Electric Transmission Lines and Substations, 60 Kilovolt and Greater, Minnesota, 2007

This page last updated: 04/07/2014
Metadata created using Minnesota Geographic Metadata Guidelines


Go to Section:
1. Overview
2. Data Quality
3. Data Organization
4. Coordinate System
5. Attributes
6. Distribution - Get Data
7. Metadata Reference

Section 1 Overview
Originator Minnesota Geospatial Information Office (MnGeo)
Title Electric Transmission Lines and Substations, 60 Kilovolt and Greater, Minnesota, 2007
Abstract The electric transmission network information consists of transmission lines, with associated substations, designed to handle 60 Kilovolts or greater. Note that the data does not have network connectivity.

A statewide map in PDF format is available online. For security reasons, MnGeo is not permitted to post the GIS data online. The existing distribution policy for Electric Transmission Lines and Substation GIS data is being reviewed by the state's Department of Commerce and the Homeland Security and Emergency Management division of the state's Department of Public Safety. As soon as an updated policy is available, this documentation will be updated.

The Minnesota Electric Transmission Mapping Project has developed two geographic information system data sets: electric transmission lines and substations. This metadata record describes both data sets.

Each utility company was mailed a request for the facility information which they could provide in either digital or paper form. The responses varied significantly in quality and quantity. In addition, the companies expressed concerns about providing the information because of security concerns. Data users are strongly encouraged to read the data quality section of this documentation. The dataset was last updated in 2007 -- most changes were to improve the positional accuracy of lines and substations from the 2003 dataset, and several new lines were added in the southern and western areas of the state. Most of the attributes from the 2003 dataset were deleted since most of them were blank and since security concerns persist about whether any detailed attributes should be released.

The Minnesota Electric Transmission Mapping Project is a collaborative effort between the Environmental Quality Board, MnGeo (formerly the Land Management Information Center or LMIC) and the Minnesota Department of Commerce.
Purpose This project will assist with state energy planning efforts and enhance public understanding of Minnesota's electric power infrastructure.
Time Period of Content Date 2007
Currentness Reference The companies provided data from December 2001 to October 2003. The editing process corrected information until the winter of 2003/2004. In 2007, the positional accuracy of many transmission lines and substations were improved using several sources (see Lineage for details), and several new lines were added based on data provided by HDR. The 2007 dataset is NOT a comprehensive update for the entire state.
Progress Complete
Maintenance and Update Frequency Irregular
Spatial Extent of Data State of Minnesota to first substation outside the state (goal of the project).
Bounding Coordinates -97.200660
-90.290680
48.814113
43.280315
Place Keywords Minnesota, MN
Theme Keywords utilitiesCommunication, Utilities, Transmission Lines, Substations, Power, Power Lines, Powerlines, Electric, Electricity, AC, DC
Theme Keyword Thesaurus ISO 19115 Topic Category
Access Constraints There are no access constraints to view or download the map at: www.gda.state.mn.us/maps/ElecTran07.pdf

Due to security concerns, the GIS data is not available online. The distribution policy is under review.
Use Constraints The use policy is under review.
Contact Person Information Norman Anderson, Senior Research Analyst
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street
St. Paul, MN  55155
Phone: 651-201-2483
Email: gisinfo.mngeo@state.mn.us
Browse Graphic Click to view a data sample
Associated Data Sets See the transmission line section of MnGeo's first-stop information webpage on utilities: www.mngeo.state.mn.us/chouse/utilities.html#transmission

Section 2 Data Quality
Attribute Accuracy No statistical attribute assessment has been performed on the data.

Substations from different companies which are in close proximity sometimes have the same or similar names.

When LMIC (now MnGeo) standardized transmission line and substation characteristics, errors may have been inadvertently introduced to values.

For several transmission lines, the VOLTAGE field is set to zero since the company did not provide the voltage to LMIC. Several lines are included in the 2007 version that have voltages lower than 60 kV, but this dataset does NOT comprehensively map lower voltge lines for the state.

For substations, LMIC attempted to expand the characteristics for the values of SUB_TYPE and VOLTAGE where they were missing.

LMIC added the SOURCE attribute to track some of the positional sources of data when the companies did not. Sometimes it refers to the organization that provided the data (e.g., HDR); sometimes it refers to the data source (e.g., an air photo). It was added midway through the dataset creation process so it is not always filled in.
Logical Consistency Data have been topologically structured and verified using the following rules:
1. Transmission lines must not overlap and must not self-intersect.
2. Substations must be covered by endpoint of transmission lines.

