Chapter 3

Text Revisions to EIR

Revisions have been made to the EIR text as a result of comments received on the RDEIR. A compilation of the revisions is provided below. Changes in the text are signified by strikeouts where text is removed and by underlined italics where text is added.

3.1 Revisions to the Executive Summary

Page ES-2

The last sentence in the second paragraph under Section ES1.3 has been changed as follows:

Because VVMHP experiences severe water velocities during inundation and has only one entrance/exit, the elderly population living residents in VVMHP find themselves in a life threatening situation in flood events of 50 year probability and greater, as do emergency personnel who must evacuate the park.

Page ES-9

The second bullet on page ES-9 has been changed as follows:

n Creation of an all weather access way to the hospital (would require further environmental review).

Page ES-10

Table ES-1 has been revised and is attached at the end of this chapter.

Page ES-37

Impact HHM-1 has been revised as follows:

HHM-1: Management of hazardous materials, including hazardous waste, may be required as part of the construction of project features and the relocation of a maximum of 31-33 mobile homes.

Page ES-39

Impact PH-1 has been revised as follows:

PH-1: The project will require the relocation of a maximum of 31-33 homes.

3.2 Revisions to Chapter 2

Page 2-6

The last line on the page has been modified as follows:

Over 20 areas acres of rich floodplain . . .

Page 2-7

The fourth bullet on page 2-7 has been modified as follows:

n The City would remove noxious weeds, giant reed (Arundo donax), periwinkle (Vinca major), and Himalaya berry (Rubus discolor) to the maximum extent possible during terrace construction. Accepted treatment methods will be used that are sensitive to riparian zones. These may include physical removal, removal by machinery (mowing, etc.) or use of herbicides, such as EPA approved Rodeo® or other herbicides also approved for use in and near wetlands. The City would completely excavate giant reed infestations out of streambanks and ensure that all plant parts would be destroyed. For periwinkle and Himalaya berry, root systems and runners would be too intermingled with other plants to eliminate entirely in many cases, but solid patches could be excavated.

Page 2-8

The first sentence under Section 2.4.1.2 has been revised as follows:

Relocation of a maximum of 31-33 homes in VVMHP would be required to accommodate Terrace B.

Page 2-9

The first sentence under Section 2.4.1.6 has been revised as follows:

Water, sanitary sewer, gas, electrical, telephone, and cable TV utilities would be disconnected and removed in the areas of home relocations and extended into the area to which a maximum of 31-33 homes would be relocated.

Additionally, the following information has been added after the first bullet on page 2-9:

The City estimates that 18 acre-feet of water will be required per year during the approximately two years in which the vegetation is being established in the terraces. The water will be delivered to the edge of the terraces via truck. The water will either be directly applied with a hose or the water will be stored in temporary water tanks above the terraces, which will gravity feed temporary irrigation systems. Watering of the terraces is expected to continue for two summers, or until vegetation is established. Vehicular access will not be permitted within the habitat areas.

The use of recycled water will not impact the City’s water supply because the City does not rely on recycled water to meet its potable water demands.

Page 2-10

The following text has been added after the first sentence in the first full paragraph on page 2-10.

The existing north-south drainage ditch extending south from Fulton Lane would be rerouted along the north side of the proposed Adams Street extension and would outfall into Terrace B after treatment. Stormwater routed along the north side of the Adams Street levee would be treated in one of the following two ways prior to discharge: 1) The ditch along Adams Street levee would be constructed as a “U”- shaped vegetated swale with check dams to slow water and trap sediment prior to discharge; or 2) The Adams Street levee ditch would be routed into of Terrace B, where the stormwater would be treated using an alternative such as described below.

Page 2-11

The last paragraph in Section 2.4.1.7 has been deleted and replaced with the following text:

Slope protection may also be required at the new storm drain outfall located 70 feet north of the VVMHP floodwall. The protection would consist of the construction of a concrete outlet apron armored with rip-rap, or other means, to reduce the flow velocity at the drain outfall. Biotechnical streambank stabilization measures will be used to stabilize the slopes of the new storm water outfall from Adams Street as well as the existing 42-inch outfall located at the VVMHP floodwall.  Both outfalls will drain into Terrace B.

Page 2-12

The paragraph in Section 2.4.1.9 has been revised as follows:

Paseo Grande Drive would be extended from its current terminus northwest to connect with Adams Street and would cover 0.3 acre. The intersection of Adams Street and Paseo Grande Drive would be gated and closed to all through traffic except emergency vehicles. The new section of Paseo Grande will be constructed to city street standards between the current terminus of the street and the relocated mobile homes. The mobile home access road will be approximately 700 feet long by 26 feet wide and will have an asphalt concrete surface. This portion of the road will also include curb and gutter on both sides and sidewalk on the north side. The portion of the road between the access road serving the new mobile homes and the levee will be a compacted and graveled all weather road, but will only be open for emergency vehicle use. The road is envisioned to connect to Adams Street and may be opened for public use when the Adams Street bridge is constructed.

The paragraph in Section 2.4.1.10 has been revised as follows:

An interpretive pedestrian path would be included in the design to provide public access through the flood terraces where no public access now exists. The path would extend from the Adams Street levee to the confluence of Sulphur Creek with the Napa River. The path may be accessed on foot through the Adams Street levee.

The public trail would comply with the following St. Helena General Plan Guiding Policies:

6.4.2 Develop a trail system within stream corridors to accommodate pedestrians, bicyclists, and equestrians if compatible with riparian vegetation and wildlife habitat.

6.4.3 Preclude public access to habitat areas when public access will significantly impact the value of the habitat area.

The purpose of the proposed trail along the Napa River is to allow public enjoyment of this important resource, while still protecting critical habitat. Use of the trail will be limited to pedestrians and bicyclists. The trail will be approximately six feet wide and constructed with a compacted surface to be accessible to persons with disabilities.

While the exact location of the trail is not set, it would begin in the vicinity of the end of the Adams Street levee at the outer edge of Terrace B and run on the river side of proposed new floodwall/levee. (See RDEIR, Figure 2-6, pink dashed line shows location of floodwall/levee).) The trail would end in the vicinity of the southern tip of Terrace B. The alignment of the trail will be designed to avoid the mitigation areas for the elderberry plants and other ecologically sensitive areas.

Page 2-13

The first and second paragraphs on page 2-13 have been revised as follows:

The proposed floodwall would be similar to a concrete retaining wall. The floodwall would be approximately 450 feet long and a maximum of 5 feet 4 feet tall. The location of the wall would be approximately 1,200 feet from the Napa River.

The entrance roadway from Thomann Lane and the service road along the west side of the ponds would be ramped up approximately 4 feet 5 feet and then lowered back to the natural grade to provide flood protection for the operations buildings. This road construction would tie into the floodwall to create an enclosed area for the operations buildings.

The first sentence of the first paragraph in Section 2.4.1.12 has been revised as follows:

The draft AMP is contained in Appendix B. The framework for the AMP can be found in the report prepared by Swanson Hydrology & Geomorphology (SH&G) entitled Geomorphic Design Report, January 6, 2003.

Page 2-16

The construction timing has been updated as follows:

Year 1 (2004)

n Construct bank protection and floodwall at confluence of Napa River and Sulphur Creek

n Remove Pope Street Bridge Sill (assuming supplemental CEQA document is complete)

n Geotechnical data gathering.

n Clear structures at the top of bank at the "point" in Vineyard Valley

n Land acquisition

n Development of relocation site plan

n Prepare plans and specifications and bid package for overall project

Year 2 & 3 (2005 & 2006)

n Construct Terraces A and B

n Construct levees and floodwalls

n Construct bank protection and floodwall at confluence of Napa River and Sulphur Creek

n Relocate homes

n Revegetate terraces (3 2 year establishment period)

n Construct WWTP protection

Year 3 & 4 (2006 & 2007)

n Construct Adams Street causeway/bridge (pending supplemental CEQA review)

n Remove Pope Street Bridge sill (pending supplemental CEQA review)

3.3 Revisions to Chapter 3

Page 3-4

The first sentence in the last paragraph on page 3-4 has been changed as follows:

Once construction of the Proposed Project was completed, a maximum of 31-33 homes would be relocated northwest of the park and 10 acres along the left bank (Terrace A) and 8 acres along the right bank (Terrace B) of the Napa River would be terraced.

Page 3-6

Mitigation measure AE-3b has been revised as follows:

Community Design Workshops will be conducted by a City selected architect in The City of St. Helena Design Review process shall incorporate public input into the development of final design of the Adams Street causeway and bridge concurrent with the project level environmental analysis.

Page 3-27

Revisions to the Biological Resources Section

The following text is the biological resources section reprinted in its entirety.

3.5 Biological Resources

3.5.1 Regulatory and Environmental Setting

3.5.1.1 Regulatory Setting

Federal and State Regulations

The Federal Endangered Species Act (ESA) defines an endangered species as any species that is in danger of becoming extinct throughout all or a significant portion of its range and a threatened species as any species “likely to become an endangered species within the foreseeable future” (16 U.S.C. § 1532 et seq.). The ESA makes it illegal for any individual to kill, collect, remove, harass, import, or export an endangered or threatened species without a permit from the Secretary of the Department of the Interior (DOI) or the Department of Commerce (DOC). The United States Fish and Wildlife Service (USFWS), a DOI agency, performs most administrative and regulatory actions under the ESA. Within the National Oceanic and Atmospheric Administration (NOAA), an agency within the DOC, an entity known as NOAA Fisheries (formerly known as NMFS) is responsible for actions that affect ocean-going marine species and anadromous species. Section 7 of the ESA delineates a method for approval, disapproval, or appeal of a proposed federal agency action that may affect threatened or endangered speciesprovides a method to ensure that no federal agency shall authorize, fund, or carry out any action that is likely to jeopardize the continued existence of an endangered or threatened species or result in the destruction or adverse modification of “critical habitat.” If the USFWS or NOAA Fisheries determines during inter-agency consultation that a proposed federal agency action will not jeopardize the species or destroy or adversely modify critical habitat, USFWS or NOAA Fisheries may authorize incidental take. Section 10 of the ESA provides the permit process by which a private entity or non-federal public entity can obtain an Incidental Take Permitallows the USFWS or NOAA Fisheries to authorize take resulting from research, habitat enhancement, or non-federal activities that are otherwise lawful.

