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E6: Upper Llagas Creek Flood Protection Project Buena Vista Avenue to Wright Avenue- Morgan Hill, San Martin, Gilroy

Preferred project: A federal-state-local partnership

This project continues a Clean, Safe Creeks project in partnership with the U.S. Army Corps of Engineers (USACE) and the state to plan, design, and construct improvements along 13.9 miles of channel. The project extends from Buena Vista Avenue to Wright Avenue, including West Little Llagas Creek in downtown Morgan Hill. The federally authorized preferred project protects the urban area of Morgan Hill from a 1% (or 100-year) flood, and reduces the frequency of flooding in surrounding areas. Construction includes channel modifications and replacement of road crossings. The District continues to work with Congress to aggressively pursue federal funds to bring this project to full fruition. In 2012, project limits were extended 2,700 feet upstream to Llagas Road to address public concerns.


  • Preferred project provides 1% flood capacity for 4 miles of channel in downtown Morgan Hill, protecting approximately 1,100 homes and 500 businesses
  • Preferred project provides 10-year flood protection to approximately 1,300 agricultural acres in Morgan Hill, Gilroy and San Martin
  • Locally-funded-only project provides 1% flood protection for a limited number of homes and businesses in Morgan Hill
  • Improves stream habitat and fisheries
  • Creates additional wetlands
  • Improves stream water quality
  • Identifies opportunities to integrate recreation improvements with the City of Morgan Hill and others as appropriate

Project Status

(As of September 2017

  • Staff is in the process of purchasing the necessary rights-of-way within Reach 4 (Buena Vista Avenue to Highway 101) and Reach 7A (Main Branch Llagas Creek near Monterey Road to Watsonville Road) and to construct the flood protection improvements within Reach 4 and Reach 7A including Lake Silveira Improvements (On-site mitigation).
  • District staff is also in the process of purchasing the necessary Phase 2 rights-of-way in the remaining reaches of Upper Llagas Creek.
  • Until there is additional financial assistance from the U.S Army Corps of Engineers, the district will continue moving the Upper Llagas Creek Flood Protection Project forward by using local Safe, Clean Water funding to complete construction of Phase I of the Project, Reach 4 (Buena Vista Avenue to Highway 101), Reach 7a (Monterey Road to Watsonville Road), and the on-site mitigation (Lake Silveira) by December 2019. In November 2000, the voters passed the Clean Safe Creeks bond measure that provided $17.1 million in Project funding. In November 2012, voters overwhelmingly passed Safe, Clean Water bond measure that will provide an additional $39.1 million in Project funding. This reduced-scale project would support future construction (Phase 2) of the full preferred project at a later date when additional funding sources are determined. The District will continue to work with and support the project′s federal partner, the Corps. As a federal project, the district may collect reimbursements from the State Department of Water Resources for expenditures to acquire the necessary Project rights-of-way.

Key Performance Indicators

  1. Preferred project with federal and local funding: Provide flood protection to 1,100 homes, 500 businesses, and 1,300 agricultural acres, while improving stream habitat.
  2. With local funding only: Provide 100-year flood protection for Reach 7 only (up to W. Dunne Avenue in Morgan Hill). A limited number of homes and businesses will be protected.

Priority E-200

FY17 Annual Report Status 

StatusAdjusted (schedule adjustment)
Project FinishThrough
FY 2022
Safe Clean Water
Program funding

$108.4 M**

(2015 Dollars)

**More financial information: 5-Year Implementation Plan, pages: 19-27
LocationMorgan Hill, San Martin and Gilroy

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