Attachment_0003_-_Riparian_Restoration_Project_Final_Biological_Assessment.pdf

United States Department of the Interior

BUREAU OF LAND MANAGEMENT

Upper Snake Field Office

1405 Hollipark Drive

Idaho Falls, Idaho 83401

(208) 524-7500

In Reply Refer To:

1170 (LLIDI01000) July 7, 2022

Elliot Traher

U.S. Fish and Wildlife Service

Idaho Fish and Wildlife Office - Chubbuck

4425 Burley Drive, Suite A

Chubbuck, Idaho 83202

Dear Mr. Traher:

With this letter the Upper Snake Field Office (USFO) of the Bureau of Land Management

(BLM) is transmitting the Final Biological Assessment (BA) for the USFO Aquatic and Riparian

Habitat Restoration Project. At this time, we request USFWS concurrence with the BA effects determinations of “May Affect, Not Likely to Adversely Affect” for Canada Lynx (Lynx canadensis), Columbia River Bull Trout (Salvelinus confluentus) and its Critical Habitat (CH), Grizzly Bear (Ursus arctos horribilis), Ute Ladies’-tresses (Spiranthes diluvialis), and Yellow-billed Cuckoo (Coccyzus americanus) and its Critical Habitat.

Please find the enclosed Final BA for the USFO Aquatic and Riparian Habitat Restoration

Project. If you have any questions or concerns, please contact Justin Frye, USFO Wildlife

Biologist, at (208) 524-7547.

Sincerely, Jeremy Casterson

Field Office Manager

BLM Upper Snake Field Office

United States Department of the Interior

Bureau of Land Management

Upper Snake Field Office

1405 Hollipark Ave.

Idaho Falls, ID 83401

Upper Snake Field Office Aquatic and Riparian Habitat Restoration

Biological Assessment

Prepared by:

Environmental Management and Planning Solutions, Inc.

3005 Center Green Drive, Suite 205

Boulder, Colorado 80301

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project i

Table of Contents

CHAPTER 1. INTRODUCTION

1.1 PURPOSE AND BACKGROUND

1.2 PROJECT AREA

1.3 ACTION AREA

1.4 LISTED SPECIES AND CRITICAL HABITATS

CHAPTER 2. DESCRIPTION OF THE PROPOSED ACTION

2.1 RIPARIAN HABITAT RESTORATION

2.1.1 Plantings

2.1.2 Plant Material Collection

2.1.3 Noxious and Invasive Vegetation

2.1.4 Fencing

2.2 AQUATIC HABITAT RESTORATION

2.2.1 Stream Bank Stabilization

2.2.2 Instream Structures

2.2.3 Floodplain Connectivity and Habitat Complexity

2.2.4 Stream Crossings

2.3 IMPLEMENTATION

2.4 MONITORING

CHAPTER 3. ENVIRONMENTAL BASELINE CONDITIONS

3.1 CANADA LYNX

3.1.1 Listing Status and Recovery Plan

3.1.2 Life History and Habitat Characteristics

3.1.3 Status and Distribution

3.1.4 Threats

3.1.5 Analysis of Effects and Determination

3.2 COLUMBIA RIVER BULL TROUT

ii Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project

3.2.1 Listing Status and Recovery Plan

3.2.2 Life History and Habitat Characteristics

3.2.3 Status and Distribution

3.2.4 Threats

3.2.5 Analysis of Effects and Determination

3.3 BULL TROUT CRITICAL HABITAT

3.3.1 Effects on Bull Trout Final Critical Habitat

3.4 GRIZZLY BEAR

3.4.1 Listing Status and Recovery Plan

3.4.2 Life History and Habitat Characteristics

3.4.3 Status and Distribution

3.4.4 Threats

3.4.5 Analysis of Effects and Determination

3.5 UTE LADIES’-TRESSES

3.5.1 Listing Status and Recovery Plan

3.5.2 Life History and Habitat Characteristics

3.5.3 Status and Distribution

3.5.4 Threats

3.5.5 Analysis of Effects and Determination

3.6 YELLOW-BILLED CUCKOO

3.6.1 Listing Status and Recovery Plan

3.6.2 Life History and Habitat Characteristics

3.6.3 Status and Distribution

3.6.4 Threats

3.6.5 Analysis of Effects and Determination

3.7 YELLOW-BILLED CUCKOO FINAL CRITICAL HABITAT

3.7.1 Effects on Yellow-billed Cuckoo Final Critical Habitat

3.7.2 Effect Determination

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project iii

CHAPTER 4. SUMMARY OF EFFECT DETERMINATIONS

CHAPTER 5. LITERATURE CITED

APPENDIXES

APPENDIX A: PROJECT AREA MAP

APPENDIX B: RESOURCE PROTECTION MEASURES

List of Tables

TABLE 1: PROJECT AREA ACREAGES BY WATER FEATURE TYPE

TABLE 2. LISTED SPECIES AND CRITICAL HABITAT ANALYZED IN THE BA

TABLE 3. MILES OF BULL TROUT CRITICAL HABITAT IN THE PROJECT AREA

TABLE 4. LISTED SPECIES AND CRITICAL HABITAT ANALYZED IN THE BA

iv Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project

Acronym or Abbreviation Full Term

°C ..................................................................................................................degrees Celsius

