Idaho Code § 42-2806
In making contracts for the construction or purchase of irrigation or drainage works or the right to the use of works constructed or to be constructed, the county commissioners shall proceed in similar manner as provided by law for the making of similar contracts by irrigation districts, but no election shall be required to authorize any such contract: provided, however, that the aggregate of all contracts entered into for the purchase or construction of works on any project under the provisions of this chapter shall provide for the ultimate completion of the project in accordance with the approved plans referred to herein at a total cost not exceeding the total sum of money derived from the sale of bonds issued for such project, and the contractor or contractors (except in cases where the United States government is the contractor) shall give the bond required by section 45-502.
The plans and specifications and all contracts for construction work contracted for by boards of county commissioners under this chapter shall first be approved by the director of the department of water resources, and any construction contract entered into by such boards shall by its terms provide that such construction work shall be completed in accordance with such plans and specifications to the approval of the director of the department of water resources except in the case of contracts with the United States government. It shall be the duty of the director of the department of water resources, upon the completion of the work under any contract entered into under the provisions of this chapter to issue a certificate of such completion to the board or boards of county commissioners.
Idaho Code § 42-2806