1. Non-Standard County Roads (Maximum of 10 Lots)
   1. Surface: earth
   2. Minimal drainage
   3. Travel way minimum width determined on a per road basis
   4. Lot drainage is each owner’s responsibility
2. ​​​​​​​Secondary Rural Road (Maximum of four Lots)
   1. ​​​​​​​Surface: earth
   2. Minimal drainage (only roadside or sheet flow)
   3. Travel way minimum width of 18 feet
   4. Lot drainage is each owner’s responsibility
3. ​​​​​​​Primary Rural Road (Maximum of four Lots)
   1. Surface: earth, rock, or Pavement
   2. Minimal drainage with outfall (only for the Roadway)
   3. Travel way minimum width of 20 feet
   4. Lot drainage is each owner’s responsibility
4. ​​​​​​​Secondary County Road
   1. Surface: rock or Pavement
   2. Drainage plan required for property and Roadway system
   3. Open ditch drainage system
   4. Travel way minimum width of 22 feet
5. Primary County Road
   1. Surface: paved
   2. Curb and gutter
   3. Drainage plan required for property and Roadway system
   4. Enclosed pipe with limited open ditch drainage system
   5. Travel way minimum width of 24 feet

1. Secondary Rural Roads shall only be allowed outside of the Urban Growth Boundary (Rural Area).
2. Primary Rural Roads shall be allowed outside of the UGB (Rural Area)and within the UGB when one of the following conditions are met, as determined by the Public Works Director:
   1. The proposed road is a Cul-de-Sac or future expansion is limited; or
   2. The Lots being created are a minimum of five acres in size or the Design Professional demonstrates adequate Lot and Roadway drainage can be provided.
3. Secondary County Roads shall be allowed outside of the UGB (Rural Area). They are allowed inside the UGB (Urban/Suburban Area) when the following conditions are met, as determined by the Public Works Director.
   1. The proposed road is a Cul-de-Sac or future expansion is limited; or
   2. The Design Professional demonstrates that stormwater Best Management Practices can be utilized to satisfactorily address water quality requirements in conjunction with an open drainage system; and
   3. The Lots are of sufficient size to accommodate an open drainage system; and
   4. The road system is an expansion to an existing open drainage system.
4. Primary County Roads shall be allowed across the County, regardless of area.
5. All proposed Public roads shall connect to an existing public road that has been accepted by a public agency (county, municipality, or state). Connection to a Right-of-Way that has only been dedicated, but not accepted into a public maintenance system, shall be prohibited.
6. Streets within commercial and industrial Developments shall be designed as Primary County Standard Streets unless approved otherwise, in writing, by the Public Works Director.​​​​​​​

7. If a land Development plan exceeds the Non-Standard County Road (maximum of 10 Lots), utilizing the maximum, construction shall be required to improve the Non-Standard County Road to the required County standards from its point of connection to an existing County standard or State public road.

1. The landowner/Developer is responsible for informing prospective Property Owners, whether solicited or unsolicited, of all conditions and responsibilities, or lack thereof, that have been placed on the property.
2. If the access or drainage connects with a County Right-of-Way or Easement, an Encroachment permit shall be obtained prior to construction.

1. Prior to issuance of Zoning Permits forland Development activities other than construction of ingress/egress Easements and private Rights-of-Way, installation of required Street Signs, Additions/renovations to existing Structures that are legally permitted, and new construction of Accessory Structures, all ingress/egress Easements and private Rights-of-Way shall be:

   1. Constructed in the location shown on the approved, recorded Plat;

   2. Constructed to comply with the International Fire Code, as adopted by County Council, from their point of connection to an existing publicly owned and maintained Right-of-Way to Lot(s) proposed for Development; and

   3. Inspected pursuant to Sec. A.2.7, County Inspection, of this Ordinance.

2. The Directors of the Zoning and Planning Department may allow use of a portion of an ingress/egress Easement or private Right-of-Way that was constructed prior to July 18, 2017 that cannot comply with the width clearance requirements of the International Fire Code when: (1) the Director determines that moving it to a different location is not possible due to site constraints, property size, Grand Trees, wetlands, etc.; (2) the Applicant submits letters from the providers of emergency services for the Subject Properties stating they can access all properties utilizing it; and (3) all future portions shall comply with the International Fire Code.

Private Rights-of-Way serving five or more Lots must be dedicated to a Homeowners’ Association. Private Rights-of-Way serving fewer than five Lots may be dedicated to an individual or entity other than a Homeowners’ Association. Charleston County is neither obligated nor responsible for private Right-of-Way maintenance.

1. Providing the County complete Roadway and/or drainage system plans for the proposed Development.
2. Securing licensed, professional personnel to prepare designs acceptable to the County;
3. Overseeing and coordinating the presentations, reviews, and revisions of the designs with the appropriate agencies, and obtain required approvals and permits;
4. Providing field staking of the designs during the construction phase;
5. Coordinating County encroachment permit approval and subsequent inspections with the Public Works Department.
6. Once the improvements proposed for public Dedication are constructed, inspected, and approved by the County, the landowner/Developer shall provide as-built record drawings, record Plats, etc. to the Public Works Director prior to final County acceptance of publicly dedicated roads. As-built record drawings must comply with Section A.6.2, Survey As-Built Checklist and Instructions, and shall be submitted to the Public Works Department for review and approval. Once the as-built drawings are approved by the Public Works Department, the public Dedication request will be scheduled for a County Council Committee meeting for recommendation and subsequent County Council meeting for final determination. Final Plats that include public Dedications of roads and/or drainage will not be recorded until and unless County Council approves the Dedication request(s) and all conditions of such approval are addressed prior to Final Plat recording.

