City of Watertown, WI Floodplain Zoning Districts

If a proposed building site is in a flood-prone area, all new construction and substantial improvements shall:

[1]

Be designed and anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;

[2]

Be constructed with flood-resistant materials;

[3]

Be constructed by methods and practices that minimize flood damages; and

[4]

Mechanical and utility equipment must be elevated to or above the flood protection elevation.

Subdivisions shall be reviewed for compliance with the above standards. All subdivision proposals (including manufactured home parks) shall include regional flood elevation and floodway data for any development that meets the subdivision definition of this chapter and all other requirements in § 532-31. Adequate drainage shall be provided to reduce exposure to flood hazards and all public utilities and facilities, such as sewer, gas, electrical, and water systems, shall be located and constructed to minimize or eliminate flood damages.

District boundaries of floodplain zoning districts. The boundaries of the regional floodplain areas shall be those areas designated on the zoning maps which have been adopted and made a part of this chapter in § 532-11.

Establishment of districts. The regional floodplain areas within the jurisdiction of this chapter are hereby divided into four districts defined as follows:

The Floodway District (FW) consists of the channel of a river or stream and those portions of the floodplain adjoining the channel required to carry the regional floodwaters and is contained within AE Zones as shown on the FIRM.

The Flood-Fringe District (FF) consists of that portion of the floodplain between the regional flood limits and the floodway and displayed as AE Zones on the FIRM.

The General Floodplain District (GFP) consists of all areas which have been or may be hereafter covered by floodwater during the regional flood and does not have a BFE or floodway boundary determined, including A, AH and AO Zones on the FIRM. It includes both the floodway and flood-fringe districts.

The Flood Storage District (FSD) is that area of the floodplain where storage of floodwaters is calculated to reduce the regional flood discharge.

Locating floodplain boundaries. Where an apparent discrepancy exists between the location of the outermost boundary of the flood-fringe district or general floodplain district shown on the Official Floodplain Zoning Map and actual field conditions, the location of the district boundary line shall be initially determined by the Zoning Administrator using the criteria set forth in Subsection D(1) or (2) below. Where the Zoning Administrator finds that there is a significant difference between the district boundary shown on the map and the actual field conditions, the map shall be amended using the procedures established in Article VII, Amendments. The Zoning Administrator can rely on a boundary derived from a profile elevation to grant or deny a building permit, whether or not a map amendment is required. The Zoning Administrator shall be responsible for documenting actual predevelopment field conditions and the basis upon which the district boundary was determined and for initiating any map amendments required under this section. Disputes between the Zoning Administrator and an applicant over the location of the district boundary line shall be settled by the Zoning Board of Appeals according to § 532-37D. Where the flood profiles are based on established base flood elevations from a FIRM, FEMA must approve any map amendment or revision pursuant to Article VII, Amendments.

[Amended 10-4-2016 by Ord. No. 16-18; 5-2-2017 by Ord. No. 17-11; 10-20-2020 by Ord. No. 20-24]

If flood profiles exist, the map scale and the profile elevations shall determine the district boundary. The regional or base flood elevations shall govern if there are any discrepancies.

Where flood profiles do not exist for projects, the location of the boundary shall be determined by the map scale.

Removal of land from floodplain. Compliance with the provisions of this chapter shall not be grounds for removing lands from the floodplain district, unless they are removed by filling to a height of at least two feet above the regional flood elevation; the fill is contiguous to lands outside the floodplain district; and the map is amended pursuant to Article VII. To remove flood insurance requirements, FEMA must first revise the Flood Insurance Rate Map or issue a Letter of Map Amendment or Revision. Also see Article VII.

Hydraulic and hydrologic analysis.

No development shall be allowed in floodplain areas which will:

Cause an obstruction to flow as defined in § 532-49; or

Cause an increase in regional flood height due to floodplain storage area lost.

The Zoning Administrator shall deny permits where it is determined the proposed development will cause an obstruction to flow or increase in regional flood height of 0.00 feet or greater unless the provisions of Article VII, Amendments, are met.

