Digital Data Submission Standards

January 7, 2008

Florence County has adopted geographic information systems (GIS) technologies to store, manage, and maintain spatially-related (geographic) data. The land development, engineering, and surveying communities have also embraced digital technologies in their respective professional communities. Because development plans are now created using computer aided design and drafting (CAD), it is the goal of Florence County to leverage such advanced techniques to expedite the design and plan review processes within the County. For such an effort to succeed, standards must be implemented to allow CAD data to be integrated into the County GIS while preserving the referential and positional accuracy of the original measurements.

All developments (residential and commercial) are required to submit preliminary (proposed) and final/as-built (plan of record) digital plans in accordance with the standards outlined below. Similarly, digital as-builts (plan of record) in accordance with the standards outlined below must be accepted by Florence County GIS Department or City of Florence Public Works Department prior to the scheduling of the final inspection and prior to the transfer of right-of-way maintenance duties and acceptance by Florence County. For commercial developments, a digital ‘as-built’ submission must be accepted by Florence County GIS Department or the City of Florence Public Works Department prior to the issuance of a certificate of occupancy.  Initially, approval of the submitted digital documents by the Florence GIS County Department or the City of Florence Public Works Department will be based on the minimum elements described below.  It is the goal of this program to have all submittals comply with an established set of standards by September 2009. 

These data submission standards are intended to improve the process of reviewing plans and help maintain a digital database of geographic information for the County. As the GIS program develops and foundation data are established, the County will be able to offer base layers to the development and engineering communities. The County understands that these GIS layers cannot be used for construction; however, the multiple layers of data are expected to provide potential users with descriptive information that will be invaluable in planning and property valuation.

The mission of the Florence County GIS Department and the City of Florence Public Works Department is to establish a foundation of geographic information to support community decision-making. The resulting foundation of fundamental geographic data elements will be a representation of features that comprise our community and is not intended to convey legal boundaries of any kind.

In addition to standard paper documents, each engineering document/plan delivered to Florence County or the City of Florence will be accompanied by several digital files relating to that submission. Digital files to be submitted include:

• • While the effective date for the Regulation requiring the digital data submission is September 1, 2007, the first 90 days will be used to develop the initial system and to submit documents for review and use, if possible.  As of January 14, 2008, the initial submittal requirements listed below will be required for approval actions to proceed.

• • For Sketch Plan submittals, a pdf document will be accepted.  The GIS Department or City Public Works will also accept and use a dxf document.  No other digital data will be required at this time.
• • For Development Plans, no digital documents are required at this time.  It is the goal of the Florence County GIS Department and the City of Florence Public Works Department to have a full set of digital documents for the Development Plan submitted at the time when requesting approval to proceed with construction.  These documents will be used to provide planning information for the Florence County Web Site and for E-911 addressing for emergency services during construction of the infrastructure.  Proposed date for this is September 2009. 
• • For Final Plat approval and Commercial As-builts:
• o Initially, the digital submission will be required for all major subdivisions, which will be defined as:
• • In Florence County, 10 or lots
• • In the City of Florence, 5 or more lots
• • A division of property with any new road
• o As of now, digital submission is optional for all other plans and plats.  However, the goal is to have all plats and commercial/industrial sites submitted digitally by September 2009.
• o For all submissions, South Carolina State Plan in grid will be used.  All other details are listed in the next section.
• o A completed original CAD drawing in .dxf and/or .dwg format named using the development name (ie. Earlewood_phases56.dxf). This file shall include all layers and graphic elements included in the submitted paper document (geography, text, legend, scale, labels, etc.). This file will include features classified in the standard layers defined in Appendix A. If the drawing contains layers that are not included in Appendix A or uses a different set of layers and names, then a list of these layers shall also be submitted (ASCII text file labeled: ‘subdivisionname_phasesXX_xlyrspec.txt’). The completed CAD drawing file shall contain text in standard fonts that can be read without third-party software.
• • Data will include any new site utilities (water and sewer to include manholes, hydrants, and values; storm drainage information including catch basin rims and inverts, pond sizes and locations, and any easements; any other underground utilities that the submitter was responsible for the design; other underground utilities, if known, will be submitted as “Possible” locations)
• • Building finished floor elevations will be provides, but site specific contour information is not required.  Elevation changes for any roads or utilities will be provided.
• • A metadata text file containing information listed in Appendix B. This file includes submittal information as well as technical parameters that may be necessary to review if problems in data conversion occur. The ASCII text file will be named using the following convention: (subdivisionname_phasesXX_meta.txt).

