The developer is responsible for submitting a stormwater management
plan and a narrative for each phase of the plan review process that
meets the design requirements of this chapter. The narrative and plans
submitted shall provide the necessary information to ensure that all
significant natural resources have been mapped and protected, all
opportunities to enhance natural areas have been explored, impervious
area minimized, nonstructural practices used, and the use of alternative
surfaces explored. Microscale practices should be used to capture
and treat runoff and structural practices may only be used when all
options for the use of environmental site design have been exhausted.
The developer shall certify on the final stormwater management plans
that all clearing, grading, drainage, construction, and development
shall be conducted in strict adherence with the plan. The developer
must submit a plan that under proposed development conditions maintains
the existing drainage patterns for each individual drainage area.
All reasonable efforts, utilizing ESD to the MEP, must be made to
avoid the redirection of runoff from a particular drainage area to
another drainage area. The minimum information for each phase of the
stormwater management plan approval process submitted for approval
shall include, but is not limited to, the following:
A. Concept plan phase. The owner/developer shall submit a concept plan that provides sufficient information for an initial assessment of the proposed project and ensure compliance with §
325-11 of this chapter and the Design Manual. Plans submitted for concept approval shall include the following minimum information:
(1) A map (minimum one-hundred-foot scale) showing the site location,
existing natural features, wetlands, streams, sensitive resources,
topography, soil boundaries, the natural drainage patterns, and the
one-hundred-year floodplain;
(2) Location of proposed and/or anticipated impervious areas (i.e., buildings,
roads, sidewalks, parking lots, driveways, etc.);
(3) Location of the proposed limit of disturbance (LOD), erodible soils,
existing slopes from 15% to 25%, existing slopes greater than 25%
and forested areas to be protected;
(4) Calculations to determine stormwater management requirements and
the selection of ESD practices to be used;
(5) Location of the proposed ESD practices to be used and all points
of discharge from the site;
(6) A soils report containing information generated from the Web Soil
Survey (http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx)
which includes the map unit symbol, map unit name, map unit acres
in the area of interest (AOI), percent of map unit in the AOI, the
map unit description for each soil type, the hydrologic soil group,
drainage class, hydric rating, depth to water table, unified soil
classification and parent material name;
(7) If the proposed site consists predominately of C and D soils, a preliminary
geotechnical study may be required to determine the location and feasibility
of proposed ESD practices. It will be the responsibility of the design
engineer to determine the level of detail required within the geotechnical
report to provide a feasible conceptual design;
(8) A narrative that supports the concept design and describes how ESD
will be implemented to the MEP. Any subsequent submissions must incorporate
a list of all comments received from all of the reviewing agencies/departments
and how each comment was addressed;
(9) Proposed sewage areas and wells;
(10)
Location of existing wells and septics within 100 feet of the
property line; and
(11)
Any additional information as specified in the Cecil County
Department of Public Works Stormwater Management Checklist.
B. Preliminary plan phase. Following concept plan approval by the Cecil
County Department of Public Works, and other appropriate departments
and/or agencies, the owner/developer shall submit a preliminary plan
that includes detailed designs for stormwater management and erosion
and sediment control practices. To ensure that all options for implementing
environmental site design have been exhausted, detailed designs, computations,
and grading plans must be submitted for a comprehensive review and
approval. Plans submitted for review shall include the following minimum
information:
(1) A map (minimum fifty-foot scale) showing existing natural features,
wetlands, streams, sensitive resources, existing topography, the natural
drainage patterns, and one-hundred-year floodplain;
(2) Final site layout with exact impervious area locations and acreages,
proposed grading (at two-foot intervals), delineated drainage areas
with all proposed points of discharge from the site, all required
easements, and the location of all environmental site design practices
and quantity control structures;
(3) Location of the proposed limit of disturbance (LOD) soil classifications,
erodible soils, steep slopes, and forested areas to be protected;
(4) Geotechnical investigation, including soil maps, borings, site-specific
recommendations, and any additional information necessary to justify
proposed design;
(5) Stormwater management volume computations to confirm the selection
of the environmental site design and structural practices being proposed;
(6) An erosion and sediment control plan that contains the construction
sequence, any phasing necessary to limit earth disturbances, impacts
to natural resources, an overlay plan showing the types and locations
of environmental site design and erosion and sediment control practices
proposed and any additional information as required by the Cecil Soil
Conservation District minimum plan requirements checklist;
(7) A narrative that supports the site development design, describes
how environmental site design will be used to meet the minimum control
requirements to the maximum extent practicable and justifies any proposed
structural stormwater management measure. The narrative must incorporate
a list of all comments received from all of the reviewing agencies/departments
and how each comment was addressed (Comments shall pertain only to
the environmental site design in each phase.);
(8) Location of existing wells and septics that are within 100 feet from
the property line;
[Amended 11-13-2012 by Ord. No. 2012-12]
(9) Proposed wells, septic reserve areas, septic tanks, pump tanks, sewer
lines, and percolation holes; and
(10)
Any additional information as specified in the Cecil County
Department of Public Works Stormwater Management Checklist.