1. Required Right-Of-Way. The minimum Right-of-Way width is 50 feet.
2. Required Minimum Street Section. Streets shall be constructed to minimum earth Street standards and have a minimum travel way width of 18 feet.
3. Required Minimum Street Elevations. The minimum Street centerline elevation at finish Grade shall be 6.5 feet above NAVD 88.
4. Required Minimum Profile Gradient. The minimum Street profile centerline gradient shall be 0.4% except for causeways where land areas adjacent to the road embankment are jurisdictional wetlands or OCRM Critical Area.
5. Street Centerline Minimum Curve Radius Criteria. Street centerline curve radii shall meet AASHTO guidelines for the design speed limit.
6. Where Streets are designed for a speed limit lower than 30 mph, the Design Professional shall provide supporting design data, including traffic control signage.
7. All roads shall be designed with a minimum road centerline radius of 125 feet.
8. Horizontal sight distances shall be considered in the design process.
9. Vertical curves shall have a minimum length of 100 feet.

1. Required Right-Of-Way. The minimum Right-of-Way width is 50 feet.
2. Required Minimum Street Section. Streets shall have a minimum travel way width of 20 feet. The travel surface shall be at least equal to the type of surface with which it is being connected (Pavement, rock, or earth). If Development characteristics warrant, the Public Works Director can approve a reduction in the surface type. Written requests for a reduction in surface type shall be directed to the Public Works Director with an accompanying justification statement.
3. Required Minimum Street Elevations. The minimum Street centerline elevation at finish Grade shall be 6.5 feet NAVD 88.

4. Required Minimum Profile Gradient. The minimum Street profile centerline gradient shall be 0.4% except for Causeways where land areas adjacent to the road embankment are jurisdictional wetlands or OCRM Critical Areas.

5. Street Centerline Minimum Curve Radius Criteria. Street centerline curve radii shall meet AASHTO guidelines for the design speed limit.

6. Where Streets are designed for a speed limit lower than 30  mph, the Design Professional shall provide supporting design data, including traffic control signage.

7. All roads shall be designed with a minimum road centerline radius of 125 feet.

8. Horizontal sight distances shall be considered in the design process.

9. Vertical curves shall have a minimum length of 100 feet.

1. The drainage system or the obstacle cannot be easily relocated;
2. Adequate and safe operational Easement space for maintenance by mechanized equipment is provided;
3. The drainage way is not obstructed; and
4. The Drainage Easement width is increased to accommodate the obstructions.

1. Required Right-Of-Way. The minimum Right-of-Way width is 50 feet, however; the road Right-of-Way width may be altered as approved by the Public Works Director, but must be of sufficient width to provide for the following:
   1. Drainage;
   2. Pavement or rock travel way;
   3. Shoulders;
   4. Signage;
   5. Trees; and
   6. Utilities such as Street lights and overhead/underground Utility lines (electric, telephone, cable TV, gas, water, and Sewer).
2. Required Minimum Street Section. Streets shall have a minimum travel way width of 22 feet. The travel surface shall be at least equal to the type of surface with which it is being connected (Pavement or rock). If Development characteristics warrant, the Public Works Director can approve a reduction in the surface type. Written requests for a reduction in surface type shall be directed to the Public Works Director with an accompanying justification statement.
3. Required Minimum Street Elevations. The minimum Street centerline elevation at finish Grade shall be 6.5 feet NAVD 88.
4. Required Minimum Profile Gradient. The minimum Street profile centerline gradient shall be 0.4% except for Causeways where land areas adjacent to the road embankment are jurisdictional wetlands or OCRM Critical Areas.
5. Street Centerline Minimum Curve Radius Criteria. Street centerline curve radii shall meet AASHTO guidelines for the design speed limit.
6. Where Streets are designed for speed limits lower than 30 mph, the Design Professional shall provide supporting design data, including traffic control signage.
7. All roads shall be designed with a minimum road centerline radius of 125 feet.
8. Horizontal sight distances shall be considered in the design process.
9. Vertical curves shall have a minimum length of 100 feet.

Outfall ditches to wetland areas shall be piped for a minimum length of 20 feet at their outfall ends, or an alternative means of defining wetlands’ limits for maintenance identification purposes shall be submitted for consideration.

1. The drainage system or the obstacle cannot be easily relocated;
2. Adequate and safe operational Easement space for maintenance by mechanized equipment is provided; 
3. The drainage way is not obstructed; and
4. The Drainage Easement width is increased to accommodate the obstructions.

