BulkTransmission/Visual Resources

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Transmission Visual Resources

Visual Resources
Present, Potentially Affected

When developing transmission line projects on federally managed lands, specific acts are triggered to comply with federal environmental standards.

The following sections from the Federal Land Policy and Management Act (FLPMA) (43 U.S.C. 1701 et. seq.) address visual resource requirements on federal lands where : • “...The public lands be managed in a manner that will protect the quality of the...scenic...values....” Section 102 (a)(8). • “Identifies “scenic values” as one of the resources for which public land should be managed.” Section 103 (c). • “The Secretary shall prepare and maintain on a continuing basis an inventory of all public lands and their resources and other values (including...scenic values)....” Section 201 (a). • “Each right-of-way shall contain terms and conditions which will... minimize damage to the scenic and esthetic values...” Section 505 (a). The National Environmental Policy Act’s (NEPA) (43 U.S.C. 4321 et. seq.) Section 101 (b.) and 102, respectively, requires: • Measures be taken to, “ ...assure for all American...esthetically pleasing surroundings....” and, • Agencies to, “Utilize a systematic, interdisciplinary approach which will ensure the integrated use of...Environmental Design Arts in the planning and decision-making....” A landscape architect, in conjunction with the land’s managing agency, conducts visual impact assessments to evaluate the land’s visual resources. Typical evaluation criterion includes, surface disturbance, scenic quality, sensitivity levels, and distant zones. The results determine the transmission line’s corridor and what major land or infrastructure features to avoid. This assessment also lays the groundwork for anticipated project impacts and mitigation measures. http://www.blm.gov/style/medialib/blm/wo/Information_Resources_Management/policy/blm_manual.Par.34032.File.dat/8400.pdf

Visual Resources Impacts & Mitigation

Transmission line projects causes major long-term visual impacts if the corridor crosses highways, historic trails, and rivers; exists in canyons, residential areas, agricultural lands, recreation areas, and campgrounds. Visual impacts increase when the corridor passes through flat, barren land. Assessing the corridor’s path will identify optimal lattice, monopole, and H-frame placements and paint color selection.

Construction sites impact the immediate areas nearby with debris build-up, light fixtures and post-construction activities. The right-of-way (ROW), or transmission corridor, may also require vegetation clearing or trimming. Reclamation, erosion control, and proper lighting techniques provide mitigation strategies.

Decrease these impacts with the following mitigation measures:

Structures

  • Design lattice, monopoles, H-frames, and substations placement away from roadways, trail and stream crossings, and natural landscape features to mitigate visual impacts, while still enabling over-road clearances.
  • If river crossings are unavoidable, pass at a right angle.
  • Assess if self-weathering steel or galvanized steel fits the landscape best. Weathering steel does not require paint to minimize reflectivity. A dull galvanized steel finish blends with natural surroundings, can have a lighter or darker hue, and is less susceptible to corrosion.
  • Use non-reflective conductors and insulators (i.e., non-ceramic or porcelain).
  • Glass insulators are not permitted in scenic areas on federally managed lands.

Construction site

  • Maintain clean workspaces (construction yards, pull sites, helicopter landing zones, and laydown areas) by storing building materials and equipment out of public viewing areas.
  • Remove construction debris (excess vegetation, building materials, chemicals, wood scraps, etc.) and inactive temporary fencing.
  • Use non-reflective chain-link fencing and cover with screening fabric or slats. Choose a material color that blends in with surroundings.

Roads and Erosion

  • Refrain from widening roads and blading in areas with highly erodible soils.

Reclamation

  • When the construction period is over, construction sites shall be cleaned up and their surfaces shall be restored as closely as possible to pre-construction conditions.
  • Re-vegetate cut- and-fill slopes. Recontour where necessary.
  • Reconstruct rock rims to original state.

Lighting

  • Equip light fixtures with hoods to eliminate glare effects and to prevent light from spilling off the site or up into the sky.
  • Add sensors or switches to minimize disturbances.

Vegetation and rocks

  • If the over and under story requires clearing for tower pads or conductor clearance, taper and feather the remaining vegetation to reflect a natural appearance.
  • Avoid paint or permanent discoloring agents on rocks, vegetation, structures, and fences that indicate survey or construction activity limits to mitigate long-lasting impacts.
  • Minimize vegetation clearing, by using drive and crush methods. This allows for re-sprouting and avoids excess root damage.
  • Maintain vegetation clearance along the ROW to not only minimize visual impacts, but also maintain safe work areas.