Watercourse alterations. Prior to any alteration or relocation of a watercourse, and prior to the issuance of any building permit which may be required for the alteration or relocation of a watercourse, the Zoning Administrator shall notify adjacent municipalities, the regional office of the Department and the appropriate office of FEMA and shall require the applicant to secure all necessary state and federal permits. The standards of this subsection must be met and the flood-carrying capacity within the altered or relocated portion of any watercourse shall be maintained. As soon as is practicable, but not later than six months after the date of the watercourse alteration or relocation and pursuant to Article VII, the community shall apply for a Letter of Map Revision (LOMR) from FEMA. Any such alterations must be reviewed and approved by FEMA and the DNR through the LOMC process.

Development under Chs. 30 and 31, Wis. Stats. Development which requires a permit from the Department, under Chs. 30 and 31, Wis. Stats., such as docks, piers, wharves, bridges, culverts, dams and navigational aids, may be allowed if the necessary permits are obtained and amendments to the floodway lines, water surface profiles, BFEs established in the FIS, or other data from the officially adopted FIRM, or other floodplain zoning maps or this chapter are made according to Article VII.

Public or private campgrounds. Public or private campgrounds shall have low flood damage potential and shall meet the following provisions:

The campground is approved by the Department of Health Services.

A building permit for the campground is issued by the Zoning Administrator.

The character of the river system and the elevation of the campground are such that a seventy-two-hour warning of an impending flood can be given to all campground occupants.

There is an adequate flood warning procedure for the campground that offers the minimum notice required under this section to all persons in the campground. This procedure shall include a written agreement between the campground owner, the municipal emergency management coordinator and the chief law enforcement official which specifies the flood elevation at which evacuation shall occur, personnel responsible for monitoring flood elevations, types of warning systems to be used and the procedures for notifying at-risk parties, and the methods and personnel responsible for conducting the evacuation.

This agreement shall be for no more than one calendar year, at which time the agreement shall be reviewed and updated by the officials identified in Subsection I(4) to remain in compliance with all applicable regulations, including those of the State Department of Health Services and all other applicable regulations.

Only camping units that are fully licensed, if required, and ready for highway use are allowed.

The camping units may not occupy any site in the campground for more than 180 consecutive days, at which time the camping unit must be removed from the floodplain for a minimum of 24 hours.

(8)

All camping units that remain on site for more than 30 days shall be issued a limited authorization by the campground operator, a written copy of which is kept on file at the campground. Such authorization shall allow placement of a camping unit for a period not to exceed 180 days and shall ensure compliance with all the provisions of this section.

(9)

The municipality shall monitor the limited authorizations issued by the campground operator to assure compliance with the terms of this section.

(10)

All camping units that remain in place for more than 180 consecutive days must meet the applicable requirements in either § 532-17, 532-18, or 532-19 for the floodplain district in which the structure is located.

[Amended 10-20-2020 by Ord. No. 20-24]

(11)

The campground shall have signs clearly posted at all entrances warning of the flood hazard and the procedures for evacuation when a flood warning is issued.

(12)

All service facilities, including but not limited to refuse collection, electrical service, natural gas lines, propane tanks, sewage systems and wells, shall be properly anchored and placed at or floodproofed to the flood protection elevation.

§ 532-17 Floodway district (FW).

Applicability. The provisions of this section apply to all areas mapped as floodway on the Official Floodplain Zoning Maps, and to those portions of the general floodplain district determined to be floodway as identified pursuant to § 532-20D.

[Amended 10-20-2020 by Ord. No. 20-24]

Permitted uses. The following open space uses are allowed within the floodway district and in the floodway portion of the general floodplain district, provided that they are not prohibited by any other regulations, that the standards contained in Subsections C and D are met, and that all permits or certificates have been issued according to § 532-30:

[Amended 10-20-2020 by Ord. No. 20-24]

Agricultural uses, such as general farming, pasturing, outdoor plant nurseries, horticulture, silviculture, truck farming, forestry, sod farming and wild crop harvesting.

