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AB-639 • 2026

Dams: exceptions.

Dams: exceptions.

Enacted

This bill passed the Legislature and reached final enactment based on the latest official action.

Sponsor
Soria
Last action
Official status
Chaptered
Effective date
Not listed

Plain English Breakdown

The official summary does not provide a detailed dictionary definition for 'weir,' so the meaning is limited to its context in this bill.

AB-639: New Exceptions for What Counts as a Dam

This law adds an exception to the definition of a dam for specific weirs that do not hold water above the top of a levee and have at least 3 feet of freeboard.

What This Bill Does

  • Adds a new exception to the legal definition of a dam.
  • Excludes certain barriers called weirs from being classified as dams if they meet specific safety rules.
  • Requires that these weirs must not hold water above the top of an existing levee.
  • Mandates at least 3 feet of freeboard, or empty space, on the levee behind the barrier.
  • Limits this new exception only to specific weirs named directly in the bill.

Who It Names or Affects

  • Owners and builders of barriers that fit the description of a weir listed in the law.
  • The Department of Water Resources, which supervises dam safety.

Terms To Know

Weir
A specific type of barrier defined in this bill that can be excluded from being called a dam if it meets certain rules.
Freeboard
The empty space, measured as at least 3 feet, between the top of a levee and the highest water level behind the barrier.

Limits and Unknowns

  • This exception applies only to weirs specifically named in the bill text.
  • The law does not change rules for barriers that hold water higher than the top of a levee.
  • Existing exceptions still apply, such as barriers under 6 feet high or holding less than 15 acre-feet.

Bill History

  1. California Legislative Information

    Chaptered

Official Summary Text

Dams: exceptions.