Zone of Visual Influence (ZVI) Maps
The Department of Energy (DOE) and New Hampshire Department of Historical Resources (NHDHR) are conducting a mandated federal Section 106 review of Northern Pass's impacts on historical resources.
Until recently, this review has not been available to the general public. On June 17, 2015, Governor Hassan requested that DOE post review documents, as well as NHDHR's preliminary comments, on the Northern Pass Environmental Impact Statement (EIS) site as soon as possible. NHDHR concurred that the public's interest demanded it. A redacted version is now available online to the public as "NH Division of Historical Resources – Project Area Form Review."
This redacted version includes "Sketch Maps" for the Section 106 review prepared by TJ Boyle, a DOE subcontractor for the EIS. The base "Sketch Maps" show the "zones of visual influence" within the "area of potential effect" (APE) along the full 187-mile length of the proposed project.
The general public may now view this viewshed analysis online; links follow at the end of this blog.
The viewshed analysis is designed for the Section 106 assessment of impacts on historical resources, not for landowners who wish to assess visual impacts on their own properties. Nevertheless, the maps serve as a limited preview of what landowners can expect from Northern Pass as currently proposed.
Another such preview is offered in the Appalachian Mountain Club's earlier visual impact assessment and flyover video. This assessment is based upon 2012 tower heights and will be updated. (See "Methodology" in the VIA for a discussion of data used to compose the videos. Links to the eleven fly over videos are included below to correspond to the Section 106 Sketch Maps.)
For the 106 review, DOE and NHDHR have decided to consider one mile either side of the center of the proposed transmission line as the APE.* (The 2012 AMC fly over videos show a wider APE.)
The zones are color coded to represent how many towers would be visible from a given location within the APE. White: 0 towers. Yellow: 1 to 5 towers. Green: 6-10 towers. Orange: 11-20 towers. Red: 21-40 towers. Burgundy: over 41 towers.
Conditions are leaf-on.
“Surface” viewsheds for all but the immediate APE include the screening effects of objects over 7 ft (2.1 m) in height (leaf-on tree conditions, buildings, etc.). Thus, should a currently forested area be cleared or drop its leaves, its viewshed could be impacted.
Following is an example of visual impacts within the APE along Streeter Pond Road in Sugar Hill. The shaded area outlined in black represents the APE. Impacts within the APE range from 0-5 towers (white, yellow) through 40+ towers (burgundy) in leaf-on conditions. Visual impacts beyond the 1-mile APE certainly exist in given locations, but they are not shown on these maps.
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| Streeter Pond Road, Sugar Hill (detail from Sketch Map G, White Mountains PAF) |
As well as the 31 host communities, within the one-mile APE are located an additional 16 towns that would be visually impacted: Andover, Boscawan, Colebrook, Dix's Grant, Epsom, Errol, Franconia, Jefferson, Landaff, Lisbon, Littleton, Nottingham, Plymouth, Salisbury, Sanbornton, Wentworth's Location.
For instance, on the map above, visual impacts extend into a "non-host" town, Franconia, on the east side of I-93 near the right-center of the map.
To see visual impacts on individual towns within the one-mile APE, click on the relevant Project Area Form link below and scroll down the Sketch Maps until you find your town, which may be represented on more than one map. Civic boundaries are not shown on these maps. You will need to know street and road names or other identifying features.
For a fuller preliminary idea of visual impacts, view both the specific Section 106 Sketch Map for your area plus the corresponding AMC fly over video.
Sect. 106 White Mountains Project Area Form. Sketch Maps for Bethlehem, Campton, Dalton, Easton, Franconia, Landaff, Lincoln, Lisbon, Sugar Hill, Thornton, Whitefield, Woodstock, (Littleton). Click here.
(Corresponding AMC fly over videos for Whitefield - Dalton - Lancaster, Sugar Hill - Bethlehem, Woodstock - Lincoln - Easton, Campton - Thornton.)
Sect. 106 Great North Woods Project Area Form. Sketch Maps for Pittsburg, Clarksville, Stewartstown, Dixville, Dix’s Grant, Colebrook, Wentworth’s Location, Errol, Millsfield, Dummer, Stark, Northumberland, Lancaster, (Jefferson). Click here.
(Corresponding AMC fly over videos for Dixsville - Stewartston - Clarksville - Pittsburg, Dummer - Millsfield, Northumberland - Stark.)
Sect. 106 Lakes Region Project Area Form. Sketch Maps for Plymouth, Holderness, Ashland, Bridgewater, New Hampton, Bristol, Sanbornton, Hill, Franklin, Andover, Northfield, Salisbury. Click here.
(Corresponding AMC fly over videos for Bristol - Bridgewater - New Hampton - Ashland - Holderness, Northfield - Franklin - Hill - New Hampton.)
Sect. 106 Merrimack Valley Project Area Form. Sketch Maps for Canterbury, Boscawen, Concord, Epsom, Pembroke, Allenstown, Nottingham, Deerfield. Click here.
(Corresponding AMC fly over videos for Concord - Canterbury, Deerfield - Allenstown - Pembroke.)
All PAF Sketch Maps and other Section 106-related materials linked to in this blog post are located on the public "Consultations - Section 106" page, the public "Project Library Documents" page, or the public "Project Library Comments" page of the DOE's Northern Pass EIS site.
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*NHDHR concurred with DOE's decision to limit the APE to 1 mile, but notes that it will adjust the APE if necessary to consider impacts on historical properties outside this area. (Northern Pass's lawyer, Maryanne Sullivan, Hogan Lovells, has commented on the APE here.) On June 19, 2015, the Forest Society and other stakeholders expressed dismay to NHDCR Commissioner Van McLeod over NHDHR's concurrence with the base 1-mile APE.