An ASCII text file containing elevation points. When submitting plans that include surveyed ground surfaces, a separate ASCII text file containing all elevation points shall be delivered. This file shall be named using the following convention: (subdivisionname_phasesXX_elev.txt)

To expedite the conversion of CAD data into the County GIS, the following requirements shall be met:

Submissions may be zipped and dropped at the Florence County Web Site (www.florenceco.org) by going to the Planning Home Page and clicking on the FTP name with the Subdivision name in the subject field and contact information in the body. If FTP is not preferred, standard transfer media will be accepted. Files will be stored on media approved by Florence County. Such media include floppy disk and CD-ROM. The submitted media shall be labeled with the title of the drawing (drawing file name), type of drawing (ie. As-built, Preliminary, etc.), project contact information (name, affiliation, phone number, etc.), and a submittal and file creation date.

All drawing elements shall be submitted referencing South Carolina State Plane (SCSP) Coordinates using grid. Features in drawing files that are stored in drawing units must be translated to represent real world locations as referenced by SCSP coordinates. As specified in the SC Code of Laws Chapter 2, Title 27 (The South Carolina Coordinate Act, amended 31Mar89), elements referencing SCSP (formally identified as the South Carolina Coordinate System) will utilize the North American Datum of 1983 – 1986 Adjustment (NAD83 [1986]) for horizontal control and be measured in International Feet (not US Survey Foot). Vertical control will reference the North American Vertical Datum of 1988 (NAVD88) and shall include measures using the US Survey Foot. The SCSP system includes a single zone identified as Federal Information Processing Standard zone 3900 (FIPS 3900). Caution must be exercised in performing all conversions involving submitted data to ensure the correct use of the International Foot. Errors in conversion can exceed four linear feet. It is not the intention of Florence County to replicate legal surveys. With this in mind, control of plan features may be tied to the SCSP system using traditional surveying or GPS methods. The method employed to gain geodetic control shall be identified in the submitted metadata file.  For this data, the Florence County GIS Department will assume data is collected and submitted at the Mapping Level of data collection.

Drawing features shall include layer names as indicated in Appendix A or as determined by the person making the submission. Features other than those thematically defined by the individual layer name/description shall not be included in that layer. Systems using numbered levels, such as Microstation, include a conversion table in the .dxf file creation process that can be used to specify named layers.  If not using the standard layers shown in Appendix A, the submission will include a layer list of each layer found on the drawing with its description.

No annotation shall be included in any feature layer and no feature shall be included in any annotation layer. Annotation for each layer shall be placed in annotation layers as specified in Appendix A.

No polylines or annotation shall be stored in blocks. Explode all blocks that do exist. (Block references migrate to GIS as a single point at the block’s insertion point.)

All points shall be stored as “POINT” or “BLOCK REFERENCE” (can’t be softdesk point or aecc_point or any other feature type).

Surveying, traverse points will not be submitted.

All Florence County required layers shall be made visible prior to submission – all other layers can be turned off.

Closure is critical in converting CAD elements to GIS features. If appropriate (ie. parcel boundaries, subdivision boundary, buildings), all polygonal features shall be ‘snapped’ closed.

Submitted .dxf or .dwg files shall contain only complete parcel polygon features. All partial polygons (parcel boundaries) shown for reference in drawings are not to be included in the PARCEL 1 layer (Appendix A). Such features can be included in an unnamed layer in the submitted .dxf file.

All elevation points shall be delivered in a single comma-delimited ASCII text file. Each line of the file shall contain values (in SCSP coordinates) for a single point as follows:

Point Number, Easting, Northing, Elevation, and Description

2012374.63 012374.63,	853633.30343,	447.52
2012371.81,	853642.06532,	447.49
2012370.56,	85365 1.25382,	447.62
2012369.81,	853660.04853,	448.02
…

Additional layers (not identified in Appendix A) may utilize any open layer beyond the 60 reserved layers. As outlined above, a list of these layers shall also be submitted (ASCII text file labeled: ‘subdivisionname_phasesXX_xlyrspec.txt’).

