Tax Liens on Blighted Properties in Louisiana

I have searched far and wide and cannot find anything on how to get a property officially declared "blighted" (or abandoned), other than New Orleans. I am trying to reduce the redemption period to 18 months from 3 years, but was told by the title clearing company they need it to be declared blighted first. Does anyone know how to do this? Do I need to call the code enforcer or file something for legal action? Properties are located in Iberia, St. Mary, and Caddo parishes. Many thanks for any responses.