This website publishes administrative rules on their effective dates, as designated by the adopting state agencies, colleges, and
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| Rule |
Rule 1501:21-13-01 | Classification of dams.
(A) For the purpose of this chapter, dams
are to be divided into four classes, which will be known as class I, class II,
class III, and class IV. The chief shall establish a dam's appropriate
classification by using the following criteria as a guideline. Such
classification will be established by the chief during the preliminary review
described by rule 1501:21-5-02 of the Administrative Code or during the
periodic inspection described by rule 1501:21-21-01 of the Administrative Code.
The chief reserves the right to reclassify any dam at any time as a result of
circumstances not in existence or not known at the time said dam was initially
classified. (1) A dam shall be
placed in class I when it has a total storage volume greater than five thousand
acre-feet or a height of greater than sixty feet or when sudden failure of the
dam would result in one of the following conditions. (a) Probable loss of human life. (b) Structural collapse of at least one residence or one
commercial or industrial business. (2) A dam shall be
placed in class II when it has a total storage volume greater than five hundred
acre-feet or a height of greater than forty feet or when sudden failure of the
dam would result in at least one of the following conditions, but loss of human
life is not probable. (a) Disruption of a public water supply or wastewater treatment
facility. (b) Release of health hazardous industrial or commercial
waste, or other health hazards. This paragraph does not apply to manure storage
or treatment facilities subject to division 901:10 of the Administrative
Code. (c) Flooding of residential, commercial, industrial, or
publicly owned structures. At the request of the dam owner, the chief may
exempt dams from the criterion of this paragraph if the dam owner owns the
potentially affected property. (d) Flooding of high-value property. At the request of the
dam owner, the chief may exempt dams from the criterion of this paragraph if
the dam owner owns the potentially affected property. (e) Damage or disruption to major roads including but not
limited to interstate and state highways, and the only access to residential or
other critical areas such as hospitals, nursing homes, or correctional
facilities as determined by the chief. (f) Damage or disruption to railroads or public
utilities. (g) Damage to downstream class I, II or III dams, class I
or II levees, or other dams or levees of high value. Damage to dams or levees
can include, but is not limited to, overtopping of the structure. At the
request of the dam owner, the chief may exempt dams from the criterion of this
paragraph if the dam owner owns the potentially affected property. (3) A dam shall be
placed in class III when it has a total storage volume greater than fifty
acre-feet or a height of greater than twenty-five feet or when sudden failure
of the dam would result in at least one of the following conditions, but loss
of human life is not probable. (a) Property losses including but not limited to rural buildings
not otherwise described in paragraph (A) of this rule, and class IV dams and
class III levees not otherwise listed as high-value property in paragraph (A)
of this rule. At the request of the dam owner, the chief may exempt dams from
the criterion of this paragraph if the dam owner owns the potentially affected
property. (b) Damage or disruption to local roads including but not limited
to roads not otherwise listed as major roads in paragraph (A) of this
rule. (4) Dams which are
twenty-five feet or less in height and have a total storage volume of fifty
acre-feet or less may be placed in class IV. When sudden failure of the dam
would result in property losses restricted mainly to the dam and rural lands,
and loss of human life is not probable, the dam may be placed in class IV.
Class IV dams are exempt from the permit provisions of section 1521.06 of the
Revised Code pursuant to paragraph (C) of rule 1501:21-19-01 of the
Administrative Code. (B) All pertinent information including
any unusual circumstances will be considered by the chief in establishing an
appropriate classification for a dam. Probable future development of the area
downstream from the dam that would be affected by its failure shall be
considered. Completed downstream hazard mitigation such as acquisition, removal
or protection of downstream property may also be considered. However, the
listed criteria will in no way preclude the chief's requirement of greater
safety in the interest of life, health, or property.
Last updated June 27, 2024 at 10:15 PM
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Rule 1501:21-13-02 | Design flood for dams and determination of critical flood.
