(a) The district may borrow money and incur indebtedness by issuing its obligations or entering into contracts for any lawful corporate purpose; provided that all such obligations and contracts, whether express or implied, shall be payable solely:
- (1) from revenues, income, receipts and profits derived by the district from its operation and management of systems;
- (2) from the proceeds of warrants, notes, revenue bonds, debentures, or other evidences of indebtedness issued and sold by the district which are payable solely from such revenues, income, receipts and profits; or
- (3) from federal or state grant gifts or other moneys received by the district which are available therefor.