°F ............................................................................................................. degrees Fahrenheit

ARMPA ................................................. approved resource management plan amendment

AOP............................................................................................... aquatic organism passage

BA ....................................................................................................... biological assessment

BAU ........................................................................................................ Bear Analysis Unit

BDA ...................................................................................................... beaver dam analogs

BLM ....................................................................................... Bureau of Land Management

BMI ............................................................................................ benthic macroinvertebrates

BMP ........................................................................................... best management practices

BMU .................................................................................................. bear management unit cfs ......................................................................................................... cubic feet per second

DCH ............................................................................................. designated critical habitat

DPS ........................................................................................... distinct population segment

EA ................................................................................................ environmental assessment

ECB ................................................................................................... erosion control blanket

ELJ .......................................................................................................... engineered log jam

ESA ................................................................................................ Endangered Species Act

FEMA ................................................................. Federal Emergency Management Agency

FMO ........................................................................ foraging, migration, and overwintering

GYE ................................................................................... Greater Yellowstone Ecosystem

IDEQ .............................................................. Idaho Department of Environmental Quality

IDFG ........................................................................... Idaho Department of Fish and Game

IDWR ....................................................................... Idaho Department of Water Resources

IGBST ....................................................................... Interagency Grizzly Bear Study Team

IDT ......................................................................................................interdisciplinary team

LAU ......................................................................................................... lynx analysis unit

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project v

LWD ....................................................................................................... large woody debris

NEPA ............................................................................ National Environmental Policy Act

NMFS .............................................................................. National Marine Fisheries Service

NTU ....................................................................................... Nephelometric Turbidity unit

OHW ..................................................................................................... ordinary high water

OHV ..................................................................................................... off-highway vehicle

PALS .......................................................................................... post-assisted log structures

PBA ...........................................................................................................programmatic BA

PBF .............................................................................................. primary biological feature

PCE ........................................................................................... primary constituent element

SOP ......................................................................................... standard operating procedure

US .................................................................................................................... United States

USFO ........................................................................................... Upper Snake Field Office

USFWS .................................................................. United States Fish and Wildlife Service

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project 1

CHAPTER 1. INTRODUCTION

The purpose of this biological assessment (BA) is to determine the effects of the Aquatic and

Riparian Habitat Restoration Project (the proposed action) on species that are federally protected under the Endangered Species Act of 1973 (ESA), as amended. The BA is intended to fulfill

Section 7(c) of the ESA and to ensure that, through consultation (or conferencing for proposed species) with the United States Fish and Wildlife Service (USFWS), the proposed action would not likely jeopardize the continued existence of federally listed species, nor result in the destruction or adverse modification of designated critical habitat, as defined in the Endangered

Species Consultation Handbook (USFWS and NMFS 1998).

1.1 Purpose and Background

The proposed project’s overlying purpose is to maintain, restore, or enhance aquatic and riparian habitats within the Bureau of Land Management (BLM) Upper Snake Field Office (USFO) boundary (project area). Healthy aquatic and riparian ecosystems provide invaluable habitat resources for more plant, fish, and wildlife species than any other ecosystem type in this semiarid landscape; this includes habitat for ESA-listed species and other special status species. These ecosystems are also essential to humans; this is because they provide clean, renewable water supplies and generate economic value through sustainable uses. The influence and interactions between the two ecosystem types are dynamic and intricately linked, and they are essential in the maintenance of existing habitat conditions and the creation of new habitats.

A history of human activities and land-use practices has altered the structure and function of many aquatic and riparian ecosystems. This has led to the degradation of habitat quality, a reduction in the spatial extent of available habitat, and the interruption of natural processes and interactions between the two ecosystem types. Passive management actions have been routinely used across the project area, most often in the form of livestock exclusion fences or motorized access controls.

However, riparian and aquatic habitat recovery can be naturally slow or inhibited by other factors. For many aquatic and riparian habitats in the project area, active management actions are needed to maintain, restore, or enhance the structure and function. These actions would advance aspects of the BLM’s sustainable multiple use mission; this is because they would contribute to the protection or improvement of water quality, support beneficial uses of surface waters, and aid the conservation and recovery of ESA-listed species or other special status species and their habitats. The proposed action’s purpose would be to:

• Facilitate natural interactions and restore processes between aquatic and riparian ecosystems to improve floodplain connectivity and promote a dynamic equilibrium between sediment delivery and channel/floodplain form and function.

• Implement actions to maintain or improve water quality, reduce sources of degradation, and support beneficial uses.

