70CNR-S2911 North Canyon Phase I Design 2010.pdf

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North Canyon Creek Restoration Project:

Phase I

April 2010 Final Report

This North Canyon Creek Restoration Project is part of a continued effort to minimize the effects of historic and recent impairments to the ecosystem and recreational opportunities within Nevada Tahoe State Park. This product would not be possible without the generous participation of the Nevada Tahoe Resource Team and its affiliated members. This product is authorized pursuant to Section 234 of the Water Resources Development Act of 1996 (PL 104‐303) which provides for coordinated interagency efforts in the pursuit of water quality and watershed planning.

This product was prepared by:

North Canyon Creek Restoration Project; Phase I FINAL REPORT

TABLE OF CONTENTS

CHAPTER 1. EXECUTIVE SUMMARY ............................................................................................................................ 1.1

CHAPTER 2. INTRODUCTION ....................................................................................................................................... 2.1

CHAPTER 3. PROJECT AREA BACKGROUND ................................................................................................................ 3.1

CHAPTER 4. EXISTING CONDITIONS ............................................................................................................................ 4.1

CHAPTER 5. EXISTING CONDITIONS SUMMARY ......................................................................................................... 5.1

CHAPTER 6. GOALS AND OBJECTIVES ......................................................................................................................... 6.1

CHAPTER 7. RESTORATION STRATEGIES ..................................................................................................................... 7.1

CHAPTER 8. OPPORTUNITIES AND CONSTRAINTS ANALYSIS ...................................................................................... 8.1

REFERENCES ................................................................................................................................................................ R.1

APPENDIX A. NORTH CANYON CREEK WETLAND DELINEATION ............................................................................... A.1

APPENDIX B. NORTH CANYON CREEK BIRD LIST ......................................................................................................... B.1

LIST OF TABLES

TABLE 3.1 SUMMARIZED PARTICLE SIZE DISTRIBUTION RESULTS. ........................................................................... 3.12

TABLE 4.1 PEAK DISCHARGE VALUES FOR NORTH CANYON CREEK ........................................................................... 4.2

TABLE 4.2 PEAK DISCHARGE ESTIMATES FOR SPOONER LAKE WATERSHED ............................................................. 4.3

TABLE 4.3 BANK STABILITY SUMMARY FOR NORTH CANYON CREEK WATERSHED .................................................. 4.4

TABLE 4.4 ENTRENCHMENT RATIO SUMMARY FOR NORTH CANYON CREEK WATERSHED ....................................... 4.6

TABLE 4.5 VEGETATION COMMUNITIES IDENTIFIED WITHIN PROJECT AREA ........................................................... 4.9

TABLE 4.6 VEGETATION UNIT BY ACREAGE ............................................................................................................. 4.11

TABLE 4.7 STEWARDSHIP BIRD SPECIES LIST ........................................................................................................... 4.18

TABLE 4.8 BIRD SPECIES OF CONSERVATION PRIORITY ........................................................................................... 4.18

TABLE 7.1A POTENTIAL RESTORATION STRATEGIES (1‐6) ......................................................................................... 7.2

TABLE 7.1B POTENTIAL RESTORATION STRATEGIES (7‐13) ....................................................................................... 7.3

TABLE 8.1 IMPORTANCE SCORING OF PROJECT OBJECTIVES .................................................................................... 8.1

TABLE 8.2 PROJECT OBJECTIVES SCORING DESCRIPTIONS ........................................................................................ 8.2

TABLE 8.3 EXAMPLE OF THE PROJECT OBJECTIVES SCORING PROCESS .................................................................... 8.2

TABLE 8.4 COST SCORING BREAKDOWN ................................................................................................................... 8.2

TABLE 8.5 RESULTS FROM PRELIMINARY ANALYSIS .................................................................................................. 8.3

TABLE 8.6 PRIORITY RESTORATION STRATEGIES ....................................................................................................... 8.4

LIST OF FIGURES

FIGURE 2.1 GENERAL PROJECT AREA OVER SHADED 2001 IKONOS ........................................................................ 2.2

FIGURE 3.1 SHADED USGS TOPOGRAPHIC MAP ...................................................................................................... 3.2

FIGURE 3.2 WATERSHED MAP ................................................................................................................................. 3.3

FIGURE 3.3 GEOLOGY MAP ...................................................................................................................................... 3.4

FIGURE 3.4 GEOLOGIC UNIT KEY .............................................................................................................................. 3.5

FIGURE 3.5 SELECTED GROUND PHOTOS ................................................................................................................. 3.7

FIGURE 3.6 SPOONER MEADOW CHANNEL NETWORK ........................................................................................... 3.9

FIGURE 3.7 EXISTING IMPACTS TO NORTH CANYON CREEK AND SPOONER MEADOW ........................................ 3.11

FIGURE 3.8 NORTH CANYON ROAD GROUND PHOTOS ......................................................................................... 3.13

FIGURE 3.9 CULVERT AND ROLLING DIP LOCATIONS ALONG NORTH CANYON ROAD .......................................... 3.14

FIGURE 3.10 AERIAL IMAGE FROM 1939 ................................................................................................................. 3.17

FIGURE 3.11 AERIAL IMAGE FROM 1939 ZOOMED INTO SPOONER MEADOW ...................................................... 3.18

FIGURE 3.12 AERIAL IMAGE FROM 1953 ................................................................................................................. 3.19

FIGURE 3.13 AERIAL IMAGE FROM 1953 ZOOMED INTO SPOONER MEADOW ...................................................... 3.20

FIGURE 3.14 AERIAL IMAGE FROM 1969 ................................................................................................................. 3.21

