Audubon Saves Habitat Through Careful Energy Development Planning

Transwest Express

Audubon supports properly sited renewable energy, including the transmission lines that carry power to population centers. As the country ramps up its renewable energy portfolio, properly sited tranmission lines to carry (properly sited) renewable energy, often generated in remote locations, to population centers is just as key. How much renewable energy do we need? Climate change and our dependence on fossil fuels is driving the need for this transition to renewables with the goal of reducing greenhouse gas pollution by 80-90% from 1990 levels by 2050 according to the Intergovernmental Panel on Climate Change.

Working with industry and local, regional and federal decision-makers, Audubon provides important information on how best to avoid bird and wildlife impacts from renewable installations. Working with developers before the bulldozers move in can avoid lengthy battles and provide better outcomes for birds, wildlife and critical habitat. Our work to promote properly sited transmission corridors helps to ensure that Important Bird Areas and other habitats critical for the survival of bird populations and migratory species are avoided.

For an excellent overview on transmission and renewnewable energy, we recomment National Public Radio's Special Series on America's Power Grid
Power Hungry: Reinventing the U.S. Electric Grid
Interactive map

Eastern Transmission Lines
Audubon's Eastern Transmission work tackles the densely populated east and mid-Atlantic parts of the country and the confusing alphabet soup of regionally-defined grids. An important new GIS-based planning tool is officially on the way to identify critical environmental areas and enable a more environmentally-friendly approach to energy development in the eastern United States. 

As a result of Audubon's efforts, the utility commissions of the 39-state eastern interconnection will tap Department of Energy's (DOE) national labs to build this important new planning tool over the next 1-2 years, to inform the siting of power generation and electric transmission facilities. A majority of utility commissions now lack ready access to such data, making smart front-end planning, and adequate analysis of environmental impacts, virtually impossible. This new decision support system will bridge that enormous gap and enable a more informed and balanced approach to energy planning.

Of equal importance, Audubon worked with utility commissions to assess where the greatest potential lies for deploying Smart Grid, demand response, energy efficiency, and distributed generation. This will be the first time that these no-build and low-build options are mapped out across the region, putting these non-traditional alternatives on even par with other approaches and reinforcing just how much opportunity lies in conservation. If executed well, this additional mapping promises to be a game changer for how our energy options are viewed when policymakers think about the need for grid buildout.

In the months to come, Audubon will be working with the Association of Fish and Wildlife Agencies and DOE's Argonne National Laboratory to help direct early steps in the development of the GIS-based planning tool for identifying environmentally sensitive areas. As part of the information needed to ensure minimal impacts to birds and wildlife, Important Bird Area (IBA) data from Audubon has been added to the mix.

As new decision tools are created for the east, it should be possible to have earlier, constructive, and more effective exchanges with planners so that energy facilities can avoid and minimize damage to ecologically important areas. With Audubon IBA data and no-build options in the mix, there is reason to hope that we will be better able to protect the many wild places critical to Audubon's mission.

Western Transmission Lines
Audubon's Western Transmissionwork is complex as well, as the world-class wind and solar potential of the west -- and the transmission lines needed to bring it to primarily the population centers in the desert southwest --collide with flyways, Important Bird Areas, endangered species like Whooping Cranes, and species of concern like the sage-grouse. Audubon Rockies' work on siting energy development projects in Wyoming, Colorado, New Mexico, Idaho and Arizona involves partnerships and is focused on the following goals: avoid or minimize impacts to birds, wildlife and habitat. 

High-voltage transmission lines, such as those featured here, typically require a 250-300 foot right-of-way width within a 2-mile-wide transmission corridor along the entire length of the project. These transmission lines are either direct current or alternating current.  They are a range of voltages, generally 345 to 600 kilovolts.  Depending on voltages, these lines can carry as much as 3,000 megawatts (1 MW = 1 million watts), which can power as many as 1.8 million homes.

