REVIEW OF THE USE AND PHYSICAL CONDITION OF PROJECT FACILITIES ON NATIONAL FOREST SYSTEM LANDS

Transcription

1 Tacoma Hydroelectric Project FERC No REVIEW OF THE USE AND PHYSICAL CONDITION OF PROJECT FACILITIES ON NATIONAL FOREST SYSTEM LANDS Public Service Company of Colorado MARCH 2007

2 TABLE OF CONTENTS Section Title Page No. ACRONYM LIST...AL Introduction and Background Scope of Study for Condition and Use Assessment Cascade Creek Facilities Assessment of Visual Contrast of Project Facilities in Cascade Creek Area Retired and New Gauging Station on Elbert Creek Forebay Lake and Tacoma Penstock Assessment of Visual Contrast in the Forebay Lake Area Tacoma Powerhouse Assessment of Visual Contrast at Tacoma Powerhouse Area...7 i

3 LIST OF FIGURES Figure Title Page No. Figure 2-1 Forebay penstock map....5 ii

4 LIST OF PHOTOGRAPHS Photograph Title Page No. Photograph 1 Public viewpoint of flume and diversion structure (virtually indistinguishable) from access road bridge...8 Photograph 2 Opposite public viewpoint of flume from access road bridge....8 Photograph 3 View of flume and surrounding landscape (aspen and mixed conifer forest) from the public access road....9 Photograph 4 View of Cascade Creek pipeline from public access road...9 Photograph 5 View of Cascade Creek pipeline from public access road...10 Photograph 6 Storage barn (front view) Photograph 7 Storage barn (back view) Photograph 8 Fenced storage area...11 Photograph 9A Elbert Creek gauging station...11 Photograph 9B Elbert Creek gauging station Parshall flume and chart recorder Photograph 9C Elbert Creek gauging station electronic equipment enclosures and communication tower...12 Photograph 10 Low-lying section of penstock along access roads to Forebay Lake...13 Photograph 11 Raised section of penstock along access road to Forebay Lake Photograph 12 Raised section of penstock crossing access road to Forebay Lake...13 Photograph 13 Penstock parallels access road to Forebay Lake Photograph 14 Forebay Lake with Tacoma Penstock Photograph 15 Forebay Lake with Tacoma Penstock Photograph 16 Surge tank at Forebay Lake Photograph 17 Forebay Lake dam and surge tank Photograph 18 Forebay Lake...16 Photograph 19 Tacoma powerhouse view from across the river Photograph 20 Photograph 21 View of additional structures from across the river...17 View of Tacoma powerhouse facilities from whitewater boating take-out on Animas River (river left)...17 Photograph 22 View of building on river left Photograph 23 View of large shed and concrete pad (river left)...18 iii

5 Acronym List Federal/State Agencies Advisory Council on Historic Preservation (ACHP) Colorado Department of Natural Resources (CDNR) Colorado Water Conservation Board (CWCB) Colorado Department of Natural and Economic Resources, Division of Environmental Management (CDEM) Colorado Department of Wildlife (CDOW) Colorado Division of Water Quality (CDWQ) Colorado Natural Heritage Program (CNHP) Colorado State Forest Service (CSFS) Colorado State Historic Preservation Officer (CSHPO) Federal Energy Regulatory Commission (FERC) National Park Service (NPS) National Weather Service (NWS) U.S. Department of Interior (DOI) U.S. Environmental Protection Agency (USEPA) U.S. Fish and Wildlife Service (USFWS) U.S. Geological Survey (USGS) U.S. Department of Agriculture (USDA) U.S. Forest Service (USFS) Other Entities Durango and Silverton Narrow Gauge Railroad (D&SNGR) Electra Sporting Club (ESC) Public Service Company of Colorado (PSCo) Documents 401 Water Quality Certificate (401 WQC) American Disabilities Act Accessible Guidelines (ADAAG) Colorado State Water Quality Standard (COWQS) Draft Environmental Assessment (DEA) Environmental Assessment (EA) Environmental Impact Statement (EIS) Forest Service Outdoor Recreation Accessibility Guidelines (FSORAG) Memorandum of Agreement (MOA) National Wetland Inventory (NWI) Notice of Intent (NOI) Notice of Proposed Rulemaking (NOPR) Preliminary Draft Environmental Assessment (PDEA) Programmatic Agreement (PA) Scoping Document (SD) Shoreline Management Plan (SMP) AL-1