FIGURE 3.15 AERIAL IMAGE FROM 1969 ZOOMED INTO SPOONER MEADOW ...................................................... 3.22

FIGURE 3.16 AERIAL IMAGE FROM 1973 ................................................................................................................. 3.23

FIGURE 3.17 AERIAL IMAGE FROM 1973 ZOOMED INTO SPOONER MEADOW ...................................................... 3.24

FIGURE 3.18 AERIAL IMAGE FROM 2001 ................................................................................................................. 3.25

FIGURE 3.19 AERIAL IMAGE FROM 2001 ZOOMED INTO SPOONER MEADOW ...................................................... 3.26

FIGURE 4.1 BANK STABILITY RATINGS ...................................................................................................................... 4.5

FIGURE 4.2 DEGREE OF ENTRENCHMENT IN SPOONER MEADOW .......................................................................... 4.7

FIGURE 4.3 NORTH CANYON CREEK LONGITUDINAL PROFILE ................................................................................. 4.8

FIGURE 4.4 VEGETATION COMMUNITIES MAP ...................................................................................................... 4.10

FIGURE 4.5 WETLAND DELINEATION AND SOIL PIT RESULTS ................................................................................ 4.14

FIGURE 5.1 EXISTING CONDITIONS DIAGRAM ......................................................................................................... 5.2

FIGURE 7.1 GENERAL RESTORATION STRATEGY LOCATIONS .................................................................................. 7.4

FIGURE 7.2 PHOTOS SUPPORTING RESTORATION STRATEGIES 1 AND 2 ................................................................. 7.5

FIGURE 7.3 PHOTOS SUPPORTING RESTORATION STRATEGIES 3 AND 4 ................................................................. 7.6

FIGURE 7.4 PHOTOS SUPPORTING RESTORATION STRATEGIES 5 AND 6 ................................................................. 7.7

FIGURE 7.5 PHOTOS SUPPORTING RESTORATION STRATEGIES 7 AND 8 ................................................................. 7.8

FIGURE 7.6 PHOTOS SUPPORTING RESTORATION STRATEGIES 9 AND 10 ............................................................... 7.9

FIGURE 7.7 PHOTOS SUPPORTING RESTORATION STRATEGIES 11 AND 12 ........................................................... 7.10

CHAPTER 1. EXECUTIVE SUMMARY

2NDNATURE, LLC teamed with Huffman and Carpenter, under contract with US Army Corps of Engineers, to assist the Nevada Tahoe Resource Team (NTRT) with documenting existing conditions and identifying priority restoration strategies for the North Canyon Creek Restoration Project. The project area is located within the North Canyon Creek watershed, approximately 2 miles east of Lake Tahoe near Spooner Summit at the intersections of US Highway 50 and State Route 28 (Figure 2.1). Elevations range from approximately 7000 ft at Spooner Meadow to approximately 7450 ft above sea level at the top of the watershed (Figure 3.1). The Spooner Lake watershed contributes flows to Spooner Meadow from the east, but is not included in the project area.

Spooner Meadow and the upper portions of North Canyon Creek have been significantly impacted by historic human disturbances. Intensive logging operations during the Comstock Era (1860‐1900) included aggressive land clearing, flow diversions to facilitate logging flumes, and large timber staging areas within Spooner Meadow and Spooner Lake. A major flow diversion at the upper end of the project area diverted flows from Secret Harbor Creek into North Canyon Creek, increasing the catchment area from 2.5 to 4 square miles (Figure 3.2). These logging practices resulted in increased runoff, significantly higher stream flows and subsequent channel incision and bank erosion. Livestock grazing (1900‐1930) within Spooner Meadow resulted in additional water management and flow manipulation. Surface water was diverted into numerous irrigation ditches along the meadow margin to help dewater the meadow during wet months and then utilized later in the dry season to irrigate the meadow. Livestock presence within Spooner Meadow also resulted in widespread compaction of meadow soils, loss of vegetation diversity and unstable stream banks.

Continued impacts within the project area include Spooner Dam, paved roadways and an unsurfaced management road. Spooner Dam, constructed just upstream of Spooner Meadow in the early 1860’s, attenuates peak flows from Spooner Lake watershed, thereby reducing the intensity of meadow flooding. Paved highways and roads near Spooner Meadow contribute to increased surface runoff, localized erosion and decreased water quality.

Additionally, an unsurfaced management road (North Canyon Road) runs parallel to North Canyon Creek and crosses the channel at numerous locations in the canyon, often with a poorly sized and/or improperly placed culvert. North Canyon Road is a potential fine sediment source to North Canyon Creek.

Recent human disturbances are primarily the result of outdoor recreation activities including mountain biking, horseback riding, hiking, and cross‐country skiing. Though relatively minimal, the impacts associated with these activities include the construction and use of trails throughout the project area, makeshift stream crossings, vegetation clearing, soil compaction, and erosion.

An Existing Conditions evaluation (Chapter 4) was completed for the project area including assessments of hydrology, geomorphic conditions, vegetation and wildlife communities, and archeological resources. The results provide baseline quantifiable data that can be used to assess the success of future restoration projects.

Bankfull discharge for North Canyon Creek was estimated using a regional regression equation at approximately 10 cubic feet per second (cfs) and the 100 year peak discharge is estimated to be 189 cfs. The Spooner Lake watershed is approximately 1.0 square mile and contributes to North Canyon Creek baseflow; however, peak flows are attenuated due to the large amount of available storage created by Spooner Dam.

