To enable the Secretary of the Interior to complete Government reclamation projects begun prior to June 25, 1910, the Secretary of the Treasury is authorized, as of June 25, 1910, upon request of the Secretary of the Interior, to transfer from time to time to the credit of the reclamation fund created by section 391 of this title, such sum or sums, not exceeding in the aggregate $20,000,000, as the Secretary of the Interior may deem necessary to complete the said reclamation projects, and such extensions thereof as he may deem proper and necessary to the successful and profitable operation and maintenance thereof or to protect water rights pertaining thereto claimed by the United States, provided the same shall be approved by the President of the United States; and such sum or sums as may be required to comply with the foregoing authority are appropriated, as of June 25, 1910, out of any money in the Treasury not otherwise appropriated: Provided, That the sums authorized to be transferred to the reclamation fund shall be so transferred only as such sums shall be actually needed to meet payments for work performed under existing law: And provided further, That all sums so transferred shall be reimbursed to the Treasury from the reclamation fund, as hereinafter provided: And provided further, That no part of this appropriation shall be expended upon any project existing June 25, 1910, until it shall have been examined and reported upon by a board of engineer officers of the Army, designated by the President of the United States, and until it shall be approved by the President as feasible and practicable and worthy of such expenditure; nor shall any portion of this appropriation be expended upon any project initiated after June 25, 1910.