B.
Establishment of districts. The regional floodplain areas within
the jurisdiction of this chapter are divided into three districts:
(1)
The Floodway District (FW) is the channel of a river or stream and
those portions of the floodplain adjoining the channel that are required
to carry and discharge the regional floodwaters.
(2)
The Floodfringe District (FF) is that portion of the floodplain between
the regional flood limits and the floodway.
(3)
The General Floodplain District (GFP) is all areas which have been
or may be covered by floodwater during the regional flood. It includes
the Floodway and Floodfringe Districts.
C.
Locating floodplain boundaries. If a discrepancy exists between the location of the outermost boundary of the Floodfringe District or General Floodplain District on the Official Floodplain Zoning Map and actual field conditions, the district boundary shall be initially determined by the zoning administrator using the criteria in Subsection C(1) or (2) below. If the zoning administrator finds a significant difference between the district boundary shown on the map and the actual field conditions, the map shall be amended using the procedures in § 152-17H. Disputes between the zoning administrator and an applicant over the location of the district boundary shall be settled by the Board of Appeals according to § 152-32D.
(1)
Where flood profiles exist, the district boundary shall be determined
by the zoning administrator using both the map scale and the elevations
on the water surface profile of the regional flood. If a discrepancy
exists between the boundary location and actual field conditions,
the regional flood elevations govern. A map amendment is required
if there is a significant discrepancy between the map and actual field
conditions. The zoning administrator shall have the authority to immediately
grant or deny a land use permit based on a district boundary derived
from the elevations on the water surface profile of the regional flood,
whether or not a map amendment is required. The zoning administrator
shall initiate any map amendments required under this section within
a reasonable period of time.
(2)
If flood profiles do not exist, the district boundary shall be determined
by the zoning administrator using the map scale, visual on-site inspection
and any available information provided by the Department. If there
is a significant discrepancy between the district boundary on the
map and actual field conditions, the map shall be amended. If a map
amendment has been approved by both the municipal governing body and
the Department, the zoning administrator shall have the authority
to grant or deny a land use permit.
D.
Removal of lands from floodplain. Compliance with 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 § 152-17H. To remove flood insurance requirements, FEMA must first revise the Flood Insurance Rate Map, or issue a letter of map amendment or revision.
E.
Hydraulic and hydrologic analyses.
(1)
Except as provided in Subsection E(2)below, no development shall
be allowed in floodplain areas which will:
(a)
Cause an "obstruction to flow," defined in § 152-39 as any development which physically blocks the conveyance of floodwaters by itself or in conjunction with future similar development, causing an increase in regional flood height; or
(b)
Cause an increase in regional flood height due to floodplain
storage area lost, which is equal to or exceeding 0.01 foot.
(2)
Obstructions or increases equal to or greater than 0.01 foot may only be permitted if amendments are made to this chapter, the Official Floodplain Zoning Maps, including floodway lines and water surface profiles, according to § 152-17H and Article VII, and if the cumulative effect of the development will not increase the regional flood height more than 1.0 foot for the affected hydraulic reach of the stream unless a waiver is secured from FEMA for the 1.0 foot maximum increase.
(3)
The zoning administrator shall deny permits if the proposed development
will cause an obstruction to flow or increase in regional flood height
of 0.01 foot or greater.
F.
Watercourse alterations. Prior to any alteration or relocation of
a watercourse, and prior to issuing any land use permit required for
such activities, the Browntown Planning Commission shall notify adjacent
municipalities, the Department district office and the appropriate
FEMA office, and shall require the applicant to secure all necessary
state and federal permits. The flood-carrying capacity within the
altered or relocated portion of any watercourse shall be maintained.
[Amended at time of adoption of Code (see Ch. 1, General
Provisions, Art. I)]
G.
Floodproofing.
(1)
Floodproofing measures shall be designed to:
(a)
Withstand the flood pressures, depths, velocities, uplift and
impact forces, and other factors associated with the regional flood;
and
(b)
Assure protection to the flood protection elevation; and
(c)
Anchor structures to foundations to resist flotation and lateral
movement; and
(d)
Ensure that structural walls and floors are watertight to the
flood protection elevation, and the interior remains completely dry
without human intervention during flooding.