A geomorphic assessment of the larger channels from the State Route 28 crossing to Spooner Dam and up North Canyon to Secret Harbor Creek included evaluations of bank stability, entrenchment, channel profile, knick‐points, Chapter 1. Executive Summary p. 1.1 woody debris, and stream crossings. Nearly 75% of the surveyed stream banks within the project area have a moderate to extreme erosion potential risk (Table 4.3) and 75% of surveyed streams channels in Spooner Meadow have a moderate to high degree of entrenchment (Table 4.4).

Vegetation communities were surveyed and mapped for the project area. The majority of the project area was categorized as wetland or riparian areas with upland and mesic meadow areas dispersed further from North Canyon Creek. Invasive species concentrations were also mapped and a Waters of the United States wetland delineation was performed and attached as Appendix A.

Wildlife data was compiled from Nevada Department of Wildlife monitoring for fish, birds, small and medium mammals, reptiles, and benthic macro‐invertebrates. Brook Trout is the only fish species known to currently occupy the North Canyon Creek study area. Bird species that occur in the study area include water fowl, upland fowl, raptors, passerines, and non‐passerines. There are a variety of mammals known to occur within the study area including squirrels, chipmunks, bats, hares, bobcats, mountain lion, bear, fox, deer, weasels, coyote, raccoon, and shrew. Reptiles known to occur in the project area include garter snakes and alligator lizards. An aquatic invertebrate study conducted for North Canyon Creek in 2000 indicated several taxa of intolerant benthic macro‐ invertebrate including Mayflies, Stoneflies, Caddisflies and True Flies (NTRT 2003).

Archeological sites of major importance have been identified around Spooner Meadow and Spooner Lake; the study area falls directly within the Washoe cultural area. The Spooner Lake site includes archeological artifacts as old as 7,100 years and contains a long record of prehistoric occupation. Timber harvesting operations began in the early 1860s throughout the project area, followed by Basque sheep herding around 1900. Remnant irrigation ditches and logging flumes can be found within the project area.

Chapter 5 summarizes existing conditions of Spooner Meadow (2009) and presents clear hypotheses of how historic and current disturbances have resulted in observed and assumed degraded attributes within Spooner Meadow. These attributes include decreased channel stability, a degraded channel/floodplain relationship (incised channel), and degraded streambank and floodplain vegetation community conditions within Spooner Meadow.

These geomorphic and vegetation community impacts have resulted in a decrease in habitat quality for both aquatic and terrestrial wildlife. Subsequently, abundance and diversity of key wildlife species is expected to be below achievable conditions within the project area. The Existing Condition Summary is the first step in a larger Riparian Ecosystem Restoration Effectiveness Framework (2NDNATURE 2010) to identify and document a consistent approach to plan, evaluate, track and report stream restoration projects within the Basin.

The project team established general goals and objectives to focus the 2NDNATURE team efforts and overall resource management actions. The general goal for restoration actions within the project area is to mitigate and/or alleviate the historic and present human impacts to the extent feasible, through the reestablishment of physical, chemical and biological processes that naturally sustain desired biological components of Lake Tahoe riparian ecosystems, including riparian vegetation communities, aquatic species and terrestrial wildlife.

The Phase I objectives for the North Canyon Creek Restoration Project are:

1. Improve Spooner Meadow habitat quality and increase quantity.

2. Improve North Canyon Creek in‐stream and riparian habitat quality and increase quantity.

3. Implement sustainable land use strategies throughout the project area.

Based on the Existing Conditions Summary (Chapter 5) and the Phase I goal and objectives, a list of 13 restoration strategies was developed. The list included site‐specific modifications within Spooner Meadow and the upper portions of North Canyon Creek, as well as management strategies for Spooner dam, the management road, and

Chapter 1. Executive Summary p. 1.2

Chapter 1. Executive Summary p. 1.3 April 2010 outdoor recreation activities. Each restoration strategy was scored and prioritized based on its ability to meet the project goal and objectives, relative to the anticipated costs of design, permitting, construction, and recommended adaptive management.

The following top five restoration strategies are recommended for further development in Phase II of the North Canyon Creek Restoration Project. Strategies A, B and C are recommended modifications to distinct locations within Spooner Meadow (see Figure 7.1 for locations). Strategy D involves modifications to the release of water from Spooner Dam and Strategy E focuses upon the reduction of the chronic sediment generation from the management road that extends throughout the project area.

A. Utilize a “plug and pond” strategy within the North Ditch to redirect flow out onto the meadow surface to the east. Convert the North Ditch from an incised single thread channel into a more natural multi‐threaded network.

B. Remove existing culverts under the management road and replace with one larger culvert redirecting flows away from the South Ditch and back onto the meadow into an existing remnant channel. Plant aspens near and around the site of abandoned South Ditch to enhance transitional habitat.

C. Utilize bio‐engineering bank stabilization techniques to reduce bank erosion and improve aquatic habitat value. Extend plantings beyond banks to encourage establishment of riparian buffer.

D. Modify Spooner Dam to allow storm flow releases into Spooner Meadow during high flow conditions. Automate release structure so that it does not require manual management by personnel.

E. Develop management road strategies to minimize mobilized sediment delivery to surface water resources during runoff events.

Opportunities and constraints were evaluated for each of the five prioritized restoration strategies including anticipated benefits if the restoration strategy is undertaken, and preliminary design, permitting, construction and adaptive management considerations and costs. It was recommended that Restoration Strategies A, B, and C be grouped together as a single project to minimize permitting and adaptive management costs. The total estimated cost for Strategies A‐C to restore and adaptively manage targeted areas in Spooner Meadow would be $855,000.

