(1) The secretary may use surplus physical facilities at eastern state hospital as a residential habilitation center, which shall be known as the "Interlake School."

(2) The secretary may designate and select such buildings and facilities and tracts of land at eastern state hospital that are surplus to the needs of the department for mentally ill persons and that are reasonably necessary and adequate for services for persons with developmental disabilities. The secretary shall also designate those buildings, equipment, and facilities which are to be used jointly and mutually by both eastern state hospital and Interlake School.