After a district has let a contract for work which crosses or traverses a railway right-of-way and the actual construction is commenced, the engineer in charge of construction shall notify the railroad company of the probable time at which the contractor will be ready to enter upon the right-of-way of said road and construct the work thereon. It shall be the duty of the said railroad to send a representative to view the ground with the engineer and arrange the exact time at which such work can be most conveniently done. At the time agreed upon, the said railroad company shall remove its rails, ties, stringers and such other obstructions as may be necessary to permit the excavation or construction of the channel or other work of improvement across its right-of-way. The work shall be so planned and conducted as to interfere in the least possible manner with the business of the said railroad. In case the railroad company refuses and fails to remove its track or tracks so as to permit the construction of the work on its right-of-way and the passage of the necessary equipment of the contractor, it shall be held as delaying the construction of the improvement, and such company shall be liable to a penalty of $100.00 per day for each day of delay to be collected by the board of water management commissioners for the benefit of the water management district as in case of other penalties. Such penalty may be recovered in any court of competent jurisdiction and shall inure to the benefit of the water management district. Within 30 days after work is completed, an itemized bill for the actual expenses incurred by the railroad company for opening its tracks shall be made and presented to the engineer of the water management district. Such bills, however, shall not include the cost of constructing a new bridge or of strengthening or enlarging an old one except as provided in this article. The engineer shall audit this bill and, if found correct, approve the same and file it with the secretary of the board of water management commissioners who shall reimburse the said railroad company for such expense.