Any ground in the waters of this Commonwealth not assigned to anyone for planting or bathing purposes may be, on application of twenty or more citizens to the officer assigned to the district in which the land lies, laid off and designated as public clamming grounds; or the Commissioner may do so without such petition, provided in his opinion no oyster interests will suffer thereby and the clams are of sufficient quantity for a person to realize at least 225 clams or $1.50 per day catching and taking clams from such ground. If the ground is laid off, the Commissioner shall designate by stakes the metes and bounds of such ground and also have a plat made, to be recorded in the clerk’s office of the county where the ground lies. All costs of surveying, platting, and recording shall be paid by the applicant. Such ground shall be set apart and remain a public clamming ground for the common use of the citizens of Virginia for so long as the Commissioner determines, and shall not be assigned to anyone during such period.