For the purpose of this chapter, the following definitions describe
the meaning of the terms used in this chapter:
A storm with a 1% chance of being equaled or exceeded in
any given year.
Tidewater, or the point, as determined by the Engineering
Bureau, at which stormwater can be released to a channel without causing
scouring, erosion or sedimentation to the receiving channel or its
floodplain.
The Maryland Department of the Environment (MDE) Water Management
Administration (WMA).
Any deleterious effect on waters or wetlands, including their
quality, quantity, surface area, species composition, aesthetics or
usefulness for human or natural uses which are or may potentially
be harmful or injurious to human health, welfare, safety or property,
to biological productivity, diversity, or stability or which unreasonably
interfere with the enjoyment of life or property, including outdoor
recreation.
Those methods and procedures used in the cultivation of land
in order to further crop and livestock production and conservation
of related soil and water resources.
Any person, firm, or governmental agency who executes the
necessary forms to procure official approval of a project or a permit
to carry out construction of a project.
A set of representational drawings or other documents submitted
by an applicant as a prerequisite to obtaining a stormwater management
approval and containing such information and specifications as required
by the Department of Public Works of Calvert County, Maryland, and
the Calvert Soil Conservation District under the regulations adopted
in accordance with the law.
The entity responsible for the review and approval of stormwater
management plans.
A porous water-bearing geologic formation generally restricted
to materials capable of yielding an appreciable supply of water.
Activities, practices, and procedures to prevent or reduce
the discharge of pollutants directly or indirectly to stormwater,
receiving waters, or stormwater conveyance systems. BMPs also include
treatment practices or operating procedures designed to temporarily
store or treat stormwater runoff in order to mitigate flooding, reduce
pollution, provide other amenities and to control site runoff, spillage
or leaks, sludge or water disposal, or drainage from raw materials
storage.
The Board of County Commissioners of Calvert County, Maryland.
The volume used to design structural management practices
to control stream channel erosion. Methods for calculating the channel
protection storage volume are specified in the 2000 Maryland Stormwater
Design Manual, Volumes I and II.
The federal Water Pollution Control Act (33 U.S.C. § 1251
et seq.), and any subsequent amendments thereto.
The removal of trees and brush from the land but shall not
include the ordinary mowing of grass.
The first of three required plan approvals that includes
the information necessary to allow an initial evaluation of a proposed
project.
A structure which has one or more of the following attributed:
640 acres (one square mile) or larger in drainage area; a dam height
of 20 feet (measured from the upstream toe to the structure top),
and is a low hazard.
The Department of Public Works of Calvert County, Maryland.
The 2000 Maryland Stormwater Design Manual, Volumes I and
II, and all subsequent revisions that serves as the official guide
for stormwater management principles, methods, and practices.
A permanent structure for the temporary storage of runoff,
which is designed so as not to create a permanent pool of water.
To change the runoff characteristics of a parcel of land
in conjunction with residential, commercial, industrial, or institutional
construction or alteration.
A person, partnership, corporation, firm, or governmental
agency undertaking or proposing the construction of a building, a
project consisting of interrelated buildings, or other construction,
and who is primarily financially responsible for the proposed work.
The concentrated release of stormwater to tidal waters or
vegetated tidal wetlands from new development or redevelopment projects
in the critical area.
Employees or designees of the Director of the Calvert County
Department of Public Works designated to enforce this chapter.
The Calvert County Soil Conservation District.
The downstream watercourse to a point where the increase
in ten- and 100-year flow due to development is no greater than 10%
of the existing flow.
That area contributing runoff to a single point measured
in a horizontal plane, which is enclosed by a ridgeline.
The area drained by a river and all its tributaries; also
called "drainage area."
A grant or reservation by the owner of land for the use of
such land by others for a specific purpose or purposes, and which
must be included in the conveyance of land affected by such easement.
The Bureau Chief, Engineering Bureau, administrator of the
Calvert County Stormwater Management Ordinance or duly authorized
representative.
The division of the Department of Public Works responsible
for administering the Calvert County Stormwater Management Ordinance.
Using small-scale stormwater management practices, nonstructural
techniques, and better site planning to mimic natural hydrologic runoff
characteristics and minimize the impact of land development on water
resources. Methods for designing ESD practices are specified in the
Design Manual.
The process by which the ground surface is worn by the action
of wind and/or water.
Any act by which soil, earth, sand, gravel, rock or any similar
material is cut into, dug, quarried, uncovered, removed, displaced,
relocated or bulldozed, and includes the conditions resulting from
such actions.
Those land development activities that are not subject to
the stormwater management requirements contained in this chapter.
A stormwater design feature that provides gradual release
of a volume of water in order to increase settling of pollutants and
protect downstream channels from frequent storm events. Methods for
designing extended detention BMPs are specified in the Design Manual.