The Magnuson-Steven Fishery Conservation and Management Act (MSFCA) mandates that each fishery management plan identifies essential fish habitat (EFH) and requires that a collaborative effort be made to manage and maintain healthy fish populations in EFH. EFH is defined as “waters and substrate necessary to fish for spawning, breeding, feeding or growth to maturity.” The geographic scope of this act extends to federal waters within the interior United States and ocean extending 200 miles from the edge of State waters (Strach et. al., 2002). NOAA Fisheries is responsible for implementing the MSFCA. Consultations with NOAA Fisheries are triggered when proposed actions may adversely affect EFH. “Adversely affect” refers to any action that may reduce the quality or quantity of EFH (Strach et. al., 2002).

The Migratory Bird Treaty Act of 1918 (MBTA) is the domestic law that affirms, or implements, the U.S.’s commitment to four international conventions (with Canada, Japan, Mexico, and Russia) for the protection of a shared migratory bird resource. Each of the conventions protects selected species of birds that are common to both the U.S. and one or more of the countries. Bird species common to two countries occur in both countries at some point during their annual life cycle. This act makes it unlawful to pursue, hunt, kill, capture, possess, buy, sell, purchase, or barter any migratory bird, including the feathers or other parts, nests, eggs, or migratory bird products (16 U. S. Code 703-711).

Section 404 of the Clean Water Act (CWA) provides enforcement authority against activities that discharge fill material and/or requires excavation in “waters of the United States, including wetlands”. Permits pursuant to Section 404(b) require an evaluation of the project demonstrating that it is the least environmentally damaging practicable alternative. Any activity that discharges into “waters of the U.S.” requires a Section 404 permit. The permit requires mitigation of unavoidable impacts on wetlands and other Waters of the United States.

The Natural Community Conservation Planning Act (NCCPA) is part of the CDFG California Fish and Game Code, Sections 2800-2840. The NCCPA authorizes and encourages conservation planning on a regional scale in California. The NCCPA addresses the conservation of natural communities as well as individual species. The mechanism for this regional conservation is the development of natural community conservation plans (NCCPs) that provide for early coordination efforts to protect natural communities, including listed species or species that are not yet listed. To be approved by CDFG, an NCCP must adequately conserve species and natural communities within the plan area rather than minimize and mitigate the impacts of taking a listed species caused by individual projects that are carried out within the plan area, as is required under the ESA and California Endangered Species Act (CESA) (California Fish and Game Code, Section 2050 et seq). The NCCPA also provides an alternative to incidental take permits under CESA. Under the NCCPA, CDFG may issue “NCCPA authorizations” for actions that would result in the take of any species, including listed species, that are adequately conserved by an approved NCCP (CALFED, 2001).

CESA (Fish and Game Code Sections 2050 to 2097) is similar to the ESA. CDFG and the California Fish and Game Commission are is responsible for administering this act and for maintaining the California threatened and endangered species listings. CESA prohibits the “take” of listed and candidate (petitioned to be listed) species. “Take” as defined by CESA is to “hunt, pursue, catch, capture, or kill, or attempt to hunt, pursue, catch capture, or kill.” To ensure that actions proposed by an agency do not jeopardize the continued existence of any endangered or threatened species or result in destruction or adverse modification of essential habitat, lead agencies should consult with the CDFG prior to project implementation.

CDFG Fish and Game Code Sections 1600 and 1601 requires notification about public agency projects that would take place in or in the vicinity of a river, stream, lake, or its tributaries. Notification of CDFG is required before any construction would 1) divert, obstruct, or change the natural flow or the bed, channel, or bank of any river, stream, or lake, 2) use materials from a stream bed, or 3) result in the disposal or disposition of debris, waste, or other material containing crumbled, flaked, or ground pavement that could pass into a river, stream, or lake. Such activities can proceed only if CDFG enters into a “streambed alteration agreement” with an applicant. The contents of such agreements are subject to arbitration in the event that the parties cannot agree on all particulars.

Sections 3511 (birds), 4700 (mammals), 5050 (reptiles and amphibians), and 5515 (fish) of the Fish and Game Code identify fish and wildlife species for which CDFG may not authorize take, except for scientific research; these species are collectively referred to as “fully protected species.”

Section 3503 of the CDFG Code specifies that “it is unlawful to take, possess, or needlessly destroy the nest or eggs of any bird, except as otherwise provided by this code or any regulation made pursuant thereto”.

Section 3503.5 of the code specifies that it is unlawful to take, possess, or destroy any birds in the orders Falconiformes or Strigiformes (birds of prey) or to take, possess, or destroy the nest or eggs of any such bird except as otherwise provided by this code or any regulation adopted pursuant thereto.

The California Native Plant Protection Act generally prohibits the take of rare plants, but allows landowners, under most circumstances involving new development, to take listed plant species, provided that the owners first notify CDFG and give the state agency at least 10 days to come and retrieve (and presumably replant) the plants before they are plowed under or otherwise destroyed. (CDFG Code, § 1913 (exempts from “take” prohibition “the removal of endangered or rare native plants from a canal, lateral ditch, building site, or road, or other right of way”))

The Governor of California issued an executive order on August 23, 1993, that created a California State Wetlands Conservation Policy. This policy is being implemented by an interagency task force that is jointly headed by the State Resources Agency and the California EPA. The policy has three goals:

n To ensure no overall net loss and a long-term net gain in wetlands acreage and values in a manner that fosters creativity, stewardship, and respect for private property;

n To reduce the procedural complexity of state and federal wetlands conservation program administration; and

n To encourage partnerships that make restoration, landowner incentives, and cooperative planning the primary focus of wetlands conservation.

The CEQA Guidelines address biological impacts in section 15065, subdivision (a), which requires a “mandatory finding of significance” where a project “has the potential to . . . substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, [or] reduce the number or restrict the range of an endangered, rare or threatened species[.]” Section 15380 defines species as “endangered” when “its survival and reproduction in the wild are in immediate jeopardy from one or more causes, including loss of habitat, change in habitat, overexploitation, predation, competition, disease, or other factors.” The same section defines a species as “rare” when “(A) [a]lthough not presently threatened with extinction, the species is existing in such small numbers throughout all or a significant portion of its range that it may become endangered if its environment worsens; or (B) [t]he species is likely to become endangered within the foreseeable future throughout all or a significant portion of its range and may be considered ‘threatened’ as that term is used in the Federal Endangered Species Act.” A species formally “listed” under either ESA or CESA is presumed to be “endangered,” “threatened,” or “rare” for purposes of CEQA.

Local Regulations

General Plan Policies

Riparian Corridors – Guiding Policies

6.2.1 Preserve and enhance St. Helena’s riparian corridors for their value in providing visual amenity, drainage, and wildlife habitat.

6.2.3 Protect the riparian vegetation and habitat value of the City’s stream corridors by requiring development setbacks and open space easements along the Napa River, Sulphur Creek, York Creek, and Spring Creek. (Setbacks shall be measured from top of existing bank or the top of the finished bank, where channel improvements are necessary. The width of setbacks shall be established consistent with CDFG standards.)

Riparian Corridors – Implementing Policies

6.2.6 Develop standards requiring reasonable restoration of riparian corridors.

6.2.8 Encourage the development of programs for flow augmentation in the Napa River and its tributaries during period of flow in order to enhance year round fish habitat and minimize stagnation and pollution.

6.2.9 Adopt and enforce an ordinance to protect and enhance riparian corridors within St. Helena. (A riparian protection ordinance would designate riparian corridors to be protected and setbacks, and establish guidelines to ensure compatibility among agriculture, grazing, developed areas, and resource protection.)

The city has not yet adopted implementing standards/ordinances for these policies.

Vegetation and Wildlife – Guiding Policies

6.2.10 Protect natural habitats, which have the potential to support rare, endangered, or special status wildlife and plant species.

6.2.11 Preserve St. Helena’s streams and associated riparian corridors as natural open space corridors.

Vegetation and Wildlife – Implementing Policies

6.2.13 Require new development to be sited to maximize the protection of native tree species, riparian vegetation, important concentrations of natural plants, and important wildlife habitat.

6.2.14 Require all proposed projects adjacent to a riparian corridor or located in the city’s hillside areas, to submit management plans for protecting natural habitat values, including provision to:

n Employ supplemental planting and maintenance of grasses, shrubs, and trees of similar quality and quantity to provide adequate vegetation cover to keep the water sheds, on steep slopes and along streams, in good condition and to provide shelter and food for wildlife.

n Provide protection for wildlife habitat.

n Provide replacement habitat of like quantity and quality.

6.2.15 Require a biological assessment of any proposed project site where species or the habitat of species defined as sensitive or special status by the California Department of Fish and Game or the U.S. Fish and Wildlife Service might be present.

