Cal. Water Code § 46951

The same proceedings for the preparation and adoption or rejection of the report and recommendation as to the acquisition of additional property or construction of additional work, and in case of the adoption of the report and recommendation, the levying and collection of the assessments to meet the cost, shall be taken in connection with the property and work to be acquired or constructed as provided in this division for the acquisition or construction of the property or work contemplated by the original project.