All improvements required by these Subdivision Regulations shall be constructed and completed under the supervision of and to the specifications required by the agency or agencies having jurisdiction over them. Final approval of any plat shall be withheld until all required improvements are completed to the satisfaction of the agency or agencies involved, or until a bond or other financial instrument approved by the Law Director has been posted in favor of the Village or County, depending on the jurisdiction in the amount of 110 percent of the estimated cost of the improvements and the necessary inspections, or until a petition for improvements by assessment has been properly submitted under Ohio R.C. Chapter 727, provided, however, that final approval provided the Village with a bond or letter of credit continuing through the period of the assessments in the amount of 100 percent of the estimated cost of the improvements.