1. Required Right-Of-Way. The minimum Right-of-Way width is 50 feet; however, the road Right-of-Way must be of sufficient width to provide for the following:

   1. Drainage;

   2. Pavement and curb and gutter;

   3. Shoulders;

   4. Trees;

   5. Signage;

   6. Sidewalks where installed (or required); and

   7. Utilities such as Street lights and overhead/underground Utility lines (Electric, telephone, cable TV, gas, water, and Sewer).

2. Required Minimum Street Section.

   1. Streets shall be constructed as Paved Streets and conform to details in Art. A.6, Standard Construction Details.

   2. Streets shall be constructed with curb and gutter; and

   3. Streets shall have a minimum travel way width of 24 feet.

3. Required Minimum Street Elevations. The minimum Street centerline elevation at finish Grade shall be 6.5 feet NAVD 88.

4. Required Minimum Profile Gradient. The minimum Street profile centerline gradient shall be 0.4% except for Causeways where land areas adjacent to the road embankment are jurisdictional wetlands or critical areas. Additionally, for Streets using an asphalt gutter, a minimum centerline gradient of 0.5% is required.

5. Street Centerline Minimum Curve Radius Criteria. Street centerline curve radii shall meet AASHTO guidelines for the design speed limit.

6. Where Streets are designed for speed limits lower than 30 mph, the Design Professional shall provide supporting design data, including traffic control signage.

7. All roads shall be designed with a minimum road centerline radius of 125 feet.

8. Horizontal sight distances shall be considered in the design process.

9. Vertical curves shall have a minimum length of 100 feet.

1. Concrete Curb and Gutter. Either upright Curb and gutter or roll Curb and gutter may be used (see details in Art. A.6, Standard Construction Details). If upright Curb and gutter is utilized, driveway entrances for Subdivision Lots shall be shown on the construction plans and constructed as part of the Development. The distance between expansion joints unless specified otherwise herein, shall be in accordance with the CTC (SS) or the SCDOT (SS).
2. Asphalt Curb and Gutter. Asphalt curb and gutter sections shall be submitted for approval. All work, materials, methods, and equipment, unless specified otherwise herein, shall be in accordance with the CTC (SS) or the SCDOT (SS).

General Requirements for Design of Drainage Systems. The design of drainage facilities for a Development must be done with consideration being given to the entire drainage basin. Provisions must be made to receive and manage runoff from upstream areas and to ensure that downstream areas are not adversely impacted by discharges or runoff. The current zoning of upstream properties and associated runoff factors representing that land use, assumed to be fully developed, shall be used in determining design runoff rates and quantities. It is not to be assumed that existing developed properties without storm water Detention systems will have them in the future. Also, drainage design requirements for the entire Development shall conform to Sec. A.4.2, Drainage Design.

1. Where pipe under drains are required, their centerline shall be located 2.5 feet, at a minimum, behind the back of the Curb and they shall be properly connected to a permanent drainage outlet, such as a catch basin, junction box, or a manhole.
2. Piped under drains shall conform to the under drain details in Art. A.6, Standard Construction Details. Under drain inverts shall be a minimum of 24 inches below the bottom of the Curb and above any static lake/pond elevation.
3. Suitable outlets for the pipe under drains shall be provided in the drainage system design.
4. Pipes under drains shall be installed at low points in the Grade on both sides of the Street for a minimum distance of 100 feet in each direction along the Street; except at locations where the design engineer can demonstrate to the satisfaction of the Public Works Director that the water table will not be within 24 inches of centerline Subgrade elevation.
5. Pipes under drains, where required, shall be installed before the Base Course is placed.
6. Pipes under drains shall be placed in other locations as determined by the Design Professional or as required by the Public Works Director during construction.
7. Pipes under drains shall be properly laid on Grade and in accordance with these specifications and the CTC (SS) or the SCDOT (SS) and shall not be covered until they have been inspected and approved by the Charleston County Public Works Department.
8. Alternative under drain designs shall be presented to the Public Works Director for review and approval.

1. Trees are healthy, of aesthetic value, and are firmly rooted with the base of the Tree being at or near the elevation of the Curb or edge of Pavement.
2. The distance from the back of the Curb to the nearest face of the tree is not less than 5 feet.
3. Additional Right-of-Way is provided where necessary.
4. Where under drains are required, the Tree(s) shall be removed or the Right-of-way shall be relocated.

1. The drainage system or the obstacle cannot be easily relocated;
2. Adequate and safe operational Easement space for maintenance by mechanized equipment is provided;
3. The drainage way is not obstructed; and
4. The Drainage Easement width is increased to accommodate the obstructions.

In the event a Street name Sign is requested on an approved County road, approval must be obtained from the County Public Works Department. Details and color-coding are indicated in Art. A.6, Standard Construction Details.

