(1) The construction, reconstruction or improvement of any facilities shall be completed in the manner determined by the governing body and shall be free from any requirement of competitive bidding or any other restriction imposed on the procedure for award of contracts with public bodies.
(2) Nothing in ORS 468.263 to 468.272 is intended as a restriction or limitation upon any other powers which a county might otherwise have under the laws of this state, but shall be construed as cumulative.
(3) If any provision of ORS 468.263 to 468.272 or the application thereof to any person or circumstance is held to be invalid, such invalidity shall not affect other provisions of ORS 468.263 to 468.272 which can be given effect without the invalid provision or application, and to this end the provisions of ORS 468.263 to 468.272 are declared to be severable.