If any person now owns or maintains any structure on any public beach land or water over which the Board of Playground and Recreation Commissioners now has or may hereafter acquire jurisdiction and said structure has been erected under and pursuant to a grant issued by the State of California, the County of Los Angeles, or any municipality now existing, or formerly existing within the County of Los Angeles, the same may be maintained in its present condition until the expiration of the time specified in the grant. After the grant under which any such structure was erected has expired, a renewal of such grant must be secured from the Board of Playground and Recreation Commissioners in the manner outlined in this article and subject to the terms outlined therein. Any existing structure, built under a grant issued by the State of California, County of Los Angeles, or any municipality now existing or formerly existing in the County of Los Angeles, on lands that are now under the control of, or that may hereafter be under the control of the Playground and Recreation Commissioners of the City of Los Angeles, and which grant does not specify the length of time for which said grant was to run, shall expire twenty (20) years from the date of the issuance of the grant.
However, any existing structure hereinbefore mentioned in this section may be repaired and maintained in the manner specified in the original grant without the necessity of obtaining a new grant from the Board of Playground and Recreation Commissioners until the expiration of the life of the grant, as above mentioned, but such structure cannot be maintained or repaired in a manner that differs from the manner specified in the original grant for the construction of the same, and, if any such existing structure is now being maintained, or has been repaired, or the grantees or their successors hereafter attempt to maintain or repair such structure in a manner that differs from the original grant in any way that will affect or change the drift of sand, or alter the current of water, the owners of such existing structure must obtain a grant from the Board of Playground and Recreation Commissioners to maintain such existing structure in its present condition and a grant must be obtained in the event that any attempt is made to repair such existing structure in a manner that will alter the current of water or change the drift of sand in a manner different from the original drift of sand or flow of current. The Board may deny said application if in the exercise of a reasonable discretion the Board of Playground and Recreation Commissioners determines after an investigation, that the particular structure for which an application is being made has been repaired and is now being maintained or it is sought to repair or maintain a structure in a manner different from the construction of the same in its original grant and the present or contemplated condition of the structure is or would be such that it would change the current of the water or the drift of the sand in a manner different from the manner in which the original structure would affect the current or drift.