AN ORDINANCE APPROVING AMENDMENTS TO CHAPTER 9 FLOODPLAIN ZONING ORDINANCE

Background: Wisconsin Statutes §§ 59.69, 59.692, 59.694, and 87.30 provide the authority for counties to administer floodplain ordinance regulations.  Wisconsin Administrative Code ch. NR 116 establishes Wisconsin’s Floodplain Management Program, which sets the minimum requirements that must be met by development to comply with state and federal standards.  These laws and rules recognize that floodplain zoning is a necessary tool to protect human life and health, and to minimize property damages and economic losses. Sauk Co. Code Ord. § 9.002 and the appendix to Ch. 9 include by reference DNR and FEMA approved floodplain maps, flood profiles, floodway data tables, regional and base flood elevations and other information with which the county regulates floodplain development.   

In April 2000, the DNR approved a dam failure analysis for the Cazenovia Dam located in the NW Quarter of the NE Quarter of Section 13, Township 12 North, Range 2 East, Village of Cazenovia, Richland County, across the Little Baraboo River. While the dam is located in Richland County, the dam break analysis shows hydraulic shadow floodway and floodplain within Sauk County.  Sauk County adopted the 2000 hydraulic shadow map into their floodplain ordinance in September 2016.  Since that adoption, the Village of Cazenovia submitted a revised Dam Failure Analysis, which the DNR approved on August 24, 2018. Amending the ordinance is considered optional because the 2018 hydraulic shadow zoning is less restrictive than the 2000 data. However, in order to ensure that current and accurate data is reflected within the Floodplain Ordinance, an amendment to the ordinance to remove the 2000 dam failure analysis and include the new 2018 Hydraulic Shadow map and associated information is necessary. 

Additionally, in January 2019, the DNR approved a dam failure analysis for the Magruder Dam located in the NE ¼ of the SE ¼ of Section 10, Township 13 North, Range 2 East across an unnamed tributary of Plum Creek. 

In order to reflect current floodplain information, Wis. Stat. § 87.30 and Wis. Admin. Code § NR 116.05 require that the County formally adopt the reference to the new materials within 6 months of the closing of the review and comment period of January 17, 2019 for Cazenovia Dam, and February 21, 2019 for Magruder Dam.

The above changes are contained in the attached Appendix.