Upper Llagas Creek Flood Control Project

Flood Protection

This project is managed and implemented by Valley Water to provide flood protection to the Morgan Hill community 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 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 the replacement of road crossings.  

  • Phase 1: Completed
  • Phase 2A: Completed

Phase 2B: In Construction Through Spring 2027

The next phase (Phase 2B) began in October 2024 and is currently underway. Valley Water awarded the construction contract to Graniterock Company. Phase 2B scope of work includes extending the box culvert at Main Avenue and Hale Avenue to Wright Avenue, constructing a weir structure at Wright Avenue and Hale Avenue, relocating utilities along Hale Avenue, Hale Avenue widening between Main Avenue and Wright Avenue, new streetlights, undergrounding of overhead electrical lines-west side only, and a new traffic signal at Wright Avenue and Hale Road. Learn more about this project at Valley Water's Website. 

Upcoming Road Closures

Portions of Hale Avenue, between Main Avenue and Wright Avenue will be closed to traffic periodically as the contractor will now start relocating the underground utilities to make room for the new box culvert. The underground work will take months to complete. A new sewer main was installed last month. Currently under construction is the temporary water line bypass system. This will allow the new water line to be installed quicker with minimal disruption to businesses and residents. The construction of the new water line is expected to start March 3, 2025. 

Hale Avenue Between Wright and Main Avenues

  • Hale Avenue will be closing during daytime hours between Wright Avenue and Main Avenue from March 3 until April 15. Full or partial closures will typically occur between 8am and 5pm. Morning and evening traffic will still be able to use Hale Avenue during this period. 
  • From April 15 through October 2025 the roadway will be completely closed to traffic. Access to the shopping center at Main and Hale will be available via Main Avenue and via Hale Avenue (southern driveway). Access to the medical offices at the Park Plaza Professional Center will be available from Crest Avenue during the closure.
  • Detour routes – Wright Avenue to Monterey Road to Main Avenue or Wright Avenue to Peak Avenue to Main Avenue.

Cosmo Avenue at West Little Llagas Creek between Monterey and Del Monte

  • Cosmo Avenue shall be completely closed at West Little Llagas Creek over the creek from approximately April 21, 2025 to June 30, 2025.
  • Access will be available to Del Monte Avenue or Monterey Road via Spring Avenue.

Spring Avenue at West Little Llagas Creek between Monterey and Del Monte

  • Spring Avenue shall be closed over the creek from approximately July 1, 2025 to September 15, 2025.
  • Access will be available to Del Monte or Monterey Road via Cosmo Avenue.

Phase2A_FeaturesMap

Project Updates