The district board shall have authority to enter into any obligation or contract authorized by law with the United States or with the state of Washington for the supervision of the construction, for the construction, reconstruction, betterment, extension, purchase, operation or maintenance of the necessary works for the control of floods or for any other service furthering the objects for which said flood control district is created under the provisions of the law of the state of Washington or of the United States and all amendments or extensions thereof and the rules and regulations established thereunder.