HomeMy WebLinkAboutGATEWAY APARTMENTS - PDP230001 - SUBMITTAL DOCUMENTS - ROUND 1 - ECS REPORT
Gateway at Prospect
Ecological Characterization Study
June, 2020
Revised January, 2023
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Table of Contents
1.0 Introduction ................................................................................................................................ 1
2.0 Site Description ........................................................................................................................... 1
3.0 Methods ...................................................................................................................................... 2
3.1 Desktop Review ..................................................................................................................... 2
3.2 Site Assessment ..................................................................................................................... 3
4.0 Ecological characterization ........................................................................................................... 6
4.1 Vegetation ............................................................................................................................. 6
4.1.1 Noxious Weeds ..................................................................................................... 6
4.2 Wetlands ............................................................................................................................... 6
4.2.1 Desktop Analysis ................................................................................................... 6
4.2.2 Field Sampling ...................................................................................................... 7
4.3 Top of Bank Delineation ......................................................................................................... 8
4.4 Wildlife .................................................................................................................................. 8
4.4.1 Big Game .............................................................................................................. 8
4.4.2 Predators .............................................................................................................. 8
4.4.3 Other Mammals..................................................................................................... 9
4.4.4 Raptors ................................................................................................................ 9
4.4.5 Upland Game Birds .............................................................................................. 10
4.4.6 Waterfowl and Shorebirds .................................................................................... 10
4.4.7 Migratory Songbirds ............................................................................................ 10
4.4.8 Amphibians, Reptiles, and Aquatic Species ............................................................ 10
4.5 Prominent Views .................................................................................................................. 11
4.6 Sensitive and Specially Valued Species .................................................................................. 11
4.7 Wildlife Migration Corridors ................................................................................................... 13
4.8 General Ecological Functions ................................................................................................. 13
4.9 Timing of Development in Relation to Ecological Character ..................................................... 13
5.0 Mitigation measures and Recommendations ................................................................................ 14
6.0 Literature Cited and Data Sources .............................................................................................. 16
Appendix A: Soil Map ............................................................................................... Following Page 16
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In-text Maps and Tables
Map 1. Natural Habitats and Features .................................................................................................. 4
Map 2. Natural Habitats and Features Buffer Zone ................................................................................ 5
Table 1. Soils Occurring on the Site ...................................................................................................... 7
Table 2. Special Status Species With Potential to Occur on Site ............................................................ 12
Table 3. Potentially Applicable Buffers ................................................................................................ 15
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Gateway at Prospect
Ecological Characterization Study
1.0 INTRODUCTION
Gateway at Prospect proposes a phased multi-use development in the northwest corner of the East
Prospect Road and Interstate 25 intersection, consisting of multiple residential, commercial, and open
space parcels. The Site is within 500 feet of known natural habitats of high value to the City of Fort
Collins (City) – Boxelder Creek, prairie dog colonies >1 acre, and irrigation ditches (Lake Canal, Dry
Creek, and Cooper Slough), and associated wetlands. Thus, an Ecological Characterization Study is
required, under Article 3, Section 3.4.1 of the City’s Land Use Code (LUC 3.4.1). LUC 3.4.1 stipulates
buffers of varying sizes be applied the various natural resources present on Site.
This Environmental Characterization Study (ECS; dated June 2020) provides a summary of the findings of
field work, including raptor nest surveys, wildlife observations, prairie dog survey, top of bank and
wetland delineations, and characterization of vegetative communities conducted on March 4, 2020 and
May 25, 2020.
Section 2.0 provides a Site description, Section 3.0 presents the methodologies used, Section 4.0 contains
a summary of findings, and Section 5.0 provides potential mitigation measures and recommendations.
Appendix A contains the soil map of the Site.
2.0 SITE DESCRIPTION
The Site is located in eastern Fort Collins in the northwest corner of the Prospect Road and I-25
intersection. The 178.5-acre Site is entirely within Section 16, Township 7 North, Range 68 West, of the
Sixth Principal Meridian. Near the center of the Site the coordinates are 40°34’15.02”N and
105°0’24.97”W, and remains fairly level at an approximate elevation of 4,930 feet with minimal slope.