The implementation of Strategy D could potentially change the hydrologic conditions of Spooner Meadow during higher flows; and should therefore be considered before proceeding with Strategies B and C. The total estimated cost of Strategy D would be $200,000 for design, permitting and construction (management of dam would be continuous and was estimated at $5,000 annually). Strategy E calls for the development of a Management Road Sustainability Plan to supplement this Phase I report. The consulting services for this strategy were estimated at $75,000; design, permitting, construction, and adaptive management cost are premature at this time.

Phase II of the North Canyon Creek Restoration Project, will begin with a Request for Proposals (RFP) for design and permitting services to develop Strategies A‐D. The development of a Management Road Sustainability Plan (Strategy E) could be pursued prior to or in parallel with Phase II work, but does not necessarily require a full design and permitting team at this time.

CHAPTER 2. INTRODUCTION

2NDNATURE teamed with Huffman and Carpenter, under contract with US Army Corps of Engineers, to assist the Nevada Tahoe Resource Team (NTRT) with documenting existing conditions and identifying priority restoration strategies for the North Canyon Creek and Spooner Meadow project area. The project area is located approximately 2 miles east of Lake Tahoe near Spooner Summit at the intersections of State Route 28 and Highway 50 (Figure 2.1). This report includes an existing conditions analysis, ecosystem restoration goals and objectives, a list of restoration options, and the prioritized recommendation of restoration strategies based on an evaluation of opportunities and constraints. The contents within this final report will enable the NTRT to confidently select one or more restoration strategies for implementation to enhance the North Canyon Creek and Spooner Meadow ecosystem. Phase II will consist of refinement, design and permitting of the selected restoration strategies.

The over‐arching goal of any sustainable restoration effort is to implement strategies that help offset the impacts of human disturbance while simultaneously encouraging natural processes to reestablish a new equilibrium within the system. To effectively do this, we must do our best to understand the system as it existed prior to human disturbance and identify the physical, chemical and biological impairments resulting from these disturbances. A clear linkage between impairments and the existing degraded ecosystem condition can directly inform restoration strategies that are hypothesized to improve habitat conditions and complement the natural processes within the ecosystem. Effective strategies must also consider realistic opportunities and constraints including existing and future human interactions with the ecosystem as well as politics and economics.

North Canyon Creek and Spooner Meadow have been severely stressed by historic hydrologic and land use disturbances including intensive logging and grazing. However, unlike many developed watersheds within the Lake Tahoe basin, this project area is currently free of any significant human structures or infrastructure constraints. It is expected that the project area will remain undeveloped into the future as it is protected as parkland by the State of Nevada. Many restoration strategies must settle for enhancements that strike a balance between natural forces and human investments; however the expected future human impacts in Spooner Meadow and North Canyon Creek may be limited to recreation access and fire suppression. This anticipated limited future human presence in the system provides ideal opportunities to implement more system‐wide restoration strategies that encourage the balance between physical processes and critical biological habitats.

Chapter 2. Introduction p.2.1 miles

0 0.625 1.25

FIGURE 2.1: General project area plotted over a shaded 2001

IKONOS image. Dirt and paved roads within the project area are provided along with the major highways. Stream data collected from USGS 24k map.

NEVADA

CALIFORNIA

Lake Tahoe

LEGEND

Project Area

24k Stream Channel

Highway

Management Road

Paved Road

US. HWY 50

S.R. 28

CHAPTER 3. PROJECT AREA BACKGROUND

3.1 GEOGRAPHIC DESCRIPTION

North Canyon Creek and Spooner Meadow are located on the east shore of Lake Tahoe within the Central Carson Range, near the junction of State Route 28 and Highway 50. The project area consists of 1.16 square miles (740 acres) of meadow, riparian and forested landscapes, bound by State Route 28 to the south, Spooner Lake to the east, and Secret Harbor Creek to the north. Elevations range from approximately 7000 ft at Spooner Meadow to approximately 7450 ft above sea level at the top of the project area (Figure 3.1). The project area lies within the North Canyon Creek watershed, excluding the portion of the watershed west of State Route 28 (Figure 3.2).

Spooner Lake watershed contributes flows to Spooner Meadow from the east.

Lands within the project boundary are owned and managed by the State of Nevada as part of Lake Tahoe Nevada State Park. The project area is located within Douglas and Carson City counties and National Forest Service lands surround the designated project boundary.

3.2 GEOLOGIC INFLUENCES

Faulting and glaciations have played a large role in shaping the central Carson Range and the North Canyon area.

Westward tilting of the Carson Range exposes prominent northeast and northwest striking faults that dominate the landscape. Figure 3.3 shows fault data from the Lake Tahoe Basin geologic map (CGS 2008) illustrating the complex faulting within the North Canyon area. Four Pleistocene glacial periods occurred in the Lake Tahoe Basin:

Hobart (>690 kya), Donner Lake (>131 kya), Tahoe (56‐118 kya), and Tioga (9.9‐25.5 kya). Geologic evidence of the Hobart and Donner Lake glaciations has been documented within the Carson Range north of Incline Village (Schweickert et al. 2004). Abundant geomorphic evidence of the Tioga and Tahoe glaciations is widespread along the west and south shores of the Lake Tahoe Basin and in localized areas within the Carson Range. It is assumed that the Donner Lake glaciations did include glacial presence in the upper elevations on the east shore of Lake Tahoe, while the more recent Tahoe and Tioga glaciations may not have significantly influenced the drier east shore (Birkeland 1964 and Hyne et al. 1972).

