(1)    Definitions. In this section:

      (a)    “Capital costs” means the capital costs to construct, expand or improve public facilities, including the cost of land, and including legal, engineering and design costs to construct, expand or improve public facilities, except that not more than 10 percent of capital costs may consist of legal, engineering and design costs unless the municipality can demonstrate that its legal, engineering and design costs which relate directly to the public improvement for which the impact fees were imposed exceed 10 percent of capital costs. “Capital costs” does not include other noncapital costs to construct, expand or improve public facilities, vehicles; or the costs of equipment to construct, expand or improve public facilities.

      (b)    “Developer” means a person that constructs or creates a land development.

      (c)    “Impact fees” means cash contributions, contributions of land or interests in land or any other items of value that are imposed on a developer by a municipality under this section.

      (d)    “Land development” means the construction or modification of improvements to real property that creates additional residential dwelling units within a municipality or that results in nonresidential uses that create a need for new, expanded or improved public facilities within a municipality.

      (e)    “Municipality” means a city, village, or town.

      (f)    “Public facilities” means all of the following:

         1.    Highways as defined in s. 340.01 (22), and other transportation facilities, traffic control devices, facilities for collecting and treating sewage, facilities for collecting and treating storm and surface waters, facilities for pumping, storing, and distributing water, parks, playgrounds, and land for athletic fields, solid waste and recycling facilities, fire protection facilities, law enforcement facilities, emergency medical facilities and libraries. “Public facilities” does not include facilities owned by a school district.

         2.    Notwithstanding subd. 1., with regard to impact fees that were first imposed before June 14, 2006, “public facilities” includes other recreational facilities that were substantially completed by June 14, 2006. This subdivision does not apply on or after January 1, 2018.

      (g)    “Service area” means a geographic area delineated by a municipality within which there are public facilities.

      (h)    “Service standard” means a certain quantity or quality of public facilities relative to a certain number of persons, parcels of land or other appropriate measure, as specified by the municipality.

   (2)   General.

      (a)    A municipality may enact an ordinance under this section that imposes impact fees on developers to pay for the capital costs that are necessary to accommodate land development.

      (b)    Subject to par. (c), this section does not prohibit or limit the authority of a municipality to finance public facilities by any other means authorized by law, except that the amount of an impact fee imposed by a municipality shall be reduced, under sub. (6) (d), to compensate for any other costs of public facilities imposed by the municipality on developers to provide or pay for capital costs.

      (c)    Beginning on May 1, 1995, a municipality may impose and collect impact fees only under this section.

   (3)   Public hearing; notice. Before enacting an ordinance that imposes impact fees, or amending an existing ordinance that imposes impact fees, a municipality shall hold a public hearing on the proposed ordinance or amendment. Notice of the public hearing shall be published as a class 1 notice under ch. 985, and shall specify where a copy of the proposed ordinance or amendment and the public facilities needs assessment may be obtained.

   (4)   Public facilities needs assessment.

         1.    An inventory of existing public facilities, including an identification of any existing deficiencies in the quantity or quality of those public facilities, for which it is anticipated that an impact fee may be imposed.

         2.    An identification of the new public facilities, or improvements or expansions of existing public facilities, that will be required because of land development for which it is anticipated that impact fees may be imposed. This identification shall be based on explicitly identified service areas and service standards.

         3.    A detailed estimate of the capital costs of providing the new public facilities or the improvements or expansions in existing public facilities identified in subd. 2., including an estimate of the cumulative effect of all proposed and existing impact fees on the availability of affordable housing within the municipality.

      (b)    A public facilities needs assessment or revised public facilities needs assessment that is prepared under this subsection shall be available for public inspection and copying in the office of the clerk of the municipality at least 20 days before the hearing under sub. (3).

   (5)   Differential fees, impact fee zones.

      (b)    An ordinance enacted under this section may delineate geographically defined zones within the municipality and may impose impact fees on land development in a zone that differ from impact fees imposed on land development in other zones within the municipality. The public facilities needs assessment that is required under sub. (4) shall explicitly identify the differences, such as land development or the need for those public facilities, which justify the differences between zones in the amount of impact fees imposed.

