(1) The procedure for levying, collecting, and enforcing the payment of special assessments for public improvements or other services to be charged against the real property shall be governed by general ordinance.
(2) Funds raised from assessments against city water customers shall not be used for any purpose other than water purposes unless otherwise approved by the electors.
(3) Funds raised from assessments against city sewer customers shall not be used for any purpose other than sewer purposes unless otherwise approved by the electors.