The towers used to support the overhead transmission lines are usually 100-190 feet in height and span 900 to 1,500 feet apart (4-5 structures per mile), depending on structure type, terrain, span and line crossings.  In addition, there are substation converters and construction and maintenance access roads approximately 30 feet wide.

NEPA, or the National Environmental Policy Act, was one of the first laws ever written that establishes a broad national framework for protecting our environment. NEPA's basic policy is to assure that all branches of government give proper consideration to the environment prior to undertaking any major federal action that could significantly affect the environment.  For transmission lines that involve federal land, which is all of the high voltage lines featured here, companies need to obtain a right-of-way grant from a federal agency (most often the BLM) and they have to go through the NEPA process. Given the size and scope of these proposed transmission projects, Environmental Impact Statements need to be prepared for these proposed transmission projects.  This allows the public to review these projects at various stages (scoping, draft EIS, final EIS) and submit comments or concerns.


The SunZia Project consists of two extra-high voltage electric transmission lines and substations that will transport primarily renewable energy from Arizona and New Mexico to customers and markets across the southwestern United States. Learn more.

Gateway West

The furthest along of all the proposed high voltage transmission lines,  it starts just outside of Casper, Wyoming, swinging down through the southern part of the state and end in Boise, Idaho.  How it overlays with important sage-grouse and sage-dependent species, impacts to riparian areas, and other environmental considerations are all part of what Audubon is bringing to this project. This line is proposed to be an alternating current high-voltage transmission line. Learn more.

Gateway South

The Gateway South line will begin at the Aeolus substation in southeastern Wyoming, which will also house the company's Gateway West line, and will travel 400 miles south through Colorado until it terminates near Mona, Utah. When completed, Gateway South will carry approximately 1,500 megawatts of electricity, including potentially power generated from renewable resources in Wyoming. This line is proposed to be an alternating current high-voltage transmission line. Learn more. 

TransWest Express

TransWest Express is a 725-mile-long transmission line that would start in Sinclair, Wyoming, travel through Colorado and Utah, and terminate in the Las Vegas area of southern Nevada. The project has been proposed by TransWest Express LLC, a subsidiary of the Anschutz Corporation, based out of Denver. This transmission line is being proposed to complement another one of Anschutz's projects, a 3,000 megawatt wind farm in southern Wyoming (1,000 turbines - largest onshore wind farm). The Bureau of Land Management has already approved the Chokecherry and Sierra Madre Wind Energy Project, and the TransWest power line would help transport energy from this wind farm to growing energy markets in the Southwest. This line is proposed to be a direct current high-voltage transmission line.Learn more. 


Zephyr is the most recent new high-voltage transmission line proposed, and has not begun the formal public comment opportunity. The line is being proposed by Duke American Transmission Company (DATC) that would travel from Wheatland/Chugwater area in Wyoming to the Eldorado Valley south of Las Vegas, a total of 850 miles. The project aims to transport abundant renewable energy resources in Wyoming to a growing energy market in the Southwest by teaming up with Wyoming's Pathfinder Renewable Wind Project. This line is proposed to be a direct current high-voltage transmission line. Learn more. 

San Luis Valley

San Luis Valley
This proposed transmission line project would travel over La Veta Pass into Colorado's San Luis Valley, with the goal of increasing transmission reliability and access to solar resources in the San Luis Valley. The transmission line is being proposed by Tri-State Generation and Transmission Association and Public Service Company of Colorado (PSCo), an Xcel Energy Company. The region supports a variety of wildlife, and of special concern are Sandhill Cranes and other species which migrate through the valley. Learn more.

Helpful resources about western transmission projects:

Become familiar with the National Environmental Policy Act (NEPA) - a formal process that allows your voice to be heard as projects' potential effects on environmental resources (land use, threatened and endangered species, wetlands, scenic areas, cultural resources etc.) are evaluated! The National Environmental Policy Act has been a critical tool for conservation. Learn more from A Citizen's Guide to NEPA (PDF).

For additional information regarding birds and power lines, visit the Avian Power Line Interaction Committee website.