1. Causeways. Streets to be constructed on Causeways shall meet all of the requirements contained within these specifications and the Causeway shall also meet the following requirements:
   1. The minimum Street centerline elevation at finish Grade shall be 6.5 feet above NAVD 88.
   2. The minimum side slopes shall be 2:1, preferably 3:1(Horizontal/vertical).
   3. The minimum top width of the Roadway shall be as defined by the road classification plus 6 foot wide shoulders (as measured from the edge of travel way to the face of the guide rail) if SCDOT standard guide rails are constructed. If no guide rails are constructed, 9 foot wide shoulders shall be required on each side of the travel way.
   4. The Developer shall provide copies of the approved permits or application ID numbers from all applicable regulatory agencies should expanding the Causeway roadbed beyond the toe of the original roadbed be required.
2. Bridges. Bridges shall be designed in accordance with the AASHTO Standard Specifications for Highway Bridges, current edition and interims, as well as meet the following requirements:
   1. HS 20-44 loading or an alternate military loading, whichever produces the greatest stress.
   2. The minimum travel way centerline elevation shall be 6.5 feet NAVD 88.
   3. The minimum width of the Bridge shall be 24 feet clear Roadway width.
   4. The minimum clear width for all Bridges on Streets with curbed approaches should be the same as the Curb to Curb width of the approaches, but not less than 24 feet clear Roadway width.
   5. For Streets with shoulders and no Curbs, the clear Bridge width preferably should be the same as the Roadway width. However, in no case should it be less than 24 feet or the travel way width plus 2 feet on each side, whichever is greater.
   6. Pedestrian ways on the approaches shall be carried across all new Structures.
   7. SCDOT standard guide rails shall be required.
   8. All Bridges shall be concrete Structures supported on concrete piles.
   9. The Developer shall provide copies of approved permits from applicable regulatory agencies for the construction of Bridges.
   10. The Public Works Director may consider design alternatives to the aforementioned standards. Any request for design alternatives must be submitted in writing and include details and justifications for each requested alternative. Written approval by the Public Works Director of the requested alternative is required prior to proceeding with construction.
3. Stub Streets. Stub Streets extending to the boundary or property line of the Subdivision shall be constructed simultaneously with the other Streets in the Development and shall be constructed in the same manner.
4. Cul-de-Sac Streets. Cul-de-Sacs shall be provided at the terminus of closed end Streets with minimum dimensions as indicated below.
   1. Circular turnaround. See details in Art. A.6, Standard Construction Details.
   2. Y or T turnaround. Permissible only where a Cul-de-Sac Street serves 20 Dwelling Units or less and upon approval by the Public Works Director. The design engineer must demonstrate that the road configuration will allow both emergency and service vehicles to turn around.
5. Temporary Cul-de-Sacs. Temporary Cul-de-Sacs shall be provided when incremental road construction and/or phasing is requested by the Developer. Temporary Cul-de-Sacs shall be constructed as required by this section. Unpaved temporary Cul-de-Sacs shall require an additional 2 inches (compacted depth) of base course.
6. Construction Access. The Design Professional shall identify the development's construction access routes and submit its proposed road section and surface course design for approval by the Public Works Director.
7. Inverted Crown Roads. Roads designed or constructed with inverted crowns shall not qualify for public road acceptance by County Council.

1. Asphalt Sidewalk. An asphalt sidewalk shall have a minimum asphalt thickness of 1-1/2 inches and a minimum base course thickness of 4 inches. The minimum width for pedestrian ways shall be five feet. All work, materials, methods, and equipment, unless specified otherwise herein, shall be in accordance with the CTC (SS) or the SCDOT (SS). For additional ADA requirements see Sec. A.4.1.D.2, Bridges.
2. Concrete Sidewalk. A concrete sidewalk shall have a minimum thickness of 4 inches except at driveways where the minimum thickness shall be 6 inches. Transverse expansion joints shall be placed at intervals of not more than 50 feet. The minimum width for pedestrian ways shall be five feet. All work, materials, methods, and equipment, unless specified otherwise herein, shall be in accordance with the CTC (SS) or the SCDOT (SS).

1. Earth Roads. The County standard earth Roadway is identical in cross section to a County standard paved road except that roadbed stabilization may require that material be mixed into the existing soil material, as needed, to a depth of 6 inches to achieve suitable compaction. The crown shall be 6 inches. County Public Works’ inspectors will determine whether the prepared Subgrade material and earth road overlay soil are acceptable.
   1. A suitable soil is required for a minimum depth of 18 inches to provide a Street that will serve the traffic needs in extremely dry, normal, and in wet weather. Where necessary, a stabilizing type soil shall be added and properly mixed with the soil in place for a depth of not less than 0.6 inches.
   2. Earth roads, when intersecting with an existing paved road, shall have a paved apron extending 20 feet to the paved road’s Right-of-Way and when intersecting with a rocked road, shall have a rocked apron extending to the rocked road’s Right-of-Way.
2. Rock Roads. The County standard rock Roadway is also identical in cross section to a County standard paved road except that the Subgrade is mixed with a 4-inch minimum aggregate Base Course worked into the top 2 inches of the existing Subgrade, creating a 6-inch deep compacted rock surface, meeting the CTC (SS) or the SCDOT (SS). The road crown shall be a minimum of 6 inches. The rock material shall be Crusher-Run granite aggregate unless otherwise approved by the Public Works Director.

   Rocked roads, when intersecting with an existing paved road, shall have a paved apron extending 20 feet to the edge of the paved road’s Right-of-Way.