Preservation and Provision of Trees – Guiding Policies

6.4.11 Integrate existing significant trees into future development.

6.4.12 Require replacement trees where existing significant trees cannot be saved.

6.4.13 Require street trees as a condition of new development.

Preservation and Provision of Trees – Implementing Policies

6.4.14 Develop and adopt a Tree Ordinance for the purpose of protecting trees and providing for replacement trees in the City.

6.4.15 Review existing City standards and adopt standards regarding street trees for new and existing streets.

Napa County Flood Protection Sales Tax Ordinance (Measure A)

Measure A requires that all projects using Measure A funds be consistent with the LRPs. Appendix L contains a draft checklist of the LRPs that apply to this project.

3.5.1.2 Environmental Setting

Vegetation

General - St. Helena supports a variety of vegetation communities between the Napa River flood plain, and its hillsides. Six different natural communities are found in the hills to the east and west of St. Helena. These areas include: Valley and Foothill Grassland, Northern Mixed Chaparral, Oak Forest, Coast Range Mixed Coniferous Forest, Red Alder Riparian Forest, and Alluvial Redwood Forest. The mixed Coniferous Forest tends to dominate the ridges, while Oak Forests tend to occur more on the down-slope areas. Red Alder Riparian Forest, which is considered sensitive to California due to its relatively recent decline and fragile nature, occurs along intermittent streams in the city, particularly where there are poorly aerated, marshy soils and seasonally variable water table depths. Alluvial Redwood Forests, which are typically confined to northern exposures and canyon bottoms with shallow, well-drained soils, are located along the higher elevations of Sulphur Creek outside the city limits. Most of these hillside areas are fairly heavily wooded, although agriculture and residential development have removed vegetation in some areas

The Napa River watershed historically supported a dense riparian forest and significant wetland habitat. The City of St. Helena considers its riparian habitats the most valuable wildlife resource within the city; however, development and agriculture have degraded existing riparian stands. “According to the Department of Fish & Game the Napa River riparian woodlands are the third most important for game habitat in Region 3, exceeded only by the Russian and Salinas Rivers” (Napa County General Plan, 1983).

Napa River Corridor - As a part of the Geomorphic and Riparian Vegetation Assessment of the Proposed Napa River Flood Control Project (Appendix F), a field investigation of riparian and wetland vegetation alongside the Napa River was undertaken to gather data on the abundance and composition of the vegetation in the project reach. Sixty-seven plant species were found along survey cross sections. Dr. John Little of Sycamore Environmental Consultants, Inc., conducted an additional biological survey in April 2003. The results of both surveys are listed in Table 3-4. The Biological Survey Report can be found in Appendix J. Dominant species and their environmental relationships are described below. Figure 3-6 shows riparian tree species within the project area.

Valley oak was the most abundant overstory tree in terms of both numbers and basal area, occupying the highest elevations. Coast live oak was similar. Neither oak is a riparian obligate; however, valley oaks generally occur where their roots can tap into permanent, or nearly so, groundwater. Black walnut is mainly a riparian tree. It occurred over a relatively wide range of elevations above bankfull (about 4 feet). White alder showed a pattern more readily apparent in the field. Wherever this widespread riparian obligate tree occurs, it grows in the active channel, generally below bankfull elevations. Only two cottonwoods were found along the study reach. This species appears to have similar habitat preferences as alder, but more data are

needed. From experience, cottonwoods tend to grow somewhat less in the active stream channel compared to alder.

Table 3-4 Plants Found Along Cross Sections of the Napa River near St. Helena Nomenclature follows Hickman (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley, Ca. *indicates non-native species
Name	Abundance
Trees
Acer macrophyllum big leaf maple	Uncommon
Aesculus californica California buckeye	Common
Alnus rhombifolia white alder	Common
Conium maculatum hemlock	Observed
Fraxinus latifolia Oregon ash	Scattered
Juglans californica (var.hindsii) Black walnut	Common
Juglans regia English walnut	Uncommon
Prunus sp.	Uncommon
Quercus agrifolia coast live oak	Common
Quercus lobata valley oak	Common
Salix laevigata red willow	Common
Salix sp. willow	Observed
Sambucus mexicana elderberry	Scattered
Sequoia sempervirens redwood	Observed
Shrubs
Arundo donax giant reed	Scattered
Mentha sp mint	Scattered
Populus fremontii Fremont cottonwood	Uncommon
Prunus subcordata Sierra plum	Uncommon
Rosa californica wild rose	Uncommon
Salix hindsiana sand-bar willow	Scattered
Salix lasiolepis Arroyo willow	Uncommon
Salix lucida ssp. lasiandra shining willow	Uncommon
Symphoricarpos albus common snowberry	Common
Aristolochia californica pipevine	Common
Cornus glabrata brown dogwood	Uncommon
Hedera helix* english ivy	Scattered
Marah fabaceous wild cucumber	Uncommon
Rubus discolor* Himalaya berry	Common

Table 3-4 (cont’d) Plants Found Along Cross Sections of the Napa River near St. Helena Nomenclature follows Hickman (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley, Ca. *indicates non-native species
Name	Abundance
Vines
Toxicodendron diversilobum poison oak	Scattered
Vinca major* periwinkle	Common
Vitus californicus California wild grape	Common
Terrestrial herbs and grasses
Agrostis spp.* bent grass	Common
Alisma sp.	Scattered
Artemisia douglasiana mugwort	Scattered
Avena barbata* wild oak	Uncommon
Bacopa eisenii water hyssop	Common
Brassica rapa* field mustard	Common
Bromus diandrus* rip-gut brome	Uncommon
Cardamine sp.	Scattered
Carduus pycnocephalus* Italian thistle	Scattered
Carex obnupta/barbarae sedge	Common
Cerastium sp. chickweed	Uncommon
Chamomilla suaveolens Pineapple weed	Observed
Chenopodium botrys goosefoot	Common
Convolvulus arvensis* bindweed	Uncommon
Cortaderia sp.* pampas grass	Uncommon
Cynodon dactyon bermuda grass	Observed
Cynosaurus echinatus* dog-tail grass	Uncommon
Cyperus eragrostis nutgrass	Common
Daucus carrota* carrot	Scattered
Eschscholzia californica California poppy	Scattered
Epilobium brachycarpum willow herb	Common
Epilobium ciliatum	Uncommon
Equisetum telmateia horsetail	Scattered
Erodium cicutarium* filaree	Common
Foeniculum vulgare* fennel	Uncommon
Galium aparine* bedstraw	Common
Geranium dissectum* cranesbill	Common
Gnaphalium luteo-album* fragrant everlasting	Uncommon
Hirschfeldia incana* field mustard	Uncommon
Hordeum murinum* foxtail	Uncommon
Juncus sp rush	Uncommon
Lactuca serriola* wild lettuce	Uncommon
Lamium* sp.	Scattered
Leersia oryzoides cut grass	Common
Lemus triticoides	Uncommon
Limnanthes alba ssp. Versicolor meadowfoam	Scattered
Lupinus sp.	Scattered
Melilotus albus* white sweet clover	Scattered
Malva nicaeensis* bull mallow	Common
Paspalum urvellei dallis grass	Uncommon
Piptatherum milacea smilo grass	Scattered
Poe annua* Annual bluegrass	Scattered
Polypogon monspeliensis* rabbit’s foot grass	Uncommon
Ranunculus muricatus*	Scattered

Table 3-4 Plants Found Along Cross Sections of the Napa River near St. Helena Nomenclature follows Hickman (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley, Ca. *indicates non-native species
Name		Abundance
Terrestrial herbs and grasses (continued)
Rhaphanus sativa* wild radish		Uncommon
Rosa sp. wild rose		Scattered
Rumex sp.* dock		Uncommon
Scrophularia californica figwort		Uncommon
Senecio vulgaris* common groundsel		Scattered
Silybum marianum* milk thistle		Scattered
Sonchus oleraceus* common sow thistle		Scattered
Stachys ajugoides hedge nettle		Uncommon
Torilis nodosa* wild parsley		Scattered
Trifolium sp.		Common
Vicia sp.		Common
Vinca major greater periwinkle		Observed
Xanthium strumarium cockle bur		Scattered
Aquatic herbs and grasses
Alisma plantago-aquatica water plantain	Uncommon
Carex nudata Dudley’s sedge	Scattered
Ludwigia peploides water primrose	Scattered
Plantago lanceolata* english plantain	Scattered
Polygonum amphibium water smartweed	Scattered
Scirpus fluviatilis river bulrush	Uncommon
Typha latifolia cattail	Uncommon

Buckeye and elderberry, like the oaks, are not riparian obligates and occur in similar positions along the riverbank as the oaks. Riparian species like Oregon ash and red willow tend to occur much closer to low water elevation. Willows were mainly within the bankfull portion of the stream, though a few occurred well above this.

A number of valley oak and Oregon ash saplings occur at elevations closer to low water, compared to mature specimens. This suggests the adult population of trees may not indicate how close to the summer low flow elevation these species can grow now and in the future. It is likely that the vegetation is still adjusting to the relatively rapid downcutting of the riverbed that has occurred in recent decades, especially species that are slow growing and establish infrequently, like the two mentioned above.

Red willow tends to occur close to the stream. Sandbar willow lives up to its name and is found on gravelly sandbars very near the low water level. Snowberry is not a riparian obligate, but it is fairly common above bankfull elevations in the riparian corridor.