Nonstructural industrial and commercial uses, such as loading areas, parking areas and airport landing strips.

Nonstructural private and public recreational uses, such as golf courses, tennis courts, driving ranges, archery ranges, picnic grounds, boat launching ramps, swimming areas, parks, wildlife and nature preserves, game farms, fish hatcheries, shooting preserves, target ranges, trap and skeet ranges, hunting and fishing areas, and hiking and horseback riding trails.

Uses or structures accessory to open space uses, or essential for historical areas, provided they are not in conflict with the provisions in Subsections C and D.

Extraction of sand, gravel or other materials, according to Subsection C(4) below.

Functionally water-dependent uses such as docks, piers or wharves, including those used as part of a marina; other water-related uses, such as dams, flowage areas, culverts, navigational aids and river crossings of transmission lines and pipelines may be allowed if all other necessary local, state and federal permits are secured, including Ch. 30 or 31, Wis. Stats., permits, from the Department.

Public utilities, streets and bridges, according to Subsection C(3) below.

Standards for developments in floodway areas.

General.

Any development in floodway areas shall meet all of the provisions of § 532-16 and have low flood damage potential.

Applicants shall provide a cross-section elevation view of the proposal, perpendicular to the watercourse, indicating whether the proposed development will obstruct flow, or an analysis calculating the effects of the proposal on the regional flood height for the Zoning Administrator to determine the effects of the proposal according to §§ 532-16F and 532-32.

[Amended 10-20-2020 by Ord. No. 20-24]

The Zoning Administrator shall deny the permit application where it is determined the project will cause any increase in the flood elevations upstream or downstream based on the data submitted for Subsection C(1)(b) above.

Structures. Only structures which are accessory to permitted open space uses, or are essential for historical areas, or are functionally dependent on a waterfront location, may be allowed by permit, provided the structures meet all of the following criteria:

The structures are not designed for human habitation, associated with high flood damage potential, and are constructed to minimize flood damage;

[Amended 10-20-2020 by Ord. No. 20-24]

The structures do not obstruct the flow of floodwaters or cause any increase in flood levels during the occurrence of the regional flood. Structures shall be constructed with the longitudinal axis parallel to the direction of flow of floodwaters, and approximately on the same line as those of adjoining structures;

The structures are firmly anchored to resist flotation, collapse and lateral movement; and

The structures have all service facilities, such as electrical and heating equipment, at or above the flood protection elevation for the particular area and shall have a minimum of two openings on different walls having a total net area not less than one square inch for every square foot of enclosed area, the bottom of all such openings being no higher than one foot above grade. The openings shall be equipped with screens, louvers or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters.

Public utilities, streets and bridges may be allowed by permit, provided that:

Adequate floodproofing measures are provided to the flood protection elevation;

Construction does not cause an increase in the height of the regional flood according to § 532-16F, except where the water surface profiles, floodplain zoning maps and this chapter are amended, as needed, to reflect any changes resulting from such construction. Any such amendment must be reviewed and approved by the Department and FEMA. See also Article VII pertaining to amendments.

Fills or deposition of materials may be allowed by permit, provided that:

The requirements of § 532-16A and F are met;

[Amended 10-20-2020 by Ord. No. 20-24]

The fill or deposition of materials does not encroach on the channel area between the ordinary high-water mark on each bank of the stream unless a Ch. 30, Wis. Stats., permit has been granted by the Department and a permit pursuant to Section 404 of the Federal Water Pollution Control Act, Amendments of 1972, 33 U.S.C. § 1344, has been issued, if applicable, and the other requirements of this section are met;

The fill or other materials will be protected against erosion by riprap, vegetative cover, sheet piling or bulkheading sufficient to prevent erosion; and

Such fills are not associated with private or public solid or hazardous waste disposal.

Prohibited uses. All uses not listed as permitted uses in Subsection B are prohibited, in addition to the following uses which are always prohibited, in floodways and the floodway portions of the general floodplain:

Structures in, on or over floodway areas which are designed for human habitation, associated with high flood damage potential, or not associated with permanent open space uses;

The storage of any materials that are buoyant, flammable, explosive or injurious to property, water quality or human, animal, plant, fish or other aquatic life;

Any uses which are not in harmony with, or which may be detrimental to, the uses permitted in the adjoining districts;

All private or public on-site sewage disposal systems, except portable latrines that are removed during flooding, and systems associated with public recreational areas and Department-approved campgrounds that meet the applicable provisions of Ch. SPS 383, Wis. Adm. Code;

All public or private wells that are used to obtain water for ultimate human consumption, except those for recreational areas that meet the requirements of local ordinances and Chs. NR 811 and NR 812, Wis. Adm. Code;

All solid or hazardous waste disposal sites, whether public or private;

All wastewater treatment ponds or facilities except those permitted under § NR 110.15(3)(b), Wis. Adm. Code;

(8)

All sanitary sewer or water lines, except those used to service existing or proposed development outside of the floodway which complies with the regulations for the floodplain area occupied.

§ 532-18 Flood-fringe district (FF).

Applicability. The provisions of this section apply to all areas within the flood-fringe district, as shown on the Official Floodplain Zoning Maps, to those portions of the general floodplain district that are determined to be in the flood-fringe area, and identified pursuant to § 532-20D.

[Amended 10-20-2020 by Ord. No. 20-24]

Permitted uses. Any structures, land use or development, including accessory structures and uses, are allowed within the flood-fringe district and flood-fringe portions of the general floodplain district, provided that the standards contained in § 532-16A and Subsection C below are met, that the use is not prohibited by any other ordinance or local, state or federal regulation, and that all permits or certificates required under this chapter have been issued.

Standards for developments in flood-fringe areas. Any existing structure in the flood fringe must meet the requirements of Article V, Nonconforming Structures and Uses. All the provisions of § 532-16F shall apply in addition to the following requirements according to the use requested:

[Amended 10-20-2020 by Ord. No. 20-24]

Residential uses. Any existing structure in the flood fringe must meet the requirements of Article V, Nonconforming Structures and Uses. Any structure or building used for human habitation which is to be erected, constructed, reconstructed, altered or moved into the flood-fringe area shall meet or exceed the following standards:

All new construction, including placement of manufactured homes, and substantial improvement of residential structures, shall have the lowest floor elevated to or above the flood protection elevation of fill. The fill around shall be one foot or more above the regional flood elevation extending at least 15 feet beyond the limits of the structure. No area may be removed from the flood fringe district unless it can be shown to meet § 532-16E.

[Amended 3-15-2022 by Ord. No. 22-52]

Notwithstanding Subsection C(1)(a), a basement or crawl space floor may be placed at or above two feet above the regional flood elevation if the basement or crawl space is designed to make all portions of the structure below the flood protection elevation watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effect of buoyancy. No floor of any kind is allowed lower than two feet above regional flood elevation

[Amended 3-15-2022 by Ord. No. 22-52]

Contiguous dry land access, defined in § 532-49 as a vehicular access route above regional flood elevation, shall be provided from a structure or building to land which is outside the floodplain, except as provided in Subsection C(1)(d) below.

In existing developments where existing streets or sewer lines are at elevations which make compliance with Subsection C(1)(c) above impractical, the municipality may permit new development and substantial improvements where access roads are at or below the regional flood elevation, provided:

[1]

The municipality has written assurance from the appropriate local units of police, fire and emergency services that rescue and relief will be provided to the structure(s) by wheeled vehicles, considering the anticipated depth, duration and velocity of the regional flood event; or

[2]

The municipality has a DNR-approved emergency evacuation plan.

Accessory structures shall be constructed on fill with the lowest floor at or above the regional flood elevation.

