Ordinance Amendment to approve the dam failure analysis for the Sensnovis Dam and incorporate the analysis as part of the Sauk County Floodplain Zoning Ordinance.

Committee Status: 
Preliminary Review
Budget Status: 
No Fiscal Impact
Decision Impact: 
Routine
FTE Impact: 
No
Funding Source: 
Other (see budget status)

Purpose

An Amendment to approve the dam failure analysis for the Sensnovis Dam and incorporate the analysis as part of the Sauk County Floodplain Zoning Ordinance.

 

Background

BACKGROUND:

Pursuant to Wisconsin Statutes §§ 59.69, 59.692, 59.694, and 87.30 Sauk County has the authority to administer floodplain zoning 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.  

On July 7, 2025, the DNR approved a dam failure analysis for the Sensnovis Dam located in the NE Quarter of the SE Quarter of Section 22, Township 13 North, Range 02 East, Town of Woodland, Sauk County, for a tributary of the Little Baraboo River.   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 July 7, 2025 for the Sensnovis Dam.

The above changes are contained in the attached Appendix A.

Budget Status (Other/External Sources): 

NONE

Resolution Body

NOW, THEREFORE, THE SAUK COUNTY BOARD OF SUPERVISORS DOES ORDAIN AS FOLLOWS:

Section 1.  Any existing ordinances, codes, resolutions, or portions thereof in conflict with this ordinance shall be and hereby are repealed as far as any conflict exists.

Section 2.  This ordinance shall take effect the day after passage and publication as required by law.

Section 3.  If any claims, provisions or portions of this ordinance are adjudged unconstitutional or invalid by a court of competent jurisdiction, the remainder of this ordinance shall not be affected thereby.

Section 4. Section 9.002(2)(d) of the General Code of Sauk County, Wisconsin, is amended as follows [additions noted by underline, deletions noted by strikethrough]:

22. Map dated 7/7/2025 and titled “Hydraulic Shadow Map – Sensnovis Dam – U/N Tributary to the Little Baraboo River – La Valle WI.”

23. Floodway data table dated 7/7/2025 and titled “Sensnovis Dam Hydraulic Shadow Floodway Date – U/N Tributary to the Baraboo River.

24. Flood profiles dated 7/7/2025 and titled “Sensnovis Dam Hydraulic Shadow Profile – U/N Tributary to the Little Baraboo River.”

25. Floodplain Study Appendix: All DNR- and FEMA-approved floodplain maps, flood profiles, floodway data tables, regional or base flood elevations and other information is located in the appendix to this ordinance. The appendix is kept on file in the conservation, planning and zoning department. The community shall provide the most up-to-date appendix to the DNR and FEMA regional offices.

Requested Board Review Date: 
Tuesday, December 16, 2025