For the purpose of this chapter, the following documents are
incorporated by reference:
A. The 2000 Maryland Stormwater Design Manual, Volumes I and II (Maryland
Department of the Environment, April 2000), and all subsequent revisions,
is incorporated by reference by the Town of Denton and shall serve
as the official guide for stormwater principles, methods, and practices.
B. USDA Natural Resources Conservation Service Maryland Conservation
Practice Standard Pond Code 378 (January 2000), and all subsequent
revisions.
In case of a conflict between the control requirements of this
chapter and the 2000 Maryland Stormwater Design Manual, the more stringent
requirement shall govern.
The following definitions are provided for the terms used in
this chapter:
ADMINISTRATION
The Maryland Department of the Environment (MDE) Water and
Science Administration.
ADVERSE IMPACT
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.
AGRICULTURAL LAND MANAGEMENT ACTIVITIES
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.
APPLICANT
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.
APPROVING AGENCY
The entity responsible for the review and approval of stormwater
management plans.
AQUIFER
A porous, water-bearing geologic formation generally restricted
to materials capable of yielding an appreciable supply of water.
BEST MANAGEMENT PRACTICE (BMP)
A structural device or nonstructural practice designed to
temporarily store or treat stormwater runoff in order to mitigate
flooding, reduce pollution, and provide other amenities.
CHANNEL PROTECTION STORAGE VOLUME (Cpv)
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, referenced in §
106-2 of this chapter.
CLEARING
The removal of trees and brush from the land, but shall not
include the ordinary mowing of grass.
CONCEPT PLAN
The first of three required plan approvals that includes
the information necessary to allow an initial evaluation of a proposed
project.
DESIGN MANUAL
The 2000 Maryland Stormwater Design Manual, and all subsequent revisions, that serves as the official guide for stormwater management principles, methods, and practices, referenced in §
106-2 of this chapter.
DETENTION STRUCTURE
A permanent structure for the temporary storage of runoff,
which is designed so as not to create a permanent pool of water.
DEVELOP LAND
To change the runoff characteristics of a parcel of land
in conjunction with residential, commercial, industrial, or institutional
construction or alteration.
DIRECT DISCHARGE
The concentrated release of stormwater to tidal waters or
vegetated tidal wetlands from new development or redevelopment projects
in the Critical Area.
DRAINAGE AREA
That area contributing runoff to a single point measured
in a horizontal plane, which is enclosed by a ridgeline.
EASEMENT
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
shall be recorded in the land records of Caroline County, Maryland.
ENVIRONMENTAL SITE DESIGN (ESD)
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.
EXEMPTION
Those land development activities that are not subject to
the stormwater management requirements contained in this chapter.
EXTENDED DETENTION
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, referenced in §
106-2 of this chapter.
EXTREME FLOOD VOLUME (Qf)
The storage volume required to control those infrequent but
large storm events in which overbank flows reach or exceed the boundaries
of the one-hundred-year floodplain.
FINAL STORMWATER MANAGEMENT PLAN
The last of two required plan approvals that includes the
information necessary to allow all approvals and permits to be issued
by the approving agency.
FLOW ATTENUATION
Prolonging the flow time of runoff to reduce the peak discharge.
GRADING
Any act by which soil is cleared, stripped, stockpiled, excavated,
scarified, filled or any combination thereof.
IMPERVIOUS AREA or IMPERVIOUS SURFACE
A surface which has been compacted or covered with a layer
of material so that it is highly resistant or entirely resistant to
infiltration by precipitation. It includes, but is not limited to,
surfaces such as compacted clay, gravel, as well as streets, roofs,
sidewalks, parking lots, and other similar surfaces.
INFILTRATION
The passage or movement of water into the soil surface.
MAXIMUM EXTENT PRACTICABLE (MEP)
Designing stormwater management systems so that all reasonable
opportunities for using ESD planning techniques and treatment practices
are exhausted, and only where absolutely necessary, a structural BMP
is implemented.
OVERBANK FLOOD PROTECTION VOLUME (Qp)
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, referenced in §
106-2 of this chapter.
PERSON
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.
PLANNING TECHNIQUES
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.
RECHARGE VOLUME (Rev)
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, referenced in §
106-2 of this chapter.
REDEVELOPMENT
Any construction, alteration, or improvement on sites where
existing land use is commercial, industrial, institutional, or multifamily
residential and existing site impervious area exceeds 40%.
RETENTION STRUCTURE
A permanent structure that provides for the storage of runoff
by means of a permanent pool of water.
RETROFITTING
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.
SEDIMENT
Soils or other surficial materials transported or deposited
by the action of wind, water, ice, or gravity as a product of erosion.
SITE
Any tract, lot or parcel of land, or combination of tracts,
lots, or parcels of land which 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.
SITE DEVELOPMENT PLAN
The second of three required plan approvals that includes
the information necessary to allow a detailed evaluation of a proposed
project.
STABILIZATION
The prevention of soil movement by any various vegetative
and/or structural means.
STORMWATER
Water that originates from a precipitation event.
STORMWATER MANAGEMENT
For quantitative control, means 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, means a system of vegetative, structural,
and other measures that reduce or eliminate pollutants that might
otherwise be carried by surface runoff.
STORMWATER MANAGEMENT SYSTEM
Natural areas, ESD practices, stormwater management measures,
and any other structure through which stormwater flows, infiltrates,
or discharges from a site.
STRIPPING
Any activity which removes the vegetative surface cover including
tree removal, clearing, grubbing and storage or removal of topsoil.
VARIANCE
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
this chapter.
WAIVER
The reduction of stormwater management requirements by the
Town for a specific development on a case-by-case review basis.
WATER QUALITY VOLUME (WQv)
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, referenced in §
106-2 of this chapter.
WATERCOURSE
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.
WATERSHED
The total drainage area contributing runoff to a single point.
No person shall develop any land for residential, commercial, industrial, or institutional uses without having provided stormwater management measures that control or manage runoff from such developments, except as provided within this section. The stormwater management measures must be designed consistent with the Design Manual and constructed according to an approved plan for new development, or the policies stated in §
106-9 for redevelopment.
The following development activities are exempt from the provisions
of this chapter and the requirements of providing stormwater management.
A. Agricultural land management practices;
B. Additions or modifications to existing single-family detached residential structures if they comply with Subsection
C of this section;
C. Any developments that do not disturb over 5,000 square feet of land
area; and
D. Land development activities that the Administration determines will
be regulated under specific state laws, which provide for managing
stormwater runoff.
The Town of Denton Board of Appeals may grant a written variance from any requirement of Article
II, Stormwater Management Criteria, of this chapter if there are exceptional circumstances applicable to the site such that strict adherence will result in unnecessary hardship and not fulfill the intent of this chapter. A written request for variance shall be provided to the Town of Denton Board of Appeals and shall state the specific variances sought and reasons for their granting. The Town of Denton Board of Appeals shall not grant a variance unless and until sufficient justification is provided by the person developing land that the implementation of ESD to the MEP has been investigated thoroughly.