The Site is bordered by I-25 to the east, Prospect Road to the south, the Cooper Slough and a residential
neighborhood to the west, and the Lake Canal to the north. The Frontage Road bisects the southeastern
portion of the Site. The majority of the Site south of Dry Creek and east of the Frontage Road is currently
an irrigated agricultural field while the area between Lake Canal and Dry Creek is not developed in any
way. The neighborhood west of the Site purchased a 100-foot buffer from their property line to preserve
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as a neighborhood open space (Cooperslough Open Space – 970.482.6079) that encompasses the
majority of the Site’s western border.
Boxelder Creek is a perennial first-order stream flowing from north to south and eventually draining into
the Cache la Poudre River, while Lake Canal and Dry Creek are irrigation ditches that may or may not
convey perennial flow. Cooper Slough conveys water underground and does not have an ordinary high
water mark and/or top of bank, but does have wetlands associated with it. There is a stormwater
easement on the south end of the Site that contains non-jurisdictional wetlands.
Black-tailed prairie dogs (prairie dogs; Cynomys ludovicianus) occupy much of the area between Lake
Canal and Dry Creek, as well as two patches south of Dry Creek along Boxelder Creek.
3.0 METHODS
3.1 Desktop Review
A data review was conducted to gather information and assist in the evaluation of potential natural
biological resources within the property. The data review entailed an evaluation of online resources and
publications to determine the presence or potential occurrence of important natural and biological
resources. This data review included:
• U.S. Fish and Wildlife Service (USFWS) Federally Listed and Proposed Endangered, Threatened,
and Candidate Species and Critical Habitat as identified by the USFWS Information, Planning, and
Conservation System (IPaC) Official Species List and Critical Habitat Mapper;
• Migratory Bird Treaty Act (MBTA) and Bald and Golden Eagle Protection Act (BGEPA) protected
species as identified on the IPAC Trust Resources Report;
• The Colorado Natural Heritage Program database statewide species and natural community
tracking list for Larimer County;
• Colorado Parks and Wildlife (CPW) Threatened and Endangered Species List;
• City’s Natural Areas Species of Concern list (Restoration Plan 2016-25, 2016);
• The City’s Land Use Code (Article 3, Section 3.4.1);
• The City’s Natural Habitat and Features Inventory Map (2000);
• The Colorado Wetland Inventory (CWI);
• USFWS National Wetlands Inventory (NWI); and
• US Natural Resources Conservation Service (NRCS) Web Soil Survey.
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3.2 Site Assessment
Field surveys for the ECS focused on top of bank delineation, raptor nest survey, prairie dog colony
delineation, wetland delineation, vegetation characterization, noxious weed observations, and assessment
of wildlife habitat and utilization.
Top of bank for this study was identified following identification of the bankfull dimensions. The bankfull
stage is the dominant channel-forming flow over time and has a recurrence interval of approximately 1.5
years. Bankfull flows may occur every other year or even several times within a year (CDPHE 2012).
Following identification of bankfull dimensions, the top of bank was determined by locating the first major
break in the slope of the stream banks above the stream’s bankfull level. Pin flags were placed at the top
of bank and recorded with a handheld GPS device.
Surveys for the ECS were conducted by Scott Benton, Allison Robinson, and Tom McIntyre. Scott Benton,
has 15 years of experience as an environmental consultant, performing numerous wetland delineations,
wildlife (bird, reptile, mammal, and fish) surveys, and vegetative inventories. Mr. Benton also completed
a Masters of Science in natural resources from University of Wisconsin – Stevens Point in 2015. Ms.
Allison Robinson has 3 years of experience as an environmental consultant, performing top of bank and
wetland delineations, wildlife surveys, vegetative inventories, and is familiar with the regulatory
requirements for development projects. Mr. Tom McIntyre has 8 years of experience as a wildlife
biologist, performing a variety of bird, mammal, and special status species surveys.
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4.0 ECOLOGICAL CHARACTERIZATION
4.1 Vegetation
Field surveys were conducted during the growing season (April to October) on May 25, 2020 to
appropriately describe the habitat features and vegetative communities on Site.
