HomeMy WebLinkAbout1.19 Environmental Impact Report
December 14, 2020
Impact Analysis Report
Prepared by:
SGM 118 West Sixth Street, Suite 200
Glenwood Springs, CO 81601 970-384-9017
Prepared for:
Nutrient Holdings, LLC 520 River View Drive, #506
New Castle, CO 81647
Nutrient Farm PUD
Garfield County, Colorado
www.sgm-inc.com
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Table of Contents
1. Executive Summary 1
Summary of Findings 1
2. Description of the PUD 4
Project Setting 7
Traffic 7
Description of Existing Adjacent Development 8
3. Site Features within Proposed PUD Area 12
Parent Geology and Soils 12
Soils 12
Vegetation 15
Hydrology 19
Floodplain 20
4. Impact Analysis 22
Adjacent Land Use 22
Soil Impacts 22
Groundwater and Aquifer Recharge Areas 23
Environmental Impacts 25
Vegetation 25
Federally Listed Species 25
Colorado River Fish 26
Ute Ladies-tresses Orchid 28
State-Listed Species 29
Bald Eagle 29
River Otter 32
Other Wildlife Considerations 33
Traffic and Big Game Species 33
Black Bear 34
Elk 36
Mule Deer 40
Great Blue Heron 44
General Wildlife Impacts 47
Noxious Weeds 48
Weed Survey Results 48
Weed Management 49
Revegetation 49
Radiation Hazards 49
Nuisance 49
Noise 50
Hours of Operation 51
5. Summary of Impact Mitigation Recommendations 52
6. References Cited 53
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LIST OF TABLES
Table 1 – Proposed Development Summary 4
Table 2 – Impacts by Soil Type 23
Table 3 – Impacts to Vegetation Types 25
Table 4 - Federally-Listed Species Initially Considered 26
Table 5 – CRS 25-12-103 Sound Standards 50
LIST OF FIGURES
Figure 1 – Proposed Use Areas 6
Figure 2 – Aerial Photo of Existing Conditions – PUD Area 9
Figure 3 – Aerial Photo of Existing Conditions – West 10
Figure 4 – Aerial Photo of Existing Conditions – East 11
Figure 5 – Soil Types 14
Figure 6 – Vegetation Types 18
Figure 7 – Hydrologic Resources 21
Figure 8 - Bald Eagle Habitats 31
Figure 10 - Black Bear Habitats 35
Figure 11 - Elk Habitats 39
Figure 12 - Mule Deer Habitat 43
Figure 13 – Heronry and Impacts 46
LIST OF APPENDICES
Appendix A – CPW Habitat Definitions 58
Appendix B – CPW Species of Concern 60
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1. Executive Summary
The Nutrient Farm Planned Unit Development (PUD; the “Proponent”) is proposed for the undeveloped
parcels currently located in the Coal Ridge and Riverbend PUDs (the “Property”), located on the south side of
the Colorado River between New Castle and Glenwood Springs (Figures 1 and 2), immediately adjacent to the
existing Riverbend community. This report has been prepared in accordance with the requirements of the
Garfield County (GarCo) Land Use and Development Code (LUDC), including Section (§) 4-203G Impact
Analysis, §7-202 Wildlife Habitat Areas, and §7-203 Protection of Water Bodies.
The property consists of five parcels containing approximately 1,136 acres, located on a flat benched area that
lies between the Colorado River and backs up to Coal Ridge and the Grand Hogback. (Assessor Records Parcel
ID numbers are: 212335300081, 218306100057, 212334400007, 212334400005, and 218305300086; Figure
3). Per our surveyor’s research, these parcels are combined and re-organized in the property’s formal legal
description in the title work and deeds.)
All five parcels will vacate the existing PUD zoning and be rezoned to Nutrient Farm PUD. The Property is
currently dominated by grazed pastures historically irrigated by the Vulcan Ditch, with undeveloped steep
slopes to the south. The Vulcan Ditch is currently being converted from an open ditch to a piped ditch and is
anticipated to provide irrigation and other waters to the Nutrient Farm PUD area later in 2020.
Nutrient Farm would be an approximately 1,136-acre, agriculturally oriented mixed-use PUD that revolves
around the use and enjoyment of a working farm with multi-use education, entertainment and recreational
facilities (Nutrient Farm PUD Guide 2020). The PUD would include a working farm, a mix of residential homes,
a commercial/industrial area, outdoor adventure parks with outdoor entertainment/music venue, a
campground, lodge, motorized and non-motorized trails, and a retreat/spa facility.
In summary, the PUD would include 18 new single-family residences with allowances for accessory dwelling
units, occupying approximately 56 acres (or 5 percent) of the PUD area. One additional single family/ranch
home already exists on the property. Approximately 24 percent of the PUD area would support agricultural
operations. Approximately 1 percent of the PUD would support a commercial industrial area, which would be
used for support agricultural operations, commercial uses, and industrial uses. Approximately 16 percent of
the PUD area would support outdoor adventure parks, which would contain motorized and non-motorized
tracks, an outdoor entertainment and music area, a campground, a lodge and a spa/retreat facility.
The purpose of this report is to document conditions as they exist on the parcels at this time, to discuss the
potential impacts of the development being contemplated for the Property based on existing conditions and
provide measures to ensure that any potential impacts will be mitigated.
Summary of Findings
• The density, scope and scale of the residential development areas, along with the proposed
agricultural operations, would be similar to existing uses of the surrounding area.
• The outdoor music venues, recreational facilities including motorized (OHV) track, trail and outdoor
adventure parks would introduce much different land uses and human activity patterns to the area,
including increased fugitive lighting and sound from both the music venues and the motorized tracks.
These impacts would be significantly different than current land use patterns in the area, but
measures have been proposed in the PUD to help mitigate any potential impacts.
o Nutrient Farm is planning on conducting additional sound modelling and planning to reduce
sound levels at both the music venue and OHV track to bring these activities into compliance
with consistent with CRS 25-12-103 standards. Nutrient Farm PUD has already indicated that
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preventative sound barriers, insertion loss and sound mitigation strategies are being
developed to reduce sound levels.
• The agricultural, recreational and commercial use areas would introduce new local employment
opportunities to the area.
• Traffic would likely increase on County and Town roads, and increased use of existing area trails
(including the proposed LoVa Trail). There would also likely be increased visitors and use of businesses
in New Castle from increased local population at Nutrient Farm.
• Environmental Impacts
o Some portions of the PUD are located on alluvial fans; at this time these areas are stable and
development on these alluvial fans does not pose a significant risk as long as dense vegetation
continues to stabilize slopes.
o Soils on the Property do not pose significant challenges or risks from development.
o The Property does not support extensive wetlands, aside from a very narrow riparian fringe
along the Colorado River; much of the Colorado River fringe does not support any wetlands,
due to the seasonal scouring from high flows. A proposed boat ramp would have localized
direct and indirect impacts to the riparian corridor and any associated wetlands. Additional
indirect impacts to wildlife habitats around the boat ramp would also occur.
o Bald eagles may occasionally roost along the Colorado River in proximity to the Property;
however, there are no active bald eagle nests within 0.5 miles of proposed development
areas.
o The majority of the Property is dominated by grazed and dryland pastures, which provide
minimal wildlife habitat values. Proposed residential, agricultural, and commercial
development would be concentrated in these level pasture areas with low-quality habitat,
but recreational facilities and trails would be mostly placed in native shrubland habitat types
at the toe of the Grand Hogback.
o Wildlife
The Property supports elk and mule deer Severe Winter Range habitats; some of the
proposed development would directly and/or indirectly impact native habitat types
and winter ranges.
Development within the pastures would reduce availability of springtime grazing
areas for elk and mule deer, but these areas are also previously disturbed; aside from
some springtime elk and mule deer grazing, pastures have very low wildlife habitat
values.
Increase human activities, especially fugitive noise from outdoor music venues and
motorized tracks will have notable indirect impacts on surrounding habitat values
outside the PUD area.
Black bear-human conflict will likely be an issue, due to the increased density of food
availability in proximity to large tracts of relatively intact bear habitat. Development
should incorporate design criteria to minimize black bear-human conflicts.
Nutrient Farm met with Colorado Parks Wildlife (CPW) and is in the process of
developing a Wildlife Mitigation Plan to avoid, minimize, and mitigate impacts to
wildlife and habitats.
o Noxious weeds will be an issue with development if not addressed; there are well established
infestations of weeds in the dryland pastures, along roads, and along the Vulcan Ditch. A
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Weed Management Plan per section 4-203.E.18.c. has been prepared for the Property and
will be implemented with the review/approval of the PUD.
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2. Description of the PUD
The Proponent is proposing to develop the existing pastures and associated ranch infrastructure, and the
shrubby hillsides at the toe of the Grand Hogback into a diverse, multi-use area with an agricultural focus and
ancillary residential and recreational amenities (Figure 2). Agricultural, residential and mining uses are
currently allowed under the existing Riverbend and Coal Ridge PUDs. Thus, the proposed uses are generally
consistent with, and less intense than, the current land uses allowed under those PUDs, with the exception of
the proposed recreational facilities that would be a new use. Ancillary agricultural uses include agricultural
processing facilities, and agri-tourism features such as farm stands, a farm-to-table restaurant and cabin
rentals and campgrounds are also proposed. Outdoor adventure-type parks and a music performance venue
are also being proposed. In general, facilities are expected to operate year-round, except for the campgrounds
and outdoor venues, which would operate only in the summer season (roughly May 1 – Nov 1). However, the
campground cabins will remain available for rent year-round.
Please see the PUD Guide for additional details on the development proposal.
Table 1 – Proposed Development Summary
Development Areas and Open Space Tracts
Area Name Major Land Uses Size / Percentage
1 Residential Subdivision
Agricultural and Animal Related Uses
Residential Uses: 5 Dwelling Units,
Single-Unit + ADUs
5.50 Acres +/-
0.5% +/-
2 Residential Subdivision
Agricultural and Animal Related Uses
Residential Uses: 1 Dwelling Unit,
Single-Unit + ADU
42.14 Acres +/-
3.7%
3 Residential Subdivision
Agricultural and Animal Related Uses
Residential Uses: 10 Dwelling Units,
Single-Unit + ADUs
9.46 Acres +/-
0.8% +/-
4 Residential Subdivision
Agricultural and Animal Related Uses
Residential Uses: 2 Dwelling Units,
Single-Unit + ADUs
1.12 Acres +/-
0.1% +/-
5 Working Farm – East
Agricultural and Animal Related Uses
Commercial Uses
Residential Uses: 1 Dwelling Unit,
Single-Unit + ADU and Dwelling Units,
Bunkhouse
73.99 Acres +/-
6.5% +/-
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North Working Farm - West
Agricultural and Animal Related Uses
Commercial Uses
Residential Uses: Dwelling Units,
Bunkhouse
54.70 Acres +/-
4.8% +/-
6
South Working Farm - West
Agricultural and Animal Related Uses
Commercial Uses
Residential Uses: Dwelling Units,
Bunkhouse
142.21 Acres +/-
12.5% +/-
7
North Commercial/Industrial Park
Agricultural and Animal Related Uses
Commercial Uses
Industrial Uses
Residential Uses: Dwelling Units, On-
5.45 Acres +/-
0.5% +/-
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Site Employee Housing
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South Commercial/Industrial Park
Agricultural and Animal Related Uses
Commercial Uses
Industrial Uses
Residential Uses: Dwelling Units, On-
Site Employee Housing
6.86 Acres +/-
0.6% +/-
8
North
Outdoor Adventure
Parks/Campground
Agricultural and Animal Related Uses
Commercial Uses
Industrial Uses
Public/Institutional Uses
Visitor Accommodations
Residential Uses: Dwelling Units, On-
Site Employee Housing
6.14 Acres +/-
0.5% +/-
8
South
Outdoor Adventure
Parks/Campground
Agricultural and Animal Related Uses
Commercial Uses
Industrial Uses
Public/Institutional Uses
Visitor Accommodations
Residential Uses: Dwelling Units, On-
Site Employee Housing
168.25 Acres +/-
14.8% +/-
Area Major Land Uses Size / Percentage
A Private Open Space 214.63 Acres +/-
18.9% +/-
B Private Open Space 281.19 Acres +/-
24.8% +/-
C Private Open Space 65.40 Acres +/-
5.8% +/-
D Private Open Space 47.54 Acres +/-
4.2% +/-
County
Road
335
ROW
Right- of Way 11.42 Acres +/-
1.0% +/-
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Figure 1 – Proposed Use Areas
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Project Setting
The Project is located entirely on the south bank of the Colorado River, abutting a near-continuous 2.75-mile
section of the river front. The Property generally encompasses the irrigated terrace surface above and outside
the river’s channel and riparian corridor, as well as a portion of the steep slopes to the south. There is currently
one homesite (a farm house) on the parcels, as well as attendant farming/ranching infrastructure, including
the Vulcan Ditch (that being converted from open ditch to closed pipe at this time), lateral ditches, fences,
sheds, etc. The development is anticipated to be concentrated on the irrigated pasture areas, due to
considerations of constructability and access. The steeper slopes on the southern side of the Property are
derived from Mancos shales, and are not as conducive to development.
The portions of the Property that are proposed for
development are historical ranchlands typical of
grazed or dryland pasture settings in the
surrounding vicinity. The pastures are elevated
above the water table of the Colorado River, and
are dominated by upland pasture grasses and
adventitious ruderal species supported by
seasonal precipitation. Habitat diversity and value
is minimal due to the low-quality vegetation and
the dominance of non-native cultivars and weedy
species. Several swales carry ephemeral runoff
from the steep southern slopes to the Colorado
River, but do not contain any riparian features or
indications of more-than-ephemeral flow.
Riverine wetland conditions occur in small and
discontinuous patches along the banks of the Colorado River (see Section 3.2 and 3.3).
Traffic
SGM prepared a Level III Traffic Impact Study for the Nutrient Farm PUD, and this report utilizes that
information and incorporates that report by reference (SGM 2020a). County Road 335 (CR-335; Colorado River
Road) is the main access road to the PUD and to the existing Riverbend community (which collectively includes
Riverbend Subdivision, Riverbend Ranchettes, and Cedar Ridge Subdivisions). In the vicinity of the project area,
this east-west roadway consists of a two-lane cross section. The posted speed limit is 35 mph.
According to the SGM traffic study, CR 335 carries commuter traffic from subdivisions and residential
development between New Castle and from the Riverbend subdivisions adjacent to the project area (and
associated construction and service traffic to those residential areas). As there are no public roads beyond the
Riverbend subdivisions, there is no pass-through traffic. Much of the existing traffic is generated during the
morning and evening rush hours, coinciding with daily commuter traffic between bedroom communities in the
Riverbend area, and work destinations in the Glenwood Springs and Aspen areas. This results in daily traffic
volumes of approximately 470 vehicles per day (VPD) through the Nutrient Farm project area, peaking in the
morning and evening commute times. As detailed in the SGM traffic report, these peak traffic periods are
relatively short-lived, and during much of the day and especially at night, traffic patterns would be relatively
low. At full build out and peak use, traffic generated from the Nutrient Farms project would likely generate
1,730 additional VPD, raising the level of vehicle use along CR 335 to 2,200 VPD.
