All applications made and filed pursuant to Section 10500 shall be transferred to the State Water Resoures Control Board and held by the board for the purposes of this part. The board may release from priority or assign any portion of any application filed under this part when the release or assignment is for the purpose of development not in conflict with such general or coordinated plan or with water quality objectives established pursuant to law. The assignee of any such application whether heretofore or hereafter assigned, is subject to all the requirements of diligence as provided in Part 2 (commencing with Section 1200) of Division 2 of this code. “Assignee” as used herein includes, but is not limited to, state agencies, commissions and departments, and the United States of America or any of its departments or agencies.