Work on all projects shall be done under contract awarded to the lowest responsible bidder pursuant to this part, except that it may be done by day’s labor under the direction of the department, by contract upon informal bids, or by a combination thereof:
(a) In case of emergency due to the failure or threat of failure of any bridge or other highway structure.
(b) In case of emergency due to the failure or threat of failure of any dam, reservoir, aqueduct, or other water facility or facility appurtenant thereto.
(c) In case of emergency due to damage to a state-owned building or any other state-owned real property or improvements located thereon, by an act of God, including but not limited to damage by storm, flood, fire or earthquake, for work and remedial measures which are required immediately.
(d) At any time after the approval of plans, specifications and estimates of cost, if the director deems the advertising or award of a contract, the acceptance of any bid, or the acceptance of any further bids after the rejection of all submitted bids, is not in the best interests of the state.