6 Acronym List Laws/Regulations Americans with Disabilities Act (ADA) Clean Water Act (CWA) Code of Federal Regulations (CFR) Electric Consumers Protection Act (ECPA) Endangered Species Act (ESA) Federal Power Act (FPA) Fish and Wildlife Coordination Act (FWCA) National Environmental Policy Act (NEPA) National Historic Preservation Act (NHPA) Terminology Cubic feet per second (cfs) Degrees Celsius (C) Degrees Fahrenheit (F) Dissolved oxygen (DO) Feet (ft) Gallons per day (gpd) Geographic Information Systems (GIS) Gigawatt Hour (GWh) Global Positioning System (GPS) Grams (g) Horsepower (hp) International Symbol of Accessibility (IAS) Kilogram (kg) Kilowatt (kw) Kilowatt-hour (kwh) Mean Sea Level (msl) Megawatt (MW) Megawatt-hours (MWh) Micrograms per liter (µg/l) Milligrams per liter (mg/l) Millimeter (mm) Million gallons per day (mgd) National Forest System Lands (NFS) National Geodetic Vertical Datum (NGVD) National Wetlands Inventory (NWI) Non-governmental Organizations (NGOs) Ounces (oz.) Outdoor Recreation Access Route (ORAR) Outstanding Remarkable Value (ORV) Parts per billion (ppb) Parts per million (ppm) AL-2

7 Acronym List Pounds (lbs.) Power Factor (p.f.) Probable Maximum Flood (PMF) Project Inflow Design Flood (IDF) Rare, Threatened, and Endangered Species (RTE) Ready for Environmental Analysis (REA) Resource Work Groups (RWG) Revolutions per Minute (rpm) Rights-of-way (ROW) San Juan National Forest (SJNF) Stakeholders (federal and state resource agencies, NGOs, and other interested parties) Volts (V) Wastewater treatment plant (WWTP) AL-3

8 1.0 Introduction and Background Public Service Co. of Colorado (PSCo) owns and operates the Project facilities located on lands within the boundaries of the San Juan National Forest (SJNF). A study was conducted according to a study plan approved by the Federal Energy Regulatory Commission (FERC) 1 in its Study Plan Determination dated March 24, The purpose of the study is to evaluate the effects of Project facilities on the visual character of the landscape within the San Juan National Forest (SJNF). Specific Project facilities to be studied were identified in the Study Plan, as modified by FERC. The study methodology was described in the Study Plan which is incorporated herein by reference. 2.0 Scope of Study for Condition and Use Assessment The Project facilities under review include those Project works that occupy National Forest Service (NFS) lands along Cascade Creek and in the vicinity of the Tacoma powerhouse area. The Forebay Lake area was also evaluated. The study focused on the assessment of the effects on aesthetic resources and, indirectly, recreational resources. 2.1 Cascade Creek Facilities Project facilities on or adjacent to Cascade Creek include a diversion dam, intake structure, wooden flume, siphon, and ancillary operation and maintenance (O&M) facilities. The existing diversion structure was constructed in It consists of an approximately 10-foot-high concrete dam spanning 30 feet across Cascade Creek, reinforced with steel and rail sections. The crest of the dam is an ogee section topped by wooden flashboards. The diversion works include an intake with gates and sediment control facilities, which serve to deliver water to a wooden flume. The Cascade Creek flume transports water diverted at the Cascade Creek Diversion Dam about one mile to the Cascade pipeline inlet. The 4,200-foot-long flume is a 10-foot-diameter semi-circular wood flume supported on timber cradles and timber trestles across small creek beds over which the flume crosses. The Cascade Creek siphon and pipeline which begin at the end of the flume are constructed from steel pipe. The entire pipeline is roughly 14,500 feet long with a 64-inch diameter from intake to outlet, which is buried across primarily private property, including the Cascade Village and Durango Mountain Resort developments. The siphon section is approximately 1,400 feet long and crosses Forest Service lands and spans Cascade Creek on a steel bridge. The Project facilities in the Cascade Creek area are set in a narrow valley upstream of U.S. Highway 550. The creek, flume, and ancillary storage structures are nestled among a mixed-conifer and aspen forest (Photographs 1 through 8 - all photographs are located at the end of this report). The area is covered with dense ground-level vegetation. The flume is visible at several locations 1 Refer to Issue Assessment No. 7 and Study Plan Condition of Project Facilities on Cascade Creek. This study plan was modified by FERC in its Study Plan Determination dated March 24, 2006 to include Project facilities and features located at and near the Tacoma powerhouse on National Forest System Lands. 1