The magnitude of the design flood for each dam
shall be set by the chief and determined from actual streamflow and flood
frequency records or from synthetic hydrologic criteria based on current
publications prepared by the division, the United States army corps of
engineers, the United States geological survey, the national oceanic and
atmospheric administration, or others acceptable to the chief. (A) The minimum design flood will
be: (1) For class I dams, the
probable maximum flood or the critical flood; (2) For class II dams,
fifty per cent of the probable maximum flood or the critical flood;
and, (3) For class III dams,
twenty-five per cent of the probable maximum flood or the critical
flood. (B) Selection of a critical flood as the
design flood is acceptable. The design for the critical flood shall be for
site-specific conditions and based on a quantitative and relative impact
analysis of the downstream critical routing reach. In determining the critical
flood, the spillway and storage capacity for the dam shall be designed so that
there will be no additional potential for loss of life, health or property in
the critical routing reach from overtopping failure of the dam when compared to
the potential for loss of life, health or property caused by the flood in the
absence of a dam overtopping failure. (1) Where the incremental
depth of flow between the failure and non-failure floods is 2.0 feet or
greater, or the product of the average floodplain flow velocity (in feet per
second) and the incremental flood depth (in feet) is greater than 7.0,
additional potential for loss of life, health or property in the critical
routing reach is expected. (2) If the incremental
depth of flow between the failure and non-failure floods is less than 2.0 feet,
and the product of the average floodplain flow velocity (in feet per second)
and the incremental flood depth (in feet) is less than 7.0, it does not
necessarily mean that the critical flood has been determined. Further
investigation will be required to determine that no additional potential for
loss of life, health or property will occur. (C) The minimum critical flood shall be
as follows: (1) Forty per cent of the
probable maximum flood for a class I dam, (2) Twenty per cent of
the probable maximum flood for a class II dam, and (3) The one-hundred-year
flood for a class III dam. (D) The owner or applicant is to submit
to the chief, in writing, a request for consideration of the critical flood as
the design flood along with appropriate supporting calculations, as deemed
necessary by the chief. The chief will not consider risk assessment based upon
planned evacuation, probability of inhabitation, or monetary recovery of
property damage. (E) If downstream hazard conditions
change at any time during the life of the structure, a reevaluation of the
critical routing reach and modification of the critical flood may be required
by the chief.
Last updated June 27, 2024 at 10:16 PM
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Rule 1501:21-13-03 | Spillway design, general requirements.
Effective:
January 16, 2005
(A) Every dam shall have a spillway system which will safely operate during the design flood without endangering the safety of the dam. (B) Each spillway shall include a means of dissipating the energy of flow without endangering the safety of the dam. (C) The capacity of the spillway system shall be equal to the peak inflow rate of the design flood unless the applicant has demonstrated by flood routing procedures that the dam will safely pass the design flood with the spillway system. (D) Every upground reservoir shall have an overflow or other device to preclude overfilling the reservoir during normal filling operations. Local watershed drainage into the reservoir must also be included in the design of the overflow device if applicable. (1) The elevation of an overflow device shall be no more than 0.5 foot above the designed maximum operating pool level of the reservoir. (2) A device other than an overflow that is used to preclude overfilling must prevent the reservoir from rising 0.5 foot above the designed maximum operating pool level.
Last updated May 22, 2023 at 12:10 PM
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Rule 1501:21-13-04 | Pipe conduit spillways, general requirements.
(A) All pipe conduits shall convey flow
at the maximum design velocity without damage to the interior
surface. (B) Seepage control devices acceptable
to the chief shall be installed. (C) Adequate allowances shall be
incorporated in the design to compensate for settlement and possible elongation
of the pipe conduit. (D) An anti-vortex device that is
satisfactory to the chief shall be installed at the intake of all pipe and
riser spillway systems. Anti-vortex devices may also be required for other
spillway types as necessary to improve the performance of the
spillway. (E) A trash rack that is satisfactory to
the chief shall be installed at the intake of all pipe and riser and/or drop
inlet type spillway systems to prevent clogging the pipe conduit. Trash rack
devices may also be required for other spillway types as necessary to ensure
the performance of the spillway. (F) An emergency overflow spillway is
required, except when specifically exempted by the chief. A vegetated or
unlined emergency spillway will be approved by the chief, but only after the
applicant has demonstrated that it will pass the design flood without
jeopardizing the safety of the structure. The average frequency of use for a
vegetated or unlined emergency spillway must be predicted to be less than the
following criteria unless otherwise approved by the chief: (1) Once in fifty years
for class I dams; (2) Once in twenty-five
years for class II dams; and (3) Once in ten years for
class III dams. (G) The pipe conduit shall be of such
size as to remove from the reservoir within ten days following passage of the
design flood peak at least eighty percent of the water temporarily detained in
the reservoir above the elevation of the primary (principal)
spillway.
Last updated June 27, 2024 at 10:17 PM
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Rule 1501:21-13-05 | Pipe conduit spillways, special requirements.
(A) Pipe conduits shall be of such
design as to safely support the total external loads and shall
convey flow without rupture or leakage. (B) Unless otherwise approved by the
chief, the minimum inside dimension of the pipe conduit shall be: (1) Twenty-four inches
for class I and class II dams. (2) Eighteen inches for
class III dams. (C) All pipes shall have the ability to
resist corrosion from surrounding soils and impounded materials based on
current acceptable testing standards. (D) Corrugated metal pipe and corrugated
plastic pipe shall not be used.
