This project develops engineering studies to understand the actual flood risk in high priority flood-prone areas and develops options for managing the flood risks.
Studies will focus on the following reaches:
-
Alamitos Creek upstream of Almaden Lake in San José
-
Rock Springs neighborhood along Coyote Creek in San José
-
Calera Creek near Milpitas High School to Interstate 680 in Milpitas
-
Tributaries to Lower Silver Creek (Ruby, Norwood, Quimby and Fowler creeks) in San José
-
Ross Creek in San José, from Guadalupe River to Blossom Hill Road
-
Adobe and Barron Creeks in Palo Alto, between Highway 101 and Middlefield Rd.
The study includes hydrology, hydraulics, geotechnical and remapping work of the floodplain areas. If appropriate, updated maps will be submitted to Federal Emergency Management Agency (FEMA) to provide a more accurate reflection of the floodplain.
Key Performance Indicators for the Safe, Clean Water Program
KPI #1: Complete engineering studies on 7 creek reaches to address 1% flood risk.
A 2-dimensional, unsteady hydraulic model for mid-Coyote Creek was completed in early 2016; it was extended upstream to include the Rock Springs neighborhood in 2017. In FY18, the model was calibrated to flows and high water marks collected during the February 21, 2017 storm. The calibrated model has been used to create updated floodplain maps for a variety of different storm conditions (including the 100-year storm event), which will help in the Valley Water's emergency operations. The model will also serve as the basis for the mid-Coyote Flood Protection Project.
KPI #2: Update floodplain maps on a minimum of 2 creek reaches in accordance with new FEMA standards.
For Alamitos Creek, a geotechnical investigation for the levees/floodwall and a 2-dimensional model were both completed in the third quarter of 2016. Based on this information, preliminary floodplain maps were developed and presented to the City of San José in June 2017. In FY18, the model was calibrated to flows and high water marks collected during the February 2017 flood event, and the calibrated model has been used to update 100-year floodplain maps for Alamitos Creek. The updated maps will be shared with the City of San Jose in early FY19.
Updated April 2021
Preliminary 100 Year Floodplain Maps
Preliminary 10 Year Floodplain Maps
Documents
Key Performance Indicators for the Safe, Clean Water Program
-
Complete engineering studies on 7 creek reaches to address 1% flood risk.
-
Update floodplain maps on a minimum of 2 creek reaches in accordance with new FEMA standards.
Benefits
-
Provides more accurate mapping of areas at risk of flooding
-
May add or remove parcels from the FEMA regulatory floodplain, based on updated mapping standards
-
Information can be integrated into flood warning program to provide advance, real-time warnings of impending flood events
-
Provides technical basis for developing future flood protection plans, and for potential funding partnerships
Geographic Area of Benefit
Milpitas and San Jose
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.