Chapter 148
SUBDIVISION AND LAND DEVELOPMENT.
Section 148-42 STEEP SLOPES.
A. Purpose
Steep
slopes, when developed, require more
grading and land
disturbance than development of flat to gently sloping
topographical
areas. Therefore, the purpose of this
section is to establish protective regulations to:
1.
Minimize soil
disturbance on steep or critical slopes due to the potential for
erosion
problems;
2.
Assist in the
prevention of soil erosion from storm water runoff, protect downstream
buildings and yards from water and soil intrusion, and protect the
Town’s
surface and groundwater resources from siltation and contamination;
3.
Promote
stable building sites that prevent soil erosion and are structurally
sound so
as to maintain slope stability;
4. Promote accessibility for fire and rescue apparatus;
5.
Maintain the
visual and environmental resources that are part of the character of
Front
Royal; and
6.
Encourage
innovative development in Front Royal by providing the flexibility
necessary to
produce environmentally sensitive subdivisions which direct building,
parking
and street locations to terrain more suitable to development while
maximizing
conservation of the original slopes, native cover, prominent land
forms, rocky
outcrops, natural open space, wildlife habitat and scenic resources.
B.
Applicability
All
proposed subdivisions which result
in the creation of an additional building lot or lots with the
exception of
boundary line adjustments, must submit a plan, in addition to any
required
subdivision development, street construction or erosion & sediment
control
plan, identifying predevelopment areas of steep slope.
Clear cutting or grading
for the purpose of altering predevelopment slopes shall not be
permitted.
C.
Establishment of Steep Slope Areas
The
predevelopment slopes shall be
computed by rise over run from naturally occurring contour lines based
on
topographic information showing two foot contour intervals and based on
NAVD 88
vertical datum. The topographic data may
be field run or from aerial photography, provided the information is
current
and the contouring method provides the precision expected for the
contour
interval used.
1. Identification
of
Steep Slope Areas. Steep
slopes areas are classified into one of the following two categories:
a.
All areas of
slope between 15% and 25% which contain highly erodible, highly
permeable or
shrink-swell soils. Determination of
soils which are highly erodible, highly permeable or shrink-swell shall
be
based on the USDA Soil Conservation Service Soil Survey of Warren
County,
Virginia, or based on soils analysis prepared by a geotechnical
engineer or
other appropriate licensed professional.
b. All areas of slope greater than
25%.
2. Minimum
Size
of Steep Slope Area. Steep
slope standards do not apply to isolated
steep slope areas that are less than 5,000 square feet in land area. For the purposes of this provision, the
entire contiguous area of the steep slopes shall be included in the
minimum
size calculations, regardless of the number of individual lots or
different
land ownerships involved.
D.
Creation of Slope Overlays
The
plan identifying steep slopes and
critical slopes must include overlays over the entire tract involved
identifying by color coding the following:
1.
All areas of
slope between 15 to 25% which contain highly erodible, highly permeable
or
shrink-swell soils.
2.
All areas of
slope greater than 25%.
E.
Plan Requirements
An
overlot grading plan, prepared by a
professional licensed by the State of Virginia to prepare such a plan,
for the
development, management, stabilization and preservation of steep slope
areas
shall be prepared in accordance with the detail requirements of Town
Code
Section 148 and upon submission of a report by a certified soil or
geotechnical
engineer, and/or other appropriate licensed professional, indicating if
and how
the steep slope may be safely developed.
The
final subdivision plat showing any
lot or portion of any lot located within a steep slope overlay area
must
contain a note stating that the property shown hereon is subject to the
provisions of Section 148-42, Steep Slopes, of the
F.
Building Site Requirements
In
addition to the requirements of the
grading plan described herein, the plan shall include the following
standards:
1.
Site
development shall be designed in a manner that requires a minimum
amount of
alteration to the steep slope.
2. Existing vegetation shall be
preserved to the maximum extent possible.
3. No
finished
slopes are to be created with a final grade greater than 15% unless deemed feasible by a geotechnical
report.
4.
Residential
driveway grades exceeding 10% are not recommended.
Residential driveway grades greater than 10%
shall be constructed in conformance with Virginia Department of
Transportation’s (VDOT) standard CG-9 or other applicable entrance
detail
requirements. Commercial or industrial
driveway grades shall be constructed in conformance with VDOT standard
CG-11 or
other applicable entrance detail requirements. All driveways shall have
a
nonerodable surface treatment, such as asphalt or concrete pavement. Side slopes for driveway cuts shall not
exceed 25% (4:1) unless deemed feasible by a geotechnical report.