The study concludes that the development can be implemented, and the roadway system will continue to
operate at an acceptable Level of Service with the addition of a stop sign at southbound Bruce Road for normal
conditions and with the use of traffic control supervision during music festival events.
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Description of Existing Adjacent Development
As previously mentioned, the Nutrient Farm PUD area is immediately adjacent to significant existing
development. More than 60 single-family homes are currently occupied on Riverbend Drive and Glen Eagle
Circle and are accessed by CR-335 from Interstate 70 (I-70) at the New Castle exit. Impacts typical of residential
development (such as dogs, exterior lights, & light vehicle traffic) are present. Garfield County traffic data
indicated approximately 800 VPD on CR 335 in 2014 while April 2019 counts showed a reduction to 535 VPD.
Traffic counts performed by SGM in January 2020 indicated 470 VPD. Refer to the SGM Traffic Impact Study
(SGM 2020a) for detailed information and see additional discussion below.
I-70 between New Castle and Glenwood is located immediately across the Colorado River from the Property.
Recent data indicate that traffic on I-70 is approximately 25,000 VPD, including approximately 10% truck traffic.
(CDOT 2019). The noise and visual impact associated with this level of traffic is readily evident from the
Property, with only minor screening vegetation is present on either side of the Colorado River to mitigate these
traffic conditions.
The Union Pacific railroad is also immediately across the Colorado River from the Property, adjacent and north
of I-70. The railroad contributes additional visual and audible impacts to the area, primarily through freight
train use, but the impact types are similar to those associated with I-70. Approximately 10-15 train trips utilize
the tracks on a daily basis, which includes the less frequent Amtrak commuter trains.
In summary, existing housing developments and associated anthropogenic disturbance have a significant
presence in the middle of the PUD area. These existing impacts include traffic, lighting, noise, human activities
and visual modifications typical of residential subdivisions. To the south and east of the PUD, steeper slopes
with shrubby vegetation communities are dominant.
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Figure 2 – Aerial Photo of Existing Conditions – PUD Area
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Figure 3 – Aerial Photo of Existing Conditions – West
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Figure 4 – Aerial Photo of Existing Conditions – East
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3. Site Features within Proposed PUD Area
SGM has completed site visits on several occasions, including June, July, and September of 2018, and in April
of 2020. Existing vegetation conditions as they existed on the Property at the time of those inspections are
described below. This section primarily focuses on the existing vegetation, hydrology, soils and land uses in
the portions of the PUD that are planned for development.
Parent Geology and Soils
The proposed development area is located within the Storm King Mountain quadrangle and is covered in its
entirety by the “Geologic Map of the Storm King Mountain Quadrangle, Garfield County, Colorado” (Bryan
et al. 2002). Several geologic units and features are within the proposed development area including, but not
limited to, quaternary deposits and bed rock units consisting of: Mancos Shale members (Cretaceous),
Dakota Sandstone (Lower Cretaceous), Morrison Formation (Upper Jurassic), Entrada Sandstone (Middle
Jurassic), the Chinle Formation (Upper Triassic), the State Bridge Formation (Lower Triassic), and the Maroon
Formation members (Lower Permian to Middle Pennsylvanian). Several geologic hazards and geotechnical
concerns are also present in the area, such as: landslide and debris flow deposits, alluvial fan deposits
consisting of potentially hydro-collapsible soils and shrinking/swelling soils derived from the Mancos Shale
Members. Geotechnical hazards are further discussed in detail and analyzed by RJ Engineering & Consulting,
Inc. (Please see the attached Soils and Geohazards Evaluation, Riverbend PUD in Garfield County, Colorado
for details).
The majority of the site is in the geologic quaternary unit Qfy. It is described as consisting of younger fan
alluvium and debris-flow deposits (Holocene and latest Pleistocene) consisting of poorly to very poorly sorted
cobble and pebble gravel with a silty sand matrix. Clasts south of the Colorado River are angular to subangular
sandstone, subrounded basalt, and angular to subangular shale and siltstone (Bryant et al. 2002). This unit is
potentially susceptible to collapsible soils, though proper building standards and drainage engineering should
avoid structure settling issues (RJ Engineering & Consulting, Inc. 2020). The site also has quaternary deposits
of colluvium undivided (Qc), older debris-flow deposits (Qdo), and landslide deposits (Qls). Proper
engineering design and protocols should be used on and around units Qdo and Qls to avoid potential
structure issues/damage and land instability.
Bedrock units (listed above) in the site are generally dipping to the south-south west, at 45 to 50 degrees.
The Mancos Shale members can have high concentrations of bentonite, which can pose shrinking-swelling
soil issues.
According to the Garfield County Soil Hazard Profile Map, the subject parcel is not within any Moderate or
Major Soil Hazard Areas. There is a nearby area mapped as a Major Soil Hazard Area, which is discussed in
further detail in below. (Source Map: Soil Hazard Profile, Study Areas 1, 2, & 3, Garfield County, Colorado; 2-
6-02).
Soils
The soils on this site consist of various types of clay material. Conditions that were recorded in the
geotechnical report indicated that the first 20 to 30 feet consisted of a low plasticity clay. The Natural
Resources Conservation Service (NRCS) Soils Map shows the area soil types. The following soil units are within
the proposed PUD include:
10 – Begay sandy loam, 1 to 6 percent slopes: These soil units are deep, well drained, moderately sloping,
hilly, to steep soils found on valley sides and alluvial fans with elevations ranging from 5,000 to 6,500
feet. These soils formed from alluvium derived from sandstone and shale. This soil is well drained
and can be classified as prime farmland if irrigated.
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11 – Begay sandy loam, 6 to 12 percent slopes: These soil units are deep, well drained, moderately sloping
found on valley sides and alluvial fans with elevations ranging from 5,000 to 6,500 feet. These soils
formed from alluvium derived from sandstone and shale. These soils are not hydric and are not
classified as prime farmland.
14 – Chilton channery loam, 6 to 12 percent slopes: These soil units are deep, well drained, moderately
sloping found on valley sides and alluvial fans with elevations ranging from 5,000 to 6,500 feet. These
soils formed from alluvium derived from sandstone and shale. These soils are not hydric and are not
classified as prime.
29 – Heldt clay loam, 3 to 6 percent slopes: These soil units are deep, well drained, moderately sloping
found on valley sides and alluvial fans with elevations ranging from 5,000 to 6,000 feet. These soils
formed from fine-textured alluvium derived from sandstone and shale. These soils are not hydric and
are classified as Farmland of statewide importance.
30 – Heldt clay loam, 6 to 12 percent slopes: These soil units are deep, well drained, moderately sloping
found on valley sides and alluvial fans with elevations ranging from 5,000 to 6,000 feet. These soils
formed from fine-textured alluvium derived from sandstone and shale. These soils are not hydric and
are classified as Farmland of statewide importance.
47 – Nihill channery loam, 6 to 25 percent slopes: These soil units are deep, well drained, moderately
sloping, hilly, to steep soils found on valley sides and alluvial fans with elevations ranging from 5,000
to 6,500 feet. These soils formed from alluvium derived from sandstone and shale. This soil is well
drained, non-hydric, and not prime farmland.
51 – Olney loam, 6 to 12 percent slopes: These soil units are deep, well drained, moderately sloping found
on valley sides and alluvial fans with elevations ranging from 5,000 to 6,500 feet. These soils formed
from fine-textured alluvium derived from sandstone and shale. These soils are not hydric and are
classified as Farmland of statewide importance.
65 – Torrifluents nearly level: These soil units are found in flat areas, primarily around rivers and
floodplains around 5,000 to 7,000 feet. These are well-drained, and the water table can be reached
within 12 to 36 inches. These soils occasionally flood. These soils are not classified as prime farmland.
66 – Torriorthents-Camborthids-Rock outcrop complex, steep: These soil units are shallow, well drained,
and found on steep mountainsides around 5,000 to 8,500 feet. These soils formed as stony, basaltic
alluvium derived from sandstone and shale. These soils are not hydric and are not classified as prime
farmland.
67 – Torriorthents-Rock outcrop complex, steep: These soil units are shallow, well drained, and found on
steep mountainsides around 5,800 to 8,500 feet. These soils formed as stony, basaltic alluvium
derived from sandstone and shale. These soils are not hydric and are not classified as prime farmland.
69 – Vale silt loam, 6 to 12 percent slopes: These soil units are deep, well drained, and found on alluvial
fans, benches, and mesas at 5,000 to 7,200 feet. The parent material of these soils consists of
calcareous eolian deposits. These are not hydric soils and they are classified as Farmland of statewide
importance.
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Figure 5 – Soil Types
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Vegetation
The Property generally has four separate vegetation communities (and four corresponding habitat types.
The majority of the Property, including the area proposed for development, is dominated by grazed pasture
areas with gently sloping topography, located on alluvial/colluvial material which has been further leveled
by tilling. The steep slopes above the pastures are dominated by sparse pinyon-juniper woodlands and mixed
mountain shrublands with minimal understory vegetation, derived from Mancos shale; in the transitional
areas between the mixed mountain shrublands and pastures there are remnant stands of sagebrush
shrublands. The portion of the Property immediately adjacent to the Colorado River supports sparse and
discontinuous wetland/riparian vegetation on the banks of the river. No wetlands extend beyond the
immediate boundaries of the river’s channel, and in many areas, there are no wetlands, due to seasonal high
flow scouring. Each of the vegetation types is described below in more detail.
Pastures. The pasture portions of the Property are
dominated by agricultural cultivars including
smooth brome (Bromus inermis), orchardgrass
(Dactylis glomerata), western wheatgrass
(Pascopyrum smithii), as well as some native
fescues (Festuca spp.) and rabbitbrush
(Ericameria nauseosa). The noxious weed
cheatgrass (Anisantha tectorum) is common, and
weedy adventitious species such as tumble
mustard (Sisymbrium spp.) are also prevalent. In
the spring, the introduced purple mustard
(Chorispora tenella) and storkbill filaree (Erodium
cicutarium) are also common. The site was grazed
at the time of investigation, and additional
pasture grasses are likely present and identifiable
earlier in the grazing season. The condition of the
pastures is typical of grazed or dryland pasture
sites, with low levels of ground coverage and
minimal diversity.
Historically (pre-settlement) this site would have
supported a more diverse assemblage of native
forbs, with a significant shrub component (likely
sagebrush [Artemisia tridentata] and rabbitbrush)
and isolated stands of conifers, oakbrush
(Quercus gambelii) or cottonwoods depending on
groundwater availability.
Some areas of the flat terrace on the Property are not grazed or irrigated and support a sparse coverage of
sagebrush that is likely representative of original conditions.
Mixed Mountain Shrublands. The steep slopes on the south side of the Property are composed of Mancos
shale which has been uplifted and deformed by the Grand Hogback monocline, which passes through the
Property. Mancos shale typically supports limited plant diversity and lower density of vegetation, due to
challenging growing conditions associated with the formation’s high salt content, poor water infiltration, and
high erodibility. In lower elevations, Mancos shale can support a salt-desert scrub community with a high
percentage of endemic plant species. However, at the elevations found on this Property, and in the general
area surrounding the Project, Mancos shale soils types support sparse pinyon-juniper woodland (Pinus edulis
Typical conditions in the pasture areas.
Typical conditions in ungrazed terrace areas, seen in
center midground from the upgradient slope.
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– Sabina osteosperma) with mixed shrub
component of Gambel oak (Quercus gambelii),
mountain mahogany (Cercocarpus montanus and
C. ledifolius) and Utah serviceberry (Amelanchier
utahensis). The shrub component is dense in
some areas on north-facing slopes with high
moisture availability, and sparse or absent on
south-facing slopes. The steepest south-facing
slopes of Mancos shale are nearly bare of
vegetation.
Riparian/Wetlands. Within the channel of the
Colorado River, isolated and discontinuous
patches of riparian a vegetation occur on point
bars and sheltered eddy banks. Vegetation is
predominantly Chinese elm (Ulmus parvifolia),
an invasive exotic tree species. Other notable
species include narrowleaf cottonwood (Populus
angustifolia), serviceberry, and dogwood (Cornus
stolonifera). The banks are generally composed
of large-diameter cobble material, which is well-
drained and due to scouring, extensive wetlands
do not occur. However, in protected eddy zones
enough silt has collected to support small stands
of coyote willow (Salix exigua) which suggest the
presence of wetland conditions in these limited
eddy zones. There are also small occurrences of
the noxious weed species Russian olive
(Elaeaganus angustifolia) and tamarisk (Tamarix
chinensis). The riparian habitat is in poor
condition, with minimal continuous canopy
coverage over the river and a high percentage of
exotics, likely due to historic grazing pressure.
No wetlands extend beyond the immediate
vicinity of the river. A wetland delineation in
accordance with the procedures established for
wetland delineation by the U.S. Army Corps of
Engineers (USACE 1987, 2010) has not been
completed at this time, but upland conditions
clearly prevail on the majority of the property
(see Photolog, Appendix B).
Willows dominate in small backwater reaches,
adjacent to grazed pasture (right foreground).
Isolated elm and Russian olive with minor willow
Component.
Typical mixed mountain shrublandsconditions on the
Mancos slopes. Note sparse
shrub coverage on the south-facing slope (center
middle view), with greater abundance on the north-
facing slopes (left middle view).
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Sagebrush Shrublands. Around the edges of the
previously cleared and tilled pastures there are
small remnant stands of sagebrush (Artemisia
tridentata ssp. bonvillensis) shrublands. Along
washes and in more well drained soils, great
basin sagebrush (A. t. ssp. tridentata) can also be
found. Understory vegetation is often
compromised by cheatgrass, but desirable
grasses and forbs include smooth brome,
western wheatgrass, Indian ricegrass
(Acnatherum hymenoides), and needle-and-
thread grass (Hesperostipa comata).
Typical conditions in remnant sagebrush shrublands.
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Figure 6 – Vegetation Types
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Hydrology
The only significant surface water on the
property aside from the Colorado River is the
Vulcan Ditch, which traverses the southern
slopes of the Property. The Vulcan Ditch has
been and will be the primary water supply
source for the ranch. It previously carried, and
will carry in the future, in excess of 8 cubic feet
per second (cfs) on a seasonal basis, of which the
Property owns approximately 90% of the
potential flows. The ditch originally supplied
water to the Vulcan coal mine, and more
recently to pasture areas on the parcels, where
flood irrigation was used to support pasture
grass production. The ditch has older sections
where it has already been piped and flumed
across steep drainages, and some sections are
lined (with plastic sheeting and bentonite clays).
The ditch is currently dominated by invasive
weedy species typical of disturbed soils, with
significant occurrences of Russian knapweed
(Acroptilon repens) in some locations. As part of
the PUD improvements, the entire ditch would
be piped and used, likely starting in the summer
of 2020.