Last updated June 27, 2024 at 10:18 PM
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Rule 1501:21-13-06 | Requirements for drains and other pipe conduits.
(A) Unless specifically exempted by the
chief, dams in class I, class II, and class III shall include a device to
permit draining the reservoir within a reasonable period of time as approved by
the chief. Pipe conduits used for lake drains shall have a minimum inside
diameter of not less than four inches and be placed at an elevation to account
for sedimentation in the reservoir. (B) Valves or sluice gates in pipe
conduits shall be installed upstream from the centerline of the dam unless
otherwise approved by the chief. (C) All pipe conduits used as drains,
water supply lines, or other pressure-flow conduits, regardless of
classification of the dam, shall meet the legal provisions of paragraphs (A),
(B), (C), and (E) of rule 1501:21-13-04 of the Administrative Code and
paragraphs (A), (C), and (D) of rule 1501:21-13-05 of the Administrative
Code. (D) When the drain outlets into a
pipe-conduit upstream from the centerline of the dam, seepage control devices
may be omitted from the drain. (E) All new dam construction shall
include a bulkhead for the outlet works unless specifically exempted by the
chief.
Last updated June 27, 2024 at 10:18 PM
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Rule 1501:21-13-07 | Freeboard requirements for dams.
Sufficient freeboard shall be provided to prevent
overtopping of the top of the dam due to passage of the design flood and other
factors including, but not limited to, ice and wave action. The chief may
approve a lower freeboard if the dam is armored against overtopping
erosion. (A) For class I and class II dams that
are upground reservoirs, the minimum elevation of the top of the dam shall be
at least five feet higher than the elevation of the designed maximum operating
pool level unless otherwise approved by the chief. (B) For class III dams that are upground
reservoirs, the minimum elevation of the top of the dam shall be at least three
feet higher than the elevation of the designed maximum operating pool level
unless otherwise approved by the chief.
Last updated June 27, 2024 at 10:19 PM
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Rule 1501:21-13-08 | Additional design requirements for dams.
(A) The safety factors for the various
elements of the dam shall conform to good engineering practice as approved by
the chief. The safety factors and the design standards that are used by the
applicant shall agree with the approved design assumptions. (B) Inspection devices such as
piezometers, settlement platforms, stand-pipes, tell-tale stakes, monitoring
weirs, inclinometers, and permanent bench marks, may be required by the chief
for the division's and the owner's use in the inspection of the
structure during and after completion of construction. (C) The chief may require dams to have a
staff gauge to allow monitoring of lake levels within a range from the lower of
five feet below normal pool or the normal drawdown level, to the top of dam
elevation. The design of the staff gauge will be reviewed and approved by the
chief. (D) Grass vegetation or other vegetation of similar
properties are the only acceptable vegetative covers for earthen dam embankment
surfaces or vegetated earth spillways. Trees and brush are not acceptable
surface covers. (E) The applicant shall demonstrate to the satisfaction of
the chief that the structure will be consistent and in accordance with all
applicable state and local floodplain regulations.
Last updated June 27, 2024 at 10:19 PM
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Rule 1501:21-13-09 | Classification of levees.
(A) For the purpose of this chapter,
levees are to be divided into three classes, which will be known as class I,
class II, and class III. The chief will establish a levee's appropriate
classification by using use the following criteria as a guideline. Such
classification will be established by the chief during the review of the
preliminary design report described by rule 1501:21-5-02 of the Administrative
Code or during the periodic inspection described by rule 1501:21-21-01 of the
Administrative Code. The chief reserves the right to reclassify any levee at
any time as a result of circumstances not in existence or not known at the time
said levee was initially classified. (1) A levee shall be
placed in class I when sudden failure of the levee would result in one of the
following conditions. (a) Probable loss of human life. (b) Structural collapse of at least one residence or one
commercial or industrial business. (2) A levee shall be
placed in class II when sudden failure of the levee would result in at least
one of the following conditions, but loss of human life is not
probable. (a) Disruption of a public water supply or wastewater treatment
facility, or other health hazards. (b) Flooding of residential, commercial, industrial, or publicly
owned structures. (c) Flooding of high-value property. (d) Damage or disruption to major roads including but not limited
to interstate and state highways, and the only access to critical areas such as
hospitals, nursing homes, or correctional facilities as determined by the
chief. (e) Damage or disruption to railroads or public
utilities. (3) A levee having a height of not more
than three feet shall be placed in class III. A levee having a height of more
than three feet shall be placed in class III when sudden failure of the levee
would result in at least one of the following conditions, but loss of human
life is not probable. (a) Property losses including but not limited to rural buildings
not otherwise described in paragraph (A) of this rule. (b) Damage or disruption to local roads including but not limited
to roads not otherwise listed as major roads in paragraph (A) of this
rule. (c) Property losses restricted mainly to the levee and to the
owner's property or to rural lands. Class III levees are exempt from the permit
provisions of section 1521.06 of the Revised Code pursuant to paragraph (C) of
rule 1501:21-19-01 of the Administrative Code. (B) All pertinent information including
any unusual circumstances will be considered by the chief in establishing an
appropriate classification for a levee. Probable future development of the area
adjacent to the levee shall be considered. However, the above criteria will in
no way preclude the chief's requirement of greater safety in the interest
of life, health, and property.
