Water Code § 12681
ARTICLE 3. Projects in Other Watersheds
The San Bernardino County Flood Control District and the Riverside County Flood Control and Water Conservation District, in conjunction with the Department of the Army, shall execute the plan of improvement for flood control referred to in Section 12679 and exercise all powers granted by law to the districts, and the districts may make such modifications and amendments to the plan as may be necessary to execute it for the purposes of Chapters 1 and 2 of this part.