California Code, Public Resources Code - PRC § 9409

The directors may make improvements or conduct operations on public lands, with the cooperation of the agency administering and having jurisdiction thereof, and on private lands, with the consent of the owners thereof, in furtherance of the prevention or control of soil erosion, water conservation and distribution, agricultural enhancement, wildlife enhancement, and erosion stabilization, including, but not limited to, terraces, ditches, levees, and dams or other structures, and the planting of trees, shrubs, grasses, or other vegetation.