• Improve aquatic habitat conditions by increasing the complexity and frequency of diverse habitat features, habitat patches, and ecosystem functions.

2 Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project

• Affect the duration and extent of water, sediment, nutrient, and organic matter retention to improve or maintain wetland and mesic habitat conditions.

• Improve or maintain native riparian vegetation species’ composition, structural complexity, and extent by promoting establishment, regeneration, recruitment, and varying successional stages and age classes.

• Improve habitat conditions for native plants, fish, and wildlife.

• Contribute to the conservation and recovery of habitat for ESA-listed species, proposed or designated critical habitat, and BLM sensitive species. Relative to aquatic and riparian habitat, priority species could include, but are not limited to:

o Ute ladies’-tresses (Spiranthes diluvialis), bull trout (Salvelinus confluentus), yellow-billed cuckoo (Coccyzus americanus), Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), greater sage-grouse (Centrocercus urophasianus), northern leopard frog (Lithobates pipiens), and monarch butterfly (Danaus plexippus plexippus)

• Protect aquatic and riparian habitat resources through the prevention of unauthorized uses.

• Improve water crossings (such as fords, culverts, and bridges) to facilitate the passage of aquatic organisms, minimize sediment input, and minimize adverse effects on hydrologic functions.

Furthermore, there has been an increased interest in aquatic and riparian restoration and enhancement projects in this region. Potential partnership opportunities and funding sources for such projects are available through both federal and state government agencies, nongovernmental entities, and various grants. Potential project partners and interested parties could include, but are not limited to, the United States Army Corps of Engineers, USFWS, Idaho Department of Fish and Game (IDFG), Idaho Transportation Department, Idaho Department of Water Resources, Idaho Department of Environmental Quality, Henry’s Fork Foundation, and Teton Regional

Land Trust.

The Upper Snake Field Office Programmatic Aquatic and Riparian Habitat Restoration

Environmental Assessment (EA) seeks to foster partnership developments, leverage funding opportunities, and facilitate project implementation by reducing the time and effort required to duplicate National Environmental Policy Act analyses and documentation for similar projects with similar effects. A programmatic approach would substantially improve the BLM’s timeliness and responsiveness to partners and others interested in implementing collaborative restoration projects. Completion of the programmatic analysis would also benefit funding acquisition and project implementation as opportunities arise, regardless of the timing and location throughout the project area.

1.2 Project Area

The project area includes all riparian and aquatic habitats within the USFO boundary, totaling approximately 31,000 acres (Appendix A). The USFO is located within the Upper Snake River

Basin and adjacent mountain valleys of eastern Idaho. Other than the Snake River (including

Henry’s Fork, South Fork, and the main stem), identification and spatial recognition of riparian and aquatic habitats were originally derived from the National Hydrography Dataset, which was

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project 3 then verified on the ground and modified over several years of assessing riparian habitat conditions throughout the field office. Buffers, specific to the type of water feature identified, were then applied to each feature. These buffers include a 300-foot buffer on either side of a perennial stream, a 150-foot buffer on either side of intermittent and ephemeral streams, and a

150-foot buffer around lakes, reservoirs/ponds, playas, and springs. Table 1 describes the total acreages for each type of water feature within the project area.

Table 1: Project area acreages by water feature type

Feature Type Buffer Distance (feet) Acres1, 2

Ephemeral stream 150 110

Intermittent stream 150 600

Lake 150 120

Perennial stream 300 21,800

Playa 150 10

Reservoir/pond 150 40

Spring 150 830 1 Acres are rounded to the nearest 10. Acres do not total 31,000 acres due to overlapping buffers in some areas.

2 These buffer distances are generalized and assumed; the resulting acreage estimates may differ from actual wetland/riparian area inventory estimates.

Source: BLM 2021

Mapping the spatial extent of riparian habitat surrounding the Snake River, including the Henry’s

Fork, South Fork, and main steam, included using a combination of yellow-billed cuckoo critical habitat, available mapped FEMA floodplain data, and digitization based on aerial imagery, instead of a 300-foot buffer as applied to other perennial streams. This approach was intended to capture the full extent of riparian habitat near these waterways, which in many areas is greater than 300 feet wide.

Note that data sets may be incomplete, and features may exist outside of mapped areas due to mapping inaccuracies and the map scale. While the project area acres described above are generally applicable to BLM-administered lands, treatments may occur across ownership boundaries.

1.3 Action Area

The action area is defined as all areas to be affected directly or indirectly by the federal action and not merely the immediate area involved in the action (50 Code of Federal Regulations

402.02). In determining the action area, the BLM used the project area which applied substantial buffers around riparian and aquatic habitat features (Table 1). These buffers contain aquatic habitat, adjacent riparian areas and floodplains, and often upland areas beyond the reasonably expected area of impact. Potential effects of aquatic and riparian habitat restoration projects would generally occur within or immediately downstream of an individual project site and significant or measurable effects would not be expected to extend downstream of the project area. For these reasons the action area would be concurrent with the project area as defined in

Section 1.2.