3. Paved Roads. The County standard paved Roadway is shown in detail in Art. A.6, Standard Construction Details. The County standard asphalt Pavement is a minimum 2-inch compacted hot plant mix asphaltic concrete meeting the CTC (SS) or the SCDOT (SS) type one, or equal. Asphaltic concrete material is to be placed on a minimum compacted Base Course meeting the CTC (SS) or the SCDOT (SS), and an approved Subgrade (see Pavement design below).

1. Pavement Base and Surfaces Courses. The Base Course shall meet the CTC (SS) or the SCDOT (SS). The width of the Base Course shall be 12 inches greater than the width of the surface course; i.e., 6 inches on each side of the Roadway. The compacted depth of the Base Course shall be 6 inches or greater as approved by the Public Works Director. After the Base Course has been properly blended, mixed, wetted, shaped, and compacted to the approved typical section and has been seasoned sufficiently and proof-rolled, the surface course shall be applied.
   1. Proof-rolling shall be accomplished as described in the CTC (SS) or the SCDOT (SS) for the proof-rolling of the Subgrade except that the minimum total weight of the testing vehicle shall be in the 30-35 ton range.
   2. The surface course materials, placement, and protection shall meet the requirements of the SCDOT (SS) type C or equal. The compacted depth of the surface course shall be no less than 2 inches or greater as approved by the Public Works Director. Weather and seasonal restrictions to placement of the bituminous materials are described in the CTC (SS) or the SCDOT (SS).
2. Pavement Section for Typical Residential Roadway. The County standard asphalt Pavement section for use on residential Roadways is a minimum 2-inch compacted hot plant mix asphaltic concrete meeting the CTC (SS) or the SCDOT (SS), type one or equal. This material is to be placed on a 6-inch minimum compacted Base Course and an approved Subgrade. A prime coat meeting the CTC (SS) or the SCDOT (SS) is required when the Base Course will not be paved within two weeks.

   Roadways serving large residential areas or phased Subdivisions may require Pavement designs, exceeding the minimum requirements, as determined by the Public Works Director.

3. Pavement Design for Commercial/Industrial Use Roadways. The design engineer shall provide a Pavement design for all Roadways that serve commercial and industrial uses. The design shall include at a minimum 2 inches of compacted hot plant mix asphaltic concrete meeting the CTC (SS) or the SCDOT (SS) type one, or equal, and a minimum 6 inches of compacted Base Course meeting the CTC (SS) or the SCDOT (SS), with an approved Subgrade. The Pavement design shall include information on anticipated traffic counts, traffic loadings, and site-specific soils. Further, the Public Works Director may require other pertinent information. A site-specific geotechnical report prepared by a Geotechnical Engineer shall be provided to substantiate/justify the proposed design for the entire length of the Roadways to be constructed. A prime coat meeting the CTC (SS) or the SCDOT (SS) is required when the Base Course will not be paved within two weeks.
4. Alternative Pavement Designs. The County will consider alternative Pavement materials designs. The Design Professional should present appropriate design data including laboratory tests of foundation soils to substantiate/justify the proposal.