Two minor drainages occur on the southern
slopes of the Property and drain north to the
Colorado River. Both drainages are unnamed
washes that are mapped as intermittent on
USGS maps and by the U.S. Fish and Wildlife
Service (USFWS 1983). The catchment areas for
the drainages are approximately 2.5 square miles or less. Examination of the features suggests that surface
water is likely present only ephemerally. The channel morphology is poorly developed, upland vegetation
dominates the channels, and there is minimal vegetation to suggest shallow subsurface flow (i.e., there are
no cottonwoods or other deep-rooted phreatophytes). Based on observed conditions, these drainages likely
flow only briefly during the snow melt season of low-elevation snowpack in early spring, and then
ephemerally in response to precipitation. There are no notable wetland or riparian characteristics of these
drainages, including vegetation, soils, ecosystem function, or species habitats. There are no gauges or other
methods available to estimate the timing or volume of flows associated with these features.
As discussed, the Property encompasses the south bank of the Colorado River. However, interactions with,
and impacts to, the hydrology of the river are minimal due to the lack of tributary waters that traverse the
Property and flow into the river. Sediment, nutrient, and material inputs to the river are limited to overland
sheet flow and rare ephemeral storm events. However, the sediment input to the river from these sources
is likely elevated from historical levels, due to grazing pressure and the dried-up pasture conditions that has
reduced vegetation coverage and has left the soils on the Property susceptible to erosion.
The existing residential developments adjacent to the Property, located on Riverbend Drive and Glen Eagle
Court, produces stormwater and wastewater in volumes typical of such development. It is assumed that all
Typical ditch conditions dominated by weeds and
excavated in an upland setting on Mancos shale slope
Unnamed intermittent drainage near terminus with
Colorado River. Note lack of consistent flow
indicators.
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20
stormwater and wastewater derived from these residential developments are collected and treated (in the
case of wastewater), and then discharged to the Colorado River within the bounds of those properties.
Floodplain
The site is adjacent to the Colorado River and is mapped in Garfield County’s “Floodplain Overlay District”.
However, FEMA has not mapped the floodplain in this area. The area was previously surveyed and studied
on several occasions by FEMA and the CWCB but the studies were not officially adopted for this reach of the
Colorado River adjacent to Nutrient Farm. The effective FEMA panel is 0802051020B dated 12/15/1977 (not
printed). All areas are assigned Zone D areas of possible flooding.
An approximate Floodplain Zone A was created and published for public review and comment in the Garfield
County Preliminary study circa 2011. The Preliminary Flood Insurance Study and accompanying maps and
GIS digital data were made available on the County website and was widely used as the “best available”
information.
SGM obtained updated 2015 DFIRM metadata published by FEMA on 7/31/2015 and used these GIS layers
as the best available information for Nutrient Farm. This reach of the river remains as an approximate Zone
A floodplain without water surface elevations. SGM understands that FEMA is very near publishing a new
detailed floodplain study for this reach. That study will use a reduced 100-yr flowrate and is expected to
result in 100-yr water surface elevations that are lower than shown in previous studies.
Based on our review of the proposed Nutrient Farm PUD improvements with respect to all flood study
information referenced above, the development will comply with all applicable FEMA, National Flood
Insurance Program (NFIP), CWCB and Garfield County floodplain regulations. Specifically, any future
improvements will comply with the applicable Floodplain Overlay Regulation of sections 3-102 and 3-301 and
the Floodplain Specific Site Plan requirements of 4-203.O.1. of the LUDC. In addition, any future
improvements near the Colorado River will abide by section 7-203 Protection of Waterbodies of the LUDC.
This includes the required setbacks for structures and activities near a waterbody and compliance with all
applicable State and Federal regulations and permitting requirements including, but not limited to, section
404 of the Federal Clean Water Act administered by the Corps. Possible improvements that could occur
below the future 100-year flood elevation, consist of pump intakes, boat ramps, Colorado River access trails
and possibly other improvements meant to enhance the experience of the Colorado River user. All of these
can be constructed without adversely impacting the River and floodplain.
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Figure 7 – Hydrologic Resources
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4. Impact Analysis
Adjacent Land Use
The adjacent uses within a 1,500-foot radius of the site consist of agricultural hay fields, CDOT/UPRR Right-
of-Way, residential development, vacant zoned commercial land, undeveloped private land and public lands
managed by the Bureau of Land Management – Colorado River Valley Field Office (CRVFO). This PUD
proposes a development with mixed uses which includes agricultural, residential, recreational and
commercial uses. The proposed PUD is compatible with surrounding land uses and impacts to adjacent land
uses would be mitigated through appropriate planning and design. The following adjacent land uses are as
follows:
West Side: The current land use is primarily irrigated agricultural hay fields and undeveloped mixed
mountain shrublands. It is currently zoned as rural.
South Side: The adjacent south and west parcels are currently undeveloped mixed mountain
shrublands and zoned as PUD. The adjacent south and eastern parcels are public lands.
East Side: The eastern side of the proposed project area are currently public land (southeast) and
rural zones near the Colorado River and Interstate 70.
North Side: The northern boundary of the Property includes the Colorado River and Interstate 70,
but beyond that is a mixture of different residential and commercial uses. The residential and
commercial uses north of Interstate 70 will not be affected by the proposed PUD.
The Official Zoning District Map of Garfield County recognizes the existing PUDs and designates the zoning
for the Property as such. According to the Garfield County 2030 Comprehensive Plan, the future land use
designated for this area is Residential Medium High (RMH). This land use designation would allow for small
farms, estates, and clustered residential subdivisions. This land use designation is compatible with PUDs and
Rural zoning. The western portion of the proposed development falls within the New Castle Urban Growth
Boundary. Garfield County encourages development within urban growth areas.
Soil Impacts
The site is dominated by soils that have few construction constraints. However, soils derived from Mancos
shales are susceptible to shrink/swell issues due to high concentrations of bentonite clay. The soils at the site
were tested by RJ Engineering & Consulting as part of a geotechnical investigation. Laboratory results
indicated the soil exhibited low swelling to low collapse potential, with an estimated differential and total
movement of 0 to 2 inches. RJ Engineering & Consulting recommend deep foundations (drilled piers or
micropiles) for structures sensitive to movement and concluded that shallow foundations are adequate for
non-sensitive structures. Proper drainage should be engineered for structures and features to reduce water
infiltration. The soil on site is adequate to use for fill material provided it is moisture conditions to within 2%
of optimum moisture content and compacted to 95 percent of maximum standard Proctor dry density (ASTM
698).
Up to 307.96 acres of soil may be impacted by project activities, total soil impacts by soil type and
development type are summarized in Table 2. Topsoil removed for development purposed will be stockpiled
and re-applied where necessary. Topsoil will not be used for fill material.
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Table 2 – Impacts by Soil Type
Soil Disturbance
Soil Type Name
Map
Unit
Symbol
Agricultural Building Recreation Transportation Water
Total
Area
(acres)
Heldt clay loam, 3
to 6% slopes 29 55.33 8.37 0.50 9.59 0.85 74.64
Heldt clay loam, 6
to 12% slopes 30 91.29 11.94 7.46 11.92 0.59 123.20
Nihill channery
loam 6 to 25%
slopes
47 15.61 7.35 53.09 9.13 4.26 89.44
Olney loam, 6 to
12% slopes 51 2.82 2.33 - 0.47 - 5.62
Torrifluvents,
nearly level 65 - - - 0.13 - 0.13
Torriorthents-
Camborthids-Rock
outcrop complex,
steep
66 0.99 5.83 1.75 0.32 - 8.89
Torriorthents-Rock
outcrop complex,
steep
67 - 1.31 2.23 0.95 1.55 6.04
Total Project Components
Disturbance 166.04 37.13 65.03 32.51 7.25 307.96
Groundwater and Aquifer Recharge Areas
The portion of the Property planned for development and farming is underlain by the Colorado River alluvial
aquifer, connected to and recharged by Colorado River surface water. SGM reviewed well completion and
pump installation reports for information about subsurface geology and groundwater levels utilizing data
from two of the Riverbend Wells, Nos. 3 and 4 (Permit Nos. 018146-F and 018147-F, respectively). The
Riverbend Wells supply water to the existing Riverbend housing developments and are located within 200
feet of the Colorado River on the eastern portion of the Farm property (Area 5 – Working Farm East). Based
on the well completion reports, the entire drilled depth of the wells is boulders and gravels, alluvial type
deposits which allow relatively easy transmission of groundwater.
Water was found at 22 feet below ground surface for Riverbend Well No. 4, and 5 feet below ground surface
for Riverbend Well No. 3, indicating that the elevation of the water table in this alluvial aquifer is similar to
the elevation of surface water in the Colorado River at 5,590 - 5,600 feet. Further to the south on the
property, the ground surface slopes gradually upward for about 200 feet until it transitions to the steep hill
slopes of the Grand Hogback. So, while wells located close to the River have a shallow depth to groundwater,
potential sites for septic system leach fields could be located further to the south with a greater depth to
groundwater.
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Surface water return flows from water use on the Property will flow downhill and into the Colorado River.
Surface water returns are expected from flow-through water from ponds and from irrigation runoff.
Historical irrigation on the Property has been flood irrigation, which is relatively inefficient and has significant
surface returns. While initial irrigation on the Farm will likely be largely flood irrigation, the Farm anticipates
converting to more efficient irrigation practices (such as sprinklers and drip irrigation), which would have
minimal surface runoff, thereby reducing transport of sediment and nutrients from fields to the River.
Groundwater return flows from irrigation are anticipated to return to Colorado River quickly, due to the
alluvial boulder and gravel composition of the aquifer and the proximity of fields to the Colorado River.
The land under Area 5 – Working Farm East slopes gradually toward the Colorado River and portions of this
area planned as hay fields are located within the flood plain. The other areas that border the Colorado River
(Areas 1, 6, and 7) are at least thirty feet above the river due to the steep banks on the western part of the
Property. Structures and residential development on the Property will be sited above the regulatory 100-yr
flood plain.
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Environmental Impacts
Vegetation
The majority of the proposed Development (69 percent) would occur within pastures; 68 percent, which are
previously disturbed lands, and which provide minimal environmental services or habitat value. Most of the
development within the pastures would also be from agricultural activities, either in the form of orchards,
fields, or other similar land uses. New impacts to native habitats and vegetation communities would
primarily occur (32.1 percent) within the Sagebrush Shrubland habitat type, primarily through the conversion
to recreational activity areas, roads/transportation, and buildings.
Development within native vegetation types is not extensive, and most of the development, as mentioned,
occurs in previously disturbed areas. There is a high potential for the spread of noxious weeds from disturbed
areas into undisturbed vegetation types, and aggressive noxious weed management will need to be followed
as specified in the Weed Management Plan to keep undisturbed native habitat types from becoming infested
by adventitious weed species.
Table 3 – Impacts to Vegetation Types
Vegetation Disturbance
Vegetation Community
Type Agricultural Building Recreation Roads/
Trails Water Total
Acres Percent
Mancos Shales
(mostly unvegetated) - 0.22 - 0.01 0.45 0.68 0.02
Mixed Mountain
Shrubland - 0.75 2.69 0.46 1.46 5.36 1.8
Oakbrush 2.19 2.72 0.39 0.22 - 5.52 1.82
Pastures 155.23 17.89 10.38 20.29 1.32 205.11 67.6
Riparian/Wetlands - 0.35 - 0.03 - 0.38 0.01
Sagebrush Shrublands 7.51 15.09 51.27 8.53 4.01 86.41 28.5
Total Project
Components Disturbance 164.93 37.02 64.73 29.54 7.24 303.46 -
Federally Listed Species
Information on species status, distribution, and ecology was derived from U.S. Fish and Wildlife Service
(USFWS) recovery plans, Colorado Natural Heritage Program maps and reports, Colorado Parks and Wildlife
(CPW) habitat mapping, geographic information system (GIS) databases, various scientific studies and
reports, and field reviews. The wildlife species assessments have been mapped and described following all
applicable practices of the CPW.
Listed or candidate wildlife species considered and evaluated for this assessment include those identified by
the USFWS as potentially occurring in the development areas of the proposed PUD (“Project Area.”) While
all listed species were initially considered, species where there would be No effect from the project were
Nutrient Farm PUD Impact Analysis Report
26
eliminated from further consideration. The decision to eliminate a species from consideration was based on
known range distributions and/or complete habitat incompatibility (Table 4).
Table 4 - Federally-Listed Species Initially Considered
Species1 Occurrence Habitat Association
Potential
Habitat in
Project Area?
Potential
Impact/Issue?
MAMMALS
Canada lynx (FT, ST)
Lynx canadensis
High mountain areas with
large expanses of conifer
forests in Colorado
Spruce/fir and lodgepole pine
forests, sometimes aspen,
shrublands
No No
BIRDS
Mexican spotted-owl (FT, ST)
Strix occidentalis lucida
Southwest Colorado, and
along Wet Mountains,
Rampart Range
Deep shaded canyons with closed
canopy conifers and cliffs No No
Yellow-billed cuckoo (FT)
Coccyzus americanus
North Fork of Gunnison,
Colorado, Dolores, Yampa
and Rio Grande rivers
Large cottonwood stands along
larger rivers No No
FISHES
Bonytail chub (FE, SE)
Gila elegans
No known populations
remain in Colorado
Large, swift-flowing waters of the
Colorado River system No Yes
Colorado pikeminnow (FE, ST)
Ptychocheilus lucius
Colorado, Dolores, Green,
Gunnison, San Juan, White
and Yampa
Large, swift-flowing rivers that are
seasonally turbid with warm
backwaters
No Yes
Colorado River cutthroat trout
(SGCN)
Oncorhynchus clarkii pleuriticus
Widespread localized reaches Headwater streams and lakes No No
Humpback chub (FE, ST)
Gila cypha
Green, Yampa and Colorado
Rivers
Pools and eddies in areas of fast-
flowing, deep, turbid water, often
associated with cliffs and boulders
No Yes
Razorback sucker (FE, SE)
Xyrauchen texanus
Lower Yampa and lower
Colorado Rivers
Deep, clear to turbid waters of
large rivers and reservoirs, with
silt, mud, or gravel substrate.
Quiet, soft-bottom river
backwaters
No Yes
PLANTS
Ute Ladies’-tresses (FT)
Spiranthese diluvialis
Northwest Colorado, the
Roaring Fork Valley, and the
northern Front Range
Moist meadows, seasonal river
terraces, and irrigation channels
below 7000 feet in elevation
Yes No
Source: CPW 2015
FE = Federally Endangered; FT = Federally Threatened; SE = State Endangered; ST = State Threatened; SGCN = Species of Greatest
Conservation Need
The species in bold text in the table are federally listed and are identified by USFWS as potentially occurring
within the Project’s immediate vicinity. The Property does not support suitable habitat and is not within the
range of any other listed species.
Colorado River Fish
Status: FWS Endangered
Four species of fish endemic to the Colorado River system (Colorado pikeminnow [Ptychocheilus lucius],
razorback sucker [Xyrauchen texanus], bonytail [G. elegans], and humpback chub [Gila cypha]) are listed as
endangered with critical habitats designated in the Colorado River. The Colorado River adjacent to the
Nutrient Farm PUD Impact Analysis Report
27
property is approximately 20 miles upstream from occupied habitats and the nearest designated critical
habitats are in the Rifle, CO vicinity.
