Iowa Code § 327G.67: Costs in excess of deposit.

In any event before the railroad company shall be required to incur any expense whatever in the construction of such spur track the person, firm, corporation, or association primarily to be served thereby shall give the railroad company a bond to be approved by the department as to form, amount, and surety, securing the railroad company against loss on account of any expense incurred beyond the amount so deposited with the railroad company.