The board of trustees, except where otherwise provided, shall by resolution, at the time of hiring or appointing, provide for the compensation for work done and necessary expenses incurred by any officer, engineer, attorney or other employee, and shall also pay the fees, per diem, and necessary expenses of all court and county officers, who may by virtue of sections 249.010 to 249.420 render service to the district. The board of trustees shall have power to discharge any employee of the district, except the engineer and attorney at will and may discharge the engineer or attorney for cause on thirty days’ notice.