The Colorado pikeminnow was included on the 1967 list of native fish and wildlife threatened with extinction
under the Endangered Species Preservation Act of 1966 and included in Appendix D, the “United States List
of Endangered Native Fish and Wildlife” prior to enactment of the ESA of 1973. The USFWS (1994) designated
critical habitat in the Colorado River and its 100-year floodplain from approximately the Town of Rifle in
Garfield County downstream through Utah, to Lake Powell in Utah.
The razorback sucker was listed as endangered by the USFWS in 1991 because of limited numbers found
throughout the Colorado River Basin and minimal evidence of natural recruitment (USFWS 1991). Within the
Upper Colorado River Basin, naturally reproducing populations are only found in the middle Green River in
Utah and in an off-channel pond in the Colorado River near Grand Junction (USFWS 2002b). Most razorback
suckers in the Colorado River have occurred in the Grand Valley near Grand Junction, although the number
of fish captured in Grand Valley has declined dramatically since 1974 (Osmundson and Kaeding 1991). The
USFWS (1994) designated the same critical habitat for razorback suckers in the Colorado River Basin as for
Colorado pikeminnows.
The bonytail is an exceedingly rare minnow originally native to the Colorado River system of the western
United States and northern Mexico (USFWS 2002c). The bonytail was listed as endangered by the USFWS in
1980 because it had been nearly extirpated from its historical range (USFWS 1980). The USFWS designated
critical habitat for the bonytail in river channels and flooded, ponded, or inundated riverine habitats that
would be suitable for adults and young (USFWS 1994). Critical habitat for bonytail chub occurs in the
Colorado River on the Colorado-Utah border, in westernmost Mesa County, Colorado, and eastern Grand
County, Utah.
The humpback chub was listed as endangered in 1973. The distribution of humpback chub in 1990 included
the Colorado River mainstem reaches in the vicinity of Westwater Canyon, Utah and Black Rocks, Colorado
(USFWS 1990a). Humpback chubs occasionally are collected outside of documented population centers and
the lower Gunnison River (Valdez et al. 2011). The USFWS designated critical habitat for the humpback chub
in river channels and flooded, ponded, or inundated riverine habitats that would be suitable for adults and
young (USFWS 1994). Critical habitat for humpback chubs occurs in the Colorado River on the Colorado-Utah
border, in westernmost Mesa County, Colorado, and eastern Grand County, Utah.
Impact Analysis. No habitat exists within or adjacent to the Property for the Colorado pikeminnow, razorback
sucker, bonytail or humpback chub; the Colorado River in this reach is generally too cold, clear, and fast-
moving to support these species. Therefore, no direct impacts would result from this project.
It is assumed that any project development would utilize the existing water rights associated with existing
wells, the Colorado River, and the Vulcan Ditch, and that no additional depletions of surface water would
occur on a permanent basis. Potential construction water needs would be associated with dust suppression,
compaction, and other construction needs; these waters would presumably come from existing Colorado
River water rights or from the Vulcan Ditch diversion, and no additional temporary depletions are
anticipated. The 1999 Programmatic BO (USFWS 1999) concludes that implementation of the specified
elements of the Recovery Action Plan, along with existing and a specified amount of new depletions, are not
likely to jeopardize the continued existence of the endangered fish or adversely modify their critical habitat
in the Colorado River sub-basin within Colorado.
Currently, the site is likely contributing sediment to the Colorado River via overland sheet flow at rates slightly
elevated over historic conditions, due to the denuded vegetation that expose the naturally erosive soils. The
current proposal to resume intensive agriculture on the site would likely increase vegetation cover, given the
current grazed and dry conditions. Increased vegetation and greater management oversight would reduce
the presumed levels of sediment input to the Colorado River from agricultural areas.
Nutrient Farm PUD Impact Analysis Report
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When considering the conceptual plans for multi-use development on the site, it is assumed that any
stormwater generated from development would be collected and treated appropriately, and that any
hazardous materials would be stored in appropriate containment per Garfield County building code and
Colorado Department of Health and Environment (CDPHE) construction stormwater permit standards. With
adherence to stormwater permit stipulations, additional sediment reaching the Colorado River should not
occur; however, it is not uncommon for larger developments, even with a Stormwater Management Plan in
place, to have unintentional unauthorized releases of sediment. It is therefore likely that the Nutrient Farm
PUD could also potentially see temporary releases of stormwater sediments. These minor releases would
have no meaningful impacts to downstream fisheries and listed species, given the diluting abilities of the
Colorado River, and as listed fish species are not negatively impacted by minor increases in sedimentation;
listed fish species are actually extremely accustomed to heavy silt loads in their habitats.
Given the constraints within which construction and operation must take place, development is not expected
to increase the risk or release of any potential contaminated materials on the site and is not anticipated to
increase the likelihood of future contamination of downstream waters.
Development of the Project would have no direct effect on the Colorado Pikeminnow, razorback sucker,
humpback chub and bonytail chub. Construction and post development site runoff would be managed
through formalized stormwater drainage plans using best management practices. Nevertheless, it is still likely
that some increased sediment delivery would occur during and after construction; these increases are not
anticipated to have impacts to downriver listed fish species. Other minor discharges of contaminants
reaching the Colorado River are not anticipated to result in negative impacts to potentially occupied habitats
on the Colorado River, which is over 40 river miles downstream of the project area. Minor water depletions
such as those proposed with development were anticipated under the 1999 Programmatic BO (USFWS 1999,
USFWS 2000b), and guidance has been issued for the authorization and handling of water depletions.
Additional water depletions beyond current authorizations associated with the property and Vulcan Ditch
would need to be mitigated through initiation of a Recovery Agreement with the USFWS.
Ute Ladies-tresses Orchid
This species (Spiranthes diluvialis) is a perennial, terrestrial orchid approximately 8 to 20 inches tall. Ute
Ladies’-tresses blooms from late July through August; the flowers are white to ivory in color. Habitat for this
orchid occurs along riparian edges, gravel bars, old oxbows, high flow channels, and moist to wet meadows
along perennial streams. It typically occurs in stable wetland and seepy areas associated with stable features
within historical floodplains of major rivers. It also is found in wetland and seepy areas near freshwater lakes
or springs, and soils range from alluvial sands and gravels to coarse silts and clays (USFWS 2018).
This species was discovered in the Roaring Fork valley along irrigation ditches, canals, and ponds near
Carbondale in 2009 (Wheeler and Petterson 2009) and was subsequently added to County lists in the area
by USFWS. This species has not been observed much further downstream along the Roaring Fork than Cattle
Creek confluence and has not been observed on the Colorado River mainstem. Although the Property is
outside the area of known occupancy for the orchid, suitable habitat does occur along the banks of the
Colorado River. No surveys for this species have occurred at this time.
Impact Analysis. The proposed boat ramp and river access points would occur through potential orchid
habitat. Orchids have not been identified as occurring along the Colorado River, initial surveys occurred in
August 2020, and no orchids were observed. As construction of the boat ramp and any other developed
facilities that impact wetlands or waters of the U.S. would require a USACE permit, Nutrient Farm PUD would
be required to conduct additional surveys for Ute ladies’ tresses orchids for permit compliance. If orchids
are detected in these development areas, or in areas which may see potential indirect impacts (e.g., from
human trampling, etc.), then Nutrient Farm PUD would need to coordinate with the U.S. Fish and Wildlife
Service to protect occupied and other potentially suitable orchid habitats. As Ute ladies’ tresses orchids have
Nutrient Farm PUD Impact Analysis Report
29
not been identified along the Colorado River, it is assumed that it is unlikely that these orchids would occur
within the PUD area. Surveys would nevertheless be required as part of the USACE section 404 permitting
process.
Outside of the boat ramp or other improved trails along the Colorado River, the development of the Property
would have no potential direct impacts on the orchid, however, indirect impacts from increased human
activities, increased potential sedimentation issues, and other indirect impacts could affect potential habitats
and any unidentified orchids along the banks of the Colorado River.
In summary, the property contains limited potential habitat for the species (immediately adjacent to the
Colorado River) and is outside the area where the species is known to occur. Prior to any development along
the banks of the Colorado River, surveys for the species would need to occur per USACE and USFWS
requirement, and if the orchid is identified, Nutrient Farm PUD would likely need to modify their plans or
develop a mitigation plan through the USFWS processes. Because of the permitting process with the USACE
and USFWS, it is unlikely that impacts to orchids would occur (if they occur at all on the property). Aside from
direct impacts from a boat ramp or other developed features (such as a trail), the anticipated indirect impacts
of the development could result in an insignificant and temporary degradation of potential habitat for the
orchid in the vicinity of the Project primarily from stormwater runoff, but these risks would be minimized by
CDPHE-mandated stormwater controls.
State-Listed Species
Colorado Parks and Wildlife’s (CPW’s) list of Threatened and Endangered species and Species of Greatest
Conservation Need (SGCN; Tier 1 species only) was reviewed to determine if any species had potential habitat
in or adjacent to the Project Area. While all listed species were initially considered, an elimination of unlikely
species from further consideration is provided in Appendix C. These decisions are based on known range
distributions being either outside of the Project Area or complete habitat incompatibility. The Colorado River
endangered fish species have already been addressed under section 5.1 Federally Listed Species and are not
further considered in this section.
Bald Eagle
Bald eagles (Haliaeetus leucocephalus) are federally protected by the Bald and Golden Eagle Protection Act
of 1940. They are also protected under the Migratory Bird Treaty Act of 1918. In addition, CPW tracks bald
eagle populations, nesting sites, roosting habitat, and foraging areas and has developed protective
stipulations for the species, with specific recommendations for nests, winter night roosts, and hunting
perches (CPW 2008).
As currently mapped, the Project is located within bald eagle winter and summer range habitat that extend
along the length of the Colorado River. The Property is also upstream from a known bald eagle nest site,
which was confirmed to be active as of March 29, 2020. The Property is outside the protective 0.5-mile
buffer established for the active nest (Figure 4). The mapped eagle range encompasses only the Colorado
River and the immediately surrounding banks and does not extend into the portions of the Property that are
removed from the river.
No nests are currently located within or adjacent to the PUD area. There is minimal habitat of the type
preferred by nesting eagles (large deciduous tree adjacent to flowing water) on the Property, but a handful
of large ponderosa pines (Pinus ponderosa) do provide attractive perching sites, primarily upstream and at
the easternmost end of the project area. Some opportunistic perching likely occurs on larger trees adjacent
to the river, but there are very few suitable perching or nest trees along this stretch of the Colorado River.
One larger ponderosa pine in particular upstream of the project area could provide some wintertime roosting
opportunities, but in the spring and summer months this tree is occupied by a great blue heron (Ardea
Nutrient Farm PUD Impact Analysis Report
30
heodias) heronry, which would preclude bald eagles using the ponderosa pine for perching during the heron
nesting and chick rearing season (see section 4.4.4.5 Great Blue Heron below). It is also likely that eagles
could be attracted to the foraging habitat along the river, since the winter-seasonal ice coverage is limited,
and the river contains an abundance of the large prey preferred by eagles. Bald eagles (as well as golden
eagles) are also known to prey on heron chicks, so some opportunistic predation of the heronry may also
occur.
CPW recommends limited human encroachment within 0.5 miles of occupied eagle nests during the nesting
season. At this time there are no nests within 0.5 miles of the property, and there is a limited likelihood of
any new nests being constructed due to a lack of suitable nesting trees. Diurnal hunting perches of the type
that could be utilized on the Property should also be protected from direct encroachment but are less
sensitive than nesting sites.
At this time, development along the river is limited to a boat ramp and some riverside trails. No significant
impacts to eagles are anticipated given there are no suitable perching sites or nesting trees along the river in
proximity to the PUD area. If eagles are observed perching on the Property in the future, the preferred
perching sites should be considered for preservation. In general, the few large trees adjacent to the river
should not be removed, to retain perching/foraging value for eagles. The boat ramp and any riverside trails
would likely reduce bald eagle foraging habitats when humans are using these amenities, but these indirect
impacts are not considered significant, given a lack of perches near the river.
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Figure 8 - Bald Eagle Habitats
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River Otter
The Colorado River in the vicinity of the Property is mapped as habitat for the river otter (Lontra canadensis)
by CPW. Northern river otter inhabits riparian habitats that occur from low elevation deserts to high valleys
of Colorado. Otters require permanent water of relatively high quality with an abundance of fish and/or
crustaceans (crayfish; Cambarus sp.). Otters are usually found in streams with higher volumes (minimum of
10 cfs). During the winter months, otters also need streams with relatively high amounts of open, ice-free
water, deep pools, and good access to the shoreline. The river otter once occurred in most of the major river
drainages in Colorado and was extirpated. Starting in 1976, Colorado started reintroduction efforts in several
drainages, with an initial goal of establishing two populations. In 1998 a more intensive reintroduction
program was started by CPW. Historically and currently in Colorado, otters are most commonly found in larger
rivers at low or moderate elevations. Otters are also known to have colonized larger ponds, reservoirs, lakes
and flooded gravel pits.
Fish are the primary food source for otters, particularly slow-swimming fish species. In streams where they
are abundant, crayfish can make up a significant portion of otter’s diet. Most research indicates that abundant
prey is needed to support otter use of an area (Mack 1985, Malville 1990, Melquist et al. 1981).
Because of the river otter’s aquatic life, many aspects of the species’ behavior and ecology are not well
understood. They are active year-round, and do not hibernate. Otters in mid-elevation areas such as the
Colorado River in the Project vicinity are mostly diurnal in winter and more nocturnal in summer, with the
least activity in late summer and early fall. River otters are social, forming family groups led by the adult
female, who may exhibit territorial behavior. Yearling otters, unrelated juveniles, and occasional adult otters
may join with family groups.
River otters use both terrestrial resting sites and dens when not actively moving. Beaver bank dens are
particularly favored sites. Adult otters apparently have few natural predators, although individuals have been
killed by bobcats, dogs, coyotes, and foxes (Fitzgerald et al. 1994). Most mortality is thought to occur from
trapping and road kills. Habitat destruction and water pollution have an impact as well.
The section of the Colorado River adjacent to the PUD area remains at least partially ice-free during the winter
months, and because of this, river otter activity in this area could occur year-round. In addition, CPW fish
stocking and fishery data suggests that ample prey is likely available. Therefore, otter use of this stretch of
the Colorado River is likely to only be constrained by den site availability and human disturbance. Beavers and
potential den sites do not occur in significant density on this stretch of the Colorado River, and hazards from
dogs and road traffic are significant, which likely reduces the potential for otters to occur in this area on a
regular basis. River otters are not known to occur in the river immediately adjacent to the Property, but
certainly could utilize the habitat on a seasonal basis.
Impacts Analysis. While the property encompasses nearly 2.75 miles of the south bank of river, the
development is mostly set back from the river, and most of the proposed development and agricultural use
would not be expected to directly affect any individual otters that could occur in the vicinity. The adventure
farm, picnic area, restaurant and other development features are approximately 80-100 feet from the edge
of the river (to stay outside of the floodway), and at this distance most river otter activities would not be
impacted. The boat ramp and proposed riverside trail would have minor direct impacts to habitats (given a
lack of structural diversity in the banks) but would introduce areas of focused human activity at the river’s
edge. Development on the property is assumed to use constructed stormwater management basins under
final development plans and would not impact water quality values necessary for river otters or their habitat.