Data does not have network connectivity.

Several companies submitted information which was biased towards a graphical representation of features:

1. Transmission lines are typically represented by a series of segments which are broken by substations, i.e., lines are not connected to substations.
2. Transmission lines that cross and do not intersect are represented by one line arching over the other.
3. A transmission line that is a double circuit is displayed as two lines separated by a wide distance even though the lines are on the same set of poles.

Each company provided a list of features along with the map data. For three companies (Great River Energy, Otter Tail Power and Xcel Energy), there was not a one-to-one match between the feature list and the map.
Completeness Transmission lines: Each company filled out the requested information to a varying degree. The majority supplied the key characteristics for transmission lines and substations but no company supplied all the values for each requested item. Minnkota Power Cooperative, Inc. Dairyland did not provide any feature characteristics other than the company identification and voltage for their transmission lines and substations.

Substations: Several companies provided substation names but very little else.

The initial list of utilities missed two companies: East River Electric Power Cooperative and Rochester Public Utilities. This suggests that other companies could have been missed.

Otter Tail Power Company never returned review maps.

Lines added in 2007 version:
1. A missing 345 kV line in southern Minnesota.
2. 12 lines in southern and western Minnesota; they are identified as 'HDR' in the 'SOURCE' field and 'HDR added' in the 'COMMENTS' field.
Horizontal Positional Accuracy -----------------------------
2003 VERSION
-----------------------------

The utility companies were hesitant to provide positional accuracy information. When pressed for accuracy, several stated approximately 150 meters (approx. 500 feet). In a review of features, transmission lines and substations were found up to 550 meters from a location shown on aerial photographs, although at least most facilities were located on the correct side of map features such as roads and lakes.

Two companies declared more specific accuracy figures:
+/- 100 feet - Minnesota Power's GIS data.
+/- 1,500 feet - Minnkota CADD data.

To illustrate the differences in horizontal positional accuracy within the 2003 data set, LMIC (now MnGeo) overlaid transmission lines and substation locations on 2003 orthorectified aerial photos ( www.mngeo.state.mn.us/chouse/metadata/naip03.html ). See an example of relatively accurate locations:

ftp.lmic.state.mn.us/pub/data/trans_util/electrans03_accuracy1.jpg

and an example of relatively inaccurate locations (substation point is two farm fields away from the actual location):

ftp.lmic.state.mn.us/pub/data/trans_util/electrans03_accuracy2.jpg

---------------------------
2007 VERSION
---------------------------

The positional accuracy of the lines and points were improved to match either the 2004 0.3-meter resolution National Geospatial-Intelligence Agency (NGA) photos in the Twin Cities metropolitan area ( www.mngeo.state.mn.us/chouse/metadata/doq_msp04.html ), or the 2003-04 Farm Service Agency (FSA) National Agriculture Imagery Program (NAIP) 1-meter resolution photos ( www.mngeo.state.mn.us/chouse/metadata/naip03-04.html ) in areas not covered by NGA photos.
Vertical Positional Accuracy Not applicable
Lineage The Minnesota Electric Transmission Line Mapping Project is a collaborative effort between MnGeo (formerly LMIC), the Minnesota Environmental Quality Board and the Minnesota Department of Commerce.

---------------------------
2003 VERSION
---------------------------

A letter was sent to the utility companies in August, 2002 requesting information on transmission lines greater than 60 kV and their associated substations. This request asked for the mapped features (digital or paper) and characteristics describing the features (see Section 5). The list of companies contacted was provided by the Minnesota Transmission Owners consortium.

REQUESTED CHARACTERISTICS:

Electric Transmission Lines:
1. North American Electric Reliability Council (NERC) circuit ID/line #
2. Company circuit ID/line #
3. Line Ownership (list all owners)
4. Original in-service date
5. Date of latest major line alteration
6. Type of alteration: rebuilding, voltage upgrade, reconductoring or pole change-out
7. Type: AC/DC
8. Nominal operating voltage
9. Circuit length
10. Interstate: Y/N (if yes, then identify and locate the first substation outside of the Minnesota state boundary)
11. Single or double circuit structures
12. Voltage design class of structures
13. Primary structure type (e.g., wood, steel, single pole, h-frame, lattice tower)
14. Underground: Y/N (indicate on the map which portion of the line is underground)
15. Maximum continuous conductor ampacity (Category A rating)
16. Maximum temperature rise rating
17. Number of conductors, size and circular mils and type (e.g. 2-795 ASCR)
18. Summer and winter continuous circuit capacity in MVA (megavolt amperes)
19. The data's spatial accuracy

Substations:
1. Substation name
2. Location
3. Ownership
4. List bus voltages and bus number ID
5. The spatial accuracy of the recorded location
6. Source - CAD, GPS, paper map, etc.
7. Metadata - name if available


REVIEW OF DATA BY COMPANY:

Alliant Energy Corp. Services: Five ESRI coverages were received in May 2003: iowagen, iowasub, iowatrans, minnsub and minntrans.

