The council shall, subject to the applicable provisions of the general law of the State, have authority to borrow money in anticipation of the payment of special assessments made for the purpose of defraying the cost of any public improvement or in anticipation of the payment of any combination of such special assessment, and to issue bonds therefore. Such special assessment bonds may be solely an obligation of the special assessment district or districts or a general obligation of the City. All collections on each special assessment roll or combination of rolls may be set apart in a separate fund for the payment of the principle and interest of the bonds issued in anticipation of payment of such special assessment and shall be used for no other purpose.