Commercial uses. Any commercial structure or building which is to be erected, constructed, reconstructed, altered or moved into the flood-fringe area shall meet the requirements of Subsection C(1) pertaining to residential uses. Storage yards, parking lots and other accessory land uses may be at lower elevations, subject to the requirements of Subsection C(5) below, provided an adequate warning system exists to protect life and property. However, no such area in general use by the public shall be inundated to a depth greater than two feet or subjected to flood velocities greater than two feet per second during the regional flood.

Manufacturing and industrial uses. Any manufacturing or industrial structure or building which is to be erected, constructed, reconstructed, altered or moved into the flood-fringe area shall have the lowest floor (including basement) elevated to or above the flood protection elevation or meet the floodproofing standards in § 532-42. On streams or rivers having prolonged flood durations, greater protection may be required to minimize interference with normal plant operations. A lesser degree of protection may be permissible for storage yards, parking lots and other similar uses subject to the criteria in Subsection C(3) above and C(5) below.

Storage or processing of materials. The storage or processing of materials that are buoyant, flammable, explosive or which in times of flooding could be injurious to human, animal or plant life shall be at or above the flood protection elevation for the particular area or floodproofed in compliance with § 532-42. Adequate measures shall be taken to assure that these materials will not enter the river or stream during flooding.

Public utilities, streets and bridges should be designed to be compatible with the local comprehensive floodplain development plans and:

When failure or interruption of public utilities, streets and bridges would result in danger to the public health or safety or where such facilities are essential to the orderly functioning of the area, construction of and substantial improvements to such facilities may only be permitted if they are floodproofed to the flood protection elevation in compliance with § 532-42.

Minor or auxiliary roads or nonessential utilities may be constructed at lower elevations, provided that they withstand flood forces to the regional flood elevation.

Sewage systems, wells and solid waste sites.

All on-site sewage disposal systems shall be floodproofed to the flood protection elevation and shall meet the applicable provisions of all local ordinances and Ch. SPS 383, Wis. Adm. Code.

All wells, whether public or private, shall be floodproofed to the flood protection elevation and shall meet the applicable provisions of Chs. NR 811 and NR 812, Wis. Adm. Code.

All solid or hazardous waste disposal sites, whether public or private, are prohibited.

(8)

Deposition of materials for any purpose may only be allowed if the provisions of this chapter are met.

(9)

Mobile homes, manufactured homes, and mobile recreational vehicles in floodplains.

Owners or operators of all existing mobile home parks and mobile home subdivisions located in the regional floodplain shall file an evacuation plan, indicating alternate vehicular access and escape routes, including mobile home hauler routes, with the appropriate local disaster preparedness authorities and shall provide for adequate surface drainage to minimize flood damage.

In existing mobile home parks, all new homes with new pads, replacement units on existing pads, substantially improved mobile/manufactured homes, and recreational vehicles that remain on site in excess of 180 days or are unlicensed or not ready for highway use, and which are placed or improved on a site located in the regional floodplain, shall:

[1]

Have the lowest floor elevated to the regional flood elevation; and

[2]

Be anchored so they do not float, collapse or move laterally during a flood.

Outside of existing mobile home parks, including new mobile home parks, and all single units outside of existing parks, all new, replacement and substantially improved mobile/manufactured homes and recreational vehicles that remain on site more than 180 days which are unlicensed or are not ready for highway use shall meet the residential development standards for the flood-fringe in Subsection C(1) and (9)(b)[2] of this section. A mobile recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect utilities and security devices, and has no permanently attached additions.

Mobile recreational vehicles. All mobile recreational vehicles that are on site for 180 consecutive days or more or are not fully licensed and ready for highway use shall meet the elevation and anchoring requirements in Subsection C(9)(b) and (c). A mobile recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect utilities and security devices, and has no permanently attached additions.

§ 532-19 Other floodplain districts.

Other floodplain districts may be established under this chapter and reflected on the floodplain zoning map. These districts may include general floodplain districts and flood storage districts.

§ 532-20 General floodplain district (GFP).

Applicability. The provisions for this district shall apply to all floodplains mapped as A, AO or AH Zone.