Dairyland Power Cooperative: Two DXF files were received, one for lines and the other for substations, in February, 2002. A separate spreadsheet contained the feature characteristics.

East River Electric Power Cooperative: Eight PDF files were provided in October, 2003. The maps are similar to the Minnesota Department of Transportation (Mn/DOT) general highway map series with the transmission lines and substations on top. No additional feature characteristics were included with the maps. This company was missing from the original list of companies.

Great River Energy: Two ESRI shapefiles were received, one for lines and the other for substations, in February, 2002. A separate spreadsheet contained the feature characteristics.

Hutchinson Utilities Commission: No data; covered by other companies.

Minnesota Power: One MapInfo File (MIF) was received which contained both transmission lines and substations, in February, 2002. Two spreadsheets contained the feature characteristics, one for transmission lines and another for substations.

Minnkota Power Cooperative, Inc.: Several DXF files were received, one for each transmission line voltage and another for substations, in December, 2001. No feature characteristics were provided for their features.

Missouri River Energy Services: No data was provided because their facilities are included in the information provided by Otter Tail Power Company.

Otter Tail Power Company: Paper maps were provided in February, 2002. A separate spreadsheet contained the feature characteristics.

Southern Minnesota Municipal Power Agency: Paper maps were provided in February, 2002. A separate spreadsheet contained the feature characteristics.

Rochester Public Utilities: Two ESRI shapefiles were received, one for the transmission lines and the other with substations, in August, 2003. A separate spreadsheet contained the feature characteristics. This company was missing from the original list of companies.

Willmar Municipal Utilities: One paper map was provided in January, 2002. A separate spreadsheet contained the feature characteristics.

Xcel Energy, Inc.: DXF files organized by county were provided in the time period May - July, 2002. A separate spreadsheet contained the feature characteristics.


GENERAL DESCRIPTION OF DATA PREPARATION

Paper Maps:
1. Digitize transmission lines and substations.
2. Add company IDs.
3. Relate to add in feature characteristics.
4. Compare digitized features with the source materials received from the power company.

DXF Maps:
1. Convert to ESRI coverage.
2. Project to UTM, extended zone 15, NAD 83.
3. Add company IDs.
4. Combine individual county general highway map based layers into one statewide file.
5. Relate to add in feature characteristics.
6. Compare converted and combined features with the source materials received from the power company.

Map Info Files (MIF):
1. Convert to ESRI coverage.
2. Project to UTM, extended zone 15, NAD83.
3. Relate to add in feature characteristics.
4. Compare converted features with the source materials received from the power company.

ESRI Shapefiles:
1. Convert to ESRI coverage.
2. Project to UTM, extended zone 15, NAD 83.
3. Relate to add in feature characteristics.
4. Compare converted features with the source materials received from the power company.

PDF Maps:
1. Convert to JPG.
2. Geo-reference to match 1:100,000-scale public land survey lines (the Township, Range, Section (TRS) data set, described at: www.mngeo.state.mn.us/chouse/metadata/trs.html ).
3. Heads-up digitize electric transmission lines and substations based on geo-referenced image.
4. Add company IDs.
5. Relate to add in feature characteristics.
6. Compare digitized features with the source materials received from the power company.


The characteristics were standardized as much as possible. Grouped values were parsed and items listed individually were concatenated.

Once the original information was completed, proof maps were generated and sent to the companies for review in early 2003. The proof maps were created for each company by Mn/DOT county map sheet with the 2002 Mn/DOT General Highway maps in the background: www.mngeo.state.mn.us/chouse/metadata/hwy_map1.html. They were made available electronically by Acrobat PDF or in printed form. The transmission lines (voltage by color and identification by text label) and substations (identification by text label) for that company were in the foreground.

The final statewide composite data sets were created by combining all the correctly characterized transmission lines and substations from each company's individual data set.

In early 2004, the current data sets were sent to each company for their comments.