9 along the dirt access road that leads to the Project structures (barn and fenced yard) used for storage. The raised flume parallels Cascade Creek through the valley following the same terrain, and while the flume extends above the surrounding vegetated landscape in places, the wooden structure has weathered and merged visually with much of the natural character of the area. At the diversion structure itself, the major components associated with the structure are constructed of concrete and stand in only minor contrast to the immediate surrounding landscape of exposed rock. When considered as part of the wider landscape, the thick ground-level vegetation and stands of aspen and pines provide natural screening and make the diversion structure virtually indiscernible from the primary public viewpoint on the bridge over the access road (Photograph 1). Generally, the structure is not readily visible until it is approached on foot. The siphon section of the pipeline that starts at the end of the flume is set in the ground and above ground on NFS lands. The steel pipe is screened from typical public viewpoints, except, notably, for several locations along U.S. Highway 550 and the dirt access road to Cascade Creek Diversion Dam. Much of the siphon and pipeline mixes with and is screened by the surrounding landscape of mixed conifers, aspens and ground shrubs (Photograph 4) from the major public viewpoints. Where the structure is raised above the ground, the siphon is clearly visible (Photograph 5); however, the contrast with the surrounding landscape is minimal due to the dark (black) color of and background at the pipeline. In addition to the diversion, flume and pipeline, the Project utilizes several ancillary storage buildings near the Cascade Creek Diversion Dam and flume (Photographs 6 through 8). These ancillary storage buildings are located near the end of the public access road which leads to the Cascade Creek diversion facilities. The primary facilities are situated away from both Cascade Creek and the flume. The lone building is a log storage barn and an outdoor surplus storage area bounded by a basic mesh metal fence. The log storage barn dominates the visual landscape, yet it is constructed of natural materials and colors and blends well with the surrounding forested landscape and similar Forest Service cabins in this area. The building s weathered exterior (large log beams and rusted metal roof) presents an aged and darkened structure that is in character with its surroundings. The fenced outdoor storage area displays a disorderly and scattered appearance. The metal fence provides no screening and the scattered items spare log beams, gravel piles and other miscellaneous construction materials are in plain view and stand in contrast to the surrounding landscape of predominantly natural elements Assessment of Visual Contrast of Project Facilities in Cascade Creek Area The Cascade Creek Diversion Dam and associated facilities are located within the 2B Management Prescription Area. Emphasis is for rural and roaded-natural recreation opportunities. Visual resources are managed so that management activities maintain or improve the quality of recreation opportunities. Forest management activities should not be evident, remain visually subordinate, or may be dominant, but blend with the natural setting. Overall, the Project facilities located in this visual management area are evident, and with respect to the raised wooden flume and pipeline are even dominant at localized public viewpoints; however, in both instances the facilities harmonize and blend with the natural setting in compliance with the 2

10 visual management direction for the area. The main storage barn also blends with the natural setting and is similar in appearance to the cabins/residences in the same area. Finally, the outdoor fenced storage area and the spare construction materials stand in contrast to the overall landscape and do not blend well with the natural setting. These Project facilities, however, are not expected to interfere with, prevent, or inhibit recreation use in the area, and are consistent with the multi-purpose use of the SJNF. 2.2 Retired and New Gauging Station on Elbert Creek Retired Gauging Station Elbert Creek flows from the Hermosa Creek Palisades through a saddle in the Hermosa cliffs steeply down the drainage where it levels off as it crosses Highway 550. The creek meanders through a meadowland area before entering into Electra Lake. The gauging station is encased in a partially rusted metal cylinder at the creeks edge in a backwater section of the creek (Photograph 9A). The old structure is set among the riparian vegetation and surrounded at its base by sediment and woody debris. The gauge structure is not readily visible from a trail along Elbert Creek. Once in view, it stands in contrast to the thick vegetation, creek and surrounding forest, specifically due to the color contrast of the gray metal case against a predominantly green landscape. The old gauge structure is extremely small and passive in the landscape, and even in close proximity to a viewer, is not dominant. New Gauging Station (1998) The new gauging station consists of a small metal Parshall flume, chart recorder enclosure, and a colocated steel lattice tower, antenna, solar panel and equipment enclosure (see Photographs 9B and 9C). The gauge structure is not readily visible via public access from a trail along Elbert Creek. Once in view, it stands in contrast to the thick vegetation, creek and surrounding forest, specifically due to the color contrast of the gray metal case against a predominantly green landscape. The new gauge structure is small and passive in the landscape, and even in close proximity to a viewer, is not dominant. 2.3 Forebay Lake and Tacoma Penstock The Tacoma penstock consists of two distinct sections with Forebay Lake being the point of separation. The first section is a 66-inch-diameter, welded-steel pipeline constructed above ground extending from the outlet at Electra Lake 9,000 feet (half of which crosses NFS) to a bifurcation structure near Forebay Lake. This section of the penstock is supported by concrete thrust blocks and piers. The penstock runs through stands of aspen and mixed conifer trees as well as much of the low-lying ground vegetation between Electra Lake and Forebay Lake. Public access to this landscape primarily occurs along a dirt access road leading from Terminal Dam at Electra Lake. The penstock is not in view along much of the access road, but occasionally intersects or runs along the road. In these instances, the raised steel penstock, piers and concrete thrust blocks appear in contrast to the surrounding landscape (Photographs 10 through 13). 3