5.
Use of
retaining wall is encouraged to reduce the steepness of man-made slopes
and to
provide planting pockets conducive to vegetation and landscaping. All retaining walls shall require an
engineered design with the exception of non-tiered retaining walls with
level
backfill and no surcharge loading with a height of 24 inches (2.0 feet)
or less
from the finished grade. Retaining walls
shall not exceed 72 inches (6.0 feet) in height from the finished
grade,
however, the Town Council, at its discretion, may waive the maximum
height
requirement for retaining walls located within non-residentially zoned
areas. This provision is not intended to
preclude a structure’s foundation or basement wall or the creation of a
walkout
basement.
6.
Landscaping
and plantings shall be in accordance with Town Standards.
G.
As-Built Plan
Required
A
post
construction As-Built survey of the approved steep slope overlot
grading plan
shall be required prior to the issuance of an approved occupancy permit. The As-Built drawings shall clearly show any
changes or variations from the approved design, and if deemed
significant by
the Director, may require any such change or variation be brought into
compliance with the approved plan. The
As-Built
information shall be shown on the original plan and include the
following:
1.
Horizontal
variations greater than 1.0 foot should be shown dimensionally or
through plus
stations. Horizontal variations greater
than 5.0 feet should also show the graphic relocation of the object. Vertical elevation variations greater than
0.1 feet shall be provided for all shown design elevations.
2. All As-Built information shall be shown on
the original plan either as blocked in or drawn in a different text
style or
font from that as shown on the original plan.
3.
Each sheet of
the plan shall contain the words “AS-BUILT” in bold text on or near the
title
block.
4. Date, plan legend, bar scale and
north arrow.
5.
Retaining
walls. Indicate type and show elevations of the top of wall and the
lowest adjacent finished grade.
6. Curb cut, driveway and
material. Centerline grade of driveway
with spot elevations.
7.
Spot
elevations of graded areas to determine grade of finished slope. Highlight all areas of finished slopes
exceeding design grade by more than 1%.
8.
Horizontal
location with dimensions of all structures with dimensions including
porches,
decks, garages, etc. Show vertical
elevations of first floor and basement floor.
9.
Horizontal
and vertical location of roof drains, foundation drains and other
drainage
outlets. Locations of utility services.
10.
Location of required plantings.
11.
The final
as-built plan must be stamped by Licensed Land Surveyor or Professional
Engineer and include
certification that the
As-Built plan is substantially in conformance with the original plan. If a geotechnical report is used, the
appropriate licensed professional must certify that the As-Built is in
conformance with the report.
H.
Exemptions
Except
as otherwise provided herein, no
disturbance of steep slopes will be allowed except for the following
activities
which may be permitted by exemption from the Director of Planning &
Zoning:
1.
Utility
service lines, walkways, steps, landings.
2.
Emergency
action to remediate an unstable slope which poses an imminent threat to
health,
safety or welfare of the public.
3.
Normal
landscape maintenance or routine arboreal activities, including small
scale
planting of ornamental flowers or shrubs, and/or the removal of
diseased or
damaged trees, and/or the removal of undesirable trees, provided
revegetation
is in conformance with Town Standards.
4.
Disturbance
for public roadway or street
crossings, or other
public purposes as determined by the Director of Planning.
5.
Construction
of approved landscaping berms, drainage ditches or swales, ponds and
dams and
other required storm drainage conveyance facilities.
I.
Definitions
Slope:
The
steepness,
incline, gradient or grade of the natural incline of the ground
expressed as a
percentage based on computations of rise over run between existing
contours.
Slope,
Steep:
(1) Areas of slope of the natural incline of between 15% to 25% which
contain
highly erodible, highly permeable or shrink-swell soils. (2) Areas of
slope of
the natural incline greater than 25%.
Grading
Plan:
A map
or
drawing, other than a plat, prepared by the appropriate licensed professional, showing existing and
proposed topography, environmental controls, demolition and/or
improvements to
the property in accordance with the requirements of this ordinance
and/or other
applicable local, state or federal regulations.
As-Built
Plan:
A map or drawing, other than a plat, prepared by the appropriate
licensed
professional, showing existing post construction topography in
comparison to
the proposed site improvements shown on the approved site plan.
Overlot
Grading
Plan: See ‘Grading Plan’.
(Ord. No. 5-07 Amended (A-D) & Added (E-G) 2-26-07-Effective Upon
Passage)
(Ord.
No. 4-10 Amended Entire Section 4-26-10-Effective Upon
Passage)