Increases in human activity (and assumedly pet dogs) would occur, and human activities along the banks of
the river would likely reduce habitat effectiveness for river otter, and while otters may still occur in the river,
they would not likely linger for long periods or establish up dens along the riverbanks near the boat ramp or
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even near riverside trails. Foraging activity may still occur, but again if there are more continuous human
activities along the banks, then otters would likely cease foraging activities and move to stretches of the river
with less human activity.
The cumulative impacts of the proposal LoVa Trail in this area would additionally increase human activities
near the river, and could further reduce habitat effectiveness along the river, especially during the spring,
summer and fall months when the trail would be most active.
Other Wildlife Considerations
Traffic and Big Game Species
Traffic in Colorado is often the leading indirect impact to wildlife habitat and wildlife mortality. Highways and
busier roads are often located in areas of flat benches adjacent to river systems, which bisect upland habitats
from riparian habitats. As riparian habitats often attract upland wildlife species, and in some cases congregate
wildlife for significant periods of time, increased traffic levels on roadways can often form effective barriers to
wildlife movement and can then fragment habitats by dissuading wildlife from crossing roadways. For some
species, the draw of traditional habitats or water can override the fear of traffic, and wildlife will often attempt
to cross busy roadways, incurring mortality and thus negative impacts to population levels. Further, for species
such as deer and elk, vehicle strikes can often cause significant financial impacts to commuters, through
increased insurance rates, direct costs of repairing or “totaling” of vehicles, to costs of hospitalization, injury,
and even death to drivers and passengers in vehicles. There are no big game migration corridors within the
PUD area.
Research on traffic impacts to habitat connectivity and wildlife use patterns indicate that traffic levels of 4,000
to 5,000 VPD begin to create significant deterrents to wildlife crossings (Ruediger et al. 2000, Alexander et al.
2005, Gagnon et. al. 2007). Some of the other actions wildlife take when having to cross a road with 4,000-
5,000 VPD includes animals avoiding highways altogether (not even trying to cross), failed attempts (animal
tries to cross, but turns around due to traffic), injury in crossing (from vehicles strikes), or death. As mentioned,
existing traffic levels on CR 335 is not likely a barrier to wildlife crossing the road.
Impact Analysis. According to the SGM traffic study, CR-335 carries commuter traffic from residential
subdivisions between New Castle and the Riverbend, Riverbend Ranchettes and Cedar Ridge subdivisions
adjacent to the Project Area (and associated construction and service traffic to those residential areas). As
there is no public access or roads beyond these subdivisions, there is no pass-through traffic. Much of the
existing traffic is generated during the morning and evening rush hours, coinciding with daily commuter traffic
between the Riverbend area, and work destinations in the Glenwood Springs and Aspen areas. This results in
daily traffic volumes of approximately 470 VPD through the Nutrient Farm PUD, peaking in the morning and
evening commute times. As detailed in the SGM traffic report, these peak traffic periods are relatively short-
lived, and during much of the day and especially at night, traffic patterns would be relatively low.
At full build out, traffic generated from the Nutrient Farm project would likely generate 1,730 additional VPD,
raising the level of vehicle use along CR-335 to 2,200 VPD. This amount is still well below traffic levels at which
more noted avoidance of wildlife crossing attempts begin to occur. Further, given the 35 mph road speeds,
traffic levels are also mitigated by the slower road speeds.
These volumes would not likely produce temporary barriers to wildlife movement across CR-335 but may
produce conditions mildly hazardous for wildlife crossing. However, as detailed in the SGM traffic report, these
peak traffic periods are relatively short-lived, and during much of the day and especially at night, and wildlife
would easily be able to cross CR-335.
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Black Bear
Black bear (Ursus americanus) has become a significant wildlife management issue in the State of Colorado.
Bears are commonly supplementing their diets by raiding garbage cans, breaking into homes, and becoming
a hazard and a nuisance. Habitat on the Property itself is dominated by grazed and dry-land pasture meadows
which do not currently provide foraging opportunities for bears. The north-facing slopes south of the pastures
do include a mixed mountain shrub component, which provides good foraging value for bears. The Riverbend
community likely sees relatively common bear activity, given the proximity to shrubby habitats.
Conditions on the north bank of the Colorado River and I-70 are more attractive to bears currently, given the
density of human occupancy and the presence of agricultural activity including orchards along Canyon Creek.
These areas are more attractive to bears because of human-provided food sources, especially trash or orchard
fruit. This is reflected in CPW’s mapping of Black Bear Human Conflict Areas in the greater area (Figure 5), but
these Human Conflict Areas do not extend onto the Nutrient Farm PUD.
However, the proposed development would create similar conditions within the Property, since orchards are
a component of the plan, and the residential and agri-tourism areas would generate significant food waste
that would also be an attractant.
Impact Analysis. This development would have minor to insignificant impacts on bear populations or bear
habitat availability, but black bears will take advantage of the PUD to supplement their diets. Because of the
extensive orchards planned, it should be expected that the level of conflict with black bears could dramatically
increase, and the Property should be treated as a Black Bear Human Conflict Area when considering the
development proposal. Residents should use bear-proof trash containers, should not feed pets outside or
leave pet food outside, and should be cautioned against planting significant amounts of fruit-bearing trees
near their homes. The orchards will be a strong attractant for bears, and preventative game damage fencing
will help preclude most bear issues in the orchards. But regardless, it is highly likely that bears will be an issue
for Nutrient Farm residents, campers and visitors, and strict adherence to rules such as keeping trash and food
secure, and keeping fences maintained around orchards, will be needed to keep bears from becoming an even
greater issue.
The following measures will be implemented to reduce potential bear problems:
1) There should be no dumps that have edible materials associated with construction and post-
construction activities.
2) Residential garbage should be placed in bear-proof dumpsters, individual bearproof trash containers,
or kept in trash cans inside closed buildings.
3) Pets should not be fed outside.
4) Bird feeders and hummingbird feeders should be brought in during the evenings and removed
altogether during the fall months (September through late November).
5) Nut, fruit, or berry-producing trees or shrubs should not be used in landscaping in order to minimize
an attractant for bears around homes and developed areas; orchards should be within fenced areas.
6) Individual home compost piles should be discouraged or prohibited; a community-wide site can be
developed if it has adequate fencing and lighting to keep bears out, and protect people from bear
interactions, especially at night.
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Figure 9 - Black Bear Habitats
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Elk
In the southern Rocky Mountains, as elsewhere in North America, elk are often associated with edge (ecotone)
habitats where forested and meadow/shrubland systems are intermingled. During much of the year, elk are
typically found near edges where forests grow adjacent to parks, meadows, or alpine tundra (Skovlin 1982,
Fitzgerald et al. 1994). During the summer months, elk may spend significant amounts of time feeding in open
alpine environments above tree line. Use of alpine habitats is thought to be associated with the cooler
temperatures, persistent snowbanks, and breezy conditions that keep bothersome flying insects to a minimum
(Adams 1982, Lyon and Ward 1982). Similarly, during the winter elk may congregate in low elevation sagebrush
expanses, pinyon and juniper woodlands, irrigated meadows, and other open habitats that are significant
distances from forested cover (Lyon and Ward 1982). On winter ranges, elk form mixed herds of bulls, cows,
and calves (Fitzgerald et al. 1994), but in the more developed areas in Colorado, bulls may avoid traditional
winter ranges that are near high-use roads, homes, and other human developments (B. Andree, CPW pers.
comm. 2006, Dodd et al. 2007).
Generally, elk feed at twilight and at night, but they readily forage and disperse through the daylight hours.
Most elk mortality is due to predation on calves, hunting, and winter starvation. Localized mortality from
vehicle strikes may also produce noticeable impacts on herds where traffic exceeds 1,000 VPD and where traffic
travels at high speeds (Gagnon et al. 2007).
Elk are generalist feeders, but usually prefer to graze on grasses, grass-like plants, and forbs during the non-
winter months (Nelson and Leege 1982, Fitzgerald et al. 1984). The specific diet for elk in a particular locality
is largely determined by the season and palatability of available forage plants (Nelson and Leege 1982). In
Colorado, elk show a clear preference for grasses and grass-like plants (Hoover and Wills 1984). Browse species
can also vary by site and palatability of available plants. Shrubs, deciduous trees, and sometimes conifers
compose much of the winter diet when snow depth limits access to grasses, sedges, and forbs (Nelson and
Leege 1982).
On Colorado winter ranges, oakbrush, aspen (Populus tremuloides), serviceberry (Amelanchier spp.),
sagebrush, and snowberry (Symphorocarpos spp.) are the major browse species used by elk (Hoover and Wills
1984). Locally heavy feeding on aspen bark during the winter and spring can be very significant and can leave
long-lasting impacts on aspen stands.
Issues of Concern. CPW staff have indicated that most herds near mountain communities have decreased in
size from 50 to 60 percent since their peak population sizes in the mid- to late-1990s. While direct habitat loss
has slowed from the 2000s, there has been a widespread increase in outdoor uses around mountain
communities, primarily through increased trail construction, and now almost year-round recreation (C.
Wescoatt and B. Andree, CPW District Wildlife Managers, as cited in Vail Daily, 6/16/2018; J. Mao, CPW
Terrestrial Biologist, pers. comm. 10/10/2018). There is no single definitive activity or habitat impact that can
be strongly linked to elk population declines, but the current hypothesis is that the long-term reduction in
winter ranges and increased year-round human pressure (primarily through recreation) in habitats are having
cumulative impacts at a level where elk’s ability to produce a viable numbers of calves is unable to replace
yearly mortality (J. Mao pers. comm. 10/10/2018).
CPW has mapped the north-facing slopes and portions of the pastures as Severe Winter Range (Figure 6). At
this time, elk use of these pastures is limited to the winter and more so in the early spring months; this use is
very sporadic but can be notable. It is not uncommon to see a herd of 50+ elk in these meadows, but they
generally only linger a day or two, and then they may not be back for weeks or even until the next winter/spring.
It is unlikely that elk would utilize the pastures or steep north facing slope habitats heavily or regularly, since
snow accumulation on the steeper north-facing slopes restricts movement and access to forage. Such site-
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specific factors cannot be reflected in state-wide mapping, which is why much of the area within PUD is mapped
as Severe Winter Range.
As snow accumulates during the early winter, migrating elk may traverse the Property area as animals move
towards the smaller ridges with south-facing slopes located south of the Property in the Alkali Creek drainage
and in the “Vulcan” basin (southeast of the project area). The existing Riverbend housing developments also
likely limits the amount of winter residency on and in proximity to the Property. Elk wintertime use of the
Property is likely to be limited in extent and duration, but as mentioned, heavy intermittent use may occur,
especially in the spring as grasses begin to green up in the pastures.
The presence of intervening barriers between the Property and other winter ranges north of I-70 (including the
Interstate and associated big-game fencing to reduce vehicle mortality, frontage roads, railroad, residences, and
the Colorado River) make it unlikely that large numbers of elk will migrate from winter ranges north of the
Colorado River onto the Property. Elk may move north across the property to procure water at the Colorado
River.
Impact Analysis. Development of the property would not impact elk summer range habitats; during the
summer elk utilize much higher elevations. The development of the Property would not impact any Production
(calving) areas.
Development of the Property would occur in areas mapped as Severe Winter Range Habitats by CPW; however,
there is little available wintertime forage in the pastures (there are no shrubs available for browsing, aside from
a few poor-value rabbitbrush), and short-statured grasses are unavailable or limited in the winter due to snow
cover. There is also no effective refugia cover in the pastures, aside from elk being able to place themselves at
distance to roads and homes. Thus, wintertime use of the pastures and habitats near the homesites is very
limited, and the pastures likely do not support enough elk use to qualify the habitats as “Severe Winter Range.”
However, development in native shrubland habitats along the southern sides of the PUD, and towards the
eastern end of the PUD would occur in, and adjacent to, suitable elk winter range habitats supporting good
forage. And while large numbers of elk do not likely linger in these habitats, there would nevertheless still be
some direct impact and loss of winter range habitats from development. It is unknown exactly how many elk
utilize these winter ranges, given the intense but very sporadic nature of their use patterns in the area, but
conservatively we must assume the sporadic but intense use is still an important component of overall winter
range compositions, as mapped by CPW.
A potential larger concern is that elk infrequently migrate through the area later in the spring and are known
to loaf in the pastures when new grasses are emerging. Elk coming off winter ranges are often malnourished
and have caloric deficiencies, and the new springtime grass growth can be very important for elk. Proposed
development of the Property would likely halt most springtime elk use of the pastures and would further reduce
remaining habitat value or movement corridor values given the extensive fencing needed to protect orchards,
the proposed OHV area, trails, facilities, and music venue location placed in the hills south of the pastures.
However, as the most important elk use occurs in the late winter/early spring months, the music venue and
OHV track would not likely be open for the season at that time. So elk may still be able to use habitats very
near these areas, as long as human activity levels are low, pet dogs are not allowed to run free, and winter
range timing stipulations are used to minimize disturbance to elk.
While the presence of the existing housing developments has already decreased habitat effectiveness, the new
activities in native shrubland habitats at the southern and eastern ends of the PUD area will further reduce
available habitat and increase indirect impacts to big game using these areas. Elk wintering activities in shrubby
habitats in the hilly areas around the PUD would likely see reductions in use with development, even if the
music venue and OHV area is not being used, given overall increased human activities in the general PUD area.
Controlling of pet dogs and minimization of human activities in surrounding native habitat types during the fall,
winter and spring seasons will help reduce the indirect impacts to elk wintering around the PUD.
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While it is unlikely that development of this Property would result in any noticeable or significantly detrimental
impacts to elk at the herd level, the development would cumulatively reduce springtime foraging areas, which
is a very important habitat component given the poor condition most elk are in at the end of the winter season,
and would cumulatively reduce available elk winter range habitats.
Mitigation Planning. In response to these concerns, Nutrient Farms has met with CPW District Wildlife Manager
(Travis Bybee) to discuss the potential impacts of the project and develop mitigation measures to reduce
impacts. Through these discussions, Nutrient Farms will work with CPW to develop the following items as part
of a Wildlife Mitigation Plan.
• Winter timing and activity stipulations to avoid and minimize disturbance to elk
• Use of laydown fencing in some areas to allow for habitat connectivity and allow for wintertime elk
access to pastures
• Leaving taller stubble heights in pastures for more elk grazing opportunities,
• Development of wintertime water sources for elk
• Assistance with habitat improvement and water resource development on neighboring BLM lands.
Through the development of the mitigation plan, impacts to elk would be minimized and mostly mitigated.
The project would therefore not result in significant, long-term detrimental impacts resulting in reductions in
herd size or significant impacts to habitat.
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Figure 10 - Elk Habitats
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Mule Deer
Mule deer occur throughout Colorado and are relatively common in the west. Mule deer occupy all ecosystems
in Colorado from grasslands to alpine tundra, but they reach their greatest densities in shrublands on rough,
broken terrain, which provides abundant browse and cover. Their wide distribution and general adaptability
make for broad diets. However, deer are considered to be browsers (primarily eating shrubs and twigs), as
opposed to grazers (which eat mostly grasses). In Colorado the winter diets of mule deer consist of browse
from a variety of trees, shrubs (74%) and grasses and forbs (26%), depending on local browse availability. In
the spring and summer, browse contributes around 50% of the diet, and forbs and grasses make up the
remainder (Fitzgerald et al. 1994).