4 Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project

1.4 Listed Species and Critical Habitats

In compliance with the ESA, the BLM identified the species listed as threatened or endangered and designated as proposed in the action area. Federally listed threatened and endangered plant and animal species are those that the USFWS or National Marine Fisheries Service (NMFS) has formally listed under the ESA.

An endangered species is defined as one that is in danger of extinction throughout all or a significant portion of its range; a threatened species is defined as one that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range; a candidate species is one for which the USFWS has sufficient information to support a proposal to list it as endangered or threatened, but for which preparation and publication of a proposal is precluded by higher-priority listing actions.

The USFWS’s Information for Planning and Consultation tool has identified five threatened or endangered species and one candidate species in the action area (USFWS 2021a). Listed species and critical habitat with the potential to be affected by the proposed action are analyzed in detail in this BA and summarized in Table 2.

In December of 2020, the USFWS determined that listing the monarch butterfly (hereafter referred to as “monarch”) as endangered or threatened under the ESA was warranted but precluded by higher priority listing actions (USFWS 2020). As a result of this 12-month finding, the monarch became a candidate species, and is not proposed for listing at this time. There are no statutory protections under the ESA for candidate species, and Section 7 of the ESA does not contain requirements for federal agencies with respect to candidate species. However, agencies are strongly encouraged to engage in cooperative conservation efforts for these species, as they may warrant future protection under the ESA. BLM considered monarch butterfly, and its potential occurrence within the project area, when developing the proposed action and alternatives. Resource protection measures specific to monarch were developed within the EA to reduce the potential for the proposed action to result in any negative effects to the species or its habitat to a discountable level. This species is not addressed further in this BA.

The BLM determined that the proposed action will not affect the whitebark pine (Pinus albicaulis, proposed threatened). Suitable habitat for this species does not occur in the action area. This species is not addressed further in this BA.

Table 2. Listed Species and Critical Habitat Analyzed in the BA

Species or Critical Habitat Status

Mammals

Canada lynx

(Lynx canadensis)

Threatened

Grizzly bear

(Ursus arctos horribilis)

Threatened

Birds

Yellow-billed cuckoo

(Coccyzus americanus)

Threatened

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project 5

Species or Critical Habitat Status

Fish

Columbia River bull trout

(Salvelinus confluentus)

Threatened

Plants

Ute Ladies’-tresses

(Spiranthes diluvialis)

Threatened

Critical Habitat

Bull trout Final

Yellow-billed cuckoo Final

CHAPTER 2. DESCRIPTION OF THE PROPOSED ACTION

The proposed action includes a suite of programmatic actions and treatments targeted at the restoration, enhancement, or maintenance of aquatic and riparian habitat conditions on BLM-administered lands within the USFO’s boundary. The proposed action does not include site-specific project proposals; rather, it identifies and describes potential actions to be implemented throughout the project area. These actions are grouped into two main categories and are described below in Sections 2.1 (Riparian Habitat Restoration) and 2.2 (Aquatic Habitat

Restoration).

2.1 Riparian Habitat Restoration

Riparian habitat restoration projects would aim to improve the species composition, structural complexity, and extent of native riparian vegetation in the project area. Projects would focus on the establishment, recruitment, and natural regeneration of native vegetation to stabilize stream banks, increase structural diversity, improve species’ composition, and improve riparian function. These actions would be implemented to restore and improve habitat conditions for

ESA-listed species, special status species, migratory birds, and big game species in the project area.

Because of the dynamic relationship between riparian vegetation and the associated aquatic ecosystems, many riparian habitat restoration projects would be coupled with additional restoration actions. However, riparian habitat restoration actions, independent of other actions, could be adequate for certain project locations, depending on the site-specific conditions and desired objectives.

2.1.1 Plantings

Native vegetation would be planted within riparian zones that have been altered or are lacking adequate amounts of one or more vegetation components expected for that site. Vegetation species to be planted, the types and sizes of plant material to be used, and the method of planting would vary between project locations and would be based on site-specific conditions and project objectives. Prior to the implementation of specific planting projects, intact riparian areas close to the proposed planting location could be used as a reference to help inform the site potential and which species would be planted at that location. Vegetation used for planting projects could represent several different growth forms, including trees, shrubs, forbs, grasses, rushes, and sedges.

6 Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project

Preferably, plant material used for planting projects would be locally sourced; however, commercial stock could be used in some situations, depending on the availability and timing.

