This project was done in partnership with the U.S. Army Corps of Engineers (USACE) to plan, design and construct flood improvements to protect homes in Milpitas and San José, as well as Silicon Valley’s commercial district, from a 1% (100-year) flood flow. The Bay Area Rapid Transit (BART) 10-mile extension project spans from Warm Springs Station in Fremont to the North San José Berryessa area. The new Milpitas Station is underground and is located in the Berryessa Creek floodplain. The completed Berryessa Creek project is critical to the operation and public use of the BART station.
*This project was voter approved as part of the Clean, Safe Creeks and Natural Flood Protection Plan.
In 2018, Valley Water and the United States Army Corps of Engineers (USACE) completed the Upper Berryessa Creek Flood Protection Project. The project extended along Berryessa Creek for approximately 2.2 miles, from I-680 downstream to Calaveras Boulevard. This area is now protected against a 100-year storm event. A 100-year storm event has a 1% chance of occurring in any given year (a 1 in 100 chance).
Valley Water and USACE are developing a Floodplain Management Plan (plan). The purpose of the FPMP is to
- Document potential measures, practices, and policies that could reduce the impacts of future residual risks of flooding associated with the project, and
- Help preserve flood protection levels provided by the project and enhance the natural values of the floodplain and creek.
Key Performance Indicators for the Safe, Clean Water Program
Local and federal flood damage reduction for 1,662 parcels including 1,420, 170 businesses, and 5 schools/institutions.
Using local funds only, a reduced project would extend from the confluence with Lower Penitencia upstream to Montague Expressway, modifying 2 miles of channel and protecting approximately 100 parcels.
Protects up to 1,662 businesses and homes in Milpitas and San José from a 1% flood, saving potential damages in excess of $527 million
Provides protection for more than 30 miles of streets including Highway 237 and Montague Expressway
Geographic Area of Benefit
Milpitas and San José
Flooding History and Project Background
The Berryessa Creek Flood Risk Management Project encompasses approximately 2.2 miles of Berryessa Creek from Calaveras Boulevard to Interstate 680.
The Upper Berryessa Creek flood protection project offers a tremendous opportunity for a project to increase flood protection and stabilize the channel banks. Valley Water will continue to work with the community and cities to provide critical flood protection needs for Milpitas and San José.
Upper Berryessa Creek has a history of flooding, having experienced major events within the project area in 1982, 1983, and 1998. In 1982, the bank overflowed south of Calaveras Boulevard. To date, the creek has a 25 percent chance of flooding each year.
Flooding can result in millions of dollars in damage to homes, businesses, schools, and other infrastructure. Disruption to businesses and transportation networks such as the upcoming BART station at Montague Expressway will 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 from a 100-year storm event* exceeding $528 million (2011 value) per event. Approximately, 500 businesses and homes would be affected. The Santa Clara Valley Water District has initiated design of a flood protection project along 2.2 miles of the creek from Calaveras Boulevard to Interstate 680.
* A 100-year storm event, sometimes called a one-percent flood event, has a 1-in-100 chance of occurring in any given year.
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, 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.
In addition, the Program requires three independent audits, the first of which was conducted in FY 2017.