(2)
No permit or variance shall be issued until the applicant submits
a plan or document certified by a registered professional engineer
or architect that the floodproofing measures are adequately designed
to protect the structure or development to the flood protection elevation
for the area.
(3)
Floodproofing measures could include:
(a)
Reinforcing walls and floors to resist rupture or collapse caused
by water pressure or floating debris;
(b)
Adding mass or weight to structures to prevent flotation;
(c)
Placing utilities above the flood protection elevation;
(d)
Surface or subsurface drainage systems, including pumping facilities,
to relieve external foundation wall and basement floor pressures;
(e)
Constructing water supply wells and waste treatment systems
to prevent floodwaters from entering such systems;
(f)
Cutoff valves on sewer lines and eliminating gravity-flow basement
drains.
H.
Amendments.
(1)
When amendments are required, the procedures in Article VII shall apply. Actions requiring an amendment include, but are not limited to, the following:
(a)
Any change to the Official Floodplain Map, including the floodway
line or boundary of the floodplain area;
(b)
Correction of significant discrepancies between the water surface
profiles and floodplain zoning maps;
(c)
Any fill in the floodplain which elevates the filled area to
a height at or above the flood protection elevation and is contiguous
to land lying outside the floodplain;
(d)
Any fill or encroachment into the floodplain that will obstruct
flow or cause an increase of 0.01 foot or more in the height of the
regional flood; and
(e)
Any upgrading of floodplain zoning ordinances required by § NR
116.05, Wis. Adm. Code, or otherwise required by law, or for changes
by the municipality.
(2)
No amendment to the maps or text of this chapter shall become effective
until reviewed and approved by the Department of Natural Resources.
(3)
Anyone petitioning for a map amendment involving an obstruction to
flow which causes an increase in the regional flood height of 0.01
foot or more shall obtain flooding easements, or other appropriate
legal arrangements, from all adversely affected property owners and
notify affected local units of government before the amendment can
be approved by the governing body.
(4)
When considering amendments to the Official Floodplain Zoning Map in areas where no water surface profiles exist, the Planning Commission shall consider data submitted by the Department, the zoning administrator's visual on-site inspections and other available information. (See § 152-17C.)
[Amended at time of adoption of Code (see Ch. 1, General
Provisions, Art. I)]
A.
Applicability. This section applies to all areas mapped as floodway on the Official Floodplain Zoning Maps, and areas of the General Floodplain District determined to be floodway according to the procedures in § 152-20D.
B.
Permitted uses. The following open space uses are allowed within the Floodway District and in the floodway of the General Floodplain District, provided they are not prohibited by any other regulations, that the standards in § 152-18C and D are met, and that all permits or certificates required in this chapter have been issued:
(1)
Agricultural uses such as general farming, pasturing, outdoor plant
nurseries, horticulture, silviculture, truck farming, forestry, sod
farming and wild crop harvesting.
(2)
Nonstructural industrial and commercial uses such as loading areas,
parking areas and airport landing strips.
(3)
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.
(5)
Extraction of sand, gravel or other materials, according to § 152-18C(4).
(6)
Functionally water-dependent uses such as docks, piers or wharves,
including those used as part of a marina, and other water-related
uses, such as dams, flowage areas, culverts, navigational aids and
river crossings of transmission lines, and pipelines, according to
Ch. 30 or 31, Wis. Stats.
(7)
Public utilities, streets and bridges, according to § 152-18C(3).
C.
Standards for developments in floodway areas.
(1)
(2)
Structures. In or over floodway areas, only structures which are
accessory to permitted open space uses, classified as historic structures,
or are functionally dependent on a waterfront location may be allowed
by permit, if the structures meet all of the following criteria:
(a)
The structures are not designed for human habitation;
(b)
The structures are constructed and placed on the building site
so as to cause less than 0.01 foot increase in flood height and offer
minimum obstruction to flood flows. Structures shall be constructed
with the longitudinal axis parallel to the direction of flow, and
approximately on the same line as those of adjoining structures;
(c)
The structures are firmly anchored to prevent them from floating
away and restricting bridge openings or other restricted sections
of the stream or river; and
(d)
The structures have all service facilities, such as electrical
and heating equipment, at or above the flood protection elevation
for the particular area.
