(1) Use of the revolving fund established under ORS 552.635.
(2) Assessments under ORS 552.608 and 552.613 against the benefited property in the district with or without issuance of improvement bonds or warrants.
(3) Service charges and user fees collected under ORS 552.618 or 552.630 from those who are served by or use the services, works and facilities of the district.
(4) Levy of ad valorem taxes under ORS 552.623 and 552.625.
(5) Sale of bonds under ORS 552.645 to 552.660.
(6) Any combination of the provisions of subsections (1) to (5) of this section. [1969 c.606 §40]