11 The second section of the Tacoma penstock starts at the bifurcation structure near Forebay Lake and consists of two welded-steel penstocks (54 and 30 inches in diameter) installed just below the ground level for 2,056 feet until they enter the Tacoma powerhouse. The only visible portion of the structure occurs at the canyon s edge where the penstocks drop steeply down to the powerhouse. At this location, concrete thrust blocks and steel penstocks along with transmission lines are widely visible. The major penstock elements as well as ancillary structures are situated in a broad level area located east of Forebay Lake. At Forebay Lake, a 12-foot-diameter, 116-foot-high surge tank is installed at the aboveground (66-inch-diameter) penstock about 1,000 feet upstream of where the penstock splits and drops below ground and into the Animas River canyon. The structure stands starkly apart from the surrounding landscape in both color and form (Photographs 14 through 18). The lighter beige paint on the surge tank is in direct contrast to the largely darker green stands of trees and riparian vegetation that comprise the majority of the Forebay Lake visual landscape. Furthermore, the linear form of the surge tank extends vertically from the lake and towers above many of the trees where the surge tank rises from the penstock (Photograph 16). Forebay Lake itself is located downstream of Electra Lake with a small release of about 50 gallons per minute that has been released from the penstock into Forebay Lake since 1982, when Forebay Lake s use as an integral part of operations was discontinued. Project facilities and structures at Forebay Lake include Forebay Dam, a concrete spillway and a gaging house. Forebay Dam is an earth and rock dam, roughly 100 feet long and 20 feet high. A low concrete overflow structure is located south of the dam (Photograph 17). The earthen dam blends with the surrounding landscape Assessment of Visual Contrast in the Forebay Lake Area The access road to Forebay Lake and the upper penstock are located in a 2A Management Prescription Area and is not open to public motorized use. Emphasis is for semi-primitive motorized recreation opportunities. Visual resources are managed so that management activities are not evident or remain visually subordinate. The access road to Forebay Lake provides the main public non-motorized access and viewpoints of the Project facilities in this area. Along the majority of the access road to Forebay Lake, the Tacoma Penstock is not visible; however, at several locations the penstock is visible, yet remains visually subordinate to the natural landscape (Photographs 10 and 11). At several other locations (Photographs 12 and 13), the penstock is highly visible and dominates the visual landscape (Figure 2-1). These areas are few, but at these locations, the facilities stand in contrast to the natural landscape and the visual management objectives for the area. The penstock and surge tank structures at Forebay Lake, while hidden from view at times, become highly visible near Forebay Dam and adjacent shoreline of the lake. At these locations, the surge tank towers above the natural vegetation while the connecting penstock sits in front of the shoreline over the water and in front of the riparian vegetation. These Project features dominate the landscape at these locations. 4

