The determination that property sought by eminent domain proceedings is marginal lands as herein defined is a judicial question, provided that a duly adopted resolution of the commissioners of the port district that the property sought is marginal lands as the term is herein defined, setting forth the characteristics of the lands sought to be acquired which constitutes the marginal lands as herein defined, shall be prima facie evidence that such land is marginal lands as defined in this chapter.
RCW 53.25.210