The project area consists of primarily 4 bedrock types (Figure 3.3, Figure 3.4). Mid‐ to Late Cretaceous rocks (115‐ 85 million years ago (mya)) form the foundation of the Carson Range and dominate the Upper and Lower North Canyon watersheds in the form of monzogranite (Ksgr). Cretaceous granite (Kgr) is exposed in the upper portion of Upper Secret Harbor along the mountain peaks. North Canyon also contains Triassic (245‐208 mya) and Jurassic (208‐144 mya) metavolcanic (JTrmv) and metasedimentary (JTrms) rocks near State Route 28. The larger bedrock geologic units are overlain with Quaternary (0‐2.6 mya) alluvium (Q) and younger Holocene epoch (0‐11.7 thousand years ago (kya)) colluvium (Qc) deposits. Alluvium deposits by definition are unconsolidated, moderately to poorly sorted sand, silt and gravel. This locally includes alluvial fan deposits, glacial outwash and lacustrine (lake) deposits. Colluvium by definition is unsorted, poorly consolidated granitic colluvium, decomposed granite, soil, matrix supported debris flow material, sand and cobble to boulder gravel.

The “grand canyon” area, termed by the RCI (2002) report, is located at the top of North Canyon Creek watershed and consists of colluvium deposits with alluvium deposits immediately down slope in the meadow system. Spooner Meadow consists entirely of alluvium deposits with colluvium deposits extending onto the meadow from the north (further referred to as “alluvial fan” and shown in Figure 3.3). The alluvium and colluvium deposits found within

Chapter 3. Project Area Background p. 3.1

0 0.15 0.3

FIGURE 3.1: Shaded USGS topographic map for the North Canyon

Creek Project Area. Project area consists of Lake Tahoe State Park lands with bordering US Forest Service land.

Spooner Dam

State Route 28

Spooner

Meadow

Project Area

LEGEND

Property Boundary milesFIGURE 3.2: Three watersheds neighboring the project area. Upper

Secret Harbor Creek watershed is termed for discussion clarity, since natural and current fl ows from this watershed are routed west down

Secret Harbor Creek.

0 0.35 0.7

Spooner Lake

1.0 mi2

North Canyon

Creek

1.4 mi2

S la u g h te rh o u se C a n yo n N or th C an yo n Cr ee k

Upper Secret

Harbor Creek

1.5 mi2Secret H arbor Creek

Natural fl ow direction

Spooner

Meadow

Grand Canyon

S ta te R o u te

Highway 50

LEGEND

24k Stream Channel

Major Highway

Watershed Boundary

Project Area

FIGURE 3.3: Geology and generalized faulting for the North Canyon vicinity. Quaternary colluvium and alluvium deposits dominate the watershed divide between Upper Secret Harbor and North Canyon

Creek within the grand canyon area.

0 0.35 0.7

Kgr JTrmv

Qc

Mia Mia

Qc

Qc

Q

Mib

Qc

Q

Q

Q Qc

Ksgr

Ksgr

Ksgr

Ksgr

Q eg

Keg

Q

JTrmv

JTrmvJTrmv Q

Qc

Qc

Q

Mvgf

Qlt

Qfp?

JTrms

Qb

Mia

Qc

Keg

LEGEND

Watershed Boundary

24k Stream Channel

Geology

Ksgr Geologic Unit

Contact

Fault

Qcc Grand Canyon

Alluvial Fan

Map Color

Map Code

Type and Description

JTrms

Metasedimentary rocks (Jurassic and (or) Triassic) Metamorphosed sandstone, calcareous siltstone and silty limestone. Includes metaconglomerate in the Glenbrook quadrangle.

JTrmv Metavolcanic rocks (Jurassic and (or) Triassic) Metamorphosed dacitic and andesitic pyroclastic deposits and flows.

Keg

Granodiorite of East Peak (Cretaceous) Fine- to medium grained, well-foliated, equigranular to weakly porphyritic hornblende-biotite granodiorite to quartz monzodiorite.

Kgr

Granite and granodiorite, undivided (Cretaceous) Undivided fine- to coarse-grained granite and granodiorite;

locally may include alaskite, quartz diorite and diorite.

Ksgr

Monzogranite of Spooner Summit (Cretaceous) White to light-gray, medium-grained idiomorphic, slightly porphyritic with hornblende laths locally to 10 mm long.

Massive to weakly foliated with rare dioritic inclusions 1 to 20 cm long.

Mi

Intrusive rocks (Miocene) Local dikes and intrusions of andesite, latite, basaltic andesite, basalt and rhyolite; in part may be Pliocene. Mia – andesite, basaltic andesite and latite; Mib – basalt and basaltic andesite.

Mvgf

Glenbrook volcanic center (Miocene) Porphyritic hornblende-sanidine latite in irregular-shaped intrusive masses and dikes, local vitric-crystal tuff and associated hornblende trachyte flows and vent fill in the Glenbrook quadrangle (Grose, 1985).

Q

Alluvium (Holocene and Pleistocene) Unconsolidated, moderately to poorly sorted sand, silt and gravel. Locally includes alluvial fan deposits, glacial outwash and lacustrine deposits.

Qc

Colluvium (Holocene) Unsorted, poorly consolidated granitic colluvium, decomposed granite, soil, matrix supported debris flow material, sand and cobble to boulder gravel.

Qfp Flood-plain deposits (Holocene; Pleistocene) Gravelly to silty sand and sandy to clayey silt. Locally includes lacustrine and delta deposits.

Qlt

Lacustrine terrace deposits (Pleistocene) Poorly to moderately sorted silt, sand and gravel forming broad low terraces 5-10 meters above lake level. Locally includes delta deposits.