12 Figure 2-1 Forebay penstock map. 5

13 2.4 Tacoma Powerhouse The Tacoma powerhouse is located on the Animas River below Electra Lake and Forebay Lake. The powerhouse is a brick building constructed in 1906 and is approximately 108 feet long, 64 feet wide, and 30 feet high. In addition, two cabins constructed of wood with metal roofs and several small wood and metal storage sheds are located at the Tacoma powerhouse site on the right (west) bank of the river. The entire area is able to be viewed from the river itself and across the river from the Durango and Silverton Narrow Gauge Railroad (D&SNGR) tracks along the Animas River (Photographs 19 and 20). From these two similar vantage points, the brick powerhouse and ancillary buildings are clearly visible and draw visual attention; however, the brick color of the powerhouse blends with the canyon walls that dominate much of the Animas River canyon downstream of the powerhouse (and even the waters of the Animas River). The area behind and slightly downstream of the powerhouse is used for surplus storage of construction and other Project-related materials. Generally, these areas and materials are not visible due to screening by the powerhouse or vegetation, except for a small area immediately adjacent to the downstream-side of the powerhouse. In addition, both cabins at the powerhouse location are painted white with either gray or green metal roofs. While the predominant white color of both structures stands in contrast to the surrounding landscape, the older, simple structures have weathered and aged presenting an antiquated cabin appearance that tempers much of the tonal contrast to the surroundings (Photograph 21). Ancillary structures are found surrounding the cabins but present a similar antiquated appearance as the cabins and exist on a much smaller scale compared with the powerhouse and cabins. Behind the powerhouse, several unbounded areas are used for surplus storage, which lack any form of fencing and screening from the surrounding landscape. While these areas are visually unpleasing, they are not visible from the public viewpoints on the river and from the railroad as these areas are screened by the powerhouse and thick vegetation around the powerhouse. Several additional Project structures are located on the left (east) bank at the powerhouse location, where the D&SNGR tracks parallel the river. Four structures are present including one house, a large storage shed with an adjacent concrete pad, and two small sheds with hydrants. The house and large storage shed (with a concrete pad) are primarily white in color, while the small sheds (with hydrants) are painted brown. All of these structures are situated amidst a stand of pine trees. All four structures are situated near the railroad tracks across from the powerhouse and bridge. However, the two white structures are more visible from the public viewpoint at the bridge and stand in contrast to the surrounding treed landscape (Photographs 22 and 23). Also evident is the debris and materials dispersed around these buildings, which do not have any fence or screening to block the debris from the visible landscape. The remaining two small shed structures are generally subordinate visually to the surrounding landscape as they are tucked among the other larger structures and their brown color blends with the surrounding terrain and tree cover. Also located among the various structures toward the downstream edge of the area are the remnants of gas street lights which once shone among the housing and along this section of track. 6

14 2.4.1 Assessment of Visual Contrast at Tacoma Powerhouse Area The Tacoma powerhouse and related Project facilities are located in a 3A Management Prescription Area. Management emphasis is for semi-primitive non-motorized recreation in both roaded and unroaded areas. Visual resources are managed so that management activities are not visually evident or remain visually subordinate. These Project facilities lie along the historic D&SNGR, which has been in continuous operation for over 123 years. The Forest Service manages the corridor [by what authority?] the railroad passes through in order to retain its historic and scenic integrity. The prescription applied to the corridor stresses Rural and Roaded Natural recreation opportunities while retaining or enhancing scenic values inherent in the naturally appearing landscape (USDA 1983, pg. J-24). The Tacoma powerhouse and its ancillary cabins are historic structures of undetermined significance and thus may meet the Forest Service visual management objective of retaining historic integrity along the D&SNGR corridor. PSCo is in the process of determining National Historic Preservation Act eligibility via the Cultural RWG Study Plan #1. Once eligibility is determined, final SJNF historic integrity obligations will be established. J:\Projects\Xcel Energy\ Tacoma\0400-Recreation\Condition of Proj Fclts\T-Cndtns of ProjFclts doc KB/elt /8.0 March 29,

15 Photograph 1 Public viewpoint of flume and diversion structure (virtually indistinguishable) from access road bridge. Photograph 2 Opposite public viewpoint of flume from access road bridge. 8

16 Photograph 3 View of flume and surrounding landscape (aspen and mixed conifer forest) from the public access road. Photograph 4 View of Cascade Creek pipeline from public access road. 9

17 Photograph 5 View of Cascade Creek pipeline from public access road. Photograph 6 Storage barn (front view). Photograph 7 Storage barn (back view). 10

18 Photograph 8 Fenced storage area. Photograph 9A Elbert Creek gauging station. 11

19 Photograph 9B Elbert Creek gauging station Parshall flume and chart recorder. Photograph 9C Elbert Creek gauging station electronic equipment enclosures and communication tower. 12

20 Photograph 10 Low-lying section of penstock along access roads to Forebay Lake. Photograph 11 Raised section of penstock along access road to Forebay Lake. Photograph 12 Raised section of penstock crossing access road to Forebay Lake. 13

21 Photograph 13 Penstock parallels access road to Forebay Lake. Photograph 14 Forebay Lake with Tacoma Penstock. 14

22 Photograph 15 Forebay Lake with Tacoma Penstock. Photograph 16 Surge tank at Forebay Lake. 15

23 Photograph 17 Forebay Lake dam and surge tank. Photograph 18 Forebay Lake. Photograph 19 Tacoma powerhouse view from across the river. 16

24 Photograph 20 View of additional structures from across the river. Photograph 21 View of Tacoma powerhouse facilities from whitewater boating take-out on Animas River (river left). 17

25 Photograph 22 View of building on river left. Photograph 23 View of large shed and concrete pad (river left). 18