C. Final plan phase. Following preliminary plan approval by the Cecil
County Department of Public Works and other responsible departments
and/or agencies, the owner/developer shall submit final construction
drawings for sediment and erosion control and stormwater management.
The stormwater management and sediment and erosion control plans must
receive final plan approval prior to the issuance of the grading and
building permits.
(1) Plans submitted for final approval shall be of sufficient detail
to allow all approvals and permits to be issued according to the following:
(a)
Final erosion and sediment control plans in accordance with
COMAR 26.17.01.05; and
(b)
Stormwater management construction plans and computations that
include sufficient information to evaluate the effectiveness of the
proposed design.
(2) Stormwater management construction plans submitted for review and
approval shall include the following minimum information:
(b)
Existing and proposed topography (at two-foot intervals) and
drainage areas, including areas necessary to determine downstream
analysis for proposed stormwater management facilities;
(c)
All proposed improvements (i.e., buildings, driveways, parking
lots, roads etc.);
(d)
All grading and location of all nonstructural and structural
environmental site design practices and quantity control structures;
(e)
The location of existing and proposed structures and utilities;
(f)
Proposed easements and rights-of-way;
(g)
The delineation, if applicable, of the one-hundred-year floodplain
and any on-site wetlands, streams, waterways and/or other sensitive
environmental resources;
(h)
Structural and construction details, including representative
cross sections for all components of the proposed drainage system
or systems, and stormwater management facilities;
(i)
All necessary construction specifications and details;
(j)
A sequence of construction;
(k)
Data for the total site area, disturbed area, new impervious
area, and total impervious area;
(l)
A table showing the environmental site design and unified sizing
criteria volumes required in the Design Manual;
(m)
A landscape plan sealed by a Maryland-registered landscape architect,
engineer, or land surveyor which meets all requirements of the SWM
Landscape Plan Guidance Manual;
(n)
All soil borings logs and locations shown on the plan;
(o)
An inspection and maintenance schedule;
(p)
Certification by the owner/developer that all stormwater management
construction will be completed in accordance with the approved plan;
(q)
Certification by the engineer that the design is in accordance
with this chapter and the Design Manual;
(r)
An as-built certification signature block to be executed after
project completion;
(s)
Proposed sewage areas, wells, septic tanks, pump tanks, sewer
lines, percolation holes, and existing wells and septic areas 100
feet from the property line;
(t)
Stormwater management computations, including but not limited
to the following:
[1]
Geotechnical investigations, including soil maps, borings, site-specific
recommendations, and any additional information necessary to support
the stormwater management design proposed;
[2]
Drainage area maps depicting predevelopment and post-development
runoff flow path segmentation and land use;
[3]
Hydrologic computations of the applicable environmental site
design and unified sizing criteria according to the Design Manual
for all points of discharge from the site;
[4]
Hydraulic and structural computations for all environmental
site design practices and structural stormwater measures to be used;
and
[5]
A narrative that supports the final stormwater management design.
The narrative must incorporate a list of all comments received from
all of the reviewing agencies/departments and how each comment was
addressed. Comments shall pertain only to the environmental site design
in each phase.
(u)
If any stormwater management measures are proposed to act as
sediment control devices during site construction, the plan must include
details for the conversion from sediment control phase to stormwater
management phase, with a note indicating that the timing of conversion
must be approved by the Department of Public Works, but generally
conversion will not be permitted between November 15 and April 1;
and
(v)
Any additional information as specified in the Cecil County
Department of Public Works Stormwater Management Checklist.
(3) If a stormwater management plan involves the direction or redirection
of some or all runoff off of the site, it is the responsibility of
the owner/developer to obtain from adjacent property owners any easement
or other necessary property interest concerning the discharge of water
prior to approval of the final stormwater management plan. Approval
of a stormwater management plan does not create or affect any right
to redirect and/or concentrate runoff onto an adjacent property without
that property owner's permission and the developer must secure
such permission at his cost.