Within thirty days after the district court has declared the district a public corporation, the trustees appointed by the court shall meet and elect one of their number chairperson and one of their number clerk of the district. Except as otherwise provided, the board shall (1) adopt a seal, bearing the name of the district, (2) keep a record of all of its proceedings which shall be open to inspection by all owners of real estate in the district, (3) have the power to pass all necessary ordinances, orders, rules, and regulations for the necessary conduct of its business and to carry into effect the objects for which the sanitary and improvement district was formed, and (4) have authority to appoint, employ, and pay an engineer or firm of engineers, an attorney, a fiscal agent, and such clerical help as may be needed, who shall each be removable at the pleasure of the board or administrator. The clerk of the board shall be paid a salary not to exceed twelve hundred dollars per year. Upon the appointment of an administrator for the district pursuant to sections 31-771 to 31-780, the authority of the trustees to exercise the powers granted in this section shall be suspended, except that the board shall continue in existence and the administrator shall periodically, but not less frequently than monthly, report to the board in writing on all decisions and actions taken by the administrator in managing the affairs of the district. The administrator shall, during the period of his or her appointment, possess exclusive authority to exercise the powers and duties conferred in sections 31-727 to 31-770. Each trustee shall be paid fifteen dollars for each meeting of the board which he or she attends, except that each trustee shall be paid for no more than twelve meetings in each calendar year. Each trustee shall be allowed reimbursement for mileage as provided in section 81-1176.