The Western Area Power Administration (WAPA) on April 13 said that it has published the final environmental impact statement (EIS) for the Estes-Flatiron Transmission Lines Rebuild Project, which involves rebuilding and consolidating two transmission lines between the Estes substation and Flatiron substation, west of Loveland, Colo.
The final EIS is a culmination of a five-year environmental study that follows the National Environmental Policy Act, WAPA said, adding that the document defines the proposed route – also called the agency preferred alternative (APA) – for rebuilding a single, double-circuit power line that would replace two 60-year-old transmission lines.
The APA route, announced in December 2016, mostly follows existing transmission line rights of way (ROWs) to minimize environmental impacts, WAPA said.
"The existing transmission lines are aging and deteriorating," WAPA NEPA Document Manager Mark Wieringa said in the statement. "They need to be replaced to make sure the transmission system continues to deliver power reliably and safely to Front Range communities. The preferred alternative would consolidate both lines into one, eliminate about 16 miles of transmission line, and allow the abandoned right of way to revegetate naturally."
Wieringa added, "The feedback received during the scoping and draft EIS comment periods ensured this EIS would be a comprehensive analysis of the different alternatives, and ultimately informed the decision to use parts of different alternatives in the selected route."
The Canyon Lakes District of the Arapaho and Roosevelt National Forest, a cooperating agency on the EIS, concurred on the APA selection, WAPA said.
WAPA noted that it will prepare a record of decision regarding the project no earlier than 30 days from now, and that the Forest Service will issue a separate record of decision for the project.
WAPA said that if it decides to rebuild the line following the final EIS recommendation, construction would begin no earlier than May 2019.
A WAPA spokesperson on April 13 told TransmissionHub: “The project is estimated at $16.6 million for construction work. $19.7 million for the 80-year life cycle of the project, including operations and maintenance.”
As noted in the final EIS, WAPA owns, operates, and maintains two 115- kV single-circuit transmission lines, dating from 1938 and 1953, that connect Estes Park to the Flatiron substation in Larimer County, Colo.
The final EIS noted that the project would remove both existing lines and wood structures between the Flatiron substation and the intersection of Mall Road and U.S. Highway 36 in Estes Park, and replace them with one of the following options:
- One doublecircuit, 115-kV transmission line on steel monopoles within a single ROW
- A new double-circuit, 115-kV transmission line on steel monopoles within a single ROW with the western portion buried in concrete cable trenches for about 2.6 miles
- Rebuilding both lines as single-circuit transmission lines on wood-pole H-frame structures on separate ROWs
- The No Action Alternative, which would keep the existing lines in place and continue established maintenance activities
The proposed project extends between Lake Estes on the east side of Estes Park and WAPA’s Flatiron substation, the final EIS said, adding that the project area analyzed in the final EIS encompasses lands east of the Town of Estes Park and west of the City of Loveland, and includes private lands in Larimer County, as well as public lands administered by the U.S. Department of Interior Bureau of Reclamation, U.S. Forest Service (USFS), the Colorado State Land Board, Northern Colorado Water Conservancy District, and Larimer County. Major transportation corridors are U.S. Highways 34 and 36, the final EIS noted.
The APA would consist of a new double-circuit line on a consolidated ROW using a portion of two alternatives to respond to local conditions in the west and the east portions of the line, according to the final EIS. Under the APA, the four-wheel drive portion of West Pole Hill Road would not be rebuilt or improved on National Forest System land, retaining the challenge for four-wheel drive use, the final EIS said.
Additionally, special design measures would be considered for the segment within the Meadowdale Hills subdivision, including the use of structures with a lower height and shorter span, if they provide a lower visual impact, the final EIS noted. On abandoned ROW, existing structures would be removed and the ROW allowed to return to natural vegetation patterns, the final EIS said.
After reviewing all of the material developed during the EIS process, WAPA selected its preliminary APA and presented it to USFS representatives, who concurred, the final EIS said, noting that WAPA used a composite of alternative selections to create a complete APA.
Discussing the APA and its corresponding regions, the final EIS noted that in the west region, WAPA selected Alternative C, which maximizes the use of adequate and accessible ROW while decommissioning the inadequate ROW and ROW on difficult terrain. While that alternative would have visual impacts, on the whole, Alternative C would offer the best visual resource advantages while also being the most cost effective, the final EIS said.
In the central region, WAPA generally selected the North Line, or Alternative C, which is usually the closest route to the existing Pole Hill Road in that area, and would minimize the amount of access road construction and related project disturbance, thus minimizing impacts to natural resources, the final EIS said. Alternative C would also consolidate the linear development in the central region, according to the final EIS.
WAPA selected the South Line, Alternative B, for its APA on the east end of the project, the final EIS said, adding that Alternative B best meets WAPA’s purpose and need, and avoids or minimizes impacts to key Issues – such as effects of the project on scenic travel corridors – and environmental resources. The existing North Line would be removed on the east end and the ROW would be abandoned to revegetate or be used for the landowners’ purposes, the final EIS noted. While the existing transmission line would be removed from the Newell Lake View subdivision, the ROW and one pole of the existing wood pole H-frame structures would be left in place to retain the fiber optic communications connection to Pinewood Reservoir Dam, the final EIS said.
WAPA believes that given overall considerations, Alternative C would offer the best visual advantages in the west region, the final EIS said, noting that under Alternative C, the ROW would be about 0.1 mile downslope of U.S. Highway 36. Most of the ROW would be screened by trees and the highway embankment as U.S. Highway 36 enters Estes Park; additionally, existing structures immediately adjacent to U.S. Highway 36 would be removed, a substantial improvement in visual impacts compared with existing conditions, the final EIS said.
In the east region, Alternative B on the whole would be expected to have the least visual impact, the final EIS said, noting that Alternative B would be further away from residences near the Newell Lake View Subdivision and is the alternative that contains the least number of roads within 0.5 mile, resulting in less visual impacts to road viewers in the project area. Alternative B would also result in a relatively low amount of forest clearing, further lessening visual impacts, the final EIS said.
Among other things, the final EIS said that the terrain crossed by the project ranges from hilly to mountainous over most of its length. Stream courses are in low areas with relatively narrow floodplains, and can be easily spanned by the transmission line whose structures would be mainly located on higher points where structures can be shorter while still maintaining conductor clearances, the final EIS said. Access roads to structure sites can approach structure locations from either side of the stream course, or can use existing road crossings or cross at advantageous locations with the least environmental impact, the EIS noted.
Based on preliminary information, subject to change after final siting of roads and structures, in the west region, Alternatives C and C1 would have the least number of waterbodies crossed while Alternative C1 would have the least number of waters of the U.S. crossed and Alternatives B and C1 would have the least number of wetlands crossed, the final EIS said. For APA considerations, Alternatives B, C, and C1 have the least numbers of combined water resource features on the west end of the line, the final EIS said.
Discussing the effects on plants, wildlife, and fish, the final EIS noted that the alternatives were not found to have any discrimination among them for listed or sensitive species, so there is no alternative that offers less potential impact than the others. While there are some differences in the amount of elk, mule deer, and moose winter range, since most of the alternatives remain on existing ROW, any effects would be slight in any case, and largely limited to construction activities during the winter months, if any, the final EIS said. A route with the least acreage of overlap with big game winter range would be preferred, the final EIS noted, adding that no fish habitat would be impacted.