Wat. Code, § 8402

Unless the context otherwise requires, the following definitions apply throughout this chapter:

(a) “Department” means Department of Water Resources.

(b) “Board” means the State Reclamation Board.

(c) Wherever the words “department or board” or “department and board” are used together in this chapter they shall mean board as to any area within a project which by law is under the jurisdiction of the State Reclamation Board, and the department in all areas of the state outside these areas.

(d) “Public agency” means any city, city and county, county, or district organized, existing, and acting pursuant to the laws of this state.

(e) “Design flood” means the selected flood against which protection is provided, or eventually will be provided, by means of flood protective or control works. When a federal survey has been authorized the design flood will be determined by the appropriate federal agency and in all other cases it will be determined by the responsible local agency. It is the basis for design and operation of a particular project after full consideration of flood characteristics, frequencies, and potentials and economic and other practical considerations.

(f) “Designated floodway” means the channel of a stream and that portion of the adjoining flood plain required to reasonably provide for the construction of a project for passage of the design flood including the lands necessary for construction of project levees.

(g) “Restrictive zone” means the portion of the natural floodway between the limits of the designated floodway and the limits of the flood plain where inundation may occur but where depths and velocities are generally low.