Electric Transmission Texas (ETT) and Sharyland Utilities have submitted a joint application with the Public Utility Commission of Texas (PUCT) to make changes to their Certificates of Convenience and Necessity (CCN) to build a 345kV power line in Texas, US.

The proposed cross valley project will be built in parts of Hidalgo and Cameron counties in the Lower Rio Grande Valley of Texas.

ETT and Sharyland’s new transmission line will start from AEP Texas North Edinburg Substation in Hidalgo County to a location near the existing AEP Texas South McAllen Substation.

The line will thereafter, run to the Brownsville Public Utilities Board Loma Alta Substation in Cameron County near the Brownsville Ship Channel.

The transmission line could be 96 miles to 125 miles long and the final route length will depend on the route approved by PUCT.

ETT will construct the western portion of the line, while Sharyland will build the eastern part of the transmission line, which is estimated to cost between $314m and $405m.

Subject to approval by the commission, the project is targeted for completion by third quarter of 2016.

Electric Transmission Texas president Calvin Crowder said the project will ensure reliable electric supply for the Lower Rio Grande Valley.

"The Electric Reliability Council of Texas (ERCOT) has determined this project is critical for the reliability of the ERCOT system and, specifically, the Brownsville area," Crowder added.

ETT is a joint venture between subsidiaries of American Electric Power and MidAmerican Energy Holdings Company.