Permitted uses. The general floodplain district encompasses both floodway and flood-fringe areas. Therefore, a determination shall be made pursuant to Subsection D below to determine whether the proposed use is located within a floodway or flood-fringe area. Those uses permitted in § 532-17B, Floodway district (FW), above and § 532-18B, Flood-fringe district (FF), above are allowed within the general floodplain district, according to the standards of Subsection C, Standards for development in the general floodplain district, below, and provided that all permits or certificates required under this chapter and under § 532-30 have been issued

[Amended 10-20-2020 by Ord. No. 20-24]

Standards for development in the general floodplain district. Once it is determined according to Subsection D below that a proposed use is located within a floodway, the provisions of § 532-17, Floodway district (FW), above shall apply. Once it is determined that the proposed use is located within the flood-fringe, the provisions of § 532-18, Flood-fringe district (FF), above shall apply. All provisions of the remainder of this chapter apply to either district.

[Amended 3-15-2022 by Ord. No. 22-52]

New construction and substantial improvement of structures in Zone AO shall have the lowest floor, including basement elevated:

To or above the depth, in feet, as shown on the FIRM above the high adjacent natural grade, plus two additional feet of freeboard; or

If the depth is not specified on the FIRM, to or above three feet above the highest adjacent natural grade.

New construction and substantial improvement of structures in Zone AH shall have the lowest floor, including basement, elevated to or above the flood protection elevation.

In AO/AH Zones, provide plans showing adequate drainage paths to guide floodwaters around structures.

All development in Zone AO and Zone AH shall meet the requirements of § 532-18.

Determining floodway and flood-fringe limits. Upon receiving an application for development within the general floodplain district, the Zoning Administrator shall:

Require the applicant to submit, at the time of application, two copies of an aerial photograph or a plan which accurately locates the proposed development with respect to the general floodplain district limits, channel of stream, existing floodplain developments, together with all pertinent information such as the nature of the proposal, legal description of the property, fill limits and elevations, building floor elevation and floodproofing, and the flood zone as shown on the FIRM.

Require the applicant to furnish any of the following additional information as is deemed necessary by the Department for evaluation of the effects of the proposal upon flood height and flood flows and the regional flood elevation and, where applicable, to determine the boundaries of the floodway:

Plan (surface view) showing elevations or contours of the ground; pertinent structure, fill or storage elevations; size, location and spatial arrangement of all proposed and existing structures on the site; location and elevations of streets, water supply and sanitary facilities; soil types; and other pertinent information.

Specifications for building construction and materials, floodproofing, filling, dredging, channel improvement, storage of materials, water supply and sanitary facilities.

A hydrologic and hydraulic study as specified in § 532-32.

§ 532-21 Flood storage district.

General. The flood storage district delineates that portion of the floodplain where storage of floodwaters has been taken into account and is relied upon to reduce the regional flood discharge. The district protects the flood storage area and assures that any development in the storage areas will not decrease the effective flood storage capacity, which would cause higher flood elevations.

Applicability. The provisions of this section apply to all areas within the flood storage district (FSD), as shown on the official floodplain zoning maps.

Permitted uses. Any use or development which occurs in a flood storage district must meet the applicable requirements in § 532-18C.

Standards for development in flood storage districts.

Development in a flood storage district shall not cause an increase equal or greater than 0.00 of a foot in the height of the regional flood.

No development shall be allowed which removes flood storage volume unless an equal volume of storage as defined by the predevelopment ground surface and the regional flood elevation shall be provided in the immediate area of the proposed development to compensate for the volume of storage which is lost (compensatory storage). Excavation below the groundwater table is not considered to provide an equal volume of storage.

If compensatory storage cannot be provided, the area may not be developed unless the entire area zoned as flood storage district on this waterway is rezoned to the flood-fringe district. This must include a revision to the floodplain study and map done for the waterway to revert to the higher regional flood discharge calculated without floodplain storage, as per Article VII, Amendments, of this chapter.