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Permanente Creek Channel Improvements Project

About This Project

The Santa Clara Valley Water District is dedicated to keeping residents and business safe through its flood protection programs.

The project widened and deepened Permanente Creek from Mountain View Avenue to Valencia Avenue, including 600 feet of Hale Creek where it feeds into Permanente Creek. The Mountain View Ave. culvert, the reinforced concrete structure that allows Hale Creek water to flow under Mountain View Ave., was replaced to accommodate waters from a 100-year flood. A Separation Wall was installed on Hale Creek, this flood protection element separates the creek flow from the creek’s maintenance ramp.

Construction was completed in December 2018.

The Santa Clara Valley Water District and cities of Mountain View and Los Altos worked together to minimize construction impacts as much as practical and in accordance with city ordinances. Thank you to our neighbors as we worked to complete this important flood protection project.

Project highlights


  • Channel modifications from Mountain View Avenue to Valencia Avenue
  • New culvert at Mountain View Avenue to allow for increased water flow capacity


  • Provides flood protection for thousands of households and businesses in Mountain View and Los Altos, saving residents thousands of dollars on flood insurance each year
  • Fits in with densely developed urban areas
  • Low maintenance costs
  • Investing in flood protection now is our community’s insurance policy for the future
On Target
Mountain View, Los Altos
News and UpdatesNews and Updates
Reports and DocumentsReports and Documents
Environmental and Community BenefitsEnvironmental and Community Benefits
History and BackgroundHistory and Background
News & Updates

Channel widening work along Permanente and Hale Creeks

Construction on Permanent and Hale Creeks is now completed. Thank you to our neighbors for their patience as we completed this critical segment of the Permanente Creek Flood Protection Project for the communities of Los Altos and Mountain View.


Reports & Documents

Project Fact Sheet and Inserts

Public review documents and reports related to the Permanente Creek Flood Protection Project are listed in the right under the "Related Information" box.

Permanente Creek Fact Sheet (PDF)  
Floodwalls Insert (PDF)  
McKelvey Park Insert (PDF)   
Rancho San Antonio Insert (PDF) 
Public Outreach Summary Insert (PDF)  
Project Milestones Timeline (PDF) 

Final Subsequent Environmental Impact Report (November 2012)

Addendums to the Final Subsequent Environmental Impact Report

History & Background

Flooding History and Project Background 

Permanente Creek has a history of flooding, having experienced major flooding in 1862, 1911, 1940, 1950, 1952, 1955, 1958, 1963, 1968, 1995 and 1998. Flooding can result in millions of dollars in damage to homes, businesses and schools. In addition, disruption to businesses and transportation networks can result in significant loss of productivity and revenue. One of the project’s goals is to avoid utility and transportation shutdowns and prevent potential damages that could exceed $48 million (1999 value).

Each winter, thousands of households, schools and businesses in Mountain View and Los Altos are susceptible to flooding from Permanente Creek during a major storm. The Santa Clara Valley Water District has initiated planning of a flood-protection project along 10.6 miles of Permanente Creek, from San Francisco Bay’s southwest shoreline through Mountain View to Foothill Expressway in Los Altos.

The Permanente Creek Flood Protection Project offers a tremendous opportunity for a multi-purpose project to improve flood protection, create recreational opportunities and enhance the environment. The District worked with the cities and the community to design the most suitable alternative. 

About the Safe, Clean Water and Natural Flood Protection Program

In November 2012 the voters of Santa Clara County overwhelmingly approved Measure B, the Safe, Clean Water and Natural Flood Protection Program, as a countywide special parcel tax for 15 years with a sunset date of June 30, 2028. This Program replaced the Clean, Safe Creeks and Natural Flood Protection Plan, which voters approved in November 2000.

The Safe, Clean Water Program was developed with input from more than 16,000 residents and stakeholders and was created to match the community’s needs and values. The voters of Santa Clara County identified five priorities:

Priority A: Ensure a Safe, Reliable Water Supply

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

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

Priority D: Restore Wildlife Habitat and Provide Open Space

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

Other: Six projects from the Clean, Safe, Creeks Plan have been carried forward into the Safe, Clean Water Program.  

Each year, the District 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.

In addition, the Program requires three independent audits, the first of which was conducted in FY 2017.

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