When the bonds of any district have been certified as provided herein, it shall be unlawful for the district, during the life of said bonds to expend any money or incur any obligation for construction purposes without the written approval of the director of ecology, nor shall such district issue and sell any bonds not certified as herein provided, and the district shall annually at such time as said director shall prescribe, prepare and file with the director, on forms furnished by that officer, a budget of its contemplated expenditures for maintenance and operation during the ensuing year.