Advise applicants of the ordinance provisions, assist in preparing
permit applications and appeals, and assure that the regional flood
elevation for the proposed development is shown on all permit applications.
Investigate, prepare reports, and report violations of this
title to the municipal zoning agency and attorney for prosecution.
Copies of the reports shall also be sent to the Department Regional
office.
Land use permit. A land use permit shall be obtained before any development;
repair, modification or addition to an existing structure; or change
in the use of a building or structure, including sewer and water facilities,
may be initiated. Application to the Zoning Administrator shall include:
The elevation of the lowest floor of proposed buildings and
any fill using the vertical datum from the adopted study - either
National Geodetic Vertical Datum (NGVD) or North American Vertical
Datum (NAVD);
Data sufficient to determine the regional flood elevation in NGVD or NAVD at the location of the development and to determine whether or not the requirements of Chs. 21.12 or 21.13 are met; and
Data to determine if the proposed development will cause an obstruction to flow or an increase in regional flood height or discharge according to Ch. 21.08. This may include any of the information noted in § 21.12.030A.
Hydraulic and hydrologic studies to analyze development. All
hydraulic and hydrologic studies shall be completed under the direct
supervision of a professional engineer registered in the state. The
study contractor shall be responsible for the technical adequacy of
the study. All studies shall be reviewed and approved by the Department.
Hydrology. The appropriate method shall be based on the standards
in Ch. NR 116.07(3), Wis. Admin. Code, Hydrologic Analysis: Determination
of Regional Flood Discharge.
Hydraulic modeling. The regional flood elevation shall be based
on the standards in Ch. NR 116.07(4), Wis. Admin. Code, Hydraulic
Analysis: Determination of Regional Flood Elevation and the following:
Determination of the required limits of the hydraulic model
shall be based on detailed study information for downstream structures
(dam, bridge, culvert) to determine adequate starting WSEL for the
study;
A maximum distance of 500 feet between cross sections is allowed
in developed areas with additional intermediate cross sections required
at transitions in cannel bottom slope including a survey of the channel
at each location;
Additional cross sections are required at the downstream and
upstream limits of the proposed development and any necessary intermediate
locations based on the length of the reach if greater than 500 feet;
Standard accepted engineering practices shall be used when assigning
parameters for the base model such as flow, Manning's N values,
expansion and contraction coefficients or effective flow limits. The
base model shall be calibrated to past flooding data such as high
water marks to determine the reasonableness of the model results.
If no historical data is available, adequate justification shall be
provided for any parameters outside standard accepted engineering
practices;
The model must extend past the upstream limit of the difference
in the existing and proposed flood profiles in order to provide a
tie-in to existing studies. The height difference between the proposed
flood profile and the existing study profiles shall be no more than
0.00 feet.
Mapping. A work map of the reach studied shall be provided,
showing all cross section locations, floodway/floodplain limits based
on best available topographic data, geographic limits of the proposed
development and whether the proposed development is located in the
floodway.
If any part of the proposed development is in the floodway,
it must be added to the base model to show the difference between
existing and proposed conditions. The study must ensure that all coefficients
remain the same as in the existing model, unless adequate justification
based on standard accepted engineering practices is provided.
Hydrology. If the proposed hydrology will change the existing
study, the appropriate method to be used shall be based on Ch. NR
116.07(3), Wis. Admin. Code, Hydrologic Analysis: Determination of
Regional Flood Discharge.
Hydraulic model. The regional flood elevation shall be based
on the standards in Ch. NR 116.07(4), Wis. Admin. Code, Hydraulic
Analysis: Determination of Regional Flood Elevation and the following:
Duplicate effective model. The effective model shall be reproduced
to ensure correct transference of the model data and to allow integration
of the revised data to provide a continuous FIS model upstream and
downstream of the revised reach. If data from the effective model
is available, models shall be generated that duplicate the FIS profiles
and the elevations shown in the Floodway Data Table in the FIS report
to within 0.1 foot;
Corrected effective model. The corrected effective model shall
not include any man-made physical changes since the effective model
date but shall import the model into the most current version of HEC-RAS
for Department review;
Existing (pre-project conditions) model. The existing model
shall be required to support conclusions about the actual impacts
of the project associated with the revised (post-project) model or
to establish more up-to-date models on which to base the revised (post-project)
model;
Revised (post-project conditional) model. The revised model
shall incorporate the existing model and any proposed changes to the
topography caused by the proposed development. This model shall reflect
proposed conditions;
All changes to the duplicate effective model and subsequent
models must be supported by certified topographic information bridge
plans, construction plans and survey notes;
Changes to the hydraulic models shall be limited to the stream
reach for which the revision is being requested. Cross sections upstream
and downstream of the revised reach shall be identical to those in
the effective model and result in water surface elevations and topwidths
computed by the revised models matching those in the effective models
upstream and downstream of the revised reach as required. The effective
model shall not be truncated.
Consistency between the revised hydraulic models, the revised
floodplain and floodway delineations, the revised flood profiles,
topographic work map, annotated FIRMs and/or Flood Boundary Floodway
Maps (FBFMs), construction plans, bridge plans;
Certified topographic map of suitable scale, contour interval,
and a planimetric map showing the applicable items. If a digital version
of the map is available, it may be submitted in order that the FIRM
may be more easily revised;
If an annotated FIRM and/or FBFM and digital mapping data (GIS
or CADD) are used then all supporting documentation along with the
Universal Transverse Mercator (UTM) projection and State Plane Coordinate
system in accordance with FEMA mapping specifications;
All cross sections from the effective model shall be labeled
in accordance with the effective map and a cross section lookup table
shall be included to relate to the model input numbering scheme;
Expiration. All permits issued under the authority of this title
shall expire no more than 180 days after issuance. The permit may
be extended for a maximum of 180 days for good and sufficient cause.
If the permitted work has not started within 180 days of the permit
date, the development must comply with any regulation, including any
revision to the FIRM or FIS that took effect after the permit date.
Certificate of compliance. No land shall be occupied or used, and
no building which is hereafter constructed, altered, added to, modified,
repaired, rebuilt or replaced shall be occupied until a certificate
of compliance is issued by the Zoning Administrator, except where
no permit is required, subject to the following provisions:
If all ordinance provisions are met, the certificate of compliance
shall be issued with 10 days after written notification that the permitted
work is completed;
The applicant shall submit a certification singed by a registered professional engineer, architect or land surveyor that the fill, lowest floor and floodproofing elevations are in compliance with the permit issued. Floodproofing measures also require certification by a registered professional engineer or architect that the requirements of Ch. 21.21 are met;
Where applicable pursuant to § 21.14.04, the applicant
must submit a certification by a registered professional engineer
or surveyor of the elevation of the bottom of the lowest horizontal
structural member supporting the lowest floor (excluding pilings or
columns), and an indication of whether the structure contains a basement;
Where applicable pursuant to § 21.14.04, the applicant
must submit certifications by a registered professional engineer or
architect that the structural design and methods of construction meet
accepted standards of practice as required by § 21.14.04.
Other permits. Prior to obtaining a floodplain development permit
the applicant must secure all necessary permits from federal, state,
and local agencies, including but not limited to those required by
the U.S. Army Corps of Engineers under Section 404 of the Federal
Water Pollution Control Act, Amendments of 1942, 33 U.S.C. 1344.