The Texas Parks and Wildlife Department (TPWD) on Sept. 20 recommended that that Public Utility Commission of Texas select a route for a 138-kV transmission line proposed by South Texas Electric Cooperative (STEC) that would minimize adverse impacts to natural resources, such as “Alternative Route B or C.”
As noted in the filing, STEC proposes to build the new double-circuit-capable line in Cameron County, Texas. The new line would be located between the proposed Palmas switching station site located east of Farm-to-Market (FM) Road 2925 on Olmito Road to the existing East Rio Hondo substation at the intersection of FM 106 and FM 2925.
The construction of the proposed line would require a 100-foot-wide permanent right of way (ROW) that would be about six miles long, depending on the route selected. The TPWD also said that STEC anticipates that the typical support structure for the project would be a steel or concrete single-pole structure varying between 70 feet and 100 feet in height.
STEC retained POWER Engineers to select and evaluate alternative routes and to prepare the environmental assessment and alternative route analysis in support of its application to the commission to amend its certificate of convenience and necessity (CCN).
The TPWD also said that POWER evaluated eight primary alternative routes comprised of various combinations of 31 primary route links and recommended “Alternative Route B” as the route that best addressed certain requirements. That route, for instance:
- Is tied with one other route as the shortest route, at 6.21 miles
- Is tied with one other route for having the fewest habitable structures within 300 feet of the proposed ROW centerline, at two structures
- Has the third shortest length of ROW across upland woodlands/brushlands, at 0.30 mile
- Has the third fewest number of stream/canal crossings, with 10
- Has the shortest length of ROW across areas of high archaeological site potential, at 0.67 mile
“Based on a review of the natural resource impacts presented in the EA, project maps, and GIS data, Alternative Route B and Alternative [Route] C appear to best minimize adverse impacts to natural resources,” the TPWD said.
Under general construction recommendations, the TPWD said that it recommends, for instance, the judicious use, and placement of, sediment control fence to exclude wildlife from areas to be disturbed.
Discussing federal regulations, the TPWD noted that the EA provided information regarding potential bird occurrences in the study area, and that it agrees that numerous species may occur in that area as year-round or seasonal residents due to its location within the middle of the Central Migratory Flyway, as well as the range of habitats in the area that provides cover, feeding, nesting, and loafing sites for many species of birds, including Neo-tropical migrants, raptors, and waterfowl.
The TPWD recommended excluding vegetation clearing activities during the general bird nesting season – March 15 through Sept. 15 – to avoid adverse impacts to that group.
The TPWD also said that in order to avoid and/or minimize potential bird collisions with a new line, it recommends that line structures be designed in compliance with the Avian Power Line Interaction Committee (APLIC) standards.
Regarding state regulations, the TPWD noted that within or near the project study area, the Texas Natural Diversity Database contains occurrence records for the black-spotted newt, for instance. Among other things, the TPWD said that as suggested in the EA, once the commission approves an alternative route, the TPWD recommends that STEC survey the route to determine the potential of the site to support state-listed species or their habitat.