New TVA transmission line to enhance reliability in NE Mississippi

The Tennessee Valley Authority’s (TVA) new 16-mile Union-Tupelo (Miss.), No. 3 transmission line project will bring enhanced reliability and growth capacity to an area of northeast Mississippi while having minimal adverse impacts on the region.

On March 15, TVA announced the northern option as its preferred alignment for the project, a disclosure that met with the approval of officials in Saltillo, Miss., a town of about 5,000 near the eastern end of the line.

“The vast majority of [affected landowners] preferred the route TVA ended up selecting,” Mayor Bill Williams told TransmissionHub March 19. “The option is our much-preferred route; it’s much less disruptive. The other options came right through our primary growth path, which is to the west of our city.”

Last fall, the agency proposed six routes for the third line that will link the 500-kV Union substation near Sherman, Miss., about 13 miles northwest of Tupelo, to the Turner Park 161-kV substation. After evaluating those options, the agency chose the northern option as its preferred route.

“We held meetings and forums to identify the route that posed the least inconvenience for the affected communities,” a TVA spokesperson told TransmissionHub.

Williams said the route chosen was largely along flood plains and so was unlikely to impede the town’s development.

In addition to sidestepping many communities, 90% of the proposed line will either share right-of-way (ROW) with the existing 500-kV Brown’s Ferry-to-Union transmission line or use ROW on which TVA had lines previously, the spokesperson said. Existing ROW, whether occupied or unoccupied, will be easier to clear than new ROW, and will mean fewer parcels of greenfield will need to be acquired for new easements.

The new 161-kV transmission line will extend east from the Union substation to a point northeast of Saltillo, then turn south and continue to the Turner Park substation south of the town. The existing 6.6-mile Tupelo-Turner Park 161-kV transmission line will complete the connection from the Turner Park substation to Tupelo.

TVA officials say the third connection between the two substations is needed to prevent overloading of the existing lines during periods of heavy power demand as well as to provide additional capacity to the growing area, two benefits Williams welcomes.

“We’re in a growing area. The demand is going to continue to grow and … this third line will give us more reliability,” Williams said. “We want to be proactive and not reactive, and I’m glad that they’re doing this.”

The next step will be an environmental assessment, which TVA will undertake under the National Environmental Policy Act (NEPA). Following completion of the NEPA review, the agency plans to begin construction in 2015 with an anticipated in-service date of 2016.

TVA estimates the cost for the new transmission line will be $750,000 to $800,000 per mile, or approximately $12m to $13m.