Mule deer are mostly nocturnal and crepuscular in the warmer summer months and become more diurnal
during winter. Activity depends on local conditions including temperature, season, weather, and forage. Over
much of Colorado the species is migratory, summering at higher elevations and moving downslope to winter
ranges. In some areas of Colorado migrations may be over 55 miles, but in most areas, migrations are closer
to about 5 miles. The routes followed are often habitual, and deer show a certain amount of fidelity to these
routes. Snow depths of 8 to 16 inches appear to trigger fall movements, and depths over 3 feet prevent use of
an area (Loveless 1967). In some areas of northwestern Colorado mule deer begin migrations before snow
accumulation (Garrott et al. 1987, as cited in Fitzgerald et al. 1994). These authors suggest that better-quality
forage on winter range at that time of year triggers the movements. Throughout the winter mule deer will
move about winter ranges, depending on snowfall and snow-melting events, but prefer to linger on more
south-facing slopes where snow depth is shallowest.
Spring and summer ranges are most typically mosaics of meadows, aspen woodlands, alpine tundra and
Krummholz, or montane forest edges. Montane forests and pinyon-juniper woodlands with good shrubby
understories are often favored winter ranges. Because of the mule deer’s seasonal migratory movements,
estimation of home ranges is somewhat difficult; however, deer appear to be seasonally sedentary, staying
within areas of 100 to 2,200 acres. In areas where the animals do not migrate significant distances, annual
home ranges are 1,700 acres to 5,400 acres (Mackie et al. 1982). Migrating individuals show strong winter and
summer range site fidelity.
Mortality in mule deer varies with age class and region. In Colorado, annual fawn mortality can vary as much
as from 27% to 67% (Anderson and Bowden 1977). Fawn mortality is due to predation and starvation. Larger
fawns are more likely to survive, and smaller fawns are more likely to starve. However, predators will take any
size of fawn. Winter mortality of fawns may approach 75% annually. Mortality of adult deer is mostly from
hunting and starvation (Carpenter 1976). Predators include coyotes, bobcats, golden eagles, mountain lions,
black bears, and domestic dogs. Locally, coyote and mountain lion predation on fawns can account for
significant mortality within populations. Fawns comprise about half of the yearly mortality; while mature
females and bucks comprise the remaining 15% and 35%, of the annual mortality, respectively.
Similar to elk, impacts to mule deer from human activities, recreational activities, trails and dogs have been
well studied and documented in the scientific literature.
Issues of Concern. Historically, mule deer would have utilized a wide swath of habitat throughout the Colorado
River valley bottoms, but development and conversion of rangelands to pastures has constrained most
movement to areas with less disturbance, where natural topography, native shrublands and an absence of
development creates preferable conditions. The presence of existing residential developments adjacent to the
project have compounded a situation where mule deer movement and migration in the immediate vicinity has
been impacted.
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Mule deer use of the Property occurs year-round. Similar to elk, the presence of other development adjacent
to the Property likely have reduced habitat effectiveness across portions of the Property, and mule deer use
likely avoids areas with high levels of human activity.
CPW has mapped the entire PUD Boundary as Winter Range and has mapped PUD Development Area as Severe
Winter Range. However, mule deer are subject to much the same snow depth limitations as elk: snow
accumulations deeper than a foot can preclude significant utilization. Winter habitat utilization would be
concentrated on steeper slopes that support good shrub cover; however, s outh-facing slopes retain significantly
less snowpack due to greater wind scour and greater solar exposure and are preferred habitat for mule deer in
the winter. The availability of south-facing slopes are limited on the Property; therefore, although the Project
Area is within Winter Range and Severe Winter Range, the true habitat effectiveness and browse availability is
limited to areas with good shrub cover, on steeper south-facing slopes (Figure 7).
Similar to elk, mule deer use of pastures in the springtime when grasses first emerge is likely quite significant
and can be a very important habitat component for deer coming off wintertime caloric deficits.
Impact Analysis. Development of the Property would impact areas of mapped mule deer Winter Range and
Severe Winter Range. While north-facing slopes are mapped as winter range, once winter snows accumulate
mule deer would likely move to more suitable winter ranges on more south facing slopes, such as to the east
in the Vulcan basin.
Development of native shrubland habitats at the southern end of the parcel would nevertheless reduce
important early- and late-season winter range habitats, even if most recreational activities have ceased for the
winter. While it is unknown how many mule deer utilize winter range habitats in the PUD area, any losses of
winter range habitat can be concerning, and would have cumulatively negative impacts on mule deer winter
range.
Summertime use of shrubby habitats near developments, the OHV track and music venue area by mule deer
would see marked reductions in use given higher levels of human activity, the presence of motorized and non-
motorized recreational uses, and increased sound levels. Fugitive noise and light from these developments
and venues would further reduce habitat effectiveness in surrounding native habitat types. The extensive
fencing on the Property will also reduce habitat connectivity across the Property, but this is not likely a
significant impact given a lack of suitable summertime habitats across the pastures. Cumulatively, when
assessing all the various components of motorized and non-motorized venues, outdoor music venues, fenced
orchards and homesites, mule deer use across the PUD area would be mostly precluded aside from some
incidental use, and continued use on steeper, shrubby hillsides further away from centers of human activity.
While there would be significant decreases in mule deer activity in the PUD, this project would not be expected
to result in meaningful impacts to mule deer herds in the greater area but decreases in mule deer activity in
and around the PUD area would be noticeable.
Mitigation Planning. In response to these concerns, Nutrient Farms has met with CPW District Wildlife Manager
(Travis Bybee) to discuss the potential impacts of the project and develop mitigation measures to reduce
impacts. Through these discussions, Nutrient Farms will work with CPW to develop the following items as part
of a Wildlife Mitigation Plan.
• Winter timing and activity stipulations to avoid and minimize disturbance to mule deer
• Use of laydown fencing in some areas to allow for habitat connectivity and allow for wintertime mule
deer access to pastures
• Leaving taller stubble heights in pastures for more grazing opportunities,
• Development of wintertime water sources for mule deer
• Assistance with habitat improvement and water resource development on neighboring BLM lands.
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Through the development of the mitigation plan, impacts to mule deer would be minimized and mostly
mitigated. The project would therefore not result in significant, long-term detrimental impacts resulting in
reductions in herd size or significant impacts to habitat.
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Figure 11 - Mule Deer Habitat
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Great Blue Heron
Great blue herons breed across the entire North American continent. They are the largest heron species in
North America and are common and widespread. They are highly adaptable to different habitats and
environments. Great blue heron populations are generally stable or increasing throughout most of their range
and are ranked globally secure, but uncommon in Colorado (G5/S3, NatureServe 2020). The World
Conservation Union (IUCN) red list category for the great blue heron is “Least Concern”, and the Audubon
Watchlist Status is “Green” (Audubon Society 2007). As with all migratory birds, the great blue heron is
protected under the Migratory Bird Treaty Act of 1918 (as amended).
Great blue herons generally nest in colonial “heronries”. Habitat characteristics of heronries vary considerably
depending on locations within North America. Likewise, the level of human activity around established
heronries also vary widely; however, high levels of human activity have been associated with heronry
abandonment (Bjorkland 1975, Wershkul et al. 1976). The level of response from a disturbance is influenced
by a variety of factors, including breeding stage and distance (Vos et al. 1985).
Human disturbance can be a major factor influencing nesting and foraging activities of great blue heron. Some
herons do become habituated to human activities (Grubb 1979, Kelsall & Simpson 1980, Butler 1991, and
Vennesland 2000). Human recreational activities can cause herons to temporarily abandon their breeding
attempts, allow predation of eggs and young (Moul 1990), or permanently abandon a colony (Markham &
Brechtel 1979). Most heronries are located in areas away from human activity or have significant vegetative
screening from human activities (Watts & Bradshaw 1994, Gibbs & Kinkel 1997, J. Lowsky pers. comm. 2008).
Klein (1993), and Lowsky (2007 & pers. comm. 2008) reported that great blue herons in Colorado and in Pitkin
County had highly variable responses to humans in vehicles and afoot. However, in most situations, herons
responded stronger to humans on foot than on bicycles or in vehicles. This is a common theme with many
wildlife species, including elk. Rodgers and Smith (1995) reported that great blue herons flushed at a mean
distance of 32.0 + 12.3m in response to persons approaching on foot. Skagen et al. (2001) found a reduction
in the number of great blue heron nests when they were exposed to humans on foot. Vos et al. (1985) studied
a heronry in Larimer County, Colorado, and found that heron’s response to human activity changed as the
breeding season progressed through the year. Herons were most responsive to human intrusions early in the
breeding season (March), flushing from the nest at the slightest disturbance and not returning until the cause
was no longer present. During egg laying and incubation (mid-April), herons were less willing to abandon
nests and returned more readily. This “nest site fidelity” is a common theme among many bird species-
whereby as the breeding season progresses, adult birds are less likely to stay away from eggs or nestlings as
the season progresses, and is thought to be a function of “resource investment” into their young (Thompson
2007).
Vennesland (2000) experimentally showed that herons do habituate to non-threatening presence of people
near colonies. His results showed that colonies in rural areas that seldom experienced human activities left
nests more readily than colonies in urban areas. His study concluded that heron breeding productivity was
significantly diminished with higher levels of pedestrian activities within 250m of colonies due to decreased
nest protection from adults and increased secondary predation from bald eagles. But he also concluded that
“…total human activity (including pedestrians, cars, planes and land clearing equipment) had no relationship
to heron breeding”.
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Personal observation of the colony at Cattle Creek on
the Roaring Fork River during June and July of 2007
showed humans (landing rafts from float trips down
the Roaring Fork River) at the base of the ponderosa
pine trees containing nests (see photo), with no
flushing of herons (distances of less than 10m).
To reduce flushing and negative impacts to nest
success, various buffer distances are recommended.
Buffer areas generally have restrictions limiting or
modifying human access or activities which would
allow nesting herons to still fulfill life history
requirements un-harassed, but buffer areas can also
include mitigations such as vegetative screening to
hide human activities, which would still allow for
herons to continue with their daily activities un-
harassed. Buffer area restrictions generally only apply
when herons are conducting reproduction activities
(which in Colorado, is generally from mid-March
through late July). In Colorado, most studies
recommended a buffer distance of 200m (Miller 1994,
Colorado State Parks 1998) while Vos (1985)
recommended 250m.
Impact Analysis. Herons hunt all along the banks of
the Colorado River, throughout the PUD area. Most
proposed development, being 80 to 100 feet from the river, is likely far enough from the river’s edge, and is
separated by screening vegetation and topography, such that heron foraging would likely continue with little
impact from the actual structures and development. However, human activities along the river (such as
people walking down to the river), or off leash dogs, would likely flush and reduce habitat effectiveness for
foraging herons along the river, and in the case of dogs, may also rarely cause mortality. These impacts are
most likely to occur in only a few select areas, and most of the river’s edge throughout the PUD would still
provide foraging opportunities for herons.
The heronry at the far eastern side of the PUD is approximately 1,000 feet (312 meters) from the nearest
development (a livestock barn), and the heronry should not see any notable impacts from development.
Closer to the heronry would be the LoVa Trail, and those impacts are beyond the scope of this report. To err
on the side of conservation, signage should be considered discouraging people from approaching the heronry
during the spring and early summer months to prevent heronry disturbance. The pump station on the
Colorado River is a static structure, with little human visitation; this structure would not have meaningful
impacts on the heronry upriver.
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Figure 12 – Heronry and Impacts
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General Wildlife Impacts
The following section discusses considerations to minimize the potential impacts to wildlife from the proposed
development. Many of these recommendations are considered to be “best management practices” for
wildlife, which would allow for continued wildlife use of areas within the development.
Lighting: Because the area may still see use by mule deer and elk around the periphery at night, nighttime
lighting of the Property and excessive lighting of roads (beyond what is required for safe driving
conditions) is not recommended. Lighting for music and other recreational venues should only be on when
sites are in use, and down-cast lighting is recommended.
Fencing: In order to continue the effective use of the surrounding area by big game animals, wildlife-
friendly fencing should be utilized, unless necessary to protect orchards and other agricultural production
areas. Fencing that is needed to keep pets and children within private yards encouraged. Nutrient Farms
is working with CPW to develop areas with “laydown fencing” to allow for wintering foraging
opportunities.
Landscaping & Revegetation: Because the surrounding area may still see some use as winter range,
reclamation of road cuts, infrastructure routes and open spaces will occur using similar native plant
species and vegetation profiles. Revegetation will also occur as soon as possible; however, any shrub
planting in the spring after big game have left the area will be best as newly planted materials would likely
be browsed first, and plants with little time to set roots will likely be pulled up by grazing big game.
Seeding should occur in the fall. Noxious weeds will be treated in order to minimize their spread and
impact on winter range and increase the success of revegetation activities. Please see the Nutrient Farm
Reclamation Plan (SGM 2020c).
Domestic Dogs: Dogs can have a significant impact on wildlife and the ability for wildlife to effectively use
otherwise-available habitats. Dogs can chase and kill wildlife, or so exhaust and injure wildlife that it dies
later. To minimize the impacts of dogs on wildlife, the following practices will be employed:
1) Dogs will not be allowed outside of fenced yards unless under leash control.
2) Loose dogs will be prohibited outside of individual home lots and outside of the designated
Dog Park on the Property.
Domestic Cats: Domestic cats can have significant impacts on local breeding bird, small mammal,
amphibian, and reptile populations in area habitats. Keeping cats indoors or on leashes will protect a
major component of the potential non-game wildlife use in the area from predation.
Impacts to Landscaping: Since the subject Property occurs within mule deer and elk Winter Ranges, there
will likely be damage and use of landscaping by foraging big game. Any additional future property owners
will be informed of this with the understanding that that Colorado Parks & Wildlife does not provide game-
damage reimbursement for damage to landscaping.
Birds: Many bird species utilize the area; therefore, the following recommendations are presented:
1) Pet cats should remain indoors, as cats will readily prey upon these species and can have a
significant impact on bird use in the area and on bird populations.
2) Bird feeders are discouraged during spring, summer, and fall months due to the black bear
use in the area. Bird feeders can be used in the winter (from mid-November through mid-March),
as bears are hibernating during this time.
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3) All bird feeders, including hummingbird feeders, should be hung away from any window or
deck, be at least 10 feet from the ground, and be suspended between two trees or posts. Any seed
feeders should have a seed catchment pan to catch discarded seed.
Noxious Weeds
Noxious weeds can pose a threat to the integrity of the natural vegetation communities. A comprehensive
weed survey and plan has been completed for this Property; this section provides background information
regarding noxious weeds, outlines general goals, and provides suggestions for effective management. Please
see the Weed Management Plan for more information.
Weed Survey Results
The PUD area currently has several infestations of Garfield County and State of Colorado listed noxious weeds.
