Wis. Admin. Code Department of Natural Resources NR 333.03 - Definitions
(1) "Auxiliary spillway" means a secondary
spillway designed to pass water only during flows exceeding the capacity of the
principal spillway.
(2) "Base flow"
means that part of the stream flow that is derived from groundwater and
calculated as the 7-day low flow that occurs on an average of once in 2 years
or has a 50% chance of occurring in any given year. The notation is
Q7,2.
(3) "Dam" means any
artificial barrier in or across a watercourse which has the primary purpose of
impounding or diverting water. A dam includes all appurtenant works, such as a
dike, canal or powerhouse.
(4)
"Department" means the department of natural resources.
(5) "Development" means any artificial change
to improved or unimproved real estate not related to allowable open space use
including, but not limited to, the construction of buildings, structures or
accessory structures; the construction of additions or substantial improvements
to buildings, structures or accessory structures; the placement of buildings or
structures; and campgrounds.
(6)
"Floodplain with the dam nonexistent" means that area of land downstream from a
dam that would be inundated by water during the regional flood if the dam did
not exist.
(7) "Floodway" means the
channel of a river or stream and those portions of the floodplain adjoining the
channel which are required to carry the regional flood discharge.
(8) "Hydraulic shadow" means that area of
land downstream from a dam that would be inundated by water upon failure of the
dam during the regional flood.
(9)
"Land use controls in place" means future development within the hydraulic
shadow is required to conform to the criteria specified in a zoning ordinance
adopted and approved pursuant to s.
87.30, Stats.,
and also consistent with land use plans developed under s.
66.1001,
Stats., or through restrictive covenants, easements, or other appropriate legal
arrangements between the owner of the dam and the owners of all property within
the hydraulic shadow.
(10) "Maximum
headwater" means the maximum water surface elevation before overtopping would
occur.
(11) "Maximum storage
capacity" means the volume of water in acre-feet capable of being stored behind
a dam at the maximum water surface elevation before overtopping would
occur.
(12) "Minimum tailwater"
means the water level downstream from a dam at base flow.
(13) "Open space use" means a use which has a
relatively low flood damage potential, such as uses associated with
agriculture, recreation, parking, storage yards, or certain sand and gravel
operations.
(14) "Overtopping"
means the flow of water over parts of a dam which are not part of its spillway
system.
(15) "Owner" means any
individual, partnership, public utility, company, cooperative, trust,
corporation, association, state or interstate agency, city, village, town,
county or special purpose district such as a drainage district or a public
inland lake protection and rehabilitation district which has title to or
recorded easement for operation, maintenance and access to a dam or to the
specific parcel of land on which a dam exists.
(16) "Principal spillway" means the primary
structure for the discharge of normal flow through a dam.
(17) "Q10" means the flood flow having a
recurrence interval of 10 years or a 10% chance of occurring or being exceeded
in any given year.
(18) "Q50" means
the flood flow having a recurrence interval of 50 years or a 2% chance of
occurring or being exceeded in any given year.
(19) "Q100" means the flood flow having a
recurrence interval of 100 years or a 1% chance of occurring or being exceeded
in any given year.
(20) "Q500"
means the flood flow having a recurrence interval of 500 years or a 0.2% chance
of occurring or being exceeded in any given year.
(21) "Q1000" means the flood flow having a
recurrence interval of 1000 years or a 0.1% chance of occurring or being
exceeded in any given year.
(22)
"Reconstruction" means alteration of an existing dam in a manner which affects
its hydraulic capacity or structural integrity.
(23) "Regional flood" means a flood
determined to be representative of large floods known to have occurred in
Wisconsin and which may be expected to occur on a particular stream once in
every 100 years.
Note: The regional flood is based upon a statistical analysis of stream flow records available for the watershed or an analysis of rainfall or runoff characteristics in the watershed or both. The flood frequency of the regional flood is once in every 100 years. In any given year, there is a 1% chance that the regional flood may occur or be exceeded.
(24) "Structural height" means the difference
in elevation in feet between the point of lowest elevation of the top of the
dam before overtopping and the lowest elevation of the natural stream or lake
bed at the downstream toe of the dam.
(25) "Submerged" means that the difference
between the water surface elevations upstream and downstream from a dam is one
foot or less.
(26) "Total spillway
capacity" means the sum of the auxiliary spillway and principal spillway
capacities of a dam.
Notes
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