As used herein, the following words and phrases shall have the following meanings:

(1) "Lakes" means all the surface water areas of the state, including reservoirs; except

(a) Lakes less than twenty acres in size;

(b) Streams or rivers (as described in WAC 173-18-030);

(c) Shorelines of statewide significance.

(2) "Lakes of statewide significance" means those lakes, whether natural, artificial or a combination thereof, with a surface acreage of one thousand acres or more measured at the ordinary high-water mark.