The board of county commissioners of each county shall provide and establish the "general drainage improvement fund," which fund shall be used as a sinking fund for all bonds issued under sections 6131.01 to 6131.64, inclusive, of the Revised Code. Said fund shall consist of:

1. (A) Any taxes levied and collected for ditch and drainage purposes under county levies, not by law otherwise disposed of;
2. (B) The proceeds of all bonds issued and sold under sections 6131.01 to 6131.64, inclusive, of the Revised Code;
3. (C) The collections from all special assessments for benefits to property, as provided in such sections;
4. (D) Such other funds as by law are provided to be paid therein.