The Treasure Valley electric load – or demand on the system – increases by about 50 megawatts annually. That’s equal to adding a city the size of Eagle each year.

A growth rate like this will soon strain Idaho Power’s infrastructure if nothing is done to reinforce it.

This transmission line project will address growing demand in the Treasure Valley and will improve the overall reliability of the existing transmission system. It will help deliver power from the edge of the Treasure Valley into the center where the power is used.

Under certain conditions, transmission capability in the Treasure Valley is approaching full capacity. This project is needed to meet the projected electrical demand of the future.

As a transmission provider, Idaho Power has the obligation to plan and construct transmission facilities to ensure reliable electric service to its customers. View our Project Fact Sheet (PDF).

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Transmission Line Details

The new 230 kilovolt (kV) transmission line will be 12 to 14 miles long depending on the final line design. View a printable map (PDF)

The line will consist of two 230 kV circuits connecting Bowmont Substation to Hemingway Substation.

Bowmont Substation is located near Southside Boulevard and Rose Lane in southern Canyon County. Hemingway Substation is under construction in northern Owyhee County, south of the Snake River, approximately two miles west of the junction of Idaho highways 45 and 78.

The transmission line would be built using single steel poles about 100 feet in height with pole spacing about 800 feet. Exact dimensions and spacing will vary depending on the line design.

Current plans are to have the line constructed mid-year 2010.

Hemingway Substation

This substation initially will be served from Rocky Mountain Power’s 500 kV transmission line, which is near the station location.