(3)
Public utilities, streets and bridges may be allowed by permit, provided
that:
(a)
Adequate floodproofing measures are provided to the flood protection
elevation;
(4)
Fills or deposition of materials may be allowed by permit, provided
that:
(b)
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;
(c)
The fill or other materials will be protected against erosion
by riprap, vegetative cover, sheet piling or bulkheading sufficient
to prevent erosion; and
(d)
Such fills are not associated with private or public solid waste
disposal.
D.
Prohibited uses. All uses not listed as permitted in § 152-18B are prohibited, along with the following uses which are always prohibited in floodways and the floodway portions of the general floodplain:
(1)
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;
(2)
Any uses which are not in harmony with, or which may be detrimental
to, the uses permitted in the adjoining districts;
(3)
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;
(4)
All public or private water wells for human consumption, except those
for recreational areas that meet the requirements of local ordinances
and Chs. NR 811 and NR 812, Wis. Adm. Code;
(5)
All public or private solid or hazardous waste disposal sites;
(6)
All wastewater treatment ponds or facilities, except those permitted
under Ch. NR 110.15(3)(b), Wis. Adm. Code;
(7)
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.
A.
Applicability. This section applies to all areas within the Floodfringe District as shown on the Official Floodplain Zoning Maps, and to areas of the General Floodplain District that are determined to be in the floodfringe according to the procedures in § 152-20D.
B.
Permitted uses. Any structures, land use, or development, including accessory structures and uses, are allowed within the Floodfringe District and floodfringe portions of the General Floodplain District, provided that the standards contained in § 152-17 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.
C.
Standards for development in floodfringe areas. All of § 152-17 applies, along with the following requirements:
(1)
Residential uses. Any structure or building used for human habitation
which is to be erected, constructed, reconstructed, altered, or moved
into the floodfringe area shall meet or exceed the following standards:
(a)
The lowest floor, excluding the basement or crawlway, shall be placed on fill at or above the flood protection elevation (two feet above the regional flood elevation) except where Subsection C(1)(b) is applicable. The fill elevation shall be one foot or more above the regional flood elevation, extending at least 15 feet beyond the limits of the structure. The Department may authorize other floodproofing measures where existing streets or sewer lines are at elevations which make compliance impractical, provided the Board of Appeals grants a variance due to dimensional restrictions.
(b)
The basement or crawlway floor may be placed at the regional
flood elevation if its floodproofed to the flood protection elevation.
No permit or variance shall allow any floor, basement or crawlway
below the regional flood elevation.
(d)
In existing developments where existing streets or sewer lines are at elevations which make compliance with Subsection C(1)(c) 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 assurances from 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 an adequate natural disaster plan concurred
with the Division of Emergency Management and approved by the Department.
[Amended at time of adoption of Code (see Ch. 1, General
Provisions, Art. I)]
(2)
Accessory structures or uses. An accessory structure or use as defined in § 152-39, not connected to a principal structure, including nonresidential agricultural structures, shall meet all the applicable provisions of § 152-18C(2)(a), (b) and (d) and Subsection C(5), below. A lesser degree of protection, compatible with these criteria and Subsection C(3) below, may be permissible for an accessory structure or use if the site is not inundated to a depth greater than two feet or subjected to flood velocities greater than two feet per second during the regional flood.
(3)
Commercial uses. Any commercial structure or building which is to be erected, constructed, reconstructed, altered or moved into the floodfringe area shall meet the requirements of § 152-19C(1). Storage yards, parking lots and other accessory structures or land uses may be at lower elevations, subject to Subsection C(5) below. However, no area in general public use 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. Inundation to depths greater than two feet may be approved if an adequate warning system exists to protect life and property.