GEOLOGIC UNIT KEY FIGURE 3.4

the project area tend to consist of fine sand to silt material, particularly in the “grand canyon” area (see Figure 3.5A, Figure 3.5B). The “grand canyon” consists of highly erodible fine grained poorly‐sorted sediment deposit and it is possible that this area was occupied by a backwater lake during historic glacial periods. The sediments of the “grand canyon” are non cohesive, predominantly fine sand and homogenous in size and type, indicating a low energy depositional environment.

3.3 DISTURBANCES

North Canyon Creek and Spooner Meadow have been historically subjected to a number of human induced disturbances and impairments; many of which occurred more than a century ago. Below is a summary of the primary historic disturbances known to have impacted the project area.

COMSTOCK LOGGING ERA (1860‐1900)

North Canyon Creek and Spooner Meadow were severely impacted by the aggressive logging activities of the Comstock Era (1860‐1900). In 1870, a flume was constructed within North Canyon to transport fallen logs and supply water to Spooner Lake where lumber staging occurred (Stone 2003). Spooner Lake (original dam constructed in 1860s) and much of Spooner Meadow were used as staging areas for logs before they were transported to Spooner Summit and sent down the Clear Creek Flume, which ran from Spooner Summit to Carson City. Originally a shingle and mill site, much of the Spooner Lake and Glenbrook area became controlled by the Carson Tahoe Lumber and Fluming Company (CTLFC), a monopoly lumber business during the Comstock Era owning nearly one‐fifth of the basin lands. The CTLFC established an extensive network of skid trails, flumes and roads leading to the Glenbrook Headquarters. Large stands of timber along the east shore of Lake Tahoe were cut during the mid‐1870s and most of the clear cutting was completed by the 1880s (Taylor 1997). The Glenbrook Railroad transported logs from the lower elevations to Spooner Summit to be conveyed to the Carson City yard via the Clear Creek Flume (Figure 3.5C).

While clear cut logging likely had an impact on the hydrology, morphology, sediment routing and vegetation communities throughout the project area, the most pronounced effect of the Comstock Era may have been the hydrologic modifications at the top of the North Canyon Creek watershed, at the drainage divide between Secret Harbor Creek and North Canyon Creek (Figure 3.2). During this time, an earthen diversion and channel were constructed to supplement North Canyon Creek with water from the Upper Secret Harbor watershed. The diversion was constructed to increase water supply in North Canyon Creek for timber and irrigation operations in the Spooner Dam and Meadow areas. Rights to this water were ensured in a legal agreement dating back to 1872 (Water Rights Decree). The diversion effectively expanded the North Canyon Creek watershed, increasing the catchment drainage area from 2.5 square miles to 4 square miles. Increased flows from the diversion rapidly eroded the fine unconsolidated deposits at the head of the North Canyon Creek watershed forming the “grand canyon” observed today and resulted in significant sediment deposition downstream throughout the northern portion of Spooner Meadow.

The logging activities of the Comstock Era resulted in significant land disturbance and channel erosion throughout the Lake Tahoe Basin. Heyvaert (1998) estimated that rates of sediment deposition into Lake Tahoe were seven to twelve times greater than natural rates as a result of the Comstock logging disturbances.

Chapter 3. Project Area Background p. 3.6

C C: Photo taken of the Spooner Sum-mit area in 1876. Photographer is standing on a point now located on the south side of Highway 50 look-ing northwest. Glenbrook Railroad is unloading processed lumber to be sent down the Clear Creek Flume into

Carson City. Today this photo is bi-sected by Highway 50 and the slope is dominated by Jeffrey pines, which have displaced the shrubs and herbaceous vegetation (Gruell 2001). Photo cour-tesy of Nevada Historical Society.

CC

BB

A: Ground photo of the “grand canyon” area directly downstream of the divide between North Canyon and Secret

Harbor Creeks. Notice the unconsoli-dated fi ne sediments that compose the banks. (2NDNATURE October 2009)

B: Ground photo from the channel within the “grand canyon”. The bank heights are > 30 ft and nearly verti-cal. Despite the signifi cant amount of historic incision, the banks do possess a moderate amount of vegetation.

(2NDNATURE July 2009).

BB

AA

FIGURE 3.5SELECTED GROUND PHOTOS

GRAZING IMPACTS (1900‐1930)

Most of the channel adjustments present in Spooner Meadow can be attributed to grazing practices. Between the early 1900s and 1930s, cut‐over lands were sold to ranchers for grazing. High meadows such as Spooner Meadow were generally used for sheep and most herds averaged 1000‐1500 ewes. Although the earliest recorded carvings by the Basque Sheepherders date to 1899, the most intense grazing activities occurred between 1911 and 1930 (Lindstrom et al. 2001). With no restrictions in place, sheepherders grazed their livestock at will and caused a variety of ecological impacts. Overgrazing of Spooner Meadow likely reduced the abundance of perennial grasses and trampling of the stream by animals resulted in decreased bank stability. Once the lands were overgrazed by late fall, runoff events and likely higher flows resulted in channel incision and bank erosion within Spooner Meadow. The grazing impacts were somewhat reduced when allotments were assigned to individual permittees in the late 1930s to control overuse of the Sierra Nevada meadow systems (USDA 2000).

Grazing practices in montane areas require abundant water management and flow manipulation. Surface flow is frequently diverted into irrigation ditches along the margin of a meadow system to help dewater the meadow in the spring time when the meadow is wettest. These irrigation ditches are then utilized later in the season when the meadow starts to dry out. By blocking off the irrigation ditches in strategic areas, certain sections of the meadow can be rewatered from feeder channels.