The banks of the Vulcan Ditch were noted as an area with a high concentration of weeds, including Russian
knapweed (Acroptilon repens). The pasture areas have widespread, low to high densities of Scotch thistle
(Onopordum acanthium), low densities of knapweed species, and some isolated areas of hoary cress (Lepidium
draba). Pasture areas dominated by gamble’s oak shrub communities along the banks of the Colorado River
have low to medium densities of houndstongue (Cynoglossum officianale). Cheatgrass (Anisantha [Bromus]
tectorum) is present in low to high densities throughout the project area, in pastures, along the Vulcan Ditch,
near existing structures, and within native pinion-juniper shrublands. Individuals of salt cedar (Tamarix Spp.),
Russian olive (Elaeagnus angustifoilia), common mullein (Verbascum thapsus), and curley dock (Rumex
crispus) occur in pasture areas or along the banks of the Colorado River. Redstem filaree (Erodium cicutarium)
and field bindweed (Convolvulus arvensis) are likely to be present but were not observed during field visits. A
full noxious Weed Management Plan documenting conditions has been produced by SGM (2020) per section
4-203.E.18 of the LUDC.
Table 5 – Noxious Weeds Present on Site
Noxious Weeds
Common Name Scientific Name Colorado Listed
Species
Garfield County
Listed Species
Cheatgrass Anisantha tectorum Yes (List C)
Common Mullein Verbascum thapsus Yes (List C)
Curley Dock Rumex crispus - Yes
Hoary Cress Lepidium draba Yes (List B) Yes
Houndstongue Cynoglossum officianale Yes (List B) Yes
Russian knapweed Acroptilon repens Yes (List B & C) Yes
Russian Olive Elaeagnus angustifoilia Yes (List B) Yes
Salt Cedar Tamarix sp. Yes (List B) Yes
Scotch Thistle Onopordum acanthium Yes (List B) Yes
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Weed Management
Nutrient Farm has developed a noxious weed management plan; please see that plan for additional details.
In summary, the best technique (or techniques) for managing a given weed infestation is dependent on many
factors: access, growth form of the weed species (e.g., annual, biennial, or perennial), size of the weed patch,
and proximity of the weed patch to sensitive areas (water sources, rare plant or animal habitat, etc.), and the
weather and temperature at the time of control. Nutrient Farm PUD will be a certified organic facility, and
therefore use of traditional herbicides would not occur. Techniques for managing weeds could include
mechanical (e.g., pulling, mowing, and cutting), cultural controls (e.g., maintaining native plant communities,
reseeding, livestock grazing), organic-certified compliant products (vinegars), and biological controls (predator
or competitor introductions).
Impact Analysis. As the area already has noxious weeds, new ground disturbing activities including agricultural
activities, trails, and residential and commercial development, will undoubtedly allow noxious weeds to
expand their cover. Mechanical, cultural control and biological controls will need to be aggressive and
persistent, with ongoing efforts being conducted throughout the growing season in order to control existing
and new infestations. Without aggressive and persistent weed management, it is highly likely that weeds
could move beyond the boundaries of the PUD and into adjacent lands and even into native habitats.
Revegetation
Successful weed control programs may require aggressive and persistent revegetation efforts of areas
formerly occupied by noxious weeds. In the case of this project, where agricultural development is proposed,
cultivars are expected to provide ground cover for the majority of the disturbed areas. Since most weeds are
ruderal species that prefer disturbed sites, coverage should be provided as soon as possible following
disturbance; if agricultural species cannot be used due to timing conflicts, cover crops or artificial groundcover
should be used. This will minimize the likelihood that existing weed populations will infest newly disturbed
soil. If an area has been treated with organic certification compliant products (e.g., vinegar), refer to the label
on the product/herbicide to determine how soon after treatment reseeding is recommended (some
products/herbicides have varying residence time in the soils). Additionally, it is preferable to salvage topsoil
to retain viable soil as well as a native seed bank. Please see the Reclamation Plan for more information (SGM
2020c).
The undeveloped areas of the Property will not be significantly disturbed; therefore, it is unlikely that weed
abundance will increase dramatically in these areas.
Radiation Hazards
The farm will utilize biodynamic agricultural practices such as avoiding all synthetic chemical pesticides,
fertilizers, and transgenic contamination. The farm will be a self-contained, self-sustaining ecosystem
following biodynamic practices with the goal of becoming formally biodynamically certified in the near future.
Nutrient Farm is a sustainable holistic community revolving around an organic working farm. Non-organic
chemical use will be prohibited, and electro-magnetic radiation emissions will be minimized on the property
by the Owner/Developer, which could potentially cause contamination to the farm, its residents, or guests.
Nuisance
The proposed uses within the PUD area are not expected to produce any abnormal toxic or noxious
substances, smoke, odors, gas, wastes, steam, or dust. Detailed erosion control and construction plans (e.g.,
Stormwater Management Plan) will guide development of the site during all construction phases, with a goal
of minimizing fugitive dust emissions from the project site. There will likely be an increase in airborne
Nutrient Farm PUD Impact Analysis Report
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particulate matter as a result of equipment operations producing fugitive dust during construction access
improvements, vegetation clearing, and during earthwork phases of construction. This area commonly has
windy springtime months, and dust control will need to be adequately planned and scheduled during the
spring months.
To mitigate these impacts, contractors will employ dust control, and CDPHE stormwater permitting will
require the removal of mud from vehicles before they track mud onto local roads. The proposed land uses are
anticipated to integrate well with neighboring existing land uses. For the above stated reasons, the PUD is
considered to have minimal nuisance impacts on adjacent lands and is generally consistent with those
adjacent uses and their associated impacts.
Noise
As part of Article 4-203.G of the Garfield County Land Use and Development Code (LUDC), an Impact Analysis
is required that evaluates:
“7. Nuisance. Impacts on adjacent land from generation of vapor, dust, smoke, noise, glare or vibration,
or other emanations.”
Additionally, Article 7-1001 of the LUDC has the following requirement:
“F. Noise. Noise shall not exceed State noise standards pursuant to C.R.S., Title 25, Article 12 unless the
use is regulated by the COGCC. In this case, the use shall be subject to COGCC rules in regard to noise
abatement.”
The Colorado Revised Statues (CRS) Title 25, Article 12, Section 103 provides state guidance for noise
standards. The CRS code establishes permissible sound levels by type of property and time of day. For the
purposes of the law, sound is measured as “Levels of sound radiating from a property line at a distance of
twenty-five feet” and any sound “In excess of the dB(A) established for the following time periods and zones
shall constitute prima facie evidence that such sound is a public nuisance”. Defined sound levels are provided
in Table 5.
Table 5 – CRS 25-12-103 Sound Standards
Zone 7:00 a.m. to next
7:00 p.m.
7:00 p.m. to next
7:00 a.m.
Residential 55 dB (A) 50 dB (A)
Commercial 60 dB (A) 55 dB (A)
Light Industrial 70 dB (A) 65 dB (A)
Industrial 80 dB (A) 75 dB (A)
The stringency of the sound requirements depends on the zoning of the site; however, the CRS 25-12-103
does not reference “PUD zoning”, which is how Garfield County has zoned this area and will re-zone it. For
the purpose of this report, we assume the closest CRS 25-12-103 zone standard to be Residential.
Construction activities utilizing heavy equipment can produce intensities of around 88 dB. Most amplified
music (concerts) can range from 91 dB up to 115 dB. A motorcycle can range from 95 dB to 110 dB. Most of
these sounds, at least at their source, exceed the CRS 25-12-103 Residential sound standards; however, this
analysis would need to be conducted at the PUD boundary.
A formal sound study has been developed, based on cursory plans to determine preliminary sound levels (SGM
2020d). In summary, the predictive sound model focused on the proposed music venue and motorized OHV
Nutrient Farm PUD Impact Analysis Report
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track area, using sensitive sound receptor locations in accordance with the sound standards in CRS 25-12-103.
The numerical and graphical sound modeling results for the music venue and for the OHV track indicated that
“worst case scenarios” of sound generation are predicted to be over the CRS sound limits and would create a
”public nuisance” for Residential zone standards for both daytime and nighttime operations. Low music
amplification, sound dampening, and additional sound modelling work will be needed to develop a plan which
would keep the sound levels consistent with CRS 25-12-103 standards.
Nutrient Farm PUD has already indicated that preventative sound barriers, insertion loss and sound mitigation
strategies are being developed to reduce the numbers indicted above. By doing so, it will help prevent these
proposed uses from being a public nuisance to nearby residences
Hours of Operation
The construction phases of the proposed PUD would be limited to daytime hours. Post-construction would
have a range of hours depending on the proposed use within the PUD. The agricultural areas which include
East and West farms would have the most activity during daylight hours on both weekdays and weekends.
The outdoor recreational areas and special events within the Property would operate until midnight. This
would include potential concerts with amplified music. After midnight, all outdoor activities will cease or be
brought inside an enclosed building. These special events will have parking management plans employed to
effectively coordinate all vehicular parking needs. Other recreational uses include camping (RV and tent),
motorized OHV tracks, boat ramps, etc., would involve seasonal hours of operation.
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5. Summary of Impact Mitigation Recommendations
Most of these recommendations have already been considered and incorporated into the current
development proposal. Additional recommendations, and black bear conflict avoidance measures, will be
developed by Nutrient Farm and CPW through the proposed Wildlife Mitigation Plan.
1. Retain high value habitats by avoiding development (physical habitat modifications) and
encroachment (designated and volunteer trails) into intact blocks of native habitats, mostly limited to
the woodlands on the steep slopes on the south of the Property.
2. Locate and cluster development to the extent possible in non-native habitats and maximize setbacks
from high value habitats, including the riparian fringe. This will maximize continued effectiveness of
on-site habitats and buffer development effects on the Property from nearby habitats.
3. Recreational trails considered should be for non-motorized use (aside from OHV track) and should not
extend into the riparian habitats. Seasonal closures to protect winter habitats should be considered.
4. A non-development zone of 50 feet wide should be considered for the riparian edge of the Colorado
River, aside from limited facilities such as a boat ramp and the public access trail. The purpose of this
buffer is to facilitate continued wildlife use of the riparian habitats by species such as bald eagle, blue
heron, river otter, etc. Maintaining and establishing additional screening vegetation between the
riparian area and human developments would enhance buffering. Birds within the riparian area are
most sensitive to human disturbance during the nesting season, which extends from approximately
April 1 through June 15.
5. With the exception of fencing required for safety and to protect agricultural production areas and
orchards, fencing should be limited onsite. Fencing restricts big game movements, potential habitat
use, and can result in wildlife mortality through entanglement and road-kill. Any decorative fencing
should be designed to allow for wildlife movements. Nutrient Farm is working with CPW to develop
areas with “laydown fencing” to allow for wintertime big game movements and use of pastures.
6. Black bears will be an issue; development should avoid planting of fruit trees around homes, feeding
pets out-doors, and birdfeeders during the time when bears are active. Trash cans should be kept
inside, or bear-proof trash storage facilities or at least bear-proof trash cans should be required. Bear
awareness brochures and signage should be posted throughout the PUD Property and most
importantly, in the campground area. Sturdy fences around orchards will be needed to minimize bear
issues.
7. Dogs of residents, visitors, and contractors should not be allowed to run free. The Property is adjacent
to wildlife habitats, and free running dogs will result in larger wildlife impacts and harassment. Cats
should also not be allowed to run free, as cats are the number one predator and mortality factor to
migratory birds. The use of a dog park will help reduce the risk of dogs running free.
8. Landscaping and berm construction will occur to reduce OHV and music venue sound emissions and
to stay in compliance with CRS 25-12-103 standards.
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53
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U.S. Fish and Wildlife Service. 1990. Humpback Chub Recovery Plan. U.S. Fish and Wildlife Service, Denver,
Colorado.
U.S. Fish and Wildlife Service. 1991. Endangered and Threatened Wildlife and Plants: the Razorback Sucker
(Xyrauchan texanus) Determined to be an Endangered Species. Final Rule. Federal Register
56(205):54957-54967.
U.S. Fish and Wildlife Service. 1994. Endangered and Threatened Wildlife and Plants; Determination of
Critical Habitat for the Colorado River Endangered Fishes: Razorback Sucker, Colorado Squawfish,
Humpback Chub, and Bonytail Chub. Federal Register 59(54):13374-13400.
U.S. Fish and Wildlife Service. 1999. Final Programmatic Biological Opinion (Four Colorado River Endangered
Fish Species). US Fish and Wildlife Service, Grand Junction, Colorado.
U.S. Fish and Wildlife Service. 2000a. Flow Recommendations to Benefit Endangered Fishes in the Colorado
and Gunnison Rivers. Recovery Program Project Number 54, Draft Final Report. US Fish and Wildlife
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U.S. Fish and Wildlife Service. 2002b. Razorback Sucker (Xyrauchen texanus) Recovery Goals. Amendment
and Supplement to the Razorback Sucker Recovery Plan. U.S. Fish and Wildlife Service, Denver,
Colorado.
U.S. Fish and Wildlife Service. 2002c. Bonytail (Gila elegans) Recovery Goals: amendment and supplement to
the Bonytail Chub Recovery Plan. U.S. Fish and Wildlife Service, Mountain-Prairie Region (6), Denver,
Colorado.
U.S. Fish and Wildlife Service. 2008. Birds of Conservation Concern 2008. United States Department of
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Valdez, R.A., A.M. Widmer, and K.R. Bestgen. 2011. Research Framework for the Upper Colorado River Basin.
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Burnaby, B.C.
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Nutrient Farm PUD Impact Analysis Report
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Appendix A - CPW Habitat Definitions
The following section defines the ungulate seasonal activity area definitions used by CDOW in their habitat
mapping protocol.
ELK
HIGHWAY CROSSING: Those areas where elk movements traditionally cross roads, presenting potential
conflicts between elk and motorists.
MIGRATION CORRIDORS: A specific Mappable site through which large numbers of animals migrate and loss
of which would change migration routes.
OVERALL RANGE: The area which encompasses all known seasonal activity areas within the observed range
of an elk population.
PRODUCTION AREA: That part of the overall range of elk occupied by the females from May 15 to June 15 for
calving. (Only known areas are Mapped and this does not include all production areas for the DAU).
RESIDENT POPULATION: An area used year-round by a population of elk. Individuals could be found in any
part of the area at any time of the year; the area cannot be subdivided into seasonal ranges. It is most likely
included within the overall range of the larger population.
SEVERE WINTER: That part of the range of a species where 90 percent of the individuals are located when the
annual snowpack is at its maximum and/or temperatures are at a minimum in the two worst winters out of
ten. The winter of 1983-84 is a good example of a severe winter.
SUMMER CONCENTRATION: Those areas where elk concentrate from mid-June through mid-August. High
quality forage, security, and lack of disturbance are characteristics of these areas to meet the high energy
demands of lactation, calf rearing, antler growth, and general preparation for the rigors of fall and winter.
SUMMER RANGE: That part of the range of a species where 90% of the individuals are located between spring
green-up and the first heavy snowfall, or during a site specific period of summer as defined for each DAU.
Summer range is not necessarily exclusive of winter range; in some areas winter range and summer range
may overlap.
WINTER CONCENTRATION: That part of the winter range of a species where densities are at least 200% greater
than the surrounding winter range density during the same period used to define winter range in the average
five winters out of ten.