Species that would commonly be used for planting projects include, but are not limited to:

• Narrowleaf cottonwood (Populus angustifolia)

• Black cottonwood (Populus balsamifera)

• Redosier dogwood (Cornus sericea)

• Coyote willow (Salix exigua)

• Booth’s willow (Salix boothii)

• Geyer willow (Salix geyeriana)

• Showy milkweed (Asclepias speciosa)

• Woods’ rose (Rosa woodsii)

• Water whorlgrass (Catabrosa aquatica)

• Beaked sedge (Carex rostrata)

• Nebraska sedge (Carex nebrascensis)

• Baltic rush (Juncus balticus)

Some soil disturbance would occur as a result of the planting process. The disturbance’s size would vary based on the type of plant material and the hole preparation method used. Plant materials used for these projects would depend on the site-specific conditions and desired objectives for planting locations. These materials could include:

• Containerized plants

• Balled-and-burlapped plants

• Bare-root plugs

• Cuttings, stakes, and poles

• Rhizomes

• Seed

• Sod mats

• Whole willow clumps

Container volumes would typically range from 10 cubic inches to 15 gallons for most projects;

however, certain projects could use larger plant material (such as whole willow clumps and balled-and-burlapped plants), depending on the availability and desired objectives. Generally, planting projects would require 3-inch-diameter to 2-foot-diameter holes to be prepared for individual plants or small clusters. Projects using larger plant materials could require a 4-foot-diameter hole, or larger. A depth to wetted soil would be desired for most planting projects and would vary depending on the location within the riparian zone and other site characteristics.

Planting efforts would typically be conducted during the spring and/or fall dormancy months.

However, depending on the site-specific conditions, ability, and timing of other aspects of potential projects, planting efforts could be conducted during other times of the year.

Hand Planting

Hand planting efforts would be the preferred planting method in areas where the desired soil depth (that is, the depth to wetted soil) can be achieved with the use of hand tools. Hand tools that could be used for these planting efforts would include dibble bars, hoedads, digging bars, shovels, and handheld power augers. Typically, hand planting methods would be used when planting smaller plant materials, such as stem cuttings, bare-root plugs, rhizomes, and 5-gallon or smaller containerized plants. Sod mats would also typically be installed using hand tools, by rolling the mat to cover the desired area, and securing to the ground using live cuttings or wooden stakes. Hand plantings would also be conducted in locations where vehicle or equipment access is limited due to the topography, vegetation, or sensitive resource concerns. Vehicles

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project 7 could be used at some hand planting locations to facilitate the transport of plant materials and equipment, but travel would be minimized to reduce potential resource damage.

Mechanical Planting

The use of mechanized equipment could be required to achieve the necessary planting depth in areas where the soil substrate is too coarse for hand tools, or when large-diameter hole preparation is necessary. Mechanized equipment used for planting efforts could include, but would not be limited to, a skid steer, excavator, or backhoe equipped with an auger, bucket, expandable stinger, or hydraulic driver/pounder. Generally, mechanical planting methods would be used for larger plant materials, such as containerized plants exceeding 5 gallons, balled-and-burlapped plants, pole cuttings, and whole willow clumps.

Whole willow clumps, when used, could be harvested from within the specific project area or from outside the project area from locations that would not compromise slope or stream bank stability. Mechanized equipment would be used to excavate the root mass, transport the intact clump, and place it in a prepared hole. Excavated areas created by willow clump harvest would be contoured to blend with the surrounding terrain; also, these areas would be revegetated with seed, sod mats, or additional plantings.

Seeding

Seeding efforts could be conducted to stabilize soils, decrease the potential for noxious and invasive weed establishment or expansion, and improve native plant diversity and structure in riparian areas that contain degraded understory conditions, or where project implementation has resulted in localized areas of surface disturbance. In general, seeding efforts would focus on the establishment of native understory herbaceous vegetation, such as grasses and forbs, but could also include other native vegetation growth forms.

Hand broadcast seeding would be the preferred application method for most seeding efforts, particularly for small-scale projects less than 1 acre. Broadcast seeding by hand would include the use of handheld tools, such as crank broadcast spreaders or blower spreaders, followed by raking or harrowing of the soil to cover the seed and help ensure adequate seed-to-soil contact.

Larger seeding projects could require the use of broadcast seeding implements pulled behind a vehicle or mechanized equipment, followed by a cultipacker or roller. Hydroseeding, using a water-based slurry of seed and mulch, could also be considered as an alternative for some seeding projects, where site conditions allow. This technique would include transporting the slurry in a truck or trailer-mounted tank and applying the slurry to a prepared site with a high-pressured hose. The use of mechanized equipment for seeding efforts would only be conducted in areas where there is not an undue risk of damage to sensitive resources.

Supplemental Watering

Short-term supplemental watering of seeded disturbance and planted vegetation treatments would be conducted as needed. Following planting efforts using containerized trees and shrubs, harvested willow clumps, sod mats, or other planted vegetation, intermittent watering would be needed until at least seasonal plant dormancy occurs or as needed to ensure establishment.

Supplemental watering would most commonly employ hand-carried 5-gallon buckets filled from

8 Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project the project area and dispersed onto planted trees and shrubs. Where access to water in the project area is limited or planting zones occur off channel away from surface waters, vehicle-mounted water tanks could be used to implement supplemental watering.