1. Soil Testing. The Public Works Director will determine the quality of foundation soils by visual observations and adequate soil testing provided by the Design Professional. Without such testing, the Public Works Director will utilize judgment and experience to determine the quality of the foundation material and shall require appropriate action including, but not limited to, undercutting or mucking and replacing the excavated material with suitable earth materials.
   1. The soil-testing program shall be presented to, and approved by, the Public Works Director prior to the beginning of the testing. The testing program shall show the number and approximate locations of borings, sampling depths, and type of test to be made. Ample notice of testing schedules shall be given and a copy of all results, including recommendations, shall be provided upon completion of the tests.
   2. The testing program may establish levels or degrees of testing. For example, the testing program may call for a minimum number of tests for determination of general soil classifications and water table data for preliminary site evaluation. For the design of Pavement, the testing program shall include, but is not limited to, the determination of the maximum elevation of the groundwater table, the soil classification according to the Unified Soil Classification System (laboratory test determination), and the California Bearing Ratio (CBR) (laboratory test determination utilizing 96 hour saturation). Proctor testing for determination of optimum moisture and maximum Density using the modified Proctor-Test ASTM D l557 Method A, and field moisture and Density tests may be required by the Public Works Director.
2. Grading. Streets shall be graded to the designed typical section in accordance with the approved plans and profiles. Grade stakes shall be set on centerlines at intervals of not more than 100 feet on tangent Grades and not more than 50 feet on vertical curves. Additional Grade stakes may be required to ensure that the final Grade matches the designed typical section in the profile.
   1. Grading work, materials, methods, and equipment, unless approved otherwise, shall be in accordance with the requirements of the CTC (SS) or the SCDOT (SS).
   2. No base or surfacing materials shall be placed before the Subgrade is inspected and approved by the Public Works Director.
   3. In general, soils classified lower than “SC,” according to the Unified Soil Classification System, are not acceptable for the upper 24 inches of the Subgrade.
   4. The compacted Subgrade shall be proof-rolled prior to placement of any base or surfacing materials. Testing shall be performed in the presence of the Public Works Director. The testing procedure shall consist of driving a loaded tandem truck (10 cubic yard minimum load capacity, 30-35 ton minimum total weight), or other equivalent vehicle (as determined by the Public Works Director) at slow-walking speed longitudinally along the length of the Roadway test area. Any areas exhibiting pumping or breaking of the surface shall be stabilized or removed to appropriate depth and replaced with suitable material, recompacted, and retested.
3. Subgrade. Work shall consist of the construction and preparation of the Subgrade - that part of the Roadway intended to receive the Base Course, Pavement, pedestrian way, Curb, Curb and gutter, and/or shoulders.
   1. Roads shall be graded to the designed typical section in accordance with the approved plan and profile, and shall be free of roots, trash, and other unsuitable materials for a minimum depth of 24 inches below the finished Subgrade.
   2. A suitable soil is required for a minimum depth of 18 inches immediately below the Base Course to provide a road that will serve the traffic needs in extremely dry, normal, and in wet weather. Where necessary, a stabilizing type soil shall be added and properly mixed with the soil in place for a depth of not less than 6 inches.
   3. When unstable material is encountered and it is necessary to perform mucking work, the Roadway shall be mucked for its entire width, ditch line to ditch line or extending 2 feet beyond the backs of Curbs; backfilled with a suitable, stable-type soil; and properly compacted. All objectionable loose rock or boulders shall be removed or broken off to a depth of not less than 24 inches below the surface of the Subgrade.
   4. The Subgrade is to be sufficiently wetted and shall be compacted for a width extending 2 feet outside the edges of the proposed Pavement before the Base Course is placed.
   5. The Subgrade, from a distance of 24 inches outside the area to be occupied by the Pavement or Curb and gutter, shall be compacted to not less than 98 percent of maximum Density. The compaction shall be accomplished by using suitable construction procedures with the Subgrade at optimum construction moisture content. Sprinkling to secure proper compaction may wet the Subgrade. ASTM D 1557 Method A will determine maximum densities.
   6. The Subgrade shall be maintained in a smooth and compacted condition, free from ruts and depressions, and shall be adequately drained. In no case shall any base, surface course, or Pavement be placed on a frozen, muddy, or unstable Subgrade. Storing or stockpiling of materials directly on the Subgrade will not be permitted except with the approval of the Public Works Director.
4. Seeding and Mulching. All unpaved areas within the Right-of-Way shall be seeded and mulched. The Developer shall be responsible for maintenance of such seeded and mulched areas as described in the CTC (SS) or the SCDOT (SS) until the Street and/or drainage system is accepted into the County maintenance system.

1. Pipeline discharge capacities shall exceed maximum peak runoff rates. Ponding or head pressure shall not be considered in pipeline size determination. Computations for all drainage way size determinations shall be provided to the Public Works Director. Drainage ways located laterally off of the Street should be piped to the back Lot Line or for the first 150 feet from the Street Right-of-Way line, whichever comes first.
2. Where a drainage outlet pipe extends into a lake or other similar outlet, rip- rap shall be placed under and around the end joint or joints of pipe as needed and on slopes at the end of the pipe.
3. Minimum longitudinal slope shall be 0.4% except where specifically approved in writing by the Public Works Director.
4. Submerged piping or partially submerged piping shall not be used unless where specifically approved in writing by the Public Works Director. Submerged pipe systems shall require a means of accessing the submerged pipe for maintenance purposes.
5. Catch basins or junction boxes shall not be located within the radius portion of Street intersections. No manhole covers or water valves will be located within the Curb or gutter area or within the paved area of the Roadway.
6. To allow for backfill and compaction operations, a 2-foot minimum horizontal clearance between pipelines or Structures shall be provided. Reinforced concrete or rip rap of a material and gradation approved by the Public Works Director shall be placed at the ends of all culverts, bends, or junction points in drainage ways and/or other locations as determined by the Public Works Director (see details in Art. A.6, Standard Construction Details).

1. Where drainage ways are piped, catch basins shall be provided as required to appropriately receive and discharge incoming drainage. In no case shall the catch basins be more than 300 feet apart.
2. Junction boxes with stubs shall be constructed at both ends of cross-line pipes for cross-ditches, at the outlet end of cross line pipes at outlet ditches, and at other locations as appropriate. Reinforced concrete pipes of the required sizes shall be used for all inlet and outlet stubs. Stub pipes of the required sizes shall be used to convey the Street ditch drainage into the junction boxes and the inlet invert of the stub shall normally be installed approximately 0.3 feet below the Street ditch Grade. Stub pipes shall be extended a minimum of 20 feet from the junction box to provide maintenance vehicle access to maintenance shelves along outfall ditches.
3. For minor swale ditches of 1-foot depth or less alongside or Rear Lot Lines that only drain a small interior area and where Street drainage is not involved, a Drainage Easement not less than 15 feet in width may be utilized.