Two pernicious exotic invasive weeds are common along the project area: Himalaya berry (Rubus discolor) and giant reed (Arundo donax). Both species spread vegetatively, producing extensive, impenetrable monocultures, which can largely exclude native vegetation. A third species, periwinkle (Vinca major), is slower growing and generally only found near plantings of itself. However, it does appear to be a problem in the study area. Both the Himalaya blackberry and periwinkle occur over a range of elevations and can form dense monocultures. The native species that appears to be most displaced by these weeds is California wild grape, which is nonetheless common over a range of elevations. A fourth vine that is also widely distributed within the riparian corridor is pipevine, a species with a very unusual flower and the host plant of the magnificent pipevine Swallowtail butterfly.

Both sedges and cutgrass were common right at the water’s edge. Sedges were also scattered higher above the river. Additional sedge species occur in the active stream channel, forming remarkable columnar clumps. The most common herbaceous plant away from the river’s immediate edge was the introduced bedstraw.

Upland/Agriculture - In addition to the fieldwork conducted by the geomorphology study team, a survey was undertaken November 12, 2002 to preliminarily assess vegetation not associated with the Napa River riparian corridor. Several drainage ditches and agricultural ponds/sumps occur within the vineyard on the right bank of the river to the northwest of Vineyard Valley. The drainage ditch varies from extremely shallow to approximately 4 feet deep as it crosses the vineyards. This ditch contains weedy, ruderal vegetation that has been mowed for portions of the ditch. The larger of the two agricultural ponds/sumps within the project area contains water for most of the year and is essentially devoid of vegetation. The smaller agricultural pond/sump is seasonal and is predominantly vegetated by grasses and cattails.

The right bank vineyard area also includes a number of trees and shrubs scattered around the property, as well as trees along the existing floodwall in Vineyard Valley and within the fenceline of the Hunts Grove Apartments. These trees include a number of large (> 6” diameter at breast height [dbh]) ornamentals (i.e. Sweet Gum, etc.), ash, and oak. Also scattered along the existing floodwall are numerous small and approximately 3 large (> 5” dbh) elderberry shrubs.

The vineyard located on the left bank of the Napa River was recently planted and does not contain any other habitat not associated with the riparian corridor.

WWTP – At the entrance to the WWTP is a small vineyard plot ringed by olive and other ornamental trees. Ornamental trees can also be found scattered throughout the grounds of the WWTP. Olives and other trees such as oaks line Thomann Lane approaching the WWTP.

Wildlife

There is a wide range of naturally occurring mammals, birds, amphibians and reptiles within the study area. Typical mammals include gophers, rabbits, mice, rats and moles with occasional sightings of deer, raccoon, opossum or skunk. Birds include blackbirds, woodpeckers, jays, magpies, starlings, sparrows, finches, quail, pigeons and robins. Amphibians include newts, toads, salamanders and frogs. Reptiles that are present in the city include garter snakes, gopher snakes, rattlesnakes, western fence lizards, coast horned lizards, and alligator lizards.

Environmental Science Associates surveyed the St. Helena area in order to prepare the City of St. Helena General Plan Update EIR (1993). Species observed in riparian and adjacent upland areas during these surveys included black-tailed deer, northern flicker, western gray squirrel, and acorn woodpecker.

A biological survey was performed for the St. Helena Comprehensive Flood Control Project on 16 April 2003. The study area included portions of the riparian zone of the Napa River and adjacent areas. Species observed are shown in Table 3-5.

Table 3-5 Wildlife Species Observed During 16 April 2003 Biological Survey
Common Name	Scientific Name
American Crow	Corvus brachyrhynchos
Phoebe	Sayornis sp.
Red-tailed hawk	Buteo jamaicensis
Rock dove	Columba livta
Western scrub jay	Aphelocoma californica

Fisheries

The hydrology of the Napa River in the project reach follows the typical pattern for the Mediterranean climate of coastal California. The bulk of stream flow occurs during winter rainstorms between October and April with minimum flows of less than 1 cfs occurring in the late summer and fall months. Winter flood flows vary in their intensity and recent flood history includes periodic El Nino events causing peak flows up to 21,000 cfs. Because of these variations in flow, the Napa River in the vicinity of St. Helena does not support a commercial fishery, and at best may support a limited recreational fishery. The summer low flow period also coincides with high instream temperatures, which are “generally high enough to favor exotic warm-water fauna over salmonids and to preclude the possibility of successful summer rearing by salmonids in the mainstem” (Stillwater Sciences 2002). However, the river is habitat for migrating salmon and steelhead. The NOAA Fisheries has designated the Napa River as critical habitat for the Central Coast steelhead.

A preliminary survey was conducted by the City’s fisheries biologist in October, 2003. The survey indicated habitat within the project area was in poor condition and summer rearing of juvenile steelhead was unlikely. The reasons for his initial determination included:

· Poor dissolved oxygen generation from the few riffles within the project area. The riffles are short, narrow and shallow with little turbulent flow that could incorporate adequate amounts of dissolved oxygen during the summer low flow period. In some years the riffles become intermittent during the summer, which further reduces dissolved oxygen production.

· A significant amount of decaying vegetation was observed in the pool habitats, which could further decrease dissolved oxygen concentrations.

· Summer air temperatures in the Napa Valley frequently exceed 90-100 degrees for several days at a time. The long shallow pools/flatwaters within the project area are mostly exposed to solar radiation and likely become very warm and may exceed the temperature tolerance limits for steelhead. The pools appeared to border on stagnation due to the minimal inflow and outflow.

· The riffles, for the most part, were composed of relatively small substrate particles that were moderately to highly embedded with sand. This reduces benthic macro-invertebrate production that provides the drift insects used as the primary food source by juvenile steelhead.

· Large numbers of piscivorous Sacramento pikeminnow were observed in pools during the October field review. The larger of these fish would prey on rearing juvenile steelhead that may be in pools due to displacement out of the shallow or dry riffles. The smaller pikeminnows would compete with juvenile steelhead for food, oxygen, and space.

Although the river within the project area is likely unsuitable for summer rearing of salmonids it does contain suitable habitat for migrating and spawning Chinook salmon and steelhead, which generally would not take place during construction in or near the river. Downstream migration by juvenile steelhead and Chinook usually occurs from March through June with the peak in late April and May. Upstream migration into the project area by straying Chinook generally occurs in late fall when flows allow entry. Chinook spawning is usually over by mid-January or early February.  Steelhead adult migration and spawning generally begins in December and continues through April.  Steelhead tend to be more tributary spawners while Chinook spawn in mainstem river channels or larger tributaries.  Access to the mainstem by juvenile steelhead rearing in tributaries may also be limited due to intermittent flow in many smaller streams and thermal barriers.  The seasonal restriction on instream construction activities is set to avoid or minimize impacts to salmonids when they may be present.

Table 3-6 lists typical species that inhabit the Napa River between Napa and Calistoga.

Table 3-6 Typical Fish Species in the Napa River between Napa and Calistoga.
Sacramento sucker (Catostomus occidentalus)	Prickly sculpin (Cottus asper)
Riffle sculpin (Cottus gulosus)	Threespine stickleback (Casteroteus aculeatus)
California roach (Hesperolecus symmetricus)	Tule Roach (Hysterocarpus traski)
White catfish (Aneiurus catus)	Green sunfish (Lepomis cyanellus)
Bluegill (Lepomis macrochirus)	Smallmouth bass (Micropterus dolomieiu)
Hard Head (Mylopharodon dolomieui)	Sacramento pikeminnow (Ptychoheilus grandis)
Steelhead (Oncorhynchus mykiss)	Chinook salmon (Oncorhynchus tshawytscha)

Source: Stillwater Sciences 2002

Special-Status Species

The ESA of 1973 (16 U.S.C. § 1532 et seq.’; see also 50 CFR 17) provides legal protection and requires definition of critical habitat and development of recovery plans for plant and animal species in danger of extinction. The State provides parallel legal protection in the CESA of 1977. The status of an animal or plant is listed as endangered, threatened, or in the case of plants, rare by the ESA and CESA. Lists of species of special concern based on factors such as limited distribution, declining population size, diminishing habitat acreage or value, or unusual scientific, recreational, or educational value are also maintained by Federal and State agencies. Legal protection for species of special concern is limited compared to listed species but these species may be added to official lists in the future if their decline is not halted.

Again, a biological survey was performed for the St. Helena Comprehensive Flood Control Project on 16 April 2003, and included portions of the riparian zone of the Napa River and adjacent areas. The surveyor focused on the special-status species listed in Table 3-7 along with conducting a general wildlife and habitat assessment.

The City of St. Helena General Plan states that no rare, endangered, or special status plant or animal species have been identified in the city. A search of the CDFG’s Natural Diversity Database (2000), a USFWS species request list, and a literature review of other environmental documents prepared for sites in the study area resulted in Table 3-8. This table gives details of special status species in and near the study area as well as information on habitat requirements and distribution.