Portable, gas-operated pumps could also be used to draft water from the project area’s surface waters to support supplemental watering using drip lines, sprinklers, or other means. If portable pumps or vehicle-mounted tanks are operated or filled from natural surface waters, a temporary water right would be obtained from the IDWR. During drafting or pumping from fish-bearing waterbodies, intake screens would be used to avoid entrainment of fish.

2.1.2 Plant Material Collection

Native plant materials could be collected for direct use in various projects, or for use in nursery propagation efforts for future projects. Typically, plant materials would be harvested from within the same drainage or watershed as the location where the materials are intended to be used.

However, the lack of adequate native plant materials could require harvest to occur from nearby drainages or watersheds. Plant materials that could be collected for project use would commonly include, but not be limited to, stem cuttings, seed, and wetland sod mats. Stem cuttings of willow, cottonwood, or dogwood would be harvested using hand tools (for example, loppers, pruning shears, and hand saw). Harvesting activities would be conducted in a manner to ensure the health and appearance of the source stand would not be impaired (see guidance provided in

NRCS 2007).

Wetland sod mats would typically include an intact section of wetland soil and vegetation, approximately 6 to 8 inches thick. Sod mats could be harvested by hand using shovels. They also could require the use of mechanized equipment equipped with a bucket, depending on the size and amount of sod needed for the specific project. Sod mat harvest locations would generally include areas that are expected to be inundated or disturbed as a result of project implementation and are expected to recover relatively quickly (1 to 3 years) following harvest.

Root wads or whole trees could also be used in the implementation of some projects. However, the harvest of these products on BLM-administered lands is beyond the scope of this EA. A separate site-specific National Environmental Policy Act (NEPA) analysis would be conducted for harvest activities, when applicable. Generally, root wads and whole trees would be harvested from forested areas being cleared for development, or selectively removed in conjunction with forest management projects. Root wads, whole trees, or logs could also be collected from areas where they have uprooted and fallen from natural causes, such as floods, blowdown, or avalanches.

Selective felling of individual trees from within the riparian zone could be conducted in some situations. These treatments would be conducted to mimic and/or accelerate channel recruitment of large woody debris (LWD), promote regeneration of desirable woody species and establishment of early successional habitats, or remove undesirable or nonnative species (such as saltcedar and Russian olive). Implementation would include cutting the tree using hand tools (for example, chainsaw, loppers, and hand saw) and letting the tree lay as it falls, placing the felled tree in the desired location, lopping and scattering it, or removing it from the project location.

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project 9

Selective felling would only be conducted in a manner to promote improved habitat (aquatic or riparian) composition and structural diversity. It would not be done in areas where it could compromise the stability of a slope or stream bank, or where it could cause habitat fragmentation or degradation.

2.1.3 Noxious and Invasive Vegetation

Chemical or mechanical treatments to control the spread of noxious and invasive vegetation would be conducted to improve the native riparian plant community’s composition throughout the project area. These treatments would be subject to standard operating procedures. The analysis of proposed noxious and invasive vegetation treatments to control targeted species is tiered to the Upper Snake-Pocatello Integrated Weeds Control Program Environmental

Assessment (Programmatic Weeds EA; BLM 2017).

2.1.4 Fencing

Fences could be constructed to protect riparian areas that contain sensitive resources, or to protect project investments such as plantings or bank stabilization efforts. Various types of fences could be installed (that is, metal t-posts and wire, post and cable, buck and pole, etc.) as either permanent or temporary exclosures, depending on site-specific conditions and fencing objectives. Some fence types would require fence posts to be installed in the ground, while others would have bucks or jacks that sit on the surface. Posts installed in the ground would either be pounded into the ground or placed in prepared holes and backfilled. Installation could include localized clearing or trampling of vegetation along the fence line, but clearing and trampling would be minimized to the extent practicable.

2.2 Aquatic Habitat Restoration

Most actions proposed in this category would apply to lotic aquatic ecosystems (streams and rivers); however, some concepts could also apply to lentic systems (springs, wetlands, meadows, and lakes). For purposes of this EA, aquatic habitat includes both lotic and lentic systems.