   (6)   Standards for impact fees. Impact fees imposed by an ordinance enacted under this section:

      (a)    Shall bear a rational relationship to the need for new, expanded or improved public facilities that are required to serve land development.

      (am)    May not include amounts for an increase in service capacity greater than the capacity necessary to serve the development for which the fee is imposed.

      (b)    May not exceed the proportionate share of the capital costs that are required to serve land development, as compared to existing uses of land within the municipality.

      (c)    Shall be based upon actual capital costs or reasonable estimates of capital costs for new, expanded or improved public facilities.

      (d)    Shall be reduced to compensate for other capital costs imposed by the municipality with respect to land development to provide or pay for public facilities, including special assessments, special charges, land dedications or fees in lieu of land dedications under ch. 236 or any other items of value.

      (e)    Shall be reduced to compensate for moneys received from the federal or state government specifically to provide or pay for the public facilities for which the impact fees are imposed.

      (f)    May not include amounts necessary to address existing deficiencies in public facilities.

      (fm)    May not include expenses for operation or maintenance of a public facility.

      (g)    Except as provided under this paragraph, shall be payable by the developer or the property owner to the municipality in full upon the issuance of a building permit by the municipality. Except as provided in this paragraph, if the total amount of impact fees due for a development will be more than $75,000, a developer may defer payment of the impact fees for a period of 4 years from the date of the issuance of the building permit or until 6 months before the municipality incurs the costs to construct, expand, or improve the public facilities related to the development for which the fee was imposed, whichever is earlier. If the developer elects to defer payment under this paragraph, the developer shall maintain in force a bond or irrevocable letter of credit in the amount of the unpaid fees executed in the name of the municipality. A developer may not defer payment of impact fees for projects that have been previously approved.

   (7)   Low-cost housing. An ordinance enacted under this section may provide for an exemption from, or a reduction in the amount of, impact fees on land development that provides low-cost housing, except that no amount of an impact fee for which an exemption or reduction is provided under this subsection may be shifted to any other development in the land development in which the low-cost housing is located or to any other land development in the municipality.

   (7r)   Impact fee reports. At the time that the municipality collects an impact fee, it shall provide to the developer from which it received the fee an accounting of how the fee will be spent.

   (8)   Requirements for impact fee revenues. Revenues from each impact fee that is imposed shall be placed in a separate segregated interest-bearing account and shall be accounted for separately from the other funds of the municipality. Impact fee revenues and interest earned on impact fee revenues may be expended only for the particular capital costs for which the impact fee was imposed, unless the fee is refunded under sub. (9).

   (9)   Refund of impact fees. Except as provided in this subsection, impact fees that are not used within 8 years after they are collected to pay the capital costs for which they were imposed shall be refunded to the payer of fees for the property with respect to which the impact fees were imposed, along with any interest that has accumulated, as described in sub. (8). Impact fees that are collected for capital costs related to lift stations or collecting and treating sewage that are not used within 10 years after they are collected to pay the capital costs for which they were imposed, shall be refunded to the payer of fees for the property with respect to which the impact fees were imposed, along with any interest that has accumulated, as described in sub. (8). The 10-year time limit for using impact fees that is specified under this subsection may be extended for 3 years if the municipality adopts a resolution stating that, due to extenuating circumstances or hardship in meeting the 10-year limit, it needs an additional 3 years to use the impact fees that were collected. The resolution shall include detailed written findings that specify the extenuating circumstances or hardship that led to the need to adopt a resolution under this subsection. For purposes of the time limits in this subsection, an impact fee is paid on the date a developer obtains a bond or irrevocable letter of credit in the amount of the unpaid fees executed in the name of the municipality under sub. (6) (g).

   (10)   Appeal. A municipality that enacts an impact fee ordinance under this section shall, by ordinance, specify a procedure under which a developer upon whom an impact fee is imposed has the right to contest the amount, collection or use of the impact fee to the governing body of the municipality.