Idaho Code § 42-2804
Before any public irrigation or drainage work specified in this chapter shall be established, a petition signed by one hundred (100), or twenty-five per cent (25%) of the owners of the land described in such petition, as the land proposed to be benefited, setting forth the necessity therefor, that the same will be a public benefit and will promote the public welfare or public health, the description of the proposed irrigation or drainage works in general terms, together with a description of the land intended to be benefited thereby, shall be filed with the county auditor. Upon the filing of such petition, one or more of such petitioners shall deposit with the county treasurer of such county from time to time sums of money in an amount to be determined and fixed by the board of county commissioners to be used by them to defray all costs and expenses incurred under the provisions of this chapter to and including all expenses of the bond election and until such time as funds for said work are otherwise available: provided, that the amount of such deposits shall be included in the cost of the works in the event the indebtedness for the same shall be authorized at such election and reimbursement shall thereafter be made to the parties depositing the same.
Idaho Code § 42-2804