Aquatic habitat restoration and enhancement projects aim to improve aquatic ecosystems’ structure and function and facilitate natural interactions between these systems and their associated riparian zones. Past human activities and land-use practices have degraded the aquatic habitat quality and interrupted natural processes and interactions between aquatic and riparian ecosystems. Objectives for aquatic restoration projects would typically be multifaceted; they intend to:

• Stabilize stream banks or shorelines

• Restore or improve hydrologic connectivity with the adjacent floodplain

• Promote the balance between typical rates of bed and bank scour and the transport, sorting, and deposition of alluvial materials

• Increase aquatic habitat structural diversity and complexity, and restore or enhance habitat features (for example, riffles, steps, pools, meanders, and point bars)

• Restore stream channels and improve stream road crossings for aquatic organism passage

(AOP) using stream simulation principles to restore fish habitat connectivity

10 Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project

2.2.1 Stream Bank Stabilization

Actions would be taken to restore unnaturally unstable stream banks and shorelines in areas where erosion is creating a chronic source of sediment input, where stream banks or shorelines do not support adequate riparian vegetation cover, or where existing or proposed infrastructure is threatened. One purpose of stream bank restoration efforts would be to enhance the shape and structural integrity of a bank or shoreline to restore the dynamic equilibrium between sediment delivery and channel/floodplain form and function. Natural stream bank stability would reduce the amount of sediment input to the aquatic system and allow for improved water quality. It also would prevent further erosion in areas where sensitive resources or infrastructure could be threatened. Another purpose would be to improve the bank or shoreline’s ability to support native riparian vegetation, restore ecological functions and riparian processes, and improve hydrologic connectivity with the adjacent floodplain.

Most actions proposed in this category would apply to banks along lotic systems; however, many of the concepts could also apply to shorelines along lentic systems. For purposes of this EA, stream bank stabilization in this document includes both lotic banks and lentic shorelines.

Bank stabilization would typically include shaping the bank and/or installing reinforcements to increase floodplain roughness and strengthen bank cohesion. Reinforcements could include plant materials, such as live plantings and LWD; natural biodegradable materials to provide temporary stabilization; and inert materials, such as rock and hard structures. Actions within this category have been divided into two subcategories, plant-based and rock-based bank stabilization. The type of actions to be used at a specific project site would be determined by the desired goals for that specific project, as well as site-specific conditions and potential threats to the infrastructure or sensitive resources.

2.2.1.1 Plant-Based Bank Stabilization

Plant-based bank stabilization treatments include a variety of actions that use live plant materials as the project design’s primary elements. These treatment methods would rely on live vegetation to reduce water velocity and stabilize the bank, while still allowing for bank dynamics (scour and deposition) to occur at a more natural rate. Plant-based bank stabilization treatments would typically be conducted in areas where the goal is to restore the dynamic equilibrium between bank scour and deposition, improve aquatic and riparian habitat structural diversity, increase the extent of riparian habitat, and improve floodplain connectivity to restore ecological functions and allow for natural riparian processes.

Treatments in this category could be used independently or in conjunction with other actions.

They would include planting live native vegetation, placement of large wood and other plant material, shaping and contouring banks, and installing soil reinforcements and erosion controls.

These treatment types would be the preferred method of bank stabilization efforts, where site conditions allow.

Many of the planting techniques that would be conducted, including stem cuttings and whole willow clumps, are further described under Section 2.1.1, Plantings. Additional plantings—or

Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project 11 using plant material—could include bundles, brush layering, brush mattresses, and installation of root wads or other large wood.

Live Bundles

Live bundles consist of dormant stem cuttings (typically willow, cottonwood, or dogwood) bound together into linear cylindrical bundles, using natural-fiber twine or rope. Inert fascines consist of the same concept but use nonliving branch cuttings. Bundles would be used to increase channel and floodplain roughness, absorb flow velocity, reduce erosion and sedimentation, and promote deposition of sediment and nutrients suspended in flows. Once established, live bundles could increase the bank’s vegetation cover, and the root systems could provide further soil stabilization. Individual bundles used for bank stabilization efforts would typically range from 4 to 8 feet in length and 6 to 18 inches in diameter; however, they could be larger depending on site-specific project requirements.

Installation would typically be conducted with one of two methods, depending on site-specific project goals. One method would include excavating a trench along the bank face that is roughly the same depth and diameter as the bundle’s width, placing the bundle into the trench, and backfilling around the bundle’s sides and interior gaps. Wood stakes, live cuttings, or a combination of the two would then be driven through the bundles to secure them into the ground.

Trench excavation would typically be conducted using hand tools, and trench orientation could run either perpendicular or parallel to the bank slope, depending on project objectives. Another installation method would include staking the fascines directly into the bank, at or slightly below base flow levels, without using a trench. Installation of bundles could be conducted independently or in conjunction with other bank stabilization treatments.

Fiber Logs

Coir logs consist of interwoven coconut fibers bound together with biodegradable netting to form long cylindrical rolls. These items, as well as other fiber logs or bales made from biodegradable organic fibers or coupled with wetland sod mats, could be used to increase roughness, reduce erosion, trap sediment and promote deposition, and provide a growth medium for vegetation. The length and diameter of individual fiber logs and bales would vary and depend on site-specific conditions.

There are two main potential applications for fiber logs associated with stream bank stabilization.

They could be used on the face of an eroding bank, or a recently rebuilt bank, to temporarily prevent excessive amounts of sediment from entering a stream while vegetation can become established. For this application, fiber logs would either be installed directly on the bank face’s surface and secured using wood stakes or live cuttings above and below fiber logs. Alternatively, they would be installed in a shallow trench similar to that described under bundle installation.

