Grant County, WI Environmental Rules: Stormwater Management (2026)

Section 305-23 of the Grant County Code sits in Ch. 305, the Grant County Subdivision Regulation Ordinance, which § 305-4 says has full force and effect in the unincorporated areas of Grant County. Part B of the section is the drainage rule. Provision must be made for the adequate disposal of surface water, either to a natural drainage course or to a storm sewer system, and the County Engineer approves which one is used. All surface drainage facilities must connect to an adequate drainage course.

Land that is subject to flooding periodically must receive whatever improvements are required to remove flooding hazards from the proposed subdivision lots. Part A of the same section ties drainage to utilities: water and sewage lines must be constructed to the property line before the streets are built, and where no approved public water supply or sanitary sewer is in proximity, a private system must meet the standards of the Grant County Private Sewage System and Sanitation Ordinance, now Ch. 225 of the Code. The rule is applied during plat review.

A subdivider files a preliminary plat with the Grant County Zoning Administrator, and the Planning and Zoning Committee has 90 days to approve, approve conditionally or reject it. Under § 305-29 the Committee can condition approval of any plat on stated conditions it deems necessary for the welfare or safety of the residents of Grant County. The Committee must approve, deny or conditionally approve a final plat within 60 days of its submission. Before final approval the improvements must be installed or guaranteed by a surety bond, a certified check or other collateral under § 305-25.

Plat review fees under § 305-35A are $10 plus $1 for each lot or parcel on the preliminary plat, and $10 plus $1 per lot on the final plat. Near water, Ch. 316 adds its own rules, and § 316-39 excludes impervious surfaces treated by stormwater ponds, infiltration basins, rain gardens or bioswales from shoreland impervious calculations.