(4)
Manufacturing and industrial uses. Any manufacturing or industrial structure which is to be erected, constructed, reconstructed, altered or moved into the floodfringe area shall be protected to the flood protection elevation utilizing fill, levees, floodwalls, or other adequate floodproofing measures according to § 152-17G, or any combination of these. 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, compatible with the criteria in Subsection C(3) and (5), may be permissible for storage yards, parking lots and other similar uses.
(5)
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 § 152-17G. Adequate measures shall be taken to assure that these materials will not enter the river or stream during flooding.
(6)
Public utilities, streets and bridges. All utilities, streets and
bridges should be designed to be compatible with the local comprehensive
floodplain development plans and:
(a)
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 § 152-17G.
(b)
Minor or auxiliary roads or nonessential utilities may be constructed
at lower elevations, providing they withstand flood forces to the
regional flood elevation.
(7)
Sewage systems, wells, solid waste sites.
(a)
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.
(b)
All public or private wells shall be floodproofed to the flood
protection elevation and shall meet the applicable provisions of Chs.
NR 811 and NR 812, Wis. Adm. Code.
(c)
All public or private solid or hazardous waste disposal sites
are prohibited.
(8)
Deposition of materials. Deposition of materials for any purpose
may only be allowed if the provisions of this chapter are met.
(9)
Mobile homes and manufactured homes.
(a)
Owners or operators of all manufactured or mobile home parks
and subdivisions located in the regional floodplain shall provide
for adequate surface drainage to minimize flood damage and prepare,
secure approval and file an evacuation plan, indicating vehicular
access and escape routes, with the appropriate local emergency management
authorities.
(b)
In existing mobile home parks, all new homes with new pads,
replacement units on existing pads, and 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:
(c)
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 floodfringe in § 152-19C(1).
A.
Applicability. The provisions for this district shall apply to all
floodplains for which regional flood data is not available, or where
regional flood data is available but floodways have not been delineated.
As adequate regional flood data becomes available and floodways are
delineated for portions of this district, such portions shall be placed
in the Floodfringe or Floodway District, as appropriate.
B.
Permitted uses. The General Floodplain District encompasses both floodway and floodfringe areas. Therefore, a determination shall be made, pursuant to Subsection D, to determine whether the proposed use is located within a floodway or floodfringe area. Those uses permitted in floodways (§ 152-18) and floodfringe areas (§ 152-19) are allowed within the General Floodplain District, according to the standards of Subsection C and provided that all permits or certificates required under this chapter have been issued.
C.
Standards for development in the General Floodplain District. Once it is determined according to Subsection D that a proposed use is located within a floodway, the provisions of § 152-18 shall apply. Once determined that the proposed use is located within the floodfringe, the provisions of § 152-19 shall apply. All provisions of the remainder of this chapter apply to either district.
D.
Determining floodway and floodfringe limits. Upon receiving an application
for development within the General Floodplain District, the zoning
administrator shall:
(1)
Require the applicant to submit with the application two copies of
an aerial photograph or a plan which accurately locates the proposed
development with respect to the General Floodplain District limits,
stream channel, existing floodplain developments, and all pertinent
information such as the nature of the proposal, legal description
of the property, fill limits and elevations, building floor elevations
and floodproofing measures.
(2)
Require the applicant to furnish any of the following additional
information deemed necessary by the Department for evaluation of the
effects of the proposal upon flood height and flood flows, the regional
flood elevation and, where applicable, to determine the boundaries
of the floodway:
(a)
A typical valley cross-section showing the channel of the stream,
the floodplain adjoining each side of the channel, the cross-sectional
area to be occupied by the proposed development, and all historic
high-water information.
(b)
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.
(c)
Profile showing the slope of the bottom of the channel or flow
line of the stream.
(d)
Specifications for building construction and materials; floodproofing;
filling; dredging; channel improvement; storage of materials; water
supply and sanitary facilities.
(3)
Transmit one copy of the information described in Subsection D(1) and (2) to the Department with a written request to provide technical assistance to establish regional flood elevations and, where applicable, floodway data. Where the provisions of § 152-28B(3) data requirements apply, the applicant shall provide all required information and computations.
