Oregon Revised Statutes Water Resources: Irrigation, Drainage, Flood Control, Reclamation § 547.310

(1) The board of supervisors shall have full power and authority to:

(2) The board may after advertising for bids, let a contract for construction of the whole or any part of the drainage or irrigation works to the lowest responsible bidder, which contract shall be in writing. The complete plans and specifications for the drainage or irrigation of the lands shall be attached to and made a part of each contract. Good and sufficient bond, running in favor of the district, shall be required of each contractor, conditioned that the contractor will well and truly comply with all the provisions of the contract and perform all work in accordance with the terms thereof.

(3) The chief engineer shall be superintendent of all the works and improvements and shall, whenever required, and at least once each year, make a full report to the board of all work done and improvements and make such suggestions and recommendations to the board as the chief engineer deems proper.