The department of human services shall develop a plan for an integrated, multidisciplinary continuum of services for individuals with serious and persistent mental illness. The continuum may consist of an array of services provided by private mental health professionals, private agencies, county social service agencies, human service centers, community-based residential care and treatment facilities, and private and public inpatient psychiatric hospitals. When appropriate, access to the continuum must be through human service centers. The continuum of care must provide that a person requiring treatment be submitted to the least restrictive available conditions necessary to achieve the purposes of treatment. The department shall ensure appropriate cooperation with county social service agencies and private providers in achieving the continuum of care.