The department is directed to develop construction programs for facilities for individuals with an intellectual disability and community mental health centers for the mentally ill, which shall be based respectively on statewide inventories of existing facilities for individuals with an intellectual disability and the mentally ill and surveys of need, and which shall provide in accordance with regulations prescribed under the federal act, for facilities which will provide adequate services for individuals with an intellectual disability and adequate community mental health services for the people residing in this state and for furnishing needed services to persons unable to pay therefor.