print Font Size: small font medium font large font

E3: Flood Risk Reduction Studies

This project develops engineering studies to increase understanding of flood risks in high priority, flood-prone areas, and develops options for managing those risks. The studies  focus on four areas:

  • The Rockspring neighborhood along Coyote Creek in San Jose
  • Alamitos Creek, upstream of Lake Almaden in San Jose
  • Calera Creek, from Milpitas High School to Interstate 680 in Milpitas
  • Tributaries to Lower Silver Creek (Ruby, Norwood, Quimby and Fowler Creeks) in San Jose

Studies include hydrologic, hydraulic and geotechnical data, and remapping work of the floodplain areas. If appropriate, updated maps are submitted to the Federal Emergency Management Agency (FEMA) to more accurately reflect the floodplain.


  • Provides more accurate mapping of areas at risk of flooding
  • May remove hundreds of parcels from 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

Project Status

(As of October 2016)

  1. A two-dimensional model for mid-Coyote Creek was completed in early 2016; it is planned to be extended to include the Rockspring Neighborhood reach within the next few months.
  2. For Alamitos Creek, a geotechnical investigation for the levees/floodwall and a two-dimensional model were both completed in the third quarter of 2016. The floodplain mapping is currently being finalized and the project team will work with upper management to determine if submitting updated maps to FEMA is necessary.

Key Performance Indicators

  1. Complete engineering studies on 7 creek reaches to address 1 percent flood risk
  2. Update floodplain maps on a minimum of 2 creek reaches in accordance with new FEMA standards



Priority E-200

Project Information

Project Start FY 2014
Project Finish FY 2022
Safe Clean Water
Program funding

$8.7 M**

(2015 Dollars)

**More financial information: 5-Year Implementation Plan, pages: 19-27
Status Planning
Location Countywide

For more information:


Completed Work

   Preliminary 100 Year Flooplain Maps (PDF)