Hells Canyon Complex Aesthetic Resource Inventory and Evaluation Idaho Power Company
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Cryy8h8yr 6rurvpSr pr Dr hq@hyhv U@8CID86GS@QPSU 'DYLG(YDQVDQG$VVRFLDWHV,QF 6HDQ6XOOLYDQ :DUUHQ%DFRQ -RGL5LRV &LQG\0DHGD UrpuvphySr 6rqv@%" 1RYHPEHU +HOOV&DQ\RQ&RPSOH[ )(5&1R &RS\ULJKWE\,GDKR3RZHU&RPSDQ\ Aesthetic Resource Inventory and Evaluation Idaho Power Company ABSTRACT This technical report describes a study that is part of the Federal Energy Regulatory Commission (FERC) relicensing process for the Idaho Power Company (IPC) Hells Canyon Complex (FERC No. 1971) hydroelectric project (Project). The study was commissioned by IPC and conducted by David Evans and Associates, Inc. (DEA), and its purpose was to evaluate the effects of Pro- ject facilities and operations on the aesthetic environment within the Study Area. The Project is located on the Snake River, the largest river in Idaho, in the southern portion of Hells Canyon. The Project includes Brownlee, Oxbow, and Hells Canyon reservoirs and the dams, powerhouses, and appurtenant facilities associated with the reservoirs. The Study Area in- cludes the Project and adjacent lands, the Hells Canyon National Recreation Area (HCNRA), and 14 transmission lines that cover approximately 658 miles and extend through northeastern Oregon and southwestern and southern Idaho. Because most of the public land in the Study Area is under either Bureau of Land Management (BLM) or US Forest Service (USFS) jurisdiction, the protocols for visual resource assessment used by these two agencies were used to conduct the study. The BLM’s protocol is called Visual Resource Management (VRM) and relies on a Visual Contrast Rating to determine the visual condition of a landscape. The USFS’s protocol is called Scenery Management System (SMS) and relies on an assessment of landscape character and scenic integrity to determine the visual and aesthetic condition of a landscape. Of 152 potential sites in the Study Area, 91 were chosen for evaluation primarily because Project facilities, operations, or effects of the operations were visible from these sites. Project facilities and operations include transmission lines, power-generating facilities and appurtenant facilities, access and service roads, and hardscape elements. Effects of operations include reservoir and river water-level fluctuation and alterations to vegetation. Of the 91 sites that were evaluated, 79 (87 percent) were determined to need some kind of miti- gation to address the visual and aesthetic impact of Project facilities or operations. Specific miti- gation measures are suggested. For suggested mitigation measures that may not be reasonable (e.g., moving transmission structures), alternative solutions are suggested. Recommendations for selecting mitigation measures for IPC’s FERC relicensing application and for a long-term visual and aesthetic resource management strategy are also given. Hells Canyon Complex Page i Aesthetic Resource Inventory and Evaluation Idaho Power Company 1 Introduction...............................................................................................................................................1 1.1 Report organization...........................................................................................................................2 1.2 Links to other technical reports.........................................................................................................3 1.3 Study Area ........................................................................................................................................4 1.3.1 A brief history...........................................................................................................................4 1.3.2 Existing conditions...................................................................................................................5 1.3.2.1 Vegetation and climate ..................................................................................................5 1.3.2.2 Land use ........................................................................................................................7 1.3.2.3 Dam and reservoir operations .......................................................................................8 2 VRM Study...............................................................................................................................................10 2.1 Goals and objectives.......................................................................................................................10 2.2 VRM Study Area .............................................................................................................................11 2.3 Overview of the VRM system..........................................................................................................13 2.3.1 Visual Resource Inventory (VRI)...........................................................................................15 2.3.1.1 Scenic quality...............................................................................................................15 2.3.1.2 Visual sensitivity...........................................................................................................15 2.3.1.3 Distance zones ............................................................................................................15 2.3.2 VRM Class.............................................................................................................................15 2.3.3 Visual Contrast Rating...........................................................................................................16 2.4 Application of the VRM system to this study...................................................................................17 2.4.1 VRM Study Area Objective 1.................................................................................................17 2.4.1.1 Method.........................................................................................................................17 2.4.1.2 Results.........................................................................................................................21 2.4.2 VRM Study Area Objective 2.................................................................................................23 2.4.2.1 Method.........................................................................................................................23 2.4.2.2 Results.........................................................................................................................23 2.4.3 VRM Study Area Objective 3.................................................................................................24 2.4.3.1 Method.........................................................................................................................25 2.4.3.2 Results.........................................................................................................................25 2.4.4 VRM Study Area Objective 4.................................................................................................31 2.4.4.1 Method.........................................................................................................................31 2.4.4.2 Results.........................................................................................................................31 2.4.5 VRM Study Area Objective 5.................................................................................................32 2.4.5.1 Method.........................................................................................................................32 2.4.5.2 Results.........................................................................................................................32 3 SMS Study...............................................................................................................................................35 3.1 Goals and Objectives......................................................................................................................35 Page ii Hells Canyon Complex Aesthetic Resource Inventory and Evaluation Idaho Power Company 3.2 SMS Study Area .............................................................................................................................36 3.3 Overview of the SMS ......................................................................................................................37 3.3.1 Constituent information .........................................................................................................39 3.3.2 Special Places.......................................................................................................................40 3.3.3 Ecological factors ..................................................................................................................40 3.3.4 Existing landscape character ................................................................................................40 3.3.5 Existing scenic integrity.........................................................................................................41 3.3.6 Existing ecological integrity ...................................................................................................41 3.3.7 Recommended landscape character ....................................................................................41 3.3.8 Recommended scenic integrity .............................................................................................42 3.3.9 Recommended PM&E...........................................................................................................42