1. All concrete pipes shall conform to A.S.T.M. Specifications C-76, Class III, Wall B. Joints shall conform to A.S.T.M., C-443. Jointing materials shall be all-weather preformed joint sealant.
2. Other piping materials may be considered. Specifications should be submitted to the Public Works Director along with the design data and construction plans showing the specific intended use. Materials and methods approved by the SCDOT will be considered upon submittal of SCDOT documentation and recommendations pertaining to the use of such materials.
3. Ample cover shall be provided to properly protect pipelines during construction as well as for designed usage. Minimum allowable cover for pipe at Subgrade shall be not less than 6 inches for paved areas, and 12 inches for unpaved areas and in no case less than that recommended by the manufacturer.
4. Minimum cover for other materials and usages shall be considered at the time of submittal of construction plans to the Public Works Director.
5. All Structures shall be shown clearly on the construction plans with details to show all lines, Grades, elevations, joints, reinforcing, materials of construction, etc. All appropriate specification data shall be shown on the construction plans.
6. Junction boxes, Curb inlets, outfall boxes, or any other enclosed drainage Structure exceeding 4 feet 6 inches in depth shall be constructed with interior step fixtures.
7. Precast concrete Structures will be considered. Design and specification data should be submitted to the Public Works Director along with the design and construction plans showing the specific intended use.
8. A performance bond guaranteeing restoration work must be posted with Charleston County and remain in effect for a period of two years from the date of acceptance of the restoration work (date of release by the Director of the Department of Public Works). This bond must be in a format approved by the County Attorney and in accordance with terms and conditions of CHAPTER 8, Subdivision Regulations.

1. The encroaching entity will submit all permit requests on the Charleston County APPLICATION FOR ENCROACHMENT PERMIT FORM for review. Application fees will be in accordance with current Charleston County User Fee schedules. Permit applications will be reviewed and issued comments, approved, or denied by the Public Works Director within 30 days of receipt.
2. If, in the opinion of Charleston County, the South Carolina Department of Transportation, or any other public agency, it should ever become necessary to relocate or remove the Encroachment, or any part thereof, due to the improvement, relocation, or widening of the road, Street, or drainage system, or for any other reason, such Moving or removing will be done on demand of the Public Works Director at the expense of the permittee.

3. The Public Works Director may require the removal of unpermitted Encroachments (driveways, piping of any kind, physical Structures, etc.). The Landowner/Developer will be notified of the illegal Encroachment by letter and will be given 30 days to remove the unpermitted Encroachment or obtain a permit. Should the encroachment not be removed or permitted within this timeframe, Charleston County, or an agent of the County, will remove the Encroachment at the expense of the Landowner/Developer.

4. Encroachment permits may be issued with a provision requiring Charleston County staff, or agents of the County, to inspect the installation of the encroaching Structure. Failure to notify Charleston County of installation will nullify the Encroachment permit.

5. Adequate provisions shall be made for the protection of the traveling public at all times when performing work under an Encroachment permit. During the progress of the work, all necessary detours, barricades, warning Signs, and flagmen will be provided by, and at the expense of, the permittee to ensure safety.
6. Restoration work shall be immediately accomplished to return the road and/or drainage system to prior condition or better. The liability of the permittee will not be released until all work is inspected and approved by the Public Works Director.

7. Any proposed infrastructure encroachment into a public Easement which crosses a parcel boundary shall be accompanied with written permission from affected landowner(s).

8. Encroachments shall not cause increases to surface water elevation, either upstream or downstream of the Encroachment, during the 100-year, 24-hour rain event. This is further described within the Charleston County Stormwater Program Permitting Standards and Procedures Manual.

1. Driveway encroachment permit applications shall be designed in accordance with Art. A.6, Standard Construction Details. Residential driveway widths shall be limited to a minimum 12 feet and maximum 20 feet. Driveways shall not be located closer to the outside travel lane of an intersection than two times the driveway width plus 22 feet (2w + 22). Driveway aprons shall be at least equal to the type of surface with which it is being connected (Pavement, rock, or earth). The permittee may be required to provide as-built information for the driveway, and up to one driveway Culvert upstream and one driveway Culvert downstream.

2. The piping of open conveyances shall be sized appropriately to accommodate the drainage of upstream and downstream flow. A minimum of one 4-foot by 4-foot junction box or inlet shall be required to accept Roadway sheet flow, though more may be required at the discretion of the Public Works Director. Request for piping of roadside ditches may be rejected, at the discretion of the Public Works Director, based on site conditions.

3. Sprinkler Systems. Water-sprinkling systems shall not be allowed within the public Right-of-Way or Easement without an approved encroachment permit. Each application will be reviewed on a site specific basis by the Public Works Director.

4. The installation of physical Structures (including, but not limited to, Fences, Trees, Bridges, piping, landscaping beds, roads, driveways) shall require Encroachment permits. Charleston County Public Works reserves the right to deny Encroachment permit applications.

