Every county water district which executes a contract with the United States for the purposes set forth in Section 31151 shall, within the meaning of the act of Congress approved August 11, 1916, entitled “An act to promote the reclamation of arid lands” and of the act of Congress approved May 15, 1922, entitled “An act to provide for the application of the reclamation law to irrigation districts,” be deemed to be an irrigation district organized and created under the irrigation district laws of this State.