The storage volume required to control those infrequent but
large storm events in which overbank flows reach or exceed the boundaries
of the 100-year floodplain.
Any act, by which soil, earth, sand, gravel, rock, or any
similar material is deposited, placed, pushed, pulled, or transported
and shall include the conditions resulting from such actions.
The last of three required plan approvals that includes the
information necessary to allow all approvals and permits to be issued
by the approving agency.
The final grade or elevation of the ground surface, which
conforms to the approved grading plan.
A storm with a 20% chance of being equaled or exceeded in
any given year.
A flat area along the course of a stream that is naturally subject
to flooding.
That area along or adjacent to a stream or body of water within
the waters of the state.
That area adjacent to a stream or river that is flooded as a
natural occurrence when flow exceeds the capacity of the stream channel,
and whose boundary is generally defined by the frequency of the flood
event, i.e., 100-year, fifty-year, etc.
A program of identifying areas prone to flooding and providing
regulation for the use of those areas by a number of possible alternatives,
including building codes, land use regulations and public acquisition.
The area adjoining a particular river or stream which would
be inundated by the discharge of the regulatory flood. The regulatory
flood is that of a 100-year frequency storm.
The river or stream channel and portions of the floodplain
immediately adjacent, which are required to convey the discharge or
the regulatory flood without increasing flood heights more than one
foot.
Prolonging the flow time of runoff to reduce the peak discharge.
Any act by which soil is cleared, stripped, stockpiled, excavated,
scarified, filled or any combination thereof.
Any material, including any substance, waste, or combination
thereof, which because of its quantity, concentration, or physical,
chemical, or infectious characteristics may cause, or significantly
contribute to, a substantial present or potential hazard to human
health, safety, property, or the environment when improperly treated,
stored, transported, disposed of, or otherwise managed.
Any direct or indirect non-stormwater discharge to the storm
drain system, except as exempted by this chapter.
Either of the following:
Any drain or conveyance, whether on the surface or subsurface,
which allows an illegal discharge to enter the storm drain system,
including but not limited to any conveyances which allow any non-stormwater
discharge, including sewage, process wastewater, and wash water, to
enter the storm drain system and any connections to the storm drain
system from indoor drains and sinks, regardless of whether said drain
or connection had been previously allowed, permitted, or approved
by an authorized enforcement agency; or
Any drain or conveyance connected from a commercial or industrial
land use to the storm drain system which has not been documented in
plans, maps, or equivalent records and approved by an authorized enforcement
agency.
Any surface that does not allow stormwater to infiltrate
into the ground.
Activities subject to NPDES industrial permits as defined
in 40 CFR 122.26(b)(14).
Existing platted lots within an existing subdivision (considered
new development, not redevelopment).
The passage or movement of water into the soil surface.
A professional land surveyor duly registered by the State
of Maryland to practice professional land surveying in accordance
with the provisions of the Annotated Code of Maryland, as currently
amended.
Any fill, grading or excavation which may result in soil
erosion or the covering of land surfaces with an impermeable material.
Designing stormwater management systems so that all reasonable
opportunities for using ESD planning techniques and treatment practices
are exhausted and only where absolutely necessary is a structural
BMP implemented.
A permit issued by EPA [or by a state under authority delegated
pursuant to 33 U.S.C. § 1342(b)] that authorizes the discharge
of pollutants to waters of the United States, whether the permit is
applicable on an individual, group, or general area-wide basis.
The ground surface in its existing state before grading,
stripping, excavating or filling, and other land-disturbing activities
commencing or continuing after the effective date of this chapter.
The United States Department of Agriculture, Natural Resource
Conservation Service.
Any discharge to the storm drain system that is not composed
entirely of stormwater.
The design and construction of a facility necessary to control
stormwater from more than one development.
The design and construction of systems necessary to control
stormwater within an immediate development.
The volume controlled by structural practices to prevent
an increase in the frequency of out of bank flooding generated by
development. Methods for calculating the overbank flood protection
volume are specified in the Design Manual.
A person or business entity that has as an objective the
promotion of the development of land for nonpublic uses, or the construction
of structures on parcels of land.
The controlled shallow surface ponding on parking lots.
The federal government, the state, any county, municipal
corporation, or other political subdivision of the state, or any of
their units, or an individual receiver, trustee, guardian, executor,
administrator, fiduciary, or representative of any kind, or any partnership,
firm, association, public or private corporation, or any other entity.
A combination of strategies employed early in project design
to reduce the impact from development and to incorporate natural features
into a stormwater management plan.