Table 3-7 Special-Status Species Surveyed for During the 16 April 2003 Biological Survey.
Plants	Wildlife
Amorpha californica var. napensis	Steelhead
Arctostaphylos bakeri	Chinook salmon
Astragalus clarianus	California freshwater shrimp
Brodiaea californica var. leptandra	Northwestern pond turtle
Ceanothus confususconfuses	Bald eagle
Ceanothus divergens	Northern spotted owl
Ceanothus sonomensis	Townsend’s western big-eared bat
Erigeron angustatus	Pallid bat
Hesperolinon bicarpellatum	Valley elderberry longhorn beetle
Hesperolinon sp. Nov. “serpentinum”
Layia septentrionalis
Limnanthes vinculans
Linanthus jepsonii
Lupinus sericatus
Navarretia leucocephala ssp. bakeri
Penstemon newberryi var. sonomensis
Sidalcea oregana ssp. hydrophila

Table 3-8 Special-Status Species with Potential to Occur in the Project Area
Species	Status^1Fed/St/CNPS^2	Habitat Requirements	Distribution	Occurrence in Study Area
Fish
Green Sturgeon Acipenser medirostris	C	Open ocean, estuaries or freshwater. Spawning takes place March-July in deep, fast, cold water.	Oceans off North America. Spawns in the Sacramento and Klamath Rivers.	Unlikely to occur in the area because of the lack of suitable habitat.
Delta Smelt Hypomesus transpacificus	FT	Mostly estuarine areas or shallow, fresh or slightly brackish waters for spawning.	Sacramento and San Joaquin Rivers within the Delta and their tributaries. Seasonally in Suisun and San Pablo Bays.	Documented occurrence in the Napa River upstream to the Cuttings Wharf area. Unlikely to occur in the area because of the lack of suitable habitat.
Central California Coastal Steelhead Oncorhynchus mykiss	FT	Ocean and freshwater rivers and streams	In streams from the Russian River to Aptos Creek, Santa Cruz County, CA (inclusive), and the drainages of San Francisco and San Pablo Bays eastward to the Napa River (inclusive), Napa County, CA, excluding the Sacramento-San Joaquin River Basin of the Central Valley.	Naturally spawning populations in Napa River, York Creek, and Sulphur Creek
Central Valley Chinook Salmon Oncorhynchus tschawytscha	C (fall/late fall), FE (winter), and FT (spring)	Ocean and freshwater rivers and streams	In streams and rivers of the Central Valley.	Occasional strays
Sacramento splittail Pogonicthys macrolepidotus	FSC	Slow moving river sections. Dead end sloughs. Requires flooded vegetation for spawning and foraging for young.	Endemic to California’s Central Valley. Found primarily in the Delta, Suisun Bay, and associated marshes.	Documented occurrence in the Napa River upstream to the Napa marshes. Unlikely to occur in the project area because of the lack of suitable habitat.
Longfin Smelt Spirinchus thaleichtys	FSC	Estuaries	Estuaries along the California coast	Unlikely to occur in the area because of the lack of estuarine habitat.
Amphibians
California Red-legged Frog Rana aurora draytonii	FT/CSC	Quiet, permanent water in woods, forest clearings, riparian areas, and grasslands	Coast, Transverse, Sierra Nevada, and Cascade Ranges	Potential habitat within York Creek and Sulphur Creek

	Species	Status^1Fed/St/CNPS^2		Habitat Requirements		Distribution		Occurrence in Study Area
	Critical Habitat, California Red-legged Frog Rana aurora draytonii				Ephemeral ponds, intermittent streams, seasonal wetlands, springs, seeps, permanent ponds, perennial creeks, man-made aquatic features, marshes, dune ponds, lagoons, riparian corridors, blackberry thickets, non-native annual grasslands, and oak savannahs.		4.1 million acres. 4 units in the north central Sierras. 27 units in the central and south coast and coastal units. 2 units in north and east Napa County.	Potential habitat occurs on tributaries to the Napa River. Unlikely to occur in the Napa River because of the lack of suitable habitat and predation by bullfrogs.
	Foothill Yellow-legged Frog Rana boylii		CSC		streams, rivers and on their banks; often suns on rocks		Northern and central coastal ranges, foothills of the Sierras	Potential habitat occurs on tributaries to the Napa River. Unlikely to occur in the Napa River because of the lack of suitable habitat.
Western Spadefoot Toad Scaphiopus hammondii			CSC		Grasslands with shallow temporary pools		Central Valley, bordering foothills, and coast ranges; southwestern United States	Unlikely to occur in the project area because of the lack of suitable habitat.
Reptiles
Northwestern Pond Turtle Clemmys marmorata marmorata			CSC		Associated with permanent or nearly permanent water bodies with abundant cover and basking sites		Parts of Washington, Oregon, Nevada, and California; below 5,000 feet	Observed in the project area. Potential habitat.
Birds
Cooper’s Hawk Accipiter cooperi			CSC		Forests and open woodlands		Migratory. Scattered across the US, Southern Canada, Mexico, and Central Mexico to Costa Rica	Potential habitat.
Tricolored Blackbird Agelaius tricolor			FSC		Dense thickets of cattails, tules, willows. Habitat must be able to support nesting colonies of about 50 pairs. Forages in grasslands and croplands		Central Valley and coastal California counties	Unlikely to occur in the project area because of the lack of suitable habitat.
Bell’s sage sparrow Amphispiza			FSC		Nests in chaparral dominated by fairly dense stands of chemise. Found in coastal sage scrub scrub in south of range.		Typically southern California, with the exception of Lake County.	Unlikely to occur in the project area because of the lack of suitable habitat.
Western Burrowing Owl Athene cunicularia hypugaea			FSC		Grasslands and scrublands		Throughout California	Unlikely to occur in the project area because of the lack of suitable habitat.

Species	Status^1Fed/St/CNPS^2	Habitat Requirements	Distribution	Occurrence in Study Area
Oak Titmouse Baeolophus inornatus	FSLC	Primarily associated with oak woodlands; can also occur in coniferous forests	Throughout California	Unlikely to occur in the project area because of the lack of suitable oak woodland habitat.
Lawrence’s Goldfinch Carduelis lawrencei	FSC	Oak woodland with intermediate canopy coverage and chaparral	Central and southern California	Unlikely to occur in the project area because of the lack of suitable habitat.
Vaux’s Swift Chaetura vauxi	FSC	Redwood, Douglas Fir, and other coniferous forests. Forages over open areas.	Northern California with old-growth redwood distribution.	Unlikely to occur in the project area because of the lack of suitable habitat.
Black Swift Cypseloides niger	FSC	Steep cliffs	Coastal belt of Santa Cruz and Monterey Counties, the Sierra Nevada, San Bernardino, and San Jacinto mountains.	Documented occurrence near Rutherford along the Napa-Sonoma county line. Unlikely to occur in the project area because of the lack of suitable habitat.
Yellow Warbler (nesting) Dendroica petechia brewsteri	CSC	Nest in shrubby growth by swamps and watercourses, in wet scrub, tree foliage, gardens, shrubberies and berry patches. Dense growth may be preferred.	Pacific Northwest and California	Documented occurrence within the Calistoga quad. Potential habitat.
White-tailed Kite Elanus leucurus	FSC	Foothill and valley margins and river bottomlands. Requires marshlands, meadows, and grasslands for foraging.	All California lowlands west of the Sierra Nevada mountains and deserts	Documented occurrence near Yountville. Unlikely to occur in the project area because of the lack of suitable habitat and continual disturbance associated with viticultural activity.
Little Willow Flycatcher Empidonax traillii brewsteri	FSC	Inhabits extensive thickets of low, dense willow on edge of wet meadow ponds 2,000-8,000 ft.	Small, scattered populations in Sierra Nevada meadows and along the Kern, Santa Margarita, San Luis Rey, and Santa Inez rivers.	Unlikely to occur in the project area because of the lack of suitable habitat.
American Peregrine Falcon Falco peregrinus anatum	D/SE	Protected edges of high cliffs, usually adjacent to marshes, lakes, or rivers that support plentiful bird populations	Nests in central and north Coast Ranges and Sierra Nevada; winters in Sacramento and San Joaquin Valleys	Unlikely to occur in the project area because of the lack of suitable habitat.

	Species	Status^1Fed/St/CNPS^2		Habitat Requirements		Distribution		Occurrence in Study Area
Bald Eagle Haliaeetus leucocephalus			FT/SE		Coniferous forests within 1 mile of lakes, reservoirs, rivers, or creeks (nesting and roosting)		Nests primarily in Lassen, Shasta, and Plumas Counties; winters in Klamath Basin, Sacramento and San Joaquin Valleys, and along some foothill streams	Documented occurrence wintering at Lake Beryessa and Lake Hennessey. Unlikely to occur in the project area because of the lack of suitable habitat.
Loggerhead Shrike Lanius ludovicianus			FSC		Open grasslands with scattered trees shrubs, posts, fences, utility lines, or other perches		Lowland and foothills throughout California	Unlikely to occur in the project area because of the lack of suitable habitat.
Lewis’ Woodpecker Melanerpes lewis			FSC		Logged or burned woodland, oak and riparian woodland, open coniferous forests with suitable insect and mast sources.		Central Valley and coast ranges	Unlikely to occur in project area due to disturbance associated with viticultural activity and the lack of suitable habitat.
Long-billed Curlew Numenius americanus			FSC		Breeds in upland shortgrass prairies and wet meadows in northeastern California		Northeastern, Central Valley, and Imperial Valley California.	Unlikely to occur in the project area because of the lack of suitable habitat.
Bank Swallow Riparia riparia			FSC		Colonial nester; nests primarily in riparian and other lowland habitats west of the desert. Requires fine-textured, sandy banks or cliffs.		Riparian and other California lowlands	Unlikely to occur in the project area because of the lack of suitable habitat.
Rufous Hummingbird Selasphorus rufus			FSC		Coniferous forests, high mountain meadows, grasslands, and brushy habitat.		Throughout California	Unlikely to occur in the project area because of the lack of suitable habitat.
	Allen’s Hummingbird Selasphorus sasin	FSC		Chaparral, open coniferous forest		Coastal California		Unlikely to occur in the project area because of the lack of suitable habitat.
	Northern Spotted Owl Strix occidentalis caurina	FT		Dense old growth, multi-layered mixed conifer, redwood, and Douglas Fir habitats. Narrow steep-sided canyons with north-facing slopes.		Washington, Oregon, California, Utah, Colorado, New Mexico, Arizona, and Mexico		Documented occurrence at Howell Mountain and Conn Creek east of St. Helena and the forests west of the city. Unlikely to occur in the project area because of the lack of suitable habitat.
	California Thrasher Toxostoma redivivum	FSC		Dense cover of chaparral or riparian thicket.		Foothills and cismontane lowlands of California		Unlikely to occur in the project area because of the lack of suitable habitat.

