The plan commission shall not consider approval of the final plat unless and until the subdivider has guaranteed the completion of all required improvements within a reasonable period and in compliance with working drawings and specifications. This guarantee shall be by one, or a combination of 2 or more, of 3 methods.
(A) The subdivider may post a performance bond prepared in a form approved by the city attorney, and underwritten by a surety company listed as approved by the city council. The amount of the bond shall be not less than 125% of the final estimate of the cost of the improvement as estimated by the city engineer. There shall be no reduction in the amount of that portion of the bond applying to a particular improvement unless and until that improvement is complete and accepted or approved by the city council. From the standpoint of acceptance, the subgrade, base course, and surface course of a street, alley, or parking area shall be considered as a single improvement.
(B) The subdivider may deposit a cash bond with the city in accordance with a specific escrow agreement approved by the city attorney and the city engineer and in an amount not less than 125% of the final estimate of the cost of the improvements as estimated by the city engineer. The deposit shall be held in a special account by the city, and the agreement may provide for partial payouts, as work progresses, in amounts approved by the city engineer as corresponding to the original estimate of unit costs. Partial payouts shall be contingent upon favorable inspection reports, and the sum of the partial payouts for a single improvement shall not exceed 90% of the original deposit for the improvement, until and unless the improvement is complete and accepted or approved by the city council. From the standpoint of acceptance, the subgrade, base course, and surface course of a street, alley, or parking area shall be considered a single improvement.
(C) Upon specific permission of the city council, as recommended by the plan commission, the subdivider may elect to complete one or more improvements prior to approval of the final plat. Where the subdivider elects to guarantee completion of an improvement by this method, approval of the final plat shall be contingent upon certification by the city engineer that the improvement has been completed in accordance with drawings and specifications, and that the inspection reports are favorable.
('69 Code, App. B, § 10.13)