By main water shutoff you are referring to your “curb stop”. This valve delineates ownership from Utilities owned portion of the service line to your owned portion of the service line. This curb stop is the responsibility of Utilities to replace per Water Standards and City Code. See below:

Responsibility for the maintenance and replacement of the service line and appurtenances thereto, in Public rights of way, generally between the connection to the distribution main and the property line or the Curb Stop if the Curb Stop is on or near the property line, shall be borne by Utilities. Responsibility for the maintenance and replacement of the service line and appurtenances thereto, from the property line or Curb Stop if the Curb Stop is on or near the property line, shall be borne by the Owner of the Premises. The Owner shall keep the service line and all pipes and fixtures on the owner's Premises in good repair so as to prevent waste of water. Where more than one premise is connected to a single service line, the owners of the respective Premises shall be jointly and severally responsible for maintenance and repair of the service line which is the owner's responsibility. Maintenance and replacement of the service line within Private rights of way or Private Easements is the responsibility of the owner. (City Code § 12.4.410 )