Designing the Transmission Line

Idaho Power follows all applicable safety codes and standards to ensure our systems operate safely and reliably. The National Electric Safety Code (NESC) is the industry–accepted safety standard which guides the design, installation, operation and maintenance of transmission lines and equipment. The NESC is used to develop the appropriate right of way width based on a number of factors, such as tower type and height, conductor type, conductor tensions, span length between towers and weather conditions.

A variety of transmission line structure designs may be used for the project. The structures may be a combination of single and double circuit towers and steel lattice and tubular steel towers.

The approximate proposed design standards are listed below. Tower heights Steel lattice: 135 to 180 feet Steel pole H-frame: 100 to 165 feet Steel pole: 130 to 150 feet Tower footprint: 40 by 40 feet Span length: (average): 1,100 to 1,200 feet Ground clearance: (average): 35 feet Right of way width: 250 feet If the federal and state agencies approve a transmission line route, Idaho Power will work with affected property owners to determine the exact line location and identify opportunities to reduce impacts to the property. Visit our People and Power Lines section for more information.

Perspective photos To view how a typical 500 kV transmission line looks from a distance of 500 feet to two miles away, visit our Perspectives Photos page in the Photo/Video Gallery.

This website is the joint Boardman to Hemingway Transmission Line Project site. Information contained on this site is approved for posting by Idaho Power. Visit the Idaho Power website.