Current through Register Vol. 49, No. 13, September 23, 2024
Subpart 1.
In
general.
Supplemental measures for floodplain management should be
included in local governmental comprehensive floodplain management programs and
adopted or provided in addition to local zoning ordinances when sufficient
technical data and resources are available for their effectuation. All local
governmental units shall provide for control of the development and use of
floodplains in flood hazard areas by adopting the following specific
regulations and measures where practical to supplement and complement
floodplain zoning ordinances and provide comprehensive floodplain
management.
Subp. 2.
Subdivision regulations.
Local government floodplain subdivision regulations shall
regulate floodplain land subdivision in order to promote the public health,
safety, and general welfare; promote wise use of floodplain lands; assure that
floodplain lands are suitable for building sites and public improvements;
provide for adequate drainage of the subdivided area; provide for ingress and
egress to all lands involved; promote proper surveying, legal description, and
monumenting of subdivided land; and establish procedures for vacating,
correcting, and revising plats. The subdivision regulations shall establish
standards for protection of roads, sewers, water supply, and other facilities
from floods. In addition the regulations shall provide that:
A. the floodplain, floodway, and flood fringe
areas as determined by standards set forth in part 6120.5600, subpart 4, be
clearly labeled on the plat;
B.
subdivision of lands within floodplain areas may not be approved if the cost of
providing governmental services would impose an unreasonable economic burden on
the local government unit; and
C.
restrictive deed covenants shall be filed with the final plat and shall provide
that the floodplain area be left essentially in the state shown on the plat,
establish finished elevations of buildings, structures, and private streets and
roads, and require that additions or modifications to these facilities will not
violate any provisions of the floodplain zoning ordinances or supplemental
regulations.
Subp. 3.
Building codes.
Building codes shall provide for the control of the design,
construction, addition, and modification of buildings or structures placed in
floodplain areas under authorized floodplain management ordinances. Floodplain
building codes shall provide for necessary construction measures to protect
health, safety, and welfare and to reduce the damaging effects and hazards of
floods subject to the following standards:
A. The degree of flood protection required
for building construction by building codes shall be based on the flood
protection elevation described in part 6120.5700, subpart 5, and on flood
velocities and duration of the regional flood for the particular
area.
B. Whenever feasible and
compatible with floodplain zoning ordinances and other regulations, all new
buildings or structures located, constructed, or reconstructed in the
floodplain shall conform to the following provisions:
(1) The first floors or basement floors of
the buildings or structures shall be at or above the flood protection elevation
in accordance with parts 6120.5700, subpart 5 and 6120.5800.
(2) Those portions of buildings, structures,
and appurtenances located below the flood protection elevation shall be
adequately floodproofed as provided in item D.
C. Alterations or additions to existing
buildings or structures may be permitted if such will:
(1) decrease the flood damage potential of
the building or structure;
(2) not
increase the degree of obstruction to flood flows;
(3) provide for adequate protection of the
building or structure to the flood protection elevations where applicable, in
accordance with the provisions of part 6120.5700, subpart 5; and
(4) not endanger human life.
D. Where floodproofing is
incorporated into new buildings or structures, and into alterations or
additions to existing nonconforming structures, floodproofing measures shall be
provided to the flood protection elevations described in part 6120.5700,
subpart 5, and designed to withstand flood velocities, depths, durations,
forces, and any other factors associated with the regional flood. A plan or
document certified by a registered professional engineer or architect that the
floodproofing measures are adequately designed to withstand regional flood
conditions shall be submitted to the local government unit for approval before
authorization is granted for the proposed work. Where this is not practical
because of the particular circumstances, the commissioner may authorize other
methods to determine the adequacy of floodproofing measures. Authorized
floodproofing measures may include such provisions as anchorage of structures
to prevent flotation, installation of watertight barriers over openings,
reinforcement of walls to resist water pressures, use of materials to reduce
wall seepage, construction or modification of water supply and waste disposal
systems to prevent entry of flood waters, placement of essential utilities
above the flood protection elevation, and installation of pumping facilities
for internal and subsurface drainage.
Subp. 4.
Sanitary regulations.
In addition to all applicable state rules, regulations,
requirements and laws, and local laws, local sanitary regulations shall:
A. Require the floodproofing of proposed
water supply systems in floodplain areas to prevent entry of flood waters by
means of floodproofing techniques consistent with subpart 3, item D.
B. Control the location, construction, or
modification of private and public liquid or solid waste treatment and disposal
facilities in floodplain areas so that:
(1) No
new construction, addition, or modification to existing sewage, industrial
waste, or other waste disposal systems shall be permitted within the floodplain
unless emergency plans and procedures for action to be taken in the event of
flooding are prepared, filed with, and approved by the state water pollution
control agency.
(2) Emergency plans
and procedures established consistent with item B, subitem (1) must provide for
measures to prevent introduction of any pollutant or toxic material into the
flood waters.
