The department of administration shall periodically make population estimates and projections. These population determinations shall be deemed to be the official state population estimates and projections. These determinations shall be used for all official estimate and projection purposes, except where otherwise directed by statute, but do not supersede s. 990.01 (29). The department shall:

   (1)   Annually make estimates of the current number of persons residing in each municipality and county of the state, and periodically make projections of the anticipated future population of the state, counties and municipalities.

   (2)   Prepare population estimates for purposes of state revenue sharing distribution under ch. 79. For this purpose:

      (a)    On or before August 10 of each year, the department shall make its preliminary population determinations and shall notify the clerk of each municipality and county of its preliminary population determinations. The reference date for all population determinations for state shared revenue distribution purposes shall be January 1.

      (b)    Municipalities and counties believing that population determinations under par. (a) are based upon incorrect information may, no later than September 15 of the same year in which the determination is made, challenge the determination by filing their specific objections, and evidence in support thereof, with the department. If the challenge is denied by the department, the municipality or county may appeal the denial, by October 1 of the same year, by notifying the department that the appellant intends to have a special census conducted by the U.S. bureau of the census in support of the appeal under par. (dm).

      (c)    On or before October 10 of each year, the department shall make any necessary adjustments in its population determinations for the November distribution, and shall notify the clerk of any affected municipality or county of these adjustments. The adjusted population determinations shall be consistent with the methods used statewide for population determinations, and adjustments from the August 10 population determinations shall be made only to accommodate corrected information.

      (cm)    The July preliminary distribution shall be based on the final population determination of the previous year.

      (d)    Except as authorized in pars. (dm) and (e), the population determinations shall be based upon the last previous federal decennial or special census or other official statewide census and shall take into consideration growth rates of municipalities.

      (dm)    The results of special censuses conducted for municipalities and counties under contract with the U.S. bureau of the census shall be used as a basis for the respective population determinations on August 10 if the final certified results of such censuses are received by the department before July 1 in the year in which the determination is made. The results of special censuses conducted for municipalities and counties under contract with the U.S. bureau of the census shall be used as a basis for the respective population determinations on October 10 if the final certified results of such censuses are received by the department before October 1 in the year in which the determination is made. If a municipality or county notifies the department in writing by October 1 of its intention to contract for a special census with the U.S. bureau of the census in support of a challenge to the August 10 population determination, and if the final certified results of such a special census are received by the department before July 15 in the following year, the department shall adjust the preceding October 10 population estimate to reflect the results of the special census. If a municipality or county notifies the department of its intention to contract for a special census but the results are not received by July 15 in the following year, the department may use the best information from the most recent federal census. The department shall report the adjusted population determination to the department of revenue before August 1 of the year subsequent to the challenge. The department shall prorate census results for census dates occurring after the reference date of any population determination back to the reference date of the estimate for all municipalities and counties under par. (a). Upon receiving an adjusted population determination, the department of revenue shall correct shared revenue distributions under subch. I of ch. 79 according to s. 79.08. If a municipality contracts with the U.S. bureau of the census for a special census, the municipality shall assure that the results of such special census are certified to the department not later than 30 days after the release of the census results by the U.S. bureau of the census.

      (e)    Before August 1 of the year following the year in which a federal decennial census is taken, the department shall adjust the October 10 population determinations of the decennial census year to correspond to the final federal decennial census results as reported to an agency of the state by the U.S. bureau of the census under 13 U.S. Code § 141 (c). The department may use preliminary results from the decennial census for any municipality or a county for which the final results are not available before August 1 of the year following the decennial census year. The department shall prorate each population determination adjustment from the decennial census date back to the reference date of the estimate for all municipalities and counties under par. (a) in the decennial census year. The department shall report the adjusted population determination to the department of revenue before August 1 of the year following the federal decennial census year. Upon receiving an adjusted population determination, the department of revenue shall correct shared revenue distributions under subch. I of ch. 79 according to s. 79.08.

      (f)    Persons who are members in the Wisconsin Veterans Home at King shall be considered residents of the town of Farmington and of Waupaca County, persons who are members in the Wisconsin Veterans Home at Chippewa Falls shall be considered residents of the city of Chippewa Falls and of Chippewa County, and persons who are members in the Wisconsin Veterans Home at Union Grove shall be considered residents of the town of Dover and of Racine County for purposes of the state revenue sharing distribution under subch. I of ch. 79.

   (3)   

      (a)    Establish a demographic services center for the purpose of developing and administering systems needed to carry out the functions of the department under subs. (1) and (2), maintaining a current repository of appropriate published and computer retrievable federal census information and cooperating with state agencies and regional planning agencies so that the department’s population estimates, projections and published reports are useful for planning and other purposes for which they are required. The center shall coordinate population information development and use. The center shall provide assistance to and encourage and coordinate efforts by state and local agencies, regional planning agencies and private businesses and associations to inform the public regarding the federal census process and the importance of obtaining a complete, accurate federal decennial census. The department may enter into agreements with state and local agencies or regional planning agencies for their assistance in the preparation of population estimates, projections and forecasts.

      (b)    Maintain and keep current throughout the decade the maps of congressional and legislative district boundaries received from the legislative reference bureau under s. 13.92 (1) (a) 6. and provide copies thereof to the elections commission.

      (c)    Serve as the state’s liaison to the U.S. bureau of the census to facilitate accurate federal decennial census counts in this state.