It depends on what the individual with a social work degree does for employment. Salaries always depend on your job, where the revenue source is coming from, your experience, geographic location, what type of agency, etc.
A simplified way to view it is.............social work is a degree you can get in college that can prepare you for various positions. There are individuals with social work degrees working in public policy; working as directors in agencies; working in the school system; working for the military as civilians in providing services to military families; working for state agencies (i.e. social services, aging services, mental health, probation/parole, juvenile services, health, etc); working in health care agencies (hospice, home health, nursing homes and hospitals); working for drug/alcohol abuse rehabilitation centers; working for adoption agencies; working for law firms (i.e. assisting with life planning and services for older clients); working in the area of planning and development; and a host of other jobs. With a Masters in Social Work, one can also become a licensed clinical social worker, and a clinical social worker can do therapy, set up private practice, or work in other settings as a therapist/counselor in various agencies. Some individuals also may work as consultants in their area of expertise. With a MSW, one can also teach at the University level as an adjunct instructor, both in seat or online.
I have a degree in social work, and my work involves ensuring health care regulatory compliance in the health care setting (i.e. quality of care and quality of life).
There is no set salary for an individual who happens to have a degree in social work. As you can see above, salary depends on various things. It is a myth that salary for a "social worker" is low. What is important is to figure out the career area(s) you are interested in and see what you may be interested in doing and check out online job ads to see what employers are looking for. This can help you see what degree(s) employers may be asking for and the required experience.
Here is general information from the U.S. Government Outlook Handbook:
http://www.bls.gov/ooh/Community-and-Social-Service/Social-workers.htm