Species	Status^1Fed/St/CNPS^2	Habitat Requirements	Distribution	Occurrence in Study Area
Mammals
San Joaquin Pocket Mouse Perognathus inornatus	FSC	Typically found in grassland and blue oak savannah.	Central and Salinas valleys of California.	Occurs only in the Central and Salinas Valleys. The project area occurs in the Coast Range.
Pacific Western Big-eared Bat Corynorhinus (=Plecotus) townsendii townsendii	FSC	Roosts in caves, buildings, tunnels, etc. Extremely sensitive to disturbance.	Widespread in California.	Documented occurrence near Angwin. Unlikely to roost in project area due to continual disturbance associated with viticultural activity.
Long-eared Myotis Myotis evotis	FSC	Brush, woodland, and forest habitats, but prefers coniferous woodlands. Roosts in buildings, caves, and snags.	Widespread in California.	Unlikely to roost in project area due to the lack of coniferous woodland and the continual disturbance associated with viticultural activity.
Fringed Myotis Myotis thysanodes	FSC	Optimal habitats are pinyon-juniper, valley foothill hardwood, and hardwood-conifer. Roosting sites easily disturbed,	Widespread in California.	Unlikely to occur in the area because of the lack of suitable habitat and the continual disturbance associated with viticultural activity.
Long-legged Myotis Myotis volans	FSC	Most common in woodland and forest habitats above 4,000 ft. Trees are important day roosts. Caves and mines are night roosts.	Widespread in California.	Unlikely to occur in the area because of the lack of suitable habitat and the low elevation of the project site.
Yuma Myotis Myotis yumanensis	FSC	Found in a wide variety of habitats. Optimal habitats are open forests and woodlands with sources of water. Roosting sites include buildings, caves, and mines.	Widespread in California.	Unlikely to roost in study area due to continual disturbance associated with viticultural activity.
Great Western Mastiff Bat Eumops perotis californicus	CSC	Open semi-arid to arid habitats with crevices in cliff faces, high buildings, trees, or tunnels for roosting. Needs large bodies of water for drinking.	Uncommon in southeastern San Joaquin Valley and Coast Ranges from Monterey County south through southern California and from the Coast eastward to the Colorado desert	Unlikely to occur in the area because of the lack of suitable habitat.

Species	Status^1Fed/St/CNPS^2	Habitat Requirements	Distribution	Occurrence in Study Area
Townsend’s Western Big-eared Bat Corynorhinus townsendii townsendii	CSC	Humid coastal regions of northern and central California. Roosts in limestone caves, lava tubes, mines, buildings, etc. Will only roost in the open, hanging from walls, and ceilings.	Subspecies relegated to California coastal ranges. Full species found throughout the west.	Unlikely to roost in study area due to continual disturbance associated with viticultural activity. Documented occurrence at the McLaughlin Mine in extreme north Napa County.
Pallid Bat Antrozous pallidus	CSC	Deserts, grasslands, shrublands, woodlands, and forests. Most common in open, dry habitats with rocky areas for roosting. Also in buildings and hollow trees.	Western United States.	The study area does not provide suitable foraging habitat.
Invertebrates
Valley Elderberry Longhorn Beetle Desmocerus californicus dimorphus	FT	Elderberry shrubs in moist valley oak woodlands along the margins of streams and rivers	San Joaquin and southern Sacramento Valleys and eastern and southern Napa County	Elderberry shrubs occur within the study area, some shrubs show evidence of potential VELB exit holes
California Freshwater Shrimp Syncaris pacifica	FE/SE	Low elevation, low gradient, perennial freshwater streams, or intermittent streams with perennial pools. Structurally diverse, undercut banks with exposed roots and overhanging vegetation.	Endemic to Marin, Sonoma, and Napa Counties	Occurs in the Napa River both north and south of the project site. near Calistoga. Potential habitat.
Plants
Napa False Indigo Amorpha californica var. napensis	FSLC/1B	Broadleafed upland forest, chaparral, cismontane woodland.	Endemic to California	Sulphur Creek and Moore Creek in the early 1900’s. Las Posadas State Forest in 1993. Unlikely to occur in the project area because of the lack of suitable habitat.
Baker’s Manzanita Arctostaphylos bakeri	1B	Chaparral, Mixed Evergreen Forest, Closed-cone Pine Forest. Serpentine substrate	Endemic to California	Unlikely to occur in the project area because of the lack of suitable habitat.

Species	Status^1Fed/St/CNPS^2	Habitat Requirements	Distribution	Occurrence in Study Area
Clara Hunt’s milk-vetch Astragalus clarianus	FE/ST	Thin rocky clay soils derived from volcanic or serpentine substrates in grasslands and openings in whiteleaf manzanita-blue-oak woodlands	Endemic to California	Documented occurrence within St. Helena city limits in early 1900’s. Documented occurrence near Lake Hennessey in 1998. Unlikely to occur in the project area because of the lack of suitable habitat.
Narrow-anthered California Brodiaea Brodiaea californica var. leptandra	FSLC/1B	Broad-leafed upland forest, lower montane coniferous forest, chaparral, serpentine	Inner north coast range, especially Napa, Lake, and Sonoma counties.	Unlikely to occur in the project area because of the lack of suitable habitat.
Rincon Ridge Ceanothus Ceanothus confususconfuses	1B	Dry, brushy slopes	Endemic to Lake, Napa, and Sonoma counties.	Unlikely to occur in the project area because of the lack of suitable habitat.
Calistoga Ceanothus Ceanothus divergens	1B	Chaparral, cismontane woodland. Rocky, serpentine, or volcanic sites.	Endemic to Lake, Napa, and Sonoma counties.	Documented occurrence within Calistoga Quad. Unlikely to occur in the project area because of the lack of suitable habitat.
Holly-leaved Ceanothus Ceanothus purpureus	FSLC/1B	Chaparral and cismontane woodland	Endemic to California. Found in Napa, Solano, and Sonoma counties.	Documented occurrence within St. Helena Quad. Unlikely to occur in the project area because of the lack of suitable habitat.
Sonoma Ceanothus Ceanothus sonomensis	1B	chaparral on sandy, serpentine or volcanic soils	Sonoma and Napa counties	Documented occurrence on Table Mountain, Howell Mountain, and near Angwin. Unlikely to occur in the project area because of the lack of suitable habitat.
Narrow-leaved Daisy Erigeron angustatus	FSLC/1B	Chaparral	Known only from Lake, Napa, and Sonoma Counties	Collected from St. Helena in 1891. Also collected from Mt. St. Helena and Soda Creek Canyon circa 1940. Unlikely to occur in the project area because of the lack of suitable habitat.

Species	Status^1Fed/St/CNPS^2	Habitat Requirements	Distribution	Occurrence in Study Area
Two-carpellate Western Flax Hesperolinon bicarpellatum	FSC/1B	Serpentine chaparral	Known only from Lake, Napa, and Sonoma counties.	Documented on Howell Mountain in the early 1900’s. Unlikely to occur in the project area because of the lack of suitable habitat.
Napa Dwarf Flax Hesperolinon sp. Nov “serpentinum”	1B	Serpentine, chaparral	Inner north coast range especially Napa and Lake Counties.	Unlikely to occur in the project area because of the lack of suitable habitat.
Colusa Layia Layia septentrionalis	FSLC/1B	Chaparral, cismontane woodland, valley and foothill grassland. Scattered colonies in fields and grassy slopes in sandy or serpentine soils.	Endemic to California	Documented occurrences within the Pope Valley and on Howell Mountain. Unlikely to occur in the project area because of the lack of suitable habitat.
Sebastopol Meadowfoam Limnanthes vinculans	FE/SE	Vernal pools, meadows and seeps	Not Known outside of Sonoma and Napa Counties	Unlikely to occur in the project area because of the lack of suitable habitat.
Jepson’s Linanthus Linanthus jepsonii	FSLC/1B	Chaparral, grassland, and cismontane woodland. On volcanics or the periphery of serpentine substrates.	Endemic to California	Documented occurrences in the Pope Valley, Calistoga, and Conn Valley. Unlikely to occur in the project area because of the lack of suitable habitat.
Cobb Mountain Lupine Lupinus sericatus	FSLC/1B	Chaparral, cismontane woodland, lower montane coniferous forest. In stands of knobcone pine-oak woodland, on open wooded slopes in gravelly soils; sometimes on serpentine.	Endemic to California	Documented occurrences on Howell Mountain and in Las Posadas State Forest. Unlikely to occur in the project area because of the lack of suitable habitat.
Baker’s Navarretia Navarretia leucocephala bakeri	FSC/1B	Cismontane woodland, meadows and seeps, vernal pools, valley and foothill grassland, lower montane coniferous forest. Adobe or alkaline soils.	Endemic to California	Documented occurrence in Calistoga and Pope Valley. Unlikely to occur in the project area because of the lack of suitable habitat.
Gairdner’s Yampah Perideridia gairdneri ssp. Gairdneri	FSC	Broadleafed upland forests, chaparral, coastal prairie, valley and foothill grasslands, and vernal pools	Endemic to California	Unlikely to occur in the project area because of the lack of suitable habitat.

