Ohio Administrative Code|Rule 1501:21-3-01 | Definitions.

                                                
The following definitions shall apply to the terms
		used in division 1501:21 of the Administrative Code:
(A) "Applicant" means the
		  individual, corporation, partnership, proprietor, or public agency which is
		  making an application for a construction permit.
(B) "Appurtenant works" means interrelated
		  elements or components of the dam including but not limited to outlet works and
		  spillway channels.
(C) "Breach" is defined as an opening in a dam
		  that prevents the dam from impounding a significant amount of
		  water.
(D) "Bulkhead" means a structure or partition to
		  reduce pressure and shut off water from entering a valve or gate chamber to
		  allow for repair and maintenance of the valve or gate.
(E) "Chief" means the chief of the division of
		  water resources of the department of natural resources, state of
		  Ohio.
(F) "Conveyance" is the hydraulic term applied to
		  the measurement of the carrying capacities of stream channels and overbank
		  areas. Conveyance is directly proportional to discharge.
(G) "Critical flood" means the flood that would
		  result in no additional loss of life, health or property along a critical
		  routing reach downstream of the dam 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.
(H) "Critical routing reach" means the entire
		  floodplain area downstream of the dam where life, health, or property is
		  potentially affected by failure of a dam.
(I) "Dam" means any artificial barrier together
		  with any appurtenant works, which either does or may impound water or other
		  liquefied material. Upground reservoirs and lagoons are considered to be dams.
		  A fill or structure intended solely for highway or railroad use that does not
		  permanently impound water or other liquefied material as determined by the
		  chief is not considered a dam.
(J) "Design flood" is the runoff from the design
		  storm taking into account the physiographic, topographic, hydrologic, and
		  hydraulic characteristics of the drainage area.
(K) "Division" means the division of water
		  resources of the department of natural resources, state of Ohio.
(L) "Emergency spill way" means a discharge
		  system designed to operate at an elevation above the principal spill way to
		  safely convey discharges that exceed the principal spill way's capacity
		  without jeopardizing the safety of the dam.
(M) "Enlargement" means increasing the elevation
		  of the top of an existing dam for the purpose of increasing the elevation of
		  the normal pool level of the impoundment, or increasing the elevation of the
		  top of an existing levee.
(N) "Flood" means a general and temporary
		  condition of partial or complete inundation of normally dry land
		  area.
(O) "Flood profile" means a graph or longitudinal
		  plot of maximum water surface elevations of a flood event versus measured
		  distance along a stream from a fixed point of reference.
(P) "Floodplain" means the land area adjoining a
		  watercourse which may be inundated during a flood.
(Q) "Freeboard" means the vertical dimension between
		  the top of the dam or levee (without camber) and the reservoir at normal pool
		  level, maximum operating pool, or stream water surface.
(R) "Height-of-dam" means the vertical dimension as
		  measured from the elevation of the natural stream bed, watercourse, or lowest
		  ground elevation at the downstream or outside toe of a dam to the elevation of
		  the top of the dam.
(S) "Length-of-dam" means the horizontal
		  dimension as measured along the crest of the dam from natural abutment to
		  natural abutment. Spillway systems over the dam but not in the abutment area
		  are included in the length determination. For upground reservoirs the length is
		  the continuous distance around the crest of the dam.
(T) "Levee" means any artificial barrier together
		  with any appurtenant works that will divert or restrain the flow of a stream or
		  other body of water for the purpose of protecting an area from inundation by
		  flood waters.
(U) "One-hundred-year flood" means the flood
		  having a one per cent probability of being equaled or exceeded in any given
		  year.
(V) "Overtopping" means an event that occurs when
		  the pool or stream elevation exceeds the elevation of the top of a dam or
		  levee.
(W) "Owner" means those who own, or propose to
		  construct a dam or levee.
(X) "Pipe conduit" means any tube or hollow
		  channel which conveys water to or from a reservoir, or through a
		  levee.
(Y) "Primary or principal spillway" means the
		  first discharge system designed to begin operation after the normal design
		  storage capacity has been exceeded.
(Z) "Probable maximum flood" or "PMF"
		  means the flood that may be expected from the most severe combination of
		  critical meteorologic and hydrologic conditions that are reasonably possible in
		  the drainage basin under study. The "PMF" is derived from the
		  probable maximum precipitation and is determined by using a hydrologic model to
		  simulate the drainage basin's response to those critical conditions which
		  produce the most severe flood runoff.
(AA) "Probable maximum precipitation" or
		  "PMP" means theoretically, the greatest depth of precipitation for a
		  given duration that is physically possible over a given size storm area at a
		  particular geographic location. The "PMP" is determined on the basis
		  of data obtained by the national oceanic and atmospheric administration or
		  other sources accepted by the chief.
(BB) "Reservoir" means any impoundment, or any
		  potential impoundment, that will be created by a dam.
(CC) "Spillway level" means the elevation of the primary
		  (principal) spillway or the elevation of the top of the dam if there is no
		  spillway.
(DD) "Storage volume" or "storage capacity"
		  means the volume of water or other liquefied material, which is or may be
		  impounded by a dam at a given elevation above the natural stream bed or above
		  the natural grade for upground reservoirs. Impounded material that can be shown
		  to the satisfaction of the chief to be non-liquefied can be excluded from the
		  storage volume.
(EE) "Total storage volume" means the total volume of
		  water or other liquefied material impounded when the pool level is at the top
		  of the dam immediately before it is overtopped. Impounded material that can be
		  shown to the satisfaction of the chief to be non-liquefied can be excluded from
		  the total storage volume.
(FF) "Upground reservoir" means a reservoir formed by
		  artificial barriers on two or more sides and which impounds water or liquefied
		  material pumped or otherwise imported from an exterior source. Lagoons are
		  considered upground reservoirs.