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McKelvey Park Detention Basin

About This Project

The McKelvey Park Detention Basin Project is one of the elements of the Permanente Creek Flood Protection Project.

After years of planning and design, the Santa Clara Valley Water District is preparing to construct flood protection improvements along Permanente Creek. Once completed, the Permanente Creek Flood Protection Project will provide natural flood protection for at least 2,200 properties in Mountain View and Los Altos, create recreational opportunities and enhance the environment.

The McKelvey Park detention basin is the second project element to begin construction. Construction began in January 2017 and is now completed. 

Project highlights


  • New 0.7 acre mini park facility with playgrounds and other features
  • Construction of an inlet and outlet to allow water flows to enter and exit the fields
  • Architecturally treated retaining wall around the lowered fields
  • Basin to collect peak storm flows from Hale and Permanente creeks during an approximately 50-year flood event or larger


  • Flood protection for thousands of homes and businesses in Mountain View and Los Altos, saving residents thousands of dollars on flood insurance each year
  • Provides new facilities and amenities to park users
  • Reduces construction impacts to downstream residential and business areas


An artist rendering of the completed project is available for viewing.  

McKelvey Park Little Ballfield
McKelvey Park Little Ballfield completed
On Target
Mountain View
Start January 2017/ Finish end of Feb 2020
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 progress and completion

The detention basin project is one of three major elements of the larger Permanente Creek Flood Protection Project that will provide natural flood protection for approximately 2,200 properties in Mountain View and Los Altos. Valley Water completed the McKelvey Park Detention Basin in February 2020. 


McKelvey Park Detention Basin Project works in conjunction with the Rancho San Antonio County Park Detention Basins and the Permanente Creek Channel Improvements Project. All three elements are currently in construction. Upon completion and Federal Emergency Management Agency (FEMA) certification, the project will save residents thousands of dollars on flood insurance each year. Additional benefits at McKelvey Park include a new mini-park facility with playgrounds, new and improved ball fields with terraced bleachers, a new concession and scorekeeper’s booth, new storage, new restrooms and a new community room.

Thank you for your patience and understanding during the construction of this project and for attending the community celebration.

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Environmental & Community Benefits

What to expect during construction

The Santa Clara Valley Water District and City of Mountain View are working together to minimize construction impacts as much as practical and in accordance with local ordinances. We appreciate your understanding and cooperation as we embark on this important flood protection project.

  • Regular construction work hours are 7:30 a.m. to 4 p.m. Work is scheduled Monday through Friday, excluding legal holidays. Work on or affecting Miramonte Avenue will occur between 9 a.m. and 3 p.m
  • Majority of the construction work will remain within the McKelvey Park site boundaries.
  • Traffic control will be implemented on Mountain View Avenue, Park Drive and Miramonte Avenue north of the site during the first phase of construction when Park Drive is being realigned and the utilities relocated.
  • Alternate playing fields will be made available for McKelvey Park users during the construction phase.
  • For safety and to minimize traffic impacts, trucks will use El Camino Real, Miramonte Avenue and Mountain View Avenue north of Park Drive. Hauling will be limited between 9 a.m. and 3 p.m. No trucks will be allowed through the residential areas to the west or east of McKelvey Park, nor along Miramonte Avenue or Mountain View Avenue south of the site.
  • The safety of the community and our employees is a priority. Barricades, railings, lights, fences and other warning devices will be used for public safety and convenience.

What is a flood detention area?

Flood protection methods can include berms around buildings, widening channels, raising floodwalls, elevating structures and roadways, and/or constructing a bypass channel. In areas where development limits widening the creek or raising floodwalls, flood storage basins are used to temporarily divert and store floodwaters until a major storm passes

The McKelvey Park detention area will be approximately 4.5 acres in size and 18 feet deep with architecturally treated retaining walls. The parking lot will also be sloped with the top of the lot at street level and the bottom at field level. Flood flows would inundate the site very rarely and quickly drain away. A 100-year flood, which has a 1 percent chance of occurring in any given year, would fill the detention area and would drain out in one to four days. Post-flood cleanup could take approximately two to four weeks, after which the playing fields would be ready for use again.

Use Access Valley Water to submit questions, complaints or compliments directly from your computer or smart phone to a water district staff person who can help you.

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.