Said plans, specifications and estimates, together with the data upon which the same are based, shall be submitted by the board of directors to the school of engineering of the state university or state agricultural university for correction and approval, and all work done by said engineering school in connection with said plans, specifications and estimates shall be free of cost to the district. The district engineer shall make such changes in said plans, specifications and estimates as may be recommended by said school of engineering, unless they are found to be so grossly inaccurate as to render necessary an entirely new survey and new plans, specifications and estimates; in which event the board of directors shall forthwith appoint another engineer, who shall prepare a new set of plans, specifications and estimates in harmony with this act and in line with the recommendations of the school of engineering, and these plans, specifications and estimates shall be submitted for approval and correction to said school of engineering as hereinbefore provided.