There are two main drainages contributing water to Spooner Meadow: North Canyon Creek and Spooner Lake, both of which were diverted into irrigation ditches (Figure 3.6). These irrigation ditches, as well as a network of feeder channels constructed in the early 1900s by the ranchers, are still present today.

A caretaker based out of Spooner Meadow diverted North Canyon Creek from its natural channel into a series of parallel irrigations ditches around 1920 (Lindstrom et al. 2001). One of these ditches still conveys a portion of North Canyon Creek flows and is exceedingly incised with high, dry, exposed banks (North Ditch; Figure 3.6). The channel cuts through conifers along the western edge of the meadow with limited access to the floodplain and meadow system. An archeology report (Lindstrom et al. 2001) indicates that water was diverted out of North Ditch onto various portions of the meadow and on either side of the alluvial fan (i.e., feeder channels; Figure 3.6).

It also states that more than seven feeder channels were used to irrigate the northern portion of Spooner Meadow, most of which are still present today.

The majority of flow from Spooner Dam is diverted into a linear irrigation ditch to the south edge of Spooner Meadow (South Ditch; Figure 3.6). A review of North Canyon Road maintenance designs indicates that culverts were intentionally placed to direct flows into existing irrigation ditches. The South Ditch is approximately 3 ft higher in elevation than the lowest portion in the adjacent meadow where water would naturally flow. The South Ditch is extremely incised, with a very low entrenchment ratio (high degree of entrenchment) and most likely, even during higher flows, does not flow out of bank. It extends in a straight path approximately 1,500 ft before taking an abrupt turn toward the confluence with North Canyon Creek, likely following a feeder channel created during the grazing era. Recent field surveys suggest that the linear South Ditch historically continued another 800 feet beyond the confluence; however that portion of the ditch has since been filled.

In addition to significant alterations to Spooner Meadow as a result of water management, ranchers also burned the landscape to promote regrowth of new and richer vegetation for their livestock. This micro‐burning had been originally initiated by the Native American population for thousands of years before the Comstock Era.

Settlements and grazing allotments were routinely burned until the Post‐Comstock Era between 1900 and 1950s when management regulations were installed. The burning practices over thousands of years not only

Chapter 3. Project Area Background p. 3.8

FIGURE XX:

feet

0 350 700

Figure 3.6: Shaded 2001 IKONOS image with Spooner

Meadow channel network displayed. Nomenclature provided to assist with identifi cation of specifi c locations and features.

Alluvial fan main channel west channel

State Route 28 South Ditch

N or th D itc h confl uence remnant channel south

Project Area

LEGEND

Management Road

Existing Irrigation Channel

Estimated Tributary Locations

GPS Stream Channel

Estimated Irrigation Channel feeder channels

Feeder Channel promoted new growth and kept fuel loads down, it adapted local vegetation to tolerate or even require fire disturbance on regular intervals for regeneration.

SPOONER DAM

The original dam at Spooner Lake was constructed in the early 1860’s to supplement water supplies for at least two sawmills operating in Spooner Meadow (Lindstrom et al. 2001). The size of Spooner Lake may have been increased once CTLFC controlled most logging and fluming activities around Spooner Summit. The dam was rebuilt in 1929 for use as an irrigation source for Spooner Meadow and later modified in the 1940s to enlarge the reservoir. In the 1980’s, the dam was rebuilt by Nevada Department of Wildlife (NDOW) and Spooner Lake was maintained for recreational purposes. Currently, the earthen dam impounds an approximately 100‐acre reservoir from a contributing drainage of approximately 1 square mile (600 acres). At full capacity the reservoir impounds 1580 acre‐feet; however the water surface is currently maintained 10 feet below capacity (NDSP 2006) in order to preserve archeological sites along the lake shore.

Spooner Dam remains a minor impairment to current (2009) hydrology by muting larger winter and spring hydrographs and reducing peak flows to Spooner Meadow. However, the presence of the dam extends summer season baseflow release to Spooner Meadow. Opportunities to improve the winter and spring release sequences may be worth exploring further.

PAVED ROADWAYS

A portion of the State Route 28 corridor was used during the Comstock Era for the transport of logs on the Glenbrook Railroad. The presence of the bounding hill to the west of State Route 28 suggests that road construction may have slightly reduced the meadow area, but the natural stream path from Spooner Meadow to the Lake side of State Route 28 was likely in a similar location as today. North Canyon Creek passes under Route 28 via a corrugated metal culvert. The creek is partially constricted by the road grade, running straight and parallel next to the highway for about 50 yards before passing into the culvert (Figure 3.7).

Route 28 and Highway 50, as well other paved pathways near Spooner Lake, have contributed to increased surface runoff and erosion adjacent to these areas. Winter treatment of these roadways also contributes additional fine sediment that is a known pollutant affecting downstream water quality within Lake Tahoe (LRWQCB

& NDEP 2009).

MANAGEMENT ROAD

North Canyon Road is a single lane dirt road connecting Spooner and Marlette Lakes (Figure 3.7). Portions of the road corridor were likely created and used during the Comstock Era logging for access. The road was recently re‐ graded in 2001; work included the placement of culverts, geoweb stabilization and graded dips. A few secondary access roads exist within the watershed; however the main route that connects Spooner and Marlette Lake receives the greatest amount of both vehicular and recreational traffic.