Species	Status^1Fed/St/CNPS^2	Habitat Requirements	Distribution	Occurrence in Study Area
Sonoma Beardtongue Penstemon newberryi var. sonomensis	1B	Chaparral. Crevices in rock outcrops and talus slopes.	Endemic to California	Documented occurrences on Mt. St. Helena and at Bateman Creek and the TNC Cleary Preserve. Unlikely to occur in the project area because of the lack of suitable habitat.
Marsh Checkerbloom Sidalcea oregana hydrophila	FSC/1B	Meadows and seeps, riparian forest. Wet soil of streambanks, meadows.	Endemic to California	Documented occurrence on Howell Mountain at the turn of the last century. Unlikely to occur in the project area because of the lack of suitable habitat.
Green (=Serpentine) Jewel Flower Streptanthus breweri var. hesperidis	FSLC/1B	Chaparral, cismontane woodland, serpentine rocky sites	Endemic to California. Found in Lake and Napa Counties.	Documented occurrence on Howell Mountain and near Pope Valley and Chiles Roads.. Unlikely to occur in the project area because of the lack of suitable habitat.

^1Key to Status: Federal: (E) Endangered – Listed (in the Federal Register) as being in danger of extinction. (T) Threatened – Listed as likely to become endangered within the foreseeable future. (P) Proposed – Officially proposed (in the Federal Register) for listing as endangered or threatened. (C) Candidate – Candidate to become a proposed species. (FSC/FSLC) – Other species of concern/species of local concern to the Sacramento Fish and Wildlife Service Office. (D) Delisted – Species will be monitored for 5 years. Critical Habitat – Area essential to the conservation of a species.

State: E=Endangered T=Threatened R=Rare CSC=California Species of Concern

CNPS: 1B=Rare or Endangered in California and elsewhere ^2California Native Plant Society designation applies only to plants

Sources: CNDDB 2003, ESA 1993, USFWS 20032, NCRCD 1999

Potentially Affected Species

Steelhead Trout – Central California Coast (CCC) Evolutionary Significant Unit (ESU) (Oncorhynchus mykiss) - The steelhead is currently listed as threatened in the Napa River region. Critical habitat has been designated for the CCC ESU to include the Napa River and its tributaries. The NOAA Fisheries had originally designated the Napa River as critical habitat for the Central Coast steelhead. However, the critical habitat designation was recently vacated and NOAA Fisheries is now undertaking a more thorough analysis prior to reissuing the designation. (See Nat'l Ass'n of Home Builders v. Evans (2002) 2002 U.S. Dist. LEXIS 25521, at p. *7. )

The steelhead trout is an anadromous form of rainbow trout. It spends one to four growing seasons in the ocean before returning to spawn for the first time. Steelhead seek out small streams and tributaries where cool, well oxygenated water, and gravelly stream channels occur in order to lay their eggs. Cover in the form of deep pools, overhanging and submerged vegetation, undercut banks and submerged debris is also important for the protection of spawning and hatching rearing steelhead. In streams subject to warm summer water temperatures, rearing juveniles are found primarily in riffles or at the head of pools where high dissolved oxygen and aquatic macroinvertebrate concentrations are located. The CCC steelheadESU generally spends up to its first three years of life in freshwater before migrating to the ocean between March and June. Unlike other anadromous pacific salmonids, steelhead may survive spawning, and return to the ocean, and to spawn again ina later years. Although tThe CDFG has recorded the Napa River, Sulphur Creek, and York Creek as steelhead migration and spawning sites., The relatively poor water quality (high temperature, low dissolved oxygen)the transitory nature of the steelhead in the Napa River and the presence of predatory fish, such as the pikeminnow, makes reduces the potential for spawning and rearing salmonidssuccessful steelhead rearing in the project area unlikely.

Central Valley Chinook Salmon (Oncorhynchus tshawytscha) – The various runs of the Central Valley Chinook salmon were determined by the USFWS and NOAA Fisheries to be candidate (fall/late fall), endangered (winter), and threatened (spring) species. The Central Valley cChinook salmon is an anadromous and semelparous (spawns only once then dies) fish. These fish are known to exhibit an “ocean-type” life history because fry conduct their downstream migration to the estuaries in the winter and spring relatively soon after emerging from the gravel. By contrast, a “stream-type” life history is characterized by a downstream migration near the end of the second year of freshwater residency. That spends up to 2 years as a juvenile in freshwater before returning to the ocean. Chinook It then spend up to 6 years in the marine environment before returning to theirits home stream to spawn and then die.

There are different seasonal runs or modes in the migration of Chinook salmon from the ocean to freshwater. The fall/late fall-run Chinook salmon is found in the Central Valley between July and April. The winter-run Chinook salmon is found in the Central Valley between December and July. The spring-run Chinook salmon is found in the Central Valley between April and October where they hold over in deep pools (1-3 meters) with moderate velocities and bubble curtains prior to spawning in the late summer and early fall. There is no suitable habitat within the project area for spring-run Chinook. The Chinook salmon found within the Napa River are likelyoften late fall or winter-run strays. Low summer and fall flows limit early season upstream migrationAlthough by adults in the Napa River. is potential Chinook migration, spawning, and rearing habitat, the transitory nature of salmon in the Napa River and the presence of predatory fish such as the pike minnow reduces the potential for spawning and rearing salmonids.

Northwestern Pond Turtle (Clemmys marmorata marmorata) - The northwestern pond turtle is a California Species of Special Concern that inhabits aquatic sites with plentiful hiding and basking sites. A permanent water source is necessary to avoid dessication, especially for hatchlings. Hatchlings are preyed upon by fish (bass, pikeminnow, bluegills) bullfrogs, and wading birds such as egrets and herons. The turtle seeks aquatic plant material, beetles, aquatic invertebrates, fishes, and frogs for a food source. Mating for northwestern pond turtles begins in late April and goes through early May. Oviposition typically occurs during May and June on upland habitats that average 200 m from the turtle’s aquatic habitat (CDFG, 2001). The female seeks out nesting sites in dry soils that are not subject to flooding. Preferred locations may include grassy hillslopes with minimal overhead canopy cover and southerly exposure. Nesting success is poor in humid soils due to the tendency of the eggs to absorb water from their surroundings. Eggs have been known to burst due to excess moisture absorption. The hatchlings, it is assumed, spend the winter within the nest, and emerge the following spring. Loss of upland nesting habitat through human disturbance is a potential source for the turtles’ decline.

The turtle is common to uncommon in suitable aquatic habitats throughout California, west of the Sierra-Cascade crest. Literature reviews and queries of the California Natural Diversity Database (CNDDB) did not reveal any occurrences of the northwestern pond turtle in the St. Helena reach of the Napa River. Turtles have, however, been observed in the Napa River along VVMHP by the St. Helena study team and CDFG staff during site visits. No occurrences of the northwestern pond turtle were found during the 16 April 2003 biological survey of the area. The survey noted that the species could occur when floodwaters are not present. There is suitablepotential habitat in the Napa River, York, and Sulphur Creeks.

Cooper’s Hawk (Accipiter cooperi) – the Cooper’s hawk is a California Species of Special Concern found in areas of dense tree stands, and patchy open woodland. Nesting and foraging usually occurs near open water or riparian vegetation.

The Cooper’s hawk occurs throughout most of the wooded portions of the state. Literature reviews and queries of the CNDDB did not reveal any occurrences of Cooper’s hawks in the St. Helena reach of the Napa River; however, there is potential habitat.

Yellow Warbler (nesting) (Dendroica petechia brewsteri) – the Yellow Warbler is a California Species of Special concern that inhabits wetlands, mature and second growth riparian woodlands, and well-watered gardens. It prefers dense vegetation, such as willow thickets, in order to avoid nest parasitism.

The Yellow Warbler used to occur throughout California; however destruction of riparian habitat and cowbird parasitism are causing a decline. There are no documented occurrences at the study site. Potential habitat does exist.

California Freshwater Shrimp (Syncaris pacifica) - The California freshwater shrimp (CFS) is the State’s only native, stream-dwelling shrimp. It is a federally-listed and state-listed endangered species.

The California freshwater shrimp is found in pool areas of low-elevation, low-gradient streams, among exposed live tree roots (e.g., willows and alders) of undercut banks, overhanging woody debris, or overhanging vegetation. These streams typically have low summer flows but can transport high flows during the rainy season. The California freshwater shrimp is currhas beenently found in 15 streams and rivers within Marin, Napa and Sonoma counties. (Eng 1981; U.S. Fish & Wildlife Service 1998.) Many of these stream segments are isolated from the others by barriers, dewatered areas and low quality habitat. Although the actual historic distribution of the CFS is not known, it potentially included most low-elevation, freshwater drainages in the northern San Francisco Bay area. Historical records for the CFS near the St. Helena flood control project include the Napa River (Calistoga), plus a tributary to the river, Garnett Creek, as well as Huichica Creek which drains into the bay near the mouth of the Napa River (BUGGY data base, maintained by Entomological Consulting Services, Ltd. and California Natural Diversity Data Base). Historical records indicate that the shrimp is known from exist in stretches of the Napa River that lie both north and south of the project site in St. Helena area.

