, natural flood protection, and environmental stewardship to all the communities we serve in Santa Clara County.

While evaluating ways to improve the 2012 program, Valley Water gathered feedback from more than 21,000 community members. That helped Valley Water create the six priorities for the renewed Safe, Clean Water Program, which are:

Priority A: Ensure a Safe, Reliable Water Supply

Priority B: Reduce Toxins, Hazards and Contaminants in our Waterways

Priority C: Protect our Water Supply and Dams from Earthquakes and Other Natural Disasters

Priority D: Restore Wildlife Habitat and Provide Open Space

Priority E: Provide Flood Protection to Homes, Businesses, Schools, Streets and Highways

Priority F: Support Public Health and Public Safety for Our Community

Each year, Valley Water prepares a report providing a progress update for each of these program priorities, along with fiscal year accomplishments.

To ensure transparency and accountability to the voters, the ballot measure also created an Independent Monitoring Committee, appointed by the Santa Clara Valley Water District Board of Directors. The Independent Monitoring Committee annually reviews the program’s progress to ensure the outcomes are achieved in a cost-efficient manner and reports its findings to the Board. Additionally, the IMC also reviews each proposed 5-year implementation plan prior to its submittal for Board approval.

In addition, the program requires three independent audits.

View the Safe, Clean Water Program’s annual reports, annual IMC audit reports, and independent audits, including a staff response, on the Valley Water website.