The management road use and lack of regular maintenance is suspected to be the greatest source of total suspended sediment (TSS) and fine sediment particles (FSP; < 16µm) to the surface water stream system within the project area. FSP is the primary pollutant of concern per the Lake Tahoe TMDL (LRWQCB & NDEP 2009). The continued vehicle and bicycle pulverization of the erodible road surface results in a significant accumulation of

Chapter 3. Project Area Background p. 3.10

0 500 1000 feetFIGURE 3.7: Existing impacts to North Canyon Creek and Spooner

Meadow. Cross country trail system runs across Spooner Meadow in several locations, but creek crossings appear to be consistent over time.

I* I# po

LEGEND

Management Road

I#

I* po

Project Area

Estimated Sewer Line

Estimated Water Line

Concessionaire Lodge

Fee Booth

Restrooms

Backcountry Cabins

Well House

Temporary Crossing

24k Stream Channel

S.R. 28

S .R

. 2

North C anyo n R oad

Chapter 3. Project Area Background p. 3.12 April 2010 loose material upon the road surface in the late fall. Qualitative estimates by field personnel suggest the management road between the outlet of Spooner Lake and the top of the project area contained an average observed depth of 2.5 inches of loose material on the road surface in September 2009. The average width of the road is 10 ft and it extends 9300 ft, resulting in an estimated 115,000 cubic feet of sand‐sized or finer material available for transport from the management road during subsequent winter rain events. The actual fate and transport of this material from the road to surface water system is not considered in this estimate and will vary annually, seasonally and spatially throughout the project area.

As with most existing management roads, North Canyon Road follows the canyon formed by the stream channel and thus any sediment generated from the road surface has a high hydrologic connectivity to North Canyon Creek.

Ground photos in Figure 3.8 were taken after a strong rain storm in early October 2009, where the sediment loosened by summer traffic had washed off the road surface and deposited a large sediment fan close to North Canyon Creek. Subsequent storms could transport some fraction of this sediment source into the surface water system.

The road sediment source is considered both a chronic impairment to aquatic wildlife habitat within North Canyon Creek, as well as potential water quality impairment with respect to Lake Tahoe TMDL (LRWQCB and NDEP 2009) primary pollutant of concern, FSP. Dry sediment samples were collected from the management road, grand canyon and sediment plume (Figures 3.7 and 3.8) in September 2009 by the 2NDNATURE team for particle size distribution (PSD) analyses to document the % < 16µm from these two erodible sources. Table 3.1 summarizes the results from PSD analysis and it is estimated that 4,600 cubic feet (4.0% of the 115,000 cubic feet of total sediment) is < 16µm and available for transport and delivery into the surface water stream system. Advanced dirt road management opportunities could be explored to reduce the chronic source of fine sediment within the project area.

Table 3.1 Summarized particle size distribution results for management road and Grand Canyon.

Sample Location Average % < 16 µm Standard Deviation Average % < 2 mm Standard Deviation

Management Road 3.5 0.7 84.4 0.7

Grand Canyon 13.5 2.1 94.5 0.1

Sediment Plume 4.0 N/A 98.5 N/A

The stream crossings are typically made of corrugated metal culverts, many of which are in need of repair and/or maintenance. Many of the culverts are improperly placed such that they do not align with channel flows, have accumulated material and/or are inappropriately sized. Figure 3.9 depicts locations of the culverts along North Canyon Road and ranks them based on qualitative condition of good, fair or poor. A number of culverts at tributary crossing are currently below desirable conditions. Replacing and modifying existing stream crossings could improve channel hydraulics and eliminate existing fish barriers. Figure 3.9 also depicts locations of rolling dips and water bars along North Canyon Road and rates their effectiveness of transferring runoff onto adjacent hill slope. At the time of the July 2009 field survey, 2 of the 5 major rolling dips were ineffective. However, there were indications that most of the rolling dips were ineffective after the major rain event in October 2009.

B: Ground photo of a major sediment fan directly adjacent to management road. Sediment is backed up behind the log and estimated to contain an average sediment depth of 3in.

Red arrow indicates same location as in photo C. (2NDNA-

TURE October 2009)

A: Ground photo taken of management road after a wet storm in October 2009.

(2NDNATURE October 2009).

C: Ground photo of the terminus of the sediment fan illistrated in B above.

Red arrow indicates same location as in photo B. (2NDNATURE October 2009).

CC

AA

BB

CC

NORTH CANYON ROAD GROUND PHOTOS FIGURE 3.8

FIGURE 3.9: Culvert locations categorized by overall good, fair and poor condition along with rolling dip (water bar) locations catego-rized by effectiveness at time of July 2009 fi eld survey.

0 0.1 0.2 miles

Project Area

LEGEND

Culvert Condition

Good

Fair

Poor

Paved Road

Management Road

Rolling Dip Effectiveness

Effective

Not Effective

RECREATION

In recent years, land use within the project area is primarily year‐round recreation in the form of hiking, mountain biking, horseback riding, and cross‐country skiing. Under contract between Spooner Lake, Inc and the State of Nevada, the concessionaire operates both winter and summer recreational activities. From spring through fall, the Spooner Lake Outdoor Company offers guided bike tours, bike rentals and snacks for visitors at the Spooner Lake Lodge. Spooner Lake is also the major trail head for hikers, mountain bikers, and equestrians entering the backcountry. North Canyon Road leads to Marlette Lake and additional popular trail systems such as the Flume Trail and the Tahoe Rim Trail. The potential impacts of North Canyon Road each fall are summarized above.

During the winter months, the Spooner Lake Outdoor Company provides an extensive network of groomed cross‐ country ski trails along with lessons and ski rentals. Trails are maintained, compacted and groomed using a snowcat machine that occasionally borrows snow from adjacent areas to amend ski trails.