(3) Public or
municipal collection and treatment facilities are used where available and
where feasible.
(4) There shall be
no disposal of garbage or solid waste materials within any floodplain areas,
except at those disposal sites approved by the state water pollution control
agency provided there will be no further encroachment on the
floodway.
Subp.
5.
Warning signs and public information regulations.
Local governmental regulations shall provide for adequate
floodplain warning and public informational services as follows:
A. In urban areas the limits of the areas
which have been or would be inundated by the regional flood or by experienced
floods of greater magnitude shall be delineated in the field at reasonable
intervals by means of firmly placed markers of a sufficient size to be easily
read from a distance of 20 feet.
The markers shall record the maximum known depth of flooding
or height to the flood protection elevation, whichever is greater, as well as
the zoned land use classification of the area involved.
The local government unit may prescribe the shape, size,
lettering, and installation instructions for floodplain markers.
The cost of preparing and installing floodplain markers in
future subdivided areas should be borne by the subdivider and the markers shall
be installed prior to the sale of lots and construction of any buildings or
structures.
Provisions should be made to monument bench marks for
vertical control data as provided in part 6120.5600, subpart 4.
B. To fulfill the intent of
Minnesota Statutes 1969, section 104.03, every local governmental unit with
flood hazard areas and a floodplain management program shall submit to the
commissioner by March 30 an annual report outlining and summarizing the
previous year's activity and progress in floodplain management activities on a
form to be provided by the commissioner. The report shall include information
as to:
(1) progress in the acquisition of
technical floodplain information, including a summary of any flood crest
elevations, cross sectional data and maps or illustrative material prepared by
or for the local governmental unit;
(2) progress in floodplain management program
administration, including a summary of zoning permits issued, subdivision plats
approved, building permits issued, variances granted, enforcement action, etc.;
and
(3) flood warning and
information sources, including a summary of flood warning systems established
or implemented, emergency plans prepared, and public informational reports and
studies concerning various aspects of local floodplain management.
Subp. 6.
Measures
for flood control.
When local floodplain management plans provide for structural
works for flood control, such as levees, floodwalls, channel improvements, and
reservoirs, all structural works or land treatment practices shall be
consistent with the following statewide standards and criteria for floodplain
management practices:
A. Any proposed
work in the beds of public waters, as defined in Minnesota Statutes 1969,
chapter 105, which will change the course, current, or cross-section of public
waters of the state shall be subject to the provisions of Minnesota Statutes
1969, chapter 105, and other applicable statutes.
B. The minimum height and structural design
of any dikes, levees, floodwalls, or similar structural works in place, or
proposed to be placed in the floodplain shall be based on the flood profile of
the regional flood confined between the structures subject to the following:
(1) The minimum authorized height and design
of proposed structural works to remove an area from the regulatory floodplain
shall meet or exceed the design, operation, and maintenance standards contained
in Federal Emergency Management Agency Regulations, Code of Federal
Regulations, title 44, section 65.10. If at that elevation, the commissioner
determines that there is still a high risk of loss of life or property damage,
then the commissioner, in accordance with subpart 7, may require a higher
elevation, not to exceed the elevation of the standard project flood, as the
commissioner determines is economically feasible and reasonable in cost for the
extra protection provided.
(2)
Increases in upstream flood stages which would result from construction of
dikes, levees, floodwalls, or similar structures for protection of urban areas
and for agricultural uses in rural areas shall not increase the stage of the
regional flood in excess of amounts listed in part 6120.5700, subpart 4, item
A, and shall be reflected in the flood protection elevations for the upstream
reach.
(3) Modifications and
additions to existing structural works shall be regulated to assure that the
proposed work will provide a means of decreasing the flood damage potential in
the area and will provide the most reasonable protection of properties in
heavily populated floodplain areas consistent with these standards and
criteria. Any existing structural work which potentially threatens public
health or safety shall be modified or reconstructed in order to meet the
standards contained herein within a reasonable period of time based on
agreement between the local government unit and the commissioner.
C. Flood protection elevations and
floodway limits which reflect proposed measures for flood control shall not be
effective until such measures are constructed and operative unless the proposed
measures will increase flood heights in a given reach.
D. Floodplain development landward of any
levee or floodwall shall provide for interior drainage including designation of
ponding areas to protect against flooding from interior drainage.
Subp. 7.
Criteria for
commissioner's determination.
The criteria for the commissioner's determination of
potential for high loss of life or property damage and requirement for higher
levee elevation is as follows:
A. when
the elevation of the standard project flood is more than three feet above the
elevation of the 100-year flood;
B.
when it is not possible to provide sufficient flood warning to evacuate the
structures below the 100-year flood elevation during a flood predicted to be at
or above the 100-year flood elevation; or
C. for Army Corps of Engineers flood control
projects, the plan providing a higher level of flood protection is the
recommended plan.
Statutory Authority: MS s
103F.135;
103F.141;
103F.155;
104.05
