Sacramento Weir

Problem & Need
The Sacramento region faces significant flood risk from the Sacramento and American Rivers, with the existing Sacramento Weir operating at capacity limits since its construction 109 years ago. Current infrastructure cannot adequately handle major flood events, putting thousands of residents and critical regional infrastructure at risk.

Project Scope

The Sacramento Weir Widening Project is a comprehensive two-phase effort to expand flood protection capacity by adding 1,455 feet of weir infrastructure. The project involves constructing a passive weir system that will significantly increase the ability to divert floodwaters into bypass channels, working in coordination with the existing 48 manually-operated gates across the 1,950-foot original structure.

Current Status: Both project components are actively under construction with substantial progress:

• Sacramento Bypass Widening (DWR-led)
  • Construction underway with major earthwork and channel modifications in progress
• Sacramento Weir Widening (USACE-led)
  • Foundation and structural work advancing, with passive weir construction initiated

Completed Construction

The Sacramento Weir Expansion project has been progressing since July 2023, with significant milestones completed, including:

• Fish Passage Structure concrete placements – Fish ladder completed (2024)
• Fish Passage Phase 2 project features – Modifications to Sacramento Weir stilling basin, new rock-lined channel, and new earthen channel connecting to Tule Canal (2024)
• Earthwork activities – New North Levee setback, Old River Road embankment, and County Road 126 embankment
• Dewatering system installation – Network of groundwater pumps and piping system for excavation below groundwater level

Current Status

     The project has encountered technical challenges that will impact the overall timeline:

• North Abutment Wall – Vertical settlement exceeded design tolerances (March 2025), requiring redesign and reconstruction
• Riprap placement – Currently underway for fish passage channel
• Traffic control detour – Remains in place along Old River Road until vehicle bridge completion
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• Pile driving operations – Expected to begin in 2026 for 20-inch diameter steel pipe piles at North Abutment
• Vehicle Bridge – Expected completion by early 2027
• North Abutment corrective work – Complete corrective work by 2027
• Overall project completion – Delayed by approximately one year due to north abutment settlement issues

Sacramento Levee Upgrades (Main)

Sacramento River Levees

American River Levee Upgrades

Mitigation