Del. Code tit. 31 § 4526
An urban renewal plan which has not been approved by the governing body when recommended by the authority may again be recommended to it with any modifications deemed advisable. A redevelopment plan may be modified at any time by the authority; provided, that, if modified after the lease or sale of real property in the urban renewal project area, the modification must be consented to by the redeveloper or redevelopers, or his or her successor or their successors who acquired 75% of the land in the project area and whose interest may be affected by the proposed modification.
The notice of the proposed modification shall be sent by certified mail to the last known address of the redeveloper or redevelopers of the real property, or his or her successor or successors, who shall have 30 days from the date of the notice to state objections to the modification. These objections will be submitted to the governing body at the time of the hearing. If no objections are made within the 30 days from the date of the notice, then the authority may recommend the plan and state to the governing body that there were no objections.
31 Del. C. § 4526