For either installation technique, the fiber rolls would be placed perpendicular to the bank’s slope or slightly angled.

Another application would include using fiber logs to secure the toe of a bank slope in low-velocity settings. This application would require the excavation of a trench at the slope’s toe and parallel to the stream. It would typically be done in conjunction with other bank stabilization and

12 Biological Assessment for the Upper Snake Field Office Aquatic and Riparian Habitat Restoration Project revegetation techniques. Plantings, such as plugs, seed, and live cuttings would often be incorporated directly into fiber logs to expedite the establishment of vegetation.

Brush Mattress

A brush mattress consists of interwoven live stem cuttings laid on the bank face. It typically contains a live bundle, fiber log, and/or rock at the base. The brush mattress’s purpose is similar to live bundles—to increase roughness, decrease flow velocities at the bank, reduce sedimentation and erosion, promote deposition of sediment and organic material, and increase riparian vegetation. Dormant live cuttings would be laid on the bank face in the same direction as the bank slope, with their basal ends inserted into an excavated trench at the slope’s bottom (toe).

Cuttings would typically range from 5 to 10 feet in length and would be layered to approximately

2 to 4 inches thick; however, the length and thickness could vary depending on site-specific requirements.

Layers of cuttings would be secured to the bank using natural-fiber twine, perpendicular to the cuttings, and held in place by additional live cuttings or wooden stakes. The layered cuttings would then be lightly covered in soil to fill the interior gaps. Trench excavation would be similar to that described above for live bundle installation, and live bundles or fiber logs would typically be inserted into the trench to provide added reinforcement.

Erosion-control Blankets

Erosion-control blankets (ECBs) consist of mats, nets, or fabrics made from biodegradable organic materials. ECBs could be rolled over an eroding or disturbed bank with little to no established vegetation in an effort to temporarily slow water flow over the surface and prevent soil loss while vegetation can become established. Typically, these blankets would be installed by excavating a small trench at the top of the bank (approximately 6 to 8 inches in width and depth), placing and anchoring the blanket’s top edge into the trench, backfilling with soil over the blanket’s edge, and rolling the blanket out to cover the intended area. ECBs would then be anchored into the ground using live cuttings, wood stakes, or a combination. Other planting efforts, including seeding prior to installing the blanket, live plantings, and installing live bundles, would often be incorporated into the ECBs.

Soil Lifts

Fabric-encapsulated soil lifts consist of layers of soil wrapped in a biodegradable fabric that is penetrable by plant roots. These soil lifts could be used to temporarily strengthen soil cohesion and prevent or reduce soil loss when rebuilding or contouring a bank, until vegetation can become established and provide long-term soil stabilization. Typically, fabric-encapsulated soil lifts would be used in conjunction with brush layering, which consists of placing live vegetation

(including live cuttings and rooted plants) between the soil lift layers. Installation would include placing the fabric over the base of the bank to be rebuilt or contoured, placing and lightly compressing a layer of soil over the fabric, wrapping the fabric over the outer face of the soil layer, and anchoring the fabric into place using wood stakes or live cuttings. The height of each soil lift would vary based on site-specific conditions and the bank slope angle; it would typically range from 12 to 18 inches.

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Seed and mulch could also be added to the soil layer’s outer face prior to wrapping it with the fabric. A layer of live cuttings and/or rooted plants would then be placed on top of the soil lift and covered with a layer of soil. This sequence would then be repeated until the desired bank elevation is achieved. Each sequential soil lift layer would be placed slightly back from the face of the previous layer to create a slope angle similar to reference banks upstream and downstream from the project site. The top of the rebuilt bank could then be planted with sod mats and/or other plant material and revegetation techniques. Installation of fabric-encapsulated soil lifts would typically include the use of mechanized equipment for bank preparation and to deposit the soil layers; however, projects in smaller systems could be attainable using hand tools.

Root Wads

Root wads consist of a tree’s intact root mass, including a portion of the trunk. They could be used to increase bank roughness and dissipate flow energy, provide bank structural stability, and improve or diversify the aquatic habitat’s structure. Root wad dimensions would likely vary depending on the source material’s availability and site-specific conditions and objectives;

however, they would typically include root masses with a 5-foot or larger diameter. The trunk segment above the root mass would be approximately 10 feet in length or longer, with a basal diameter of 10 inches or more.

Installation of root wads would likely be conducted using one of two methods, both of which would require the use of mechanized equipment. In both methods, the trunk portion would be embedded into the bank’s toe perpendicular to the stream, with the root mass exposed and parallel to the bank. Generally, the root wad would be installed so that approximately half of the root mass is below water during base flow conditions. Root wads could be installed as a single unit, or as a series of several root wads adjacent to each other with overlapping root masses.

One installation method would include the use of an…