Cultural Resources Disclaimer

This map depicts data for modeling Cultural Risk for electricity transmission development in support of WECC's Regional Transmission Expansion Planning program. This map contains three cultural data layers: Cultural Risk, Inventory Areas; and Neighborhood Site Density.

The data presented in this application is intended for use in preliminary, early stage planning processes only. It is not intended to satisfy requirements under Section 106 of the National Historic Preservation Act or other laws and regulations. For project specific analyses, please consult with the appropriate State Historic Preservation Office regarding existing data and additional survey requirements.

Siting-level analyses, while they may employ some of the same data sets as planning-level analyses, will also use other project-specific data sets. Because of the scale at which the regional Transmission Expansion Planning process operates, it is not possible or appropriate to consider all project-level data that could be critical during transmission line siting. WECC recommends any potential transmission corridors generated through this mapping application be thoroughly reviewed against siting-level data and any applicable laws and regulations.

Contact Information

Special recognition and thanks are extended to the Nevada State Historic Preservation Office and the Utah Department of Heritage and Arts for spearheading data sharing, methodology development, pilot testing, outreach to other stakeholders, and ongoing consultation. Wyoming , Colorado, and Washington SHPOs have also contributed data and provided review to the process. Coordination with other states is ongoing.

Your questions, comments, and feedback are welcome:
Nevada State Historic Preservation Office
Utah Department of Heritage and Arts
History Colorado
Wyoming State Historic Preservation Office
Washington Department of Archaeology and Historic Preservation

For more information on WECC and the Cultural Resources Risk mapping, please contact:
Byron Woertz
Senior Project Manager
Western Electricity Coordinating Council
bwoertz@wecc.biz
(801) 883-6841

Cultural Layer Descriptions

The Cultural Risk Categories are as follows:

Category A. Lowest Cultural Resource Risk or Uncertainty
This category includes areas with a “Low Density” of sites that have been surveyed in the last 10 years. This category is intended to reflect the notion that recently surveyed areas where few sites were found decrease the risk and uncertainty associated with planning transmission

Category B. Moderate Cultural Resource Risk or Uncertainty
This category includes areas where a “Low Density” of sites has been identified, but where the survey information is older (>10 years). This category is intended to reflect the notion that new sites become “historic” over time, and areas found to have a low density of sites in the past may have new sites in the present. These older surveys increase the overall uncertainty associated with planning transmission through the area.

Category C. High Cultural Resource Risk or Uncertainty
Areas with a “Moderate Site Density” (regardless of when or if a survey has been conducted in the area). This category is intended to reflect the notion that an increasing number of sites in an area will increase the risk and difficult in siting a project, as well as to acknowledge that not having any survey information creates its own type of risk by substantially increasing the uncertainty around what resources will be found in a given area.

Category D. Highest Cultural Resource Risk or Uncertainty
This category includes areas with a “High Site Density” regardless of when or if a survey has been conducted in the area. This category is intended to reflect the notion an area surrounded by identified sites will substantially increase the risk and difficult in siting a project.

Category E. Unknown Cultural Resource Risk or Uncertainty
Areas with a zero site density and where no surveys have been conducted. In this case, zero-site density is interpreted as being "unknown” site density, due to the lack of surveying performed at that location.

The inventory/survey areas are evaluated to specify whether each survey was conducted within, or prior to, the last ten years.
 Areas surveyed within the past 10 years*
 Areas surveyed over 10 years ago*
*based on the date inventory/survey data was received from the cultural data provider

The site density is determined by a neighborhood analysis where every grid cell in the state is evaluated to count the number of cultural site grid cells within its 3x3 neighborhood. A value of 0-9 is possible.
High (7-9 adjacent cells have one or more sites)
Medium (4-6 adjacent cells have one or more sites)
Low (0-3 adjacent cells have one or more sites)

Environmental Layer Descriptions

To create the Environmental Risk Data shown on this mapping application, WECC applied a classification system to its catalogue of environmental data to calculate planning-level risks based on the environmental features of the landscape. WECC’s Environmental Risk Class data was developed by a diverse group of transmission stakeholders (representing industry, government, and environmental interests) who collaborated to develop a method for including environmental concerns in the regional transmission planning process. Details on that stakeholder process can be found in the document Environmental Recommendations for Transmission Planning

The Environmental Data Layer is a single GIS layer that identifies planning-level risk to transmission development based on environmental sensitivities and constraints, as defined by four risk categories:

Category 1 - Least Risk of Environmental or Cultural Resource Sensitivities and Constraints:
Areas with minimal identified environmental or cultural resource constraints and/or with existing land uses or designations that are compatible with or encourage transmission development. These areas would present few or minimal environmental and cultural mitigation requirements and are least likely to result in project delays.

Category 2 - Low to Moderate Risk of Environmental or Cultural Resource Sensitivities and Constraints:
Areas where development may encounter one or more environmental or cultural resource sensitivity areas or constraints that would require low to moderate permit complexity or mitigation costs. This category also includes areas in the Protected Areas Database of the United States (PAD-US) dataset that have an unknown land use designation or degree of restriction to transmission development.

Category 3 - High Risk of Environmental or Cultural Resource Sensitivities and Constraints:
Transmission development is likely to encounter one or more environmental or cultural resource sensitivities or constraints that would substantially increase permitting complexity and could result in project delays and high mitigation costs.

Category 4 Areas Presently Precluded by Law or Regulation:
Areas where transmission development is presently precluded by federal, state, or provincial law, policy, or regulation, as well as areas where development would represent a “fatal flaw” likely to preclude successful project completion (e.g., identified Native American Traditional Cultural Properties and sacred sites).

Latest updates were completed in December, 2014. A complete list of area types can be viewed here .

Reference Materials

Downloadable GIS Environmental Risk Class Data and the Environmental Data Products User's Manual
Mitigation Cost Study
Capital Cost Study