A county may require a community redevelopment agency to reimburse the county for any expenses incurred by the county in performing any of the services required to be performed by the county for the redevelopment agency pursuant to Sections 33670, 33675, and 33676 for a project area as to which no payments are made by the agency to the county in accordance with subdivision (b) of Section 33401 and no agreement has been entered into and either of the following situations exist:

1. (a) A final redevelopment plan for the project area is adopted on or after January 1, 1986.
2. (b) A final redevelopment plan for the project area was adopted prior to January 1, 1986, but its boundaries are changed on or after January 1, 1986, to add land to, or to exclude land from, the project area. However, in the case of a project area which changes its boundaries on or after January 1, 1986, to add land to the project area, the reimbursement shall relate only to expenses incurred by the county with respect to the added area.