5. Landscaping and Planting. Installation of landscaping and planting shall require Encroachment permits. Each application will be reviewed on a site specific basis by the Public Works Director.
6. Subdivision Entrance Signs. Subdivision name Signs at entrances to Developments shall be in compliance with CHAPTER 9, Development Standards. Building Permits must be obtained prior to installation of such entrance Signs. Subdivision name Signs will be located outside the road right-of-way except those Signs located within a Roadway median. All Signs shall be located outside of horizontal sight distance. Such signs, foundations for future signs, and conduit for electrification of signs shall be shown on the construction plans and an encroachment permit obtained prior to construction. Approval of the plans by the Public Works Director does not imply or guarantee the approval of other entities.
7. Utilities. The proposed concept for the location of all underground Utility lines, including water, sanitary Sewer, gas, electrical, telephone, or television cables, shall be shown utilizing typical Street plans, cross sections, and profiles. Non-typical locations, such as areas around Trees, shall be shown in sufficient detail for review and approval. Utility lines shall be located so that they will not interfere with the proper functioning of the drainage system. For Streets where the Curb and gutter section is used, underground Utility main lines shall be a minimum of 5 feet behind the back of the Curb. For Streets where the swale ditch section is used, Utility main lines shall be installed not less than 15 feet from the centerline of the Street and not less than 5 feet from the edge of the Pavement.
   1. Utility encroachments shall only be allowed within roads meeting the classifications of Secondary Rural Road, Primary Rural Road, Secondary County Road, and Primary County Road.
   2. The minimum allowable cover over the top of the Utility Encroachment or other apparatus shall be 36 inches. Deviations to the 36 inches cover requirement must be presented in the cross section format along with a written justification and submitted to the Public Works Director for approval.

   3. Proposed Utilities and existing stormwater Infrastructure must be vertically separated by a minimum of 36 inches. Deviations from this requirement must be presented in the cross section format along with a written justification and submitted to the Public Works Director for approval. Additional Utility protection, or notification, may be required.

   4. No work on Utility lines within the limits of the proposed publicly-maintained Rights-of-Way shall commence until the Street plans showing the proposed locations of the Utility lines have been approved. In case any Utility location is not provided, the Developer shall be responsible for notifying the Utility that installation work within the proposed publicly- maintained Right-of-Way or Drainage Easement will require the approval of the Public Works Director.
   5. Unapproved Utility work within the Right-of-Way or Drainage Easement will result in an immediate supervision of inspections until such time as the Utility plans have been reviewed and approved by the Public Works Director.
   6. Ditches and trenches dug within the Street Right-of-Way for Utilities and/or other purposes shall be properly backfilled per Art. A.6, Standard Construction Details. Backfill material shall be select material, mechanically compacted in 6-inch layers or flowable fill. Backfill material shall be mixed or wetted as required by the Public Works Director. Backfill under areas to be paved or areas within 5 feet of Pavement shall be compacted to no less than 98 percent of maximum Density. Remaining areas shall be compacted to 90 percent of maximum Density. ASTM D 1557 Method A will determine maximum densities.
   7. Where Utilities have been designed to be placed at a depth or location such that the repair of that Utility would adversely impact the flow of vehicular traffic, the Design Professional shall either address such concerns to the satisfaction of the Public Works Director or redesign the utility layout. At Grade, or above Grade infrastructure, shall not be placed within travel way, or drainage path, unless specifically approved by the Encroachment permit. The Landowner/Developer/Utility Provider may be required to obtain additional Right-of-Way, or Easement, to accommodate proposed Utility.
   8. Utilities crossing under the Street shall be at an angle of not more than 30 degrees from the perpendicular to the Street.
   9. The jetting or uncontrolled tunneling of utility lines under a Paved Street is not permitted. The cutting of the Pavement is not permitted except under extreme circumstances and only as permitted by the Public Works Director.
   10. Where Utilities are designed to be placed at a depth or location such that the repair of that Utility would adversely impact the flow of vehicular traffic, the Design Professional shall either address such concerns to the satisfaction of the Public Works Director or redesign the Utility layout. 
   11. Proposed Street lighting facilities shall be shown on the Street construction plans submitted to the Department of Public Works for approval. Street light poles shall be placed outside the Right-of-Way unless specifically approved by the Public Works Director.
   12. Fire hydrants shall be shown on the construction plans, located at the edge of the Right-of-Way within a few feet of the property corner of two adjoining Lots, or located as otherwise approved by the Public Works Director.
   13. When dry fire hydrants are required, permanent access shall be shown on the construction plans. Access design must provide adequate space and suitable surface materials for emergency vehicle maneuverability. The Design Professional shall submit written approval of the design from the local fire service provider.
   14. The Public Works Director will only permit Utilities other than drainage facilities within Drainage Easements upon specific written authorization.

   15. Encroachments of storm drainage pipes greater than 15 inches will require outfall protection with side slope stabilization for the full width of the ditch, swale, or canal (top of bank to top of bank), and upstream and downstream of the Encroachment for a minimum of 15 feet or greater in each direction, dependent on site conditions, and velocity of stormwater.

1. Any Utility, public agency, or other entity or person performing work in a County Right-of-Way or Easement must obtain an Encroachment permit prior to beginning any construction. The Applicant shall furnish information on the Encroachment permit application detailing all work. Details on restoration of all disturbed areas or Utilities will also be provided on the Encroachment permit application.
2. Restoration work will return the road, drainage system, and any impacted Utilities to prior condition or better. The liability of the permittee will not be released until all work is inspected and approved by the Public Works Director.