The procedure for levying special assessments set forth in Wis. Stat. sec. 66.0703, contemplates that the process be commenced and completed prior to construction. However the League opined  that  a municipality may possibly commence special assessment procedures pursuant to sec. 66.0703, after work on a public improvement project has commenced if the municipality has not adopted a final resolution which states that the cost of the improvement shall be paid with funds from the public treasury and the municipality has clearly indicated its intent on the record that it contemplates eventually financing the project with special assessments. Absent such a resolution or motion, a municipality is very likely precluded from using sec. 66.0703 to levy special assessments to finance an already completed public works project. See League legal opinion Special Assessments 605.

The Wisconsin Court of Appeals held Wis. Stat. sec. 66.0703 does not preclude a municipality from completing the special assessment process after the improvements have already been constructed so where the City had demonstrated an intent to specially assess the work and had followed each of the statutory steps required by sec. 66.0703, its assessment was not invalid because it was levied after the improvements were constructed. Park Avenue Plaza v. City of Mequon, 2008 WI App 39, 308 Wis.2d 439, 747 N.W.2d 703.

A municipality may possibly levy special assessments against benefited property after a public improvement project has been completed pursuant to a special assessment ordinance enacted under sec. 66.0701. Section 66.0701 authorizes municipalities to develop their own procedures, by ordinance, for specially assessing properties benefited by a public improvement project.

Such an ordinance must contain provisions for reasonable notice and hearing. A municipality that enacts an ordinance establishing its own local assessment procedures could specify in the ordinance that the assessment process can be invoked either prior or subsequent to the completion of the work. See Form 17 in the League's Special Assessments in Wisconsin handbook for a model special assessment ordinance adopted pursuant to sec. 66.0701 which allows the governing body to adopt a resolution determining to finance any public work or improvement by special assessments either before or after completion of the public work or improvement.