Florence Digital Data Submission Standards

January 7, 2008

• Appendix A

Graphic File (.dxf) Specifications

Layer Number	Layer Name	Feature Type	Layer Description
1	BLDG 1	Polyline	Building/structure outline or footprint
2	PARCEL 1	Polyline	Parcel/lot boundaries
3	SUBDIV1	Polyline	Subdivision boundaries
4	ROW1	Polyline	Rights of way delineating private/public land boundary
5	COMAREA1	Polyline	Public areas such as street islands/community entrances
6	GCP1	Point	Ground control points (existing, surveyed, or GPS)
7	POLE 1	Point	Lamp poles, power poles, traffic light poles, etc.
8
9
10	GAS	Polyline	Gas pipe
11	ELECTR	Polyline	Electrical lines
12	TELCO	Polyline	Phone lines
13	CTVFIBR	Polyline	Cable TV and/or fiber datacom lines
14
15
16	PAVEDGE1	Polyline	Edge of pavement
17	CNTRLIN1	Polyline	Street/road centerlines (paved and unpaved)
18	SIDE WLK1	Polyline	Sidewalks (including ramps, if any)
19	CURB1	Polyline	Curb/gutter
20	CARPRK1	Polyline	Parking lots
21	RAIL1	Polyline	Railroads
22	HYDLIN1	Polyline	Linear hydrography, creeks/streams
23	HYDPOL1	Polyline	Polygonal hydrography, lakes/ponds
24
25
26	EAS	Polyline	Utilities, wildlife, transp., storm drainage/detention, etc.
27	EASBLD	Polyline	Building setback
28	BUFF	Polyline	Buffers (riparian, vegetation, etc.)
29
30	FP	Polyline	Flood plain
31	FW	Polyline	Flood way
32	WETLAND	Polyline	Wetlands
33
34
35	SDLINK	Polyline	Storm drain culvert, ditch, pipe, etc.
36	SDNODE	Point	Storm drain structure (manhole, junction box, etc.)
37	SDTEXT	Text	Annotation describing storm drainage (SD) features
38
39	SSLINK	Polyline	Sanitary sewer pipe
40	SSNODE	Point	Sanitary sewer manholes, pumps, junctions, etc.
41	SSTEXT	Text	Annotation describing sanitary sewer (SS) features
42
43	WTRLINK	Polyline	Water pipe
44	WTRNODE	Point	Water access/junction box, valves, etc.

45	FIREHYD	Point	Fire hydrant
46	WTRTEXT	Text	Annotation describing water service (WTR) features
47	CTOUR1	Polyline	Un-broken contour lines (* design/as-built)
48
49
50
51	LOTNUM 1	Text	Proposed parcel lot number
52	LOTDIM1	Text	Bearings, distances, acreage, and x/y of POB
53	SUBNAM1	Text	Subdivision name
54	RDNAME1	Text	Street/road name
55	RDNAME2	Text	Road number (Federal, State, County highways, etc.)
56	PAVTYPE1	Text	* Pavement type
57	RAILNAM1	Text	Railroad name
58	HYDNAM1	Text	Hydrographic feature name
59	EASTYPE	Text	Type of easement (utility, transp., wildlife, storm, etc.)
60	CTOURVAL	Text	Elevation of individual contours

* Level 56 - Pavement type (PAVTYPE1) shall include the following standard surface designations:

Asphalt Concrete

Bituminous Surfacing

Concrete

Gravel

Dirt

Florence Digital Data Submission Standards

January 7, 2008

Appendix B

Metadata Text File (‘subdivisionname_phasesXX_meta.txt’) Specifications

Subdivision Name: County: City: Parent Parcel #: Number of Lots: Type of Geodetic Control:

Submittal Date:

Monument Reference: Y / N

Traverse to Monument

Referenced Monument Name/Number: Distance to Monument:

GPS

Unit Type:

PDOP of Control Points:

Differentially Corrected: Y / N Elevation Reference: Y / N

Vertical Datum____________

Horizontal Datum__________

Prepared by/Firm Name: Engineer of Record:

Drawing/File Name:

Software/Version Used: