Board recommends route for LCRA power line

After months of negotiations, the City of Austin and the Lower Colorado River Authority are closer to determining the route of the Friendship to Manchaca Transmission Line, crossing the recharge zone of Barton Springs Edwards Aquifer.

 

After hearing a report on the project, the Environmental Board last week expressed its preference for which route the line should take.

 

LCRA plans to build an 8.2-mile electric power line from its Friendship substation just inside Hays County to the Manchaca substation. The agency bought the right-of-way for the project from the Pedernales Electric Cooperative in 2005, and began planning the line shortly thereafter.

 

Almost five miles of the right-of-way runs parallel to the planned route of State Highway 45 Southwest, and crosses through terrain in the recharge zone that has several critical environmental features. SH 45 SW will eventually connect SH 130 to Interstate 35 and points west.

 

“You couldn’t pick a worse place to build a highway,” said Environmental Board Member John Dupnik, who chairs the board’s SH 45 Subcommittee. “But it is there and we have to make sure we protect the area where they are building it.”

 

Willie Conrad, manager of Austin’s Wildland Conservation Division, told the board that after almost three years of study and negotiation, two possible routes had been determined through the most sensitive parts of the area.

 

“The LCRA needs this project in order to improve the reliability of its transmission system,” he said. “It is also a response to growing demand in that area, particularly the Circle C area.”

 

The line runs north from the Friendship substation to the Escarpment substation, about one-half mile west of the south end of

MoPac Boulevard

. From there, the transmission lines will run southeast to the Manchaca substation on FM 1626. The Escarpment to Manchaca part of the route runs through or next to several parcels of city-owned conservation lands, one of which contains the entrance to Flint Ridge Cave.

 

“The challenge is to construct the transmission line with minimal impact to this environmentally sensitive area with known faults, fractures, caves and karst features in a manner that strives to protect the purpose for which the city bought the property,” Conrad said. “Each tower in the transmission line will have a deep piling in the ground to support it, and we need to know what’s down there.”

 

The LCRA opened talks with the City of Austin over the project in Sept. 2005. In the interim, the LCRA has conducted an archaeology survey, a natural resource review, a storm water assessment, and reviewed the requirements of the Barton Springs zone of the Edwards Aquifer. 

 

Several karst surveys were conducted to identify areas for alternate alignments. The LCRA also surveyed the area using ground-penetrating radar, resistivity, and drilled a number of soil borings.

 

The result of those studies showed “significant environmental risks” involved with the initial route that was approved by the PUC in 1999. After obtaining a PUC order for minor route deviations, the LCRA studied seven alternative routes and recently settled on two alignments for further study.

 

Route A, as it was designated, runs north of SH45 and bisects the city’s water quality protection lands. It also runs the risk of encountering potential environmental features without surface indication.

 

Route B would run south of the SH 45 right-of-way to avoid Flint Ridge Cave, then cut back across to the north side. This route would consolidate the infrastructure away from the cave and other karst features.

 

Based on its findings, the LCRA is recommending Route B to the City of Austin. The Environmental Board also recommended Route B, saying it was the best route to avoid critical environmental features.  The project will go before City Council sometime after it returns from its summer break in late July.