------------------------
2007 UPDATE
------------------------

SOURCES

The 2003 version of the dataset was updated using several sources:

1. Transmission line and substation shapefiles from HDR consulting firm, dated 5/18/07.

2. 2004 Orthophotos: 0.3-meter NGA photos of much of the Twin Cities metropolitan area. www.mngeo.state.mn.us/chouse/metadata/doq_msp04.html

3. 2003-04 Orthophotos: 1-meter FSA NAIP photos used where NGA photos were not available: www.mngeo.state.mn.us/chouse/metadata/naip03-04.html

4. Great River Energy (GRE) new 115 kV line added between Air Lake substation and Empire substation, dated 7/17/07.

If a line or substation was moved to match the HDR location, the SOURCE attribute was updated to HDR. If a line or substation was moved to match the air photo, SOURCE is AP.

Several lines were included that have voltages below 60 kV.

ATTRIBUTES STREAMLINED

Most of the attributes from the original 2003 dataset were deleted because:

1. Most companies did not provide the information to LMIC so the attributes were blank.
2. Security concerns persist about whether detailed attributes should be released.

Section 3 Spatial Data Organization (not used in this metadata)

Section 4 Coordinate System
Horizontal Coordinate Scheme Universal Transverse Mercator
UTM Zone Number 15E
Horizontal Datum NAD83
Horizontal Units meters

Section 5 Attributes
Overview TRANSMISSION LINES:

COMPANY - name of the company that provided the data - 45 characters.
CIRCUIT_ID - North American Electrical Reliability Council (NERC) circuit identification / line number - 91 characters.
COMP_ID - company circuit identification / line number - 35 characters.
ACDC - AC or DC power - 2 characters.
VOLTAGE - voltage in kilovolts (kV) - 3 digits.
INTERSTATE - yes or no - 3 characters.
COMMENTS
SOURCE - Source was added by MnGeo to track some of the positional sources of data when the companies did not (see Attribute Accuracy field above).
Codes used:
- AP: aerial photography (statewide 1 meter, metro .3 meter)
- GRE: Great River Energy
- HDR: HDR consulting firm
- Paper: paper maps
- Blanks or NULLs: before tracking

-------------------------------------------------------------------------------------

SUBSTATIONS:

COMPANY - company name - 45 characters.
COMP_ID - substation identification - 45 characters.
SUB_TYPE - substation type - 15 characters.
SOURCE - Source was added by MnGeo to track some of the positional sources of data when the companies did not (see Attribute Accuracy field above).
Codes used:
- AP: aerial photography (statewide 1 meter, metro .3 meter)
- CAD: DXF/DWG files
- GIS: Geographic Information System file
- GIS m: Geographic Information System file from Rochester Public Utilities
- GPS: GPS coordinates
- HDR: HDR consulting firm
- Blanks or NULLs: before tracking

COMMENTS
Detailed Citation
Table Detail:

Section 6 Distribution
Publisher Minnesota Geospatial Information Office (MnGeo)
Publication Date 06/20/2008
Contact Person Information Nancy Rader, GIS Data Coordinator
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street
St. Paul, MN  55155
Phone: 651-201-2489
Email: gisinfo.mngeo@state.mn.us
Distributor's Data Set Identifier Transmission lines and substations 2007
Distribution Liability MnGeo's general data disclaimer is online: www.mngeo.state.mn.us/chouse/disclaimer.html

The distribution policy for the GIS data is under review.
Ordering Instructions 1. Map: A PDF version of the 2007 statewide map showing transmission lines and substation locations is free online at:
www.gda.state.mn.us/maps/ElecTran07.pdf

2. GIS data: For security reasons, MnGeo is not permitted to post the GIS data online. The existing distribution policy for Electric Transmission Lines and Substation GIS data is being reviewed by the state's Department of Commerce and the Homeland Security and Emergency Management division of the state's Department of Public Safety. As soon as an updated policy is available, this documentation will be updated.
Online Linkage None available

Section 7 Metadata Reference
Metadata Date 04/07/2014
Contact Person Information Nancy Rader, GIS Data Coordinator
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street
St. Paul, MN  55155
Phone: 651-201-2489
Email: gisinfo.mngeo@state.mn.us
Metadata Standard Name Minnesota Geographic Metadata Guidelines
Metadata Standard Version 1.2
Metadata Standard Online Linkage http://www.mngeo.state.mn.us/committee/standards/mgmg/metadata.htm


This page last updated: 04/07/2014
Go back to top