Idaho Code § 43-315
The board of directors of an irrigation district may levy an assessment upon the lands within the district, not to exceed ten (10) cents per acre for the purpose of raising funds to be used for the extermination of gophers and other rodents. Said assessment shall be levied at the same time and in the same manner and with a like effect, as assessments levied for maintaining and operating the property of the district. Said assessments shall constitute a lien upon the property assessed and shall be collected, in like manner as assessments for maintenance and operation.
The funds realized from such assessment shall be used for the extermination of gophers and other rodents within the irrigation district, in such manner and by such means as the said board of directors may direct.
Idaho Code § 43-315