Anything which causes or contributes to pollution. Pollutants
may include, but are not limited to: paints, varnishes, and solvents;
oil and other automotive fluids; nonhazardous liquid and solid wastes
and yard wastes; refuse, rubbish, garbage, litter, or other discarded
or abandoned objects, articles, and accumulations, so that same may
cause or contribute to pollution; floatables; pesticides, herbicides,
and fertilizers; hazardous substances and wastes; sewage, fecal coliform
and pathogens; dissolved and particulate metals; animal wastes; wastes
and residues that result from constructing a building or structure
(including but not limited to sediments, slurries, and concrete rinsates);
and noxious or offensive matter of any kind.
Structures classified as a "small pond" under state law which
have all the following attributes: less than 640 acres of drainage
area; a dam height less than 20 feet (measured from the upstream toe
to the structure top); and is not a low hazard.
An engineer duly licensed by the State of Maryland to practice
professional engineering under the requirements of the Annotated Code
of Maryland, as currently amended.
The division of the Department of Public Works responsible
for the construction and maintenance inspection of stormwater management
facilities in accordance with this chapter.
Any water bodies, watercourses or wetlands into which surface
waters flow, either naturally, in man-made ditches, or in a closed
conduit system.
That portion of the water quality volume used to maintain
groundwater recharge rates at development sites. Methods for calculating
the recharge volume are specified in the Design Manual.
Any construction, alteration, or improvement performed on
sites where existing land use is commercial, industrial, institutional
or multifamily residential and existing site impervious area exceeds
40%.
A permanent structure that provides for the storage of runoff
by means of a permanent pool of water.
The implementation of ESD practices, the construction of
a structural BMP in a previously developed area, the modification
of an existing structural BMP, or the implementation of a nonstructural
practice to improve water quality over current conditions.
Soils or other surficial materials transported or deposited
by the action of wind, water, ice, or gravity as a product of erosion.
Any tract, lot, or parcel of land, or combination of tracts,
lots, parcels of land that are in one ownership, or are contiguous
and in diverse ownership, where development is to be performed as
part of a unit, subdivision, or project.
The second of three required plan approvals that includes
the information necessary to allow a detailed evaluation of a proposed
project.
The inclined surface of a fill, excavation or natural terrain.
Any earth, sand, gravel, rock or any other similar material.
The prevention of soil movement by any of various vegetative
and/or structural means.
A rainfall event.
Publicly owned facilities by which stormwater is collected
and/or conveyed, including but not limited to any roads with drainage
systems, municipal streets, gutters, curbs, inlets, piped storm drains,
pumping facilities, retention and detention basins, natural and human-made
or altered drainage channels, reservoirs, and other drainage structures.
That water which originates from a precipitation event.
For quantitative control, a system of vegetative and structural
measures that control the increased volume and rate of surface runoff
caused by man-made changes to the land; and
For qualitative control, a system of vegetative, structural,
and other measures that reduce or eliminate pollutants that might
otherwise be carried by surface runoff.
Expenses incurred in constructing stormwater management systems.
A set of drawings or other documents submitted by a person
as a prerequisite to obtaining a stormwater management approval which
contains all of the information and specifications pertaining to stormwater
management.
Natural areas, ESD practices, stormwater management measures,
and any other structure through which stormwater flows, infiltrates,
or discharges from a site.
A document which describes the best management practices
and activities to be implemented by a person or business to identify
sources of pollution or contamination at a site and the actions to
eliminate or reduce pollutant discharges to stormwater, stormwater
conveyance systems, and/or receiving waters to the maximum extent
practicable.
Any activity which removes the vegetative surface cover,
including tree removal, clearing, grubbing and storage or removal
of topsoil.
A storm with a 10% chance of being equaled or exceeded in
any given year.
A storm with a 5% of being equaled or exceeded in any given
year.
The modification of the minimum stormwater management requirements
for specific circumstances such that strict adherence to the requirements
would result in unnecessary hardship and not fulfill the intent of
the chapter.
The reduction from stormwater management requirements by
the Department of Public Works for a specific development on a case-by-case
review basis.
QUALITATIVE STORMWATER MANAGEMENT WAIVERIncludes water quality volume and recharge volume design parameters.
QUANTITATIVE STORMWATER MANAGEMENT WAIVERIncludes channel protection storage volume, overbank flood protection volume, and extreme flood volume design parameter.
Any water or other liquid, other than uncontaminated stormwater,
discharged from a facility.
The volume needed to capture and treat the runoff from 90%
of the average annual rainfall at a development site. Methods for
calculating the water quality volume are specified in the Design Manual.
Any natural or artificial stream, river, creek, ditch, channel,
canal, conduit, culvert, drain, waterway, gully, ravine or wash, in
and including any adjacent area that is subject to inundation from
overflow or floodwater.
The total drainage area contributing runoff to a single point.
An area that has saturated soils and vegetation adapted to
wet conditions and periodic flooding.
