TPWD issues recommendations on AEP Texas’ proposed 345-kV line

The Texas Parks and Wildlife Department (TPWD), in March 24 comments filed with the Public Utility Commission (PUC) of Texas, recommended that the PUC select a route for AEP Texas’ proposed Bonilla to Ladekidde 345-kV transmission project that would minimize adverse impacts to natural resources, such as Alternative Route H, P, L, or I.

As noted in the comments, American Electric Power’s (NYSE:AEP) AEP Texas proposes to design and build the new double-circuit capable line in Willacy and Cameron counties in Texas. The line would be located between the proposed AEP Texas Bonilla substation located west of the Orphanage Road and U.S. Highway (US) 77/Interstate Highway (IH) 69 intersection in Cameron County, and the proposed E.ON Climate & Renewables North American (E.ON) Ladekidde substation, located about 0.2 miles north of the County Road (CR) 3600 (Rhodes Road) and CR 415 (Rodriguez Road) intersection in Willacy County. The line, the TPWD added, is being built to connect E.ON’s 230-MW wind energy development, Magic Valley II, to the ERCOT electrical grid.

The construction of the proposed line would require a 150-foot-wide project right of way (ROW) that would be 22 miles to 32 miles long, depending on the route selected. The TPWD also noted that AEP Texas anticipates that the typical structure for the project would be a steel, single-pole structure with one curved davit arm on top until a second circuit can be installed, at which point a second curved davit arm would be added.

The structures would be about 106 feet tall, but the height would vary depending on clearance requirements, the TPWD said.

AEP Texas retained Burns & McDonnell Engineering Company to select and evaluate alternative routes, as well as to prepare an environmental assessment (EA) and alternative route analysis in support of AEP Texas’ application to the PUC for a certificate of convenience and necessity.

The TPWD added that Burns & McDonnell evaluated 21 alternative routes and recommended “Alternative Route H” as the route that best addressed the requirements of the Public Utilities Regulatory Act and balances the PUC routing criteria related to land use, ecology, and cultural resources, based on the fact that the route:

  • Is tied with “Route P” for having fewest habitable structures within 500 feet of ROW centerline – two
  • Parallels existing transmission lines for 1.45 miles
  • Parallels transmission lines, other compatible ROW and property lines for about 90% of its total length
  • Has the fourth least amount of ROW across cropland – 19.11 miles
  • Is the fifth shortest alternative – at about 22.85 miles, it is about 0.83 miles longer than the shortest route
  • Is tied for second for least amount of length crossing potential wetlands – about 0.03 miles
  • Is tied with Routes I, N, P, and U for the number of cultural resource sites crossed or within 1,000 feet
  • Crosses about 1.93 miles of high probability area HPA for cultural resources

The TPWD said that within the project study area, row crops dominate the landscape; high quality wildlife habitat is limited and occurs as patches or narrow, linear strips associated with manmade irrigation and drainage canals. Regardless of the route selected, the anticipated impact to areas that represent potential wildlife habitat would be similar.

The TPWD added that based on a review of the natural resource impacts presented in the EA, project maps, and Geographic Information Systems (GIS) data, it agrees that Alternative Routes H, P, L, and I represent alternative routes that minimize impacts to natural resources, both terrestrial and aquatic.

As indicated in the EA, the possibility that ocelots may occur within the study area exists, the TPWD said. Since federally listed ocelots prefer dense tracts and corridors of brush, the TPWD said that it recommends selecting routes that would avoid or minimize creating new fragments through woodland/brushland habitat, spanning canals, and locating support structures outside of riparian areas to preserve potential travel corridors.

The EA noted that numerous playa lakes and ponds are located throughout the study area that provide important habitat for migratory waterfowl, the TPWD said, adding that grassland bird species are expected to occur in croplands that dominate the study area.

In order to avoid and/or minimize potential bird collisions with a new transmission line, the TPWD recommended that project plans propose to install line markers on portions of the lines that cross or are located near open water wetlands, canals, and riparian corridors.

The TPWD also said that in order to minimize impacts to bird nests, eggs, nestlings, or fledgling birds not yet mobile enough to leave the ROW during construction, it recommends that AEP Texas use a biological monitor to screen the proposed disturbance areas for active nests prior to clearing activities.

The EA indicated that suitable habitat for a number of state-listed species may occur in the project area but did not indicate whether pre-construction pedestrian surveys would occur or if any best management practices, other than implementing required storm water pollution prevention plan measures, would be implemented to avoid or minimize potential impacts to state-listed species that may occur in the project area.

The TPWD added that once the PUC approves an alternative route, AEP Texas should survey the route to determine the potential of the site to support state-listed species or their habitat. For instances in which on-the-ground surveys reveal the occurrence of state-listed species, the TPWD recommended route adjustments to avoid impacting state-listed species and their habitat. If route adjustments cannot be made, the TPWD said that it recommends that AEP Texas coordinate with the department to develop impact-minimization measures specific to the species.

Among other things, the TPWD recommended that AEP Texas and Burns & McDonnell prepare a mitigation plan to provide compensatory mitigation for those habitats where impacts from the line cannot be avoided or minimized.

About Corina Rivera-Linares 3061 Articles
Corina Rivera-Linares, chief editor for TransmissionHub, has covered the U.S. power industry for the past 15 years. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial. She has also covered such topics as health, politics, and education for weekly newspapers and national magazines. She can be reached at clinares@endeavorb2b.com.