The Napa River Basin Limiting Factors Analysis (Stillwater Sciences and Professor William Dietrich 2002) “...identified a total of 35 sections of undercut bank habitat with some degree of adjacent overhanging vegetation that matched descriptions of suitable habitat for California freshwater shrimp. These sections of undercut bank ranged in length from approximately 6 to 230 ft (2 to 70 m), with an average length of 37 ft (11 m). These surveys indicated that approximately three percent of the channel length (152 ft per mile [28.5 m per km]) in the six reaches surveyed possessed suitable habitat for California freshwater shrimp. Abundance ranged from a high of 340 ft (104 m) of appropriate habitat per mile (distributed among 11 patches in the 0.6-mile [1-km] reach between Deer Park Road and Lodi Lane near St. Helena) to a low of 42 ft per mile (7.9m per km) in six patches (distributed along a 1.6-mile [2.6-km] reach extending from Dunawael Lane to Lincoln Avenue, near Calistoga)”.

Within these low-elevation drainages, the California freshwater shrimp occurs in low gradient reaches, usually with moderate to heavy overhanging riparian vegetation and a sand and gravel substrate with some mud, silt, and organic debris. Eng (1981) found the shrimp in shallow pools away from the main flow. Furthermore, during winter the shrimp was observed primarily among exposed roots beneath undercut banks or among dense overhanging vegetation, whereas in spring and summer the shrimp were observed primarily on the foliage and branches of bankside bushes, vines, or sedges which extend into the water (Eng 1981; U.S. Fish & Wildlife Service 1998). Willows (Salix), California laurel (Umbellularia californica), blackberry (Rubus), and Alder (Alnus), sedges (Carex) are plants commonly observed in reaches of good shrimp habitat. The fine roots of willows provide especially good winter habitat for the CFS. Adults have also been observed on submerged twigs and leaf litter.

Dr. Richard Arnold performed a site visit on October 17, 2003, to further assess habitat conditions for the CFS. He observed that suitable habitat occurs along the reach of the Napa River that is located within the flood control project area. Riparian habitat with overhanging vegetation, plus some undercut banks and exposed roots were observed at various locations along the Napa River. Also, several of the plants that are typically found at other locations known to provide good shrimp habitat were observed within the project reach. Sulphur Creek supported lower quality habitat.

A second visit occurred on December 2, 2003, to preliminarily map the CFS habitat. The entire reach of the proposed flood control project was inspected by wading in the river and searching for undercut banks, overhanging vegetation, submerged vegetation, and other habitat conditions favorable for the shrimp. Both the eastern and western banks of the river channel were examined.

Figure 3-6A identifies 14 smaller reaches within the project reach, which are described below.

Reaches #1 and #2 lie immediately north of the Pope Street bridge. Submerged vegetation grows in both reaches, but reach #1 also has willows that have recently been trimmed but would normally provide overhanging vegetation. Reach #3 has overhanging willows, exposed roots, and limited undercut banks, while reach #4 is characterized primarily by cat-tails (Typha) that have been pruned recently. Reach #5 has some boulders and rocks, with interstitial areas and limited undercut banks. Himalayan berry (Rubus discolor) grows above on the embankment. Reach #6 is a small slide area that is mostly unvegetated at this time. Reach #7 is a gravel bar/shoreline where much of the vegetation has recently been trimmed and/or removed. Reach #8 is a small stretch of submerged vegetation. Reaches #9, #12, #13, and #14 are generally characterized by overhanging willows along the shoreline of the river, with a few, small gaps in this cover. Undercut banks and exposed tree roots were more commonly observed in these four reaches than elsewhere within the overall project reach. Reach #10 exhibited little overhanging vegetation or undercut banks, although some scattered boulders were noted. Reach #11 is the gabion area, which has interstitial areas between the boulders and possibly some undercutting at the base.

During the habitat assessment survey in December, a total of four adults of the CFS were observed in reaches #7, #9, #12, and #13. In all cases, the shrimp were situated outside of the main channel flow and in more shallow (<6” in depth) water on submerged debris or gravel. The shrimp were not captured or otherwise handled. The observed shrimp were all approximately 1.0 to 1.5 inches in length (postorbital). Crayfish were also observed. Much of the proposed project reach along the Napa River apparently provides suitable habitat for the CFS. Furthermore, additional reaches of potential habitat were noted both north and south of the project reach, so CFS are likely to use less sheltered portions of the river channel for dispersal or get washed down river during high flow events.

The reach of Sulphur Creek, between its junction with the Napa River and the bridge a few hundred feet to the west, was dry during the October site visit and exhibited only a low and shallow flow during the December visit. Water depth was only about 3 or 4 inches. Few exposed roots and no undercut banks were evident along this reach of the creek, but some boulders were noted near the bridge, just east of the concrete lining below the bridge. Vegetation on the embankments include periwinkle and Himalayan berry, but water levels would need to be substantially higher to reach these plants. For these reasons, this reach of Sulphur Creek is not considered prime habitat for the CFS, but adults may disperse along the channel bottom when it is inundated.

Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus) – The Valley elderberry longhorn beetle (VELB), Federally listed (August 8, 1980) as threatened, is entirely dependent on the elderberry (Sambucus spp.) as its host plant. The VELB is a wood borer that emerges from late March through June to feed, reproduce, and deposit

its eggs within crevices in the bark of the elderberry shrub. Once the larva hatch, they bore into the wood where they spend 1 to 2 years feeding on the shrub’s pith before exiting the plant as adults. The adults are active from March to June, mating and feeding on the elderberry leaves and flowers.

The VELB is endemic to Central Valley riparian forests along rivers and streams. These areas are typically the first settled and are often converted entirely for human uses such as agriculture. Some estimates place the extent of destruction at 89 percent for Central Valley riparian forest habitat. In addition to the Central Valley, the VELB also occurs in the foothills of the Sierra Nevada and the Coast Range, including Napa and Lake counties. However, in the Coast Range, the VELB is replaced by its close relative, the California Elderberry Longhorn beetle (CELB), which occurs between approximately Mendocino and Los Angeles. The CELB is not listed. Habitat for the VELB is provided in the study area by elderberry shrubs (Sambucus mexicana). Numerous elderberry shrubs were documented along the north and south banks of the Napa River in the April 2003 survey, conducted by Patricia Reed according to the Conservation Guidelines for the Valley Elderberry Longhorn Beetle (USFWS, 1999) conducted l. This survey data is contained in RDEIR, Table 3-10 and RDEIR, Appendix J. Some shrubs show evidence of presumed VELB exit holes. The taxon of beetle that occurs in the St. Helena area is undetermined at this time, but this EIR assumes that the VELB is present until new information indicates otherwise.

3.5.2 Direct and Indirect Impacts

Under criteria derived from the CEQA Guidelines and the various federal and state law and policies set forth earlier in this chapter, the Proposed Project would be considered to have a significant impact on biological resources if it would:

n Substantially reduce the habitat of any fish or wildlife species.

n Cause a fish or wildlife population to drop below self-sustaining levels.

n Threaten to eliminate a plant or animal community.

n Reduce the number or restrict the range of an endangered, rare or threatened species.

n Cause a substantial adverse impact, either directly or through habitat modifications, on any species not formally listed under ESA or CESA as “endangered,” “threatened,” or “rare” but identified as a candidate, sensitive, or special stats species in local or regional plans, policies, regulations, or by the CDFG or USFWS.

n Cause a substantial adverse impact on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the CDFG or USFWS.

n Adversely impact federally protected wetlands (including, but not limited to, marsh, vernal pool, coastal, etc.) either individually or in combination with the known or probable impacts of other activities through direct removal, filling, hydrological interruption, or other means.

n Interfere substantially with the movement of any resident or migratory fish or wildlife species or with established resident or migratory wildlife corridors, or impede the use of wildlife nursery sites.

n Conflict with any local policies or ordinances protecting biological resources, such as tree preservation policy or ordinance.

n Conflict with any of the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan.

Impact BIO-1

The project has the potential to impact vegetation and wildlife during construction. (For a discussion of special-status species impacts see Impact BIO-3.) This impact is significant but can be mitigated to a less than significant level.

Floodplain Terraces & Undergrowth Clearing and Removal - The trees listed below (Table 3-9) would be removed during construction. Figure 3-7 shows the location of the trees to be disturbed and Figure 3-8 shows the location of the terraced areas that would be excavated and replanted under the Proposed Project. Figure 2-7 provides a conceptual view of these terraces post-project.

New riparian vegetation would be planted along over 1,000 feet of presently barren banks. Table 3-9A details the acreage of floodplain habitat restored and habitat affected. Areas of the upper bank that are proposed for excavation would be replaced with dense riparian plantings while the lower bank would be preserved including the dense willow forest on the west bank opposite the VVMHP. The proposed excavated terrace design involves development of surfaces with suitable soils and hydrology to support native riparian plant species. The graded elevations are such that open grassy areas (native creeping wild rye with pockets of tree and shrub cover) would be supported on the beds of main flow paths of the overflow channel; these channels will be bounded by densely vegetated banks (walnut, ash and oak forest with associated shrubs and vines). The vegetation planting design would be carried out using the project Hydrologic Engineering Center River Analysis System (HEC RAS) hydraulic model’s roughness values as an approximation of ultimate conditions. Once the project is complete, the AMP would take over and maintenance would be performance based and directed by the project team. The ultimate condition would be self-maintaining. None of these activities are deemed a significant or long-term impact to the quality of the created riparian corridor.

Table 3-9 Trees Potentially Removed Under Proposed Project
Area Species Common Name	Number of Individual Trees/Shrubs
Left Bank Floodplain Inlet
Alnus species Alder species	7
Arundo donax Giant Reed	1 stand
Juglans species Walnut species	7
Quercus agrifolia Coast Live Oak	8
Quercus lobata Valley Oak	2
Salix species Willow species	5
Sambucus species Elderberry species