If Section 33840.5 or any portion thereof is held invalid such invalidity shall not affect other provisions of this chapter which can be given effect without such invalid section; however, after such section or portion thereof has been held to be invalid: (1) no assessment district shall be established which includes real property containing one or more residential dwelling units occupied by persons and families of low or moderate income; (2) no levy shall be imposed on any real property containing one or more residential dwelling units occupied by persons and families of low or moderate income; and (3) any existing levy imposed upon real property containing one or more residential units occupied by persons and families of low or moderate income shall be deemed to be rescinded and the lien discharged. If any provision in this section is held to be invalid no levy shall be imposed on any property within a special assessment area which includes real property containing one or more residential dwelling units occupied by persons and families of low or moderate income after such section or portion thereof is found to be invalid.