Last updated June 27, 2024 at 10:20 PM
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Rule 1501:21-13-10 | Levees, general requirements.
Effective:
January 16, 2005
(A) Future development of areas upstream, downstream, and adjacent to the levee shall be considered in the design. (B) The levee shall operate safely during all floods up to the design flood elevation. (C) Provisions for drainage of the area protected by the levee shall be incorporated into the structure. Measures shall be included to prevent flooding of this area by backflow through the drainage system. (D) The levee must be protected from or designed to prevent erosive velocities along the structure and its foundation. (E) Grass vegetation or other vegetation of similar properties are the only acceptable vegetative covers for earthen levee embankment surfaces. Vetch, trees and brush are not acceptable surface covers.
Last updated May 22, 2023 at 12:11 PM
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Rule 1501:21-13-11 | Levees, special requirements.
Effective:
January 16, 2005
(A) Hydraulic analyses shall be conducted to determine flood elevations for stream reaches affected by the construction of a levee and in accordance with rule 1501:21-13-10 of the Administrative Code. The analyses must provide flood depth and velocity data during the one-hundred-year, twenty-five-year, and five-year flood events, and for the top-of-levee flood event. For construction of new levees, the flood depths and velocities must be determined with and without the levee. The impact of increased flood depths and velocities on property and structures must be provided.
Last updated May 22, 2023 at 12:11 PM
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Rule 1501:21-13-12 | Design flood for levees.
Effective:
January 16, 2005
(A) The design flood shall be established by the chief in concert with the applicant's desired level of protection, but with the utmost interest in safeguarding life, health, and property. For class I levees, the minimum design flood will be the one-hundred-year flood or the critical flood. The design for the critical flood shall be for site-specific conditions and based on a quantitative and relative impact analysis of the protected area. In determining the critical flood, the levee shall be designed so that there will be no additional potential for loss of life, health or property from overtopping failure of the levee when compared to the potential for loss of life, health or property caused by the flood in the absence of a levee overtopping failure. (B) The magnitude of the design flood shall be determined from actual streamflow and flood frequency records or from synthetic hydrologic criteria based on current publications prepared by the division, the national oceanic and atmospheric administration (NOAA), the United States army corps of engineers, the United States geological survey, or others specifically approved by the chief.
Last updated May 22, 2023 at 12:11 PM
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Rule 1501:21-13-13 | Freeboard requirements for levees.
(A) For levees in class I, the minimum elevations of the top of
the levee shall be at least three feet higher than the maximum adjacent water
surface elevations during passage of the design flood. The chief may approve a
lower freeboard with acceptable documentation. (B) For levees in class II, the minimum elevations of the top of
the levee shall be two feet higher than the maximum adjacent water surface
elevations during passage of the design flood. (C) Where special conditions of severe frost damage, ice damage,
stream obstruction, wave action, or impact of other structures may occur, the
chief may require elevations higher than set forth in paragraph (A) of this
rule.
Last updated June 27, 2024 at 10:21 PM
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Rule 1501:21-13-14 | Additional design requirements for levees.
(A) The safety factors of the various
elements of the levee shall conform to good engineering practice as approved by
the chief. The safety factors and the design standards that are used by the
applicant shall agree with the approved design assumptions. (B) Design references that are used shall
be cited in the information that is submitted to the chief. (C) Inspection devices, which include but
are not necessarily restricted to settlement platforms, tell-tale stakes,
inclinometers and permanent bench marks, may be required by the chief for the
division's and the owner's use in the inspection during and after
completion of construction. (D) The applicant will demonstrate to the
satisfaction of the chief that the structure will be consistent and in
accordance with all applicable state and local floodplain
regulations.
Last updated June 27, 2024 at 10:22 PM
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