The Texas Parks and Wildlife Department (TPWD) on Nov. 12 filed recommendations with the Public Utility Commission of Texas regarding a 345-kV transmission line proposed by CenterPoint Energy Houston Electric, including that Alternative Route 20 is the route that best minimizes impacts to natural resources.
As noted in the filing, CenterPoint proposes to build the new double-circuit transmission line in Brazoria, Matagorda, and Wharton counties in Texas. The new line would connect CenterPoint’s existing Bailey substation located in eastern Wharton County to the existing Jones Creek substation located in southeastern Brazoria County.
The TPWD also noted that the new line would be about 54 to 84 miles long, depending on the final route approved by the commission. The new double-circuit line would be supported primarily by steel lattice with a right of way (ROW) that would be about 100 feet wide, depending on location. In some instances, the TPWD added, tubular steel poles may be used. Typical structure heights may range between 136 feet to 171 feet above ground.
CenterPoint retained POWER Engineers to delineate and evaluate alternative routes and to prepare an environmental assessment (EA) to support CenterPoint’s application to the commission to amend its certificate of convenience and necessity (CCN). CenterPoint identified Route 5 as the alternative route that it believes best addresses certain requirements. The TPWD added that according to the company’s application, Route 5, for instance:
- Is the second shortest route (55.2 miles)
- Crosses the least amount of residential land use areas
- Has a comparably lower number of habitable structures within 500 feet of the route centerline
CenterPoint’s application also identified Route 28 as an alternative route that the company believes best addresses the requirements, based on, among other things, that the route:
- Is one of the shorter routes (57.8 miles)
- Has a moderate number of habitable structures within 500 feet of the route centerline
- Avoids and minimizes potential impacts to community values while environmental integrity is maximized
The TWPD added that the EA did not provide sufficient information based on surveys – aerial or field – remote sensing, modeling, or other available analysis techniques to determine which route would best minimize impacts to important, rare, and protected species. Therefore, the TPWD routing recommendation is based solely on the natural resource information provided in the CCN application and the EA, as well as publicly available information examined in Geographic Information Systems (GIS).
The TPWD also said that of the 30 routes evaluated in the EA, neither Route 5 nor Route 28 adequately minimize adverse impacts to natural resources. The TPWD added that Route 5 makes little use of other existing ROW, crosses 4.5 miles of parks/recreational areas, has 12.1 miles of the route length within the foreground visual zone of parks/recreational areas, and is among the routes with the greatest lengths crossing NWI-mapped wetlands.
Route 28 also ranks relatively poorly for utilization of other existing ROW – 11.1 miles – with 73% of the route situated parallel to apparent features, property lines, railroads, or an existing ROW, the TPWD said, adding that Route 28 has 9.8 miles of the route length within the foreground visual zone of parks/recreational areas. Also, the TPWD said, Route 28 crosses 13.4 miles of upland woodland, 3.1 miles of bottomland/riparian woodland, and 3.9 miles of NWI-mapped wetlands.
The TWPD said that it recommends Alternative Route 20 as the alternative route that best minimizes impacts to natural resources, noting that that route, for instance:
- Avoids crossing TPWD-owned property
- Has the greatest length of route parallel to existing transmission line ROW – 18.5 miles
- Has 20 miles of route parallel to other existing ROWs
- Ranks highest for percentage of route parallel with apparent features, property lines, railroads, or an existing ROW – 89%
- Has no length crossing parks/recreational areas
- Has least length of route within foreground visual zone of park and recreational facilities – 5.3 miles
The TPWD said that Route 20 was selected as the highest-ranking route alternative by the POWER ecology specialist.
The TPWD also recommended that any vegetation clearing be scheduled outside of the general bird nesting season of March 15 to Sept. 15. However, if clearing must occur during nesting season, then nest surveys should be conducted prior to clearing.
The TPWD further recommended avoiding disturbance to the Brazos River, Colorado River, San Bernard River, and their tributaries, which are habitat for the federally endangered sharpnose shiner and four candidate species of freshwater mussel. The TPWD also recommended avoiding disturbance to estuarine habitats important to the smalltooth sawfish. If disturbance is anticipated, the TPWD said that it recommends that a qualified biologist conduct pre-construction surveys for those species.
The TPWD said that if any of those species or their habitat would be impacted by the proposed project, then it recommends that CenterPoint should coordinate with the TPWD and the U.S. Fish and Wildlife Service (USFWS), as appropriate, to determine avoidance, minimization, and mitigation strategies.
In addition, the TPWD said that to avoid or minimize potential adverse impacts to aquatic species, it recommends implementing additional construction methodologies and best management practices, including constructing stream crossings that do not obstruct flow and ensuring that permanent or temporary fills do not smother freshwater mussels.
Among other things, the TPWD also recommended avoiding disturbance of the waterways within the study area that may be inhabited by the alligator snapping turtle, as well as avoiding disturbance of the Texas horned lizard, its burrows, and colonies of its primary food source, the harvester ant, during clearing and construction.
In addition, the TPWD said that it recommends that CenterPoint establish sanitation procedures to prevent the spread of invasive terrestrial plants.