WINTER RANGE: That part of the overall range of a species where 90 percent of the individuals are located
during the average five winters out of ten from the first heavy snowfall to spring green-up, or during a site
specific period of winter as defined for each DAU.
MULE DEER
CONCENTRATION AREA: That part of the overall range where higher quality habitat supports significantly
higher densities than surrounding areas. These areas are typically occupied year round and are not necessarily
associated with a specific season. Includes rough break country, riparian areas, small drainages, and large
areas of irrigated cropland.
HIGHWAY CROSSING: Those areas where mule deer movements traditionally cross roads, presenting potential
conflicts between mule deer and motorists.
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MIGRATION CORRIDORS: A specific Mappable site through which large numbers of animals migrate and loss
of which would change migration routes.
OVERALL RANGE: The area which encompasses all known seasonal activity areas within the observed range
of a mule deer population.
RESIDENT POPULATION: An area that provides year-round range for a population of mule deer. The resident
mule deer use all of the area all year; it cannot be subdivided into seasonal ranges although it may be included
within the overall range of the larger population.
SEVERE WINTER: That part of the overall range where 90% of the individuals are located when the annual
snowpack is at its maximum and/or temperatures are at a minimum in the two worst winters out of ten.
SUMMER RANGE: That part of the overall range where 90% of the individuals are located between spring
green-up and the first heavy snowfall. Summer range is not necessarily exclusive of winter range; in some
areas winter range and summer range may overlap.
WINTER CONCENTRATION: That part of the winter range where densities are at least 200% greater than the
surrounding winter range density during the same period used to define winter range in the average five
winters out of ten.
WINTER RANGE: That part of the overall range where 90 percent of the individuals are located during the
average five winters out of ten from the first heavy snowfall to spring green-up, or during a site specific period
of winter as defined for each DAU.
BLACK BEAR
FALL CONCENTRATION: That portion of the overall range occupied from August 15 until September 30 for the
purpose of ingesting large quantities of mast and berries to establish fat reserves for the winter hibernation
period.
HUMAN CONFLICT: That portion of the overall range where two or more confirmed black bear complaints per
season were received which resulted in CDOW investigation, damage to persons or property (cabins, tents,
vehicles, etc), and/or the removal of the problem bear(s). This does not include damage caused by bears to
livestock.
OVERALL RANGE: The area which encompasses all known seasonal activity areas within the observed range
of a population of black bear.
SUMMER CONCENTRATION: That portion of the overall range of the species where activity is greater than the
surrounding overall range during that period from June 15 to August 15.
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Appendix B - CPW Species of Concern
Species1 Occurrence Habitat Association Potential Habitat in Project Area?
Potential Impact/Issue?
MAMMALS
American pika (SGCN) Ochotona princeps Throughout state in suitable habitats Alpine, rocky habitats No No
Black-footed ferret (FE, SE) Mustela nigripes Rio Blanco & Moffat Counties
Reintroduced to Rio Blanco County, in white-tailed prairie
dog colony
No No
Black-tailed prairie dog (SGCN) Cynomys ludovicianus Eastern plains Shortgrass prairies No N
Botta’s pocket gopher (SGCN) Thomomy bottae rubidus Northern Front Range Foothills No No
Gray wolf (SE) Canis lupus Northern counties, no packs in State at this time Shrublands, forests and areas away from human habitation No No
Grizzly bear (SE) Ursus arctos Rare visitor from Wyoming Forests, alpine and shrublands No No
Fringed myotis (SGCN)
Myotis thysanodes
Throughout Colorado in
suitable habitats
Roosts in montane and foothills conifers and oakbrush; may forage to as low as greasewood
and saltbush shrublands. Roosts and hibernates in caves, mines, and buildings.
No No
Gunnison prairie dog (SGCN) Cynomys gunnisoni Parks in central Colorado Shortgrass steppe, open shrublands in parks No No
Little brown myotis (SGCN)
Myotis lucifigus
Throughout Colorado in
suitable habitats Widespread habitat types. No No
Lynx (FT, SE) Lynx canadensis
High mountain areas with large expanses of conifer forests in Colorado
Spruce/fir and lodgepole pine forests, sometimes aspen, shrublands No No
New Mexico meadow jumping mouse (FE, SGCN)
Zapus hudsonius leuteus
Southwestern counties in
Colorado
Wet, lush, grassy meadows and
some hydric shrublands No No
Olive-backed pocket mouse (SGCN) Perognathus fasciatus
Southern grasslands in Colorado
Arid and semiarid grasslands with sparse vegetation, sandy to clayey soils No No
Preble’s meadow jumping mouse (FT, ST)
Zapus hudsonius preblei
Front range of Colorado
north into Wyoming
Foothills riparian areas and
along front range streams No No
Spotted bat (SCGN) Euderma maculatum Throughout Colorado in suitable habitats
Areas near cliffs, including piñon-juniper woodlands and streams or water holes within ponderosa pine or mixed
coniferous forest. Usually
captured around a water source,
including desert pools or cattle tanks.
No No
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Species1 Occurrence Habitat Association Potential Habitat in Project Area?
Potential Impact/Issue?
Townsend's big-eared bat
(SGCN) Plecotus townsendii townsendii
Documented in Colorado in several cave locations
Semidesert shrublands, P-J, open
montane forests; caves and abandoned mine roosts. No No
White-tailed prairie dog (SGCN) Cynomys leucurus Western Colorado Arid grasslands and sparse arid shrublands in western CO No No
River otter (ST)
Lontra canadensis
Throughout state in
suitable habitats
Larger rivers with high fish
population levels Yes No
Wolverine (FT, SE) Gulo gulo
Historical documentation several locations in Colorado-likely extinct
Boreal forests and tundra- large ungulate populations important No No
BIRDS
Brown-capped rosy-finch (SGCN) Leucosticte australis
High mountains throughout state Alpine and high-elevation coniferous forests No No
Bald eagle (SGCN) Haliaeetus leucocephalus Throughout state near suitable habitats Larger rivers and streams, near prairie dog towns Yes Yes
Burrowing owl (ST) Athene cunicularia
Mostly found in eastern
grasslands, some occurrence on west slope Arid grassland and shrublands No No
Columbian sharp-tailed grouse (SGCN) Tympanuchus phasianellus columbianus
Mixed grassland/shrublands in northwest Colorado Mixed shrubland/grasslands No No
Ferruginous hawk (SGCN) Buteo regalis Eastern plains, larger parks Grasslands and extensive shrublands No No
Golden eagle (SGCN) Aquila chrysaetos Throughout Colorado in suitable habitats
Open habitats in alpine, shrublands, badlands, and grasslands No No
Greater sage-grouse (SGCN)
Centrocercus urophasianus Northwestern Colorado Large sagebrush shrublands No No
Sandhill crane (SGCN) Grus canadensis tabida
Migrant through plains, west slope and mountain valleys, some nesting in northern parks
Large wetlands No No
Gunnison sage-grouse (SGCN)
Centrocercus minimus
Gunnison Basin and
western counties Sagebrush shrublands No No
Least tern (FE, SE) Sterna antillarum Eastern plains Larger rivers, larger reservoir beaches No No
Lesser prairie chicken (FT, ST) Tympanuchus pallidicinctus Extreme southeastern Colorado Great plains grasslands and shrublands No No
Long-billed curlew (SGCN)
Numenius americanus
Eastern plains and larger
parks
Grasslands and sparse
shrublands No No
Mexican spotted-owl (FT, ST) Strix occidentalis lucida
Southwest Colorado, and along Wet Mountains, Rampart Range
Deep shaded canyons with closed canopy conifers and cliffs No No
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Species1 Occurrence Habitat Association Potential Habitat in Project Area?
Potential Impact/Issue?
Mountain plover (SGCN) Charadrius montanus Eastern plains of Colorado
Summers on eastern plains in
native short-grass steppe, winters in S. California & Mexico No No
Peregrine falcon (SGCN) Falco peregrinus anatum Throughout state, but near cliffs and tall buildings
Needs tall cliffs or buildings for nesting, usually occurs near water No No
Plains sharp-tailed grouse (SE)
Tympanuchus phasianellus
Extreme northeastern
Colorado Grasslands, river canyons No No
Piping plover (FT, ST) Charadrius melodus circumcinctus Eastern plains Large rivers, sandy shores around reservoirs in plains No No
Southern white-tailed ptarmigan (FP, SCGN)
Lagopus leucura altipetens
Southern Rocky Mountains Alpine habitats No No
Southwestern willow flycatcher (FE, SE) Empidonax traillii extimus
Extreme southwest Colorado, and Rio Grande River
Brushy riparian habitats at lower elevations No No
Western snowy plover (SGCN) Caradrius alexandrius Eastern plains Sandy bars in rivers and around reservoirs, playas No No
Western yellow-billed cuckoo (SGCN) Coccyzus americanus
North Fork of Gunnison, Colorado, Dolores, Yampa and Rio Grande rivers
Large cottonwood stands along larger rivers No No
Whooping crane (FE, SE) Grus americana
Migrates through eastern plains, possibly San Luis Valley Migrant No No
AMPHIBIANS
Boreal toad (SE) Anaxyrus boreas boreas
Small disjunct populations across higher elevations in the State
Subalpine forest habitats with marshes, wet meadows, streams, beaver ponds, and lakes. No No
Couch’s Spadefoot (SGCN)
Scaphiopus couchii Southeastern Colorado Sandy, dry soils with creosote
bush and mesquite No No
Great Plains narrowmouth toad (SGCN) Castrophryne olivacea Eastern Colorado Grasslands, edges of marshes, rocky hills No No
Northern cricket frog (SGCN) Acris crepitans Eastern Colorado Edges of slow-moving bodies of water No No
Northern leopard frog (SGCN) Lithobates pipiens
Common throughout mid-and lower-elevations of Colorado
Wet meadows, marshes, ponds, beaver ponds, streams. No No
Plains leopard frog (SGCN) Rana blairi Eastern Colorado Sunny, grassy wetlands No No
Wood frog (SGCN)
Rana sylvatica
Larimer and Grand
Counties Forested wetlands No No
FISHES
Arkansas darter (ST) Etheostoma cragini Arkansas River drainage in eastern Colorado
Clear, shallow, spring-fed streams with moderate current and lots of rooted aquatic
vegetation
No No
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Species1 Occurrence Habitat Association Potential Habitat in Project Area?
Potential Impact/Issue?
Bonytail chub (FE, SE)
Gila elegans
No known populations
remain in Colorado
Large, swift-flowing waters of
the Colorado River system No Yes
Brassy minnow (ST) Hybognathus kankinsoni
Native to Republican and South Platte basins, possibly in Colorado River drainage
Moderately clear tributary streams with sand or gravel bottoms, also in small ponds No No
Colorado pikeminnow (FE,
ST) Ptychocheilus lucius
Colorado, Dolores,
Green, Gunnison, San Juan, White and Yampa
Large, swift-flowing rivers that
are seasonally turbid with warm backwaters No Yes
Colorado River cutthroat trout (SGCN) Oncorhynchus clarkii pleuriticus
Widespread localized reaches Headwater streams and lakes No No
Colorado Roundtail chub (SGCN) Gila robusta
Colorado River through Glenwood Canyon, downstream on White River, Milk and Divide Creeks
Larger rivers of Colorado River basin No No
Common shiner (ST) Luxilus cornutus South Platte basin Lakes, rivers and streams, most common in the pools of streams
and small rivers
No No
Flannelmouth sucker (SGCN) Catostomus latipinnis Western Colorado rivers Utilizes mid-sized rivers and streams No No
Flathead chub (SGCN) Platygobio gracilis Arkansas River basin Main branches of turbid streams and rivers, fast currents with sand or gravel substrates No No
Greenback cutthroat trout (FT, ST) Oncorhynchus clarkia stomias
Front Range mountain streams, recently on west slope Montane clear, cold streams No No
Humpback chub (FE, ST) Gila cypha Green, Yampa and Colorado Rivers
Pools and eddies in areas of fast-flowing, deep, turbid water, often associated with
cliffs and boulders
No Yes
Iowa darter (SGCN) Etheostoma exile Plains rivers Springs No No
Lake chub (SE) Couesius plumbeus North Platte Gravel bottomed pools and streams No No
Mountain sucker (SGCN) Catostomus platyrhynchus
Numerous small to medium streams below 8600’ elevation.
Throughout west on both sides of Continental Divide-prefer clear cold creeks and small to medium rivers with rubble, gravel, or sand substrate
No No
Northern redbelly dace (SE) Phoxinus eos South Platte basin Small slow-flowing streams and connected lakes with vegetation No No
Orangespotted sunfish (SGCN) Lepomis humilis Widespread across middle and eastern U.S.
Shallow silt-laden waters, floodplain pools, backwater pools of larger streams on plains No No
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Species1 Occurrence Habitat Association Potential Habitat in Project Area?
Potential Impact/Issue?
Plains orangethroat darter
(SGCN) Etheostoma spectabile
Arikaree and Republican River drainages
Small, clear, spring-fed streams
with sand, gravel or rocky bottoms and no silt No No
Plains minnow (SE) Hybognathus placitus Arkansas & South Platte basins Main channels of rivers, also in pools below diversion projects No No
Razorback sucker (FE, SE_ Xyrauchen texanus Lower Yampa and lower Colorado Rivers
Deep, clear to turbid waters of large rivers and reservoirs,
with silt, mud, or gravel substrate. Quiet, soft-bottom river backwaters
No Yes
Rio Grande Chub (SGCN) Gila pandora Rio Grande basin Pools and streams with gravel substrate and overhanging banks and brush No No
Rio Grande cutthroat trout (SGCN) Oncorhynchus clarkia virginalis Rio Grande basin Clear, cold, swift moving creeks and streams in montane environs No No
Rio Grande sucker (SE) Catostomas plebeius Rio Grande basin Stream obligate using slow moving reaches No No
Southern redbelly dace (SE) Phoxinus erythrogaster Arkansas River basin
small, low-order streams where
the habitat includes permanent springs, seeps, and mats of vegetation
No No
Stonecat (SGCN) Noturus flavus South Platte and Republican basins
Fast riffles and runs in streams with sand or gravel bottoms with some rocks- found under rocks and debris
No No
Suckermouth minnow SE) Phenacobuis mirabilis South Platte and Arkansas River drainages Shallow, clear riffles with sand and gravel substrates No No
REPTILES
Triploid Checkered whiptail (SGCN)
Cnemidophorus neotesselatus
Arkansas drainage in Eastern Colorado
Hillsides, arroyos and canyons associated w/ Arkansas River
valley
No No
Massasagua (SGCN) Sistrurus catenatus Southeast Colorado below 5,500’ Dry plains grasslands and sandhills No No
MOLLUSKS
Cylindrical papershell (SGCN)
Anodontoides ferussacianus Boulder County Headwater creeks and streams
with silty/muddy substrates No No
Rocky Mountain Capshell (SGCN) Acroloxus coloradensis
Rocky Mountains into Canada 8,500 to 10,000’ mountain lakes No No
Source: CPW 2015 FE = Federally Endangered; FT = Federally Threatened; SE = State Endangered; ST = State Threatened; SGCN = Species of
Greatest Conservation Need