4.1.1 Noxious Weeds
A total of seven noxious weeds were observed during field surveys – leafy spurge (Euphorbia esula, A-
List), Canada thistle (Cirsium arvense, B-List), broadleaved pepperweed (Lepidium latifolium, B-List), field
bindweed (Convolvulus arvensis, C-List), nodding plumeless thistle (Carduus nutans, B-List), cheatgrass
(Bromus tectorum, C-List), and common mullein (Verbascum thapsus, C-List).
4.2 Wetlands
4.2.1 Desktop Analysis
CWI and NWI depict a total of 8.28 acres of PEM1A and 3.17 acres of PSSC wetlands intertwined along
Boxelder Creek on and immediately adjacent to the Site. A PEM1A wetland is a freshwater emergent
wetland characterized by persistent, herbaceous hydrophytic vegetation and experiences temporary
flooding by surface water during the growing season. A PSSC wetland is a freshwater forested/shrub
wetland characterized by dominant woody vegetation and surface water present early in the growing
season. NWI is based on historical aerial imagery and is primarily used for preliminary desktop analyses
of an area and is superseded by ground truthing. Top of bank delineation efforts conducted in March and
May 2020 revealed additional wetlands along Cooper Slough and the stormwater easement along the
southern border of the site which were not depicted by either CWI or NWI. The wetland associated with
Cooper Slough was delineated in May 2020. Historical imagery of the site supports that the wetlands
found within the stormwater easement are a result of stormwater engineering rather than naturally
occurring wetlands, and are thus considered non-jurisdictional by the USACE.
Soil types occurring on the site are summarized in Table 2 and depicted on the soil map in Appendix A.
Soils according to WSS are generally gently sloping, well-drained loams and clay loams, and not hydric.
The exception is the Fluvaquent type, a hydric soil characterized as a poorly drained alluvium found
between Dry Creek and Lake Canal in the northwest corner of the Site.
Historical imagery dating to 1999 does not reveal any major changes in vegetation, topography, or
stream/ditch channels that would indicate previously existing wetlands or different hydrological regime.
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4.2.2 Field Sampling
Wetlands were delineated in May 2020 (i.e., during the growing season) to ensure wetland plants could
be properly identified in accordance with Army Corps of Engineer wetland delineation methodologies.
Wetlands along Boxelder Creek, Lake Canal, Cooper Slough and the stormwater easement are displayed
in Map 1 and 2. Wetlands throughout the site consist of wetland species such as cattail (Typha
angustifolia), Timothy-grass (Phleum pratense), reed canarygrass (Phalaris arundinacea), common spike-
rush (Eleocharis palustris), and showy milkweed (Asclepias speciosa). Tree cover is sporadic along all
wetlands, consisting of species such as plains cottonwood (Populus deltoides), peachleaf willow (Salix
amygdaloides), and coyote willow (Salix exigua). Wetlands on Site provide cover, forage, and nesting
habitat for a variety of species. Additionally, these wetlands function as a flood control and groundwater
recharge system that benefits the industrial, rural, and residential uses within and nearby the Site.
To the east of SW Frontage Road, there is also a low-lying area where surplus flood irrigation collects
which appears to be dominated by tall fescue (a facultative upland species), Therefore, this mesic area
would not pass any of the hydric vegetation tests required for wetland delineation from the Army Corps
of Engineers.
Table 1 Gateway at Prospect - Soils Occurring on the Site 1
Soil Map Unit Number
and Name Description Hydric Acres %
22 - Carusco clay loam,
0-1% slopes
Somewhat poorly drained clay loam; depth to water table about
24-48 inches.No 22.1 12.4
24 - Connerton-Barnum
Complex, 0-3% slopes
Well-drained loam and sandy loam; depth to water table more
than 80 inches.No 5.5 3.1
33 - Fluvaquents, nearly
level
Poorly drained sandy/clayey alluvium; depth to water table about
12-42 inches.Yes 7.5 4.2
35 - Fort Collins loam, 0-3%
slopes
Well-drained loam and clay loam; depth to water table more than
80 inches.No 0.4 0.2
54 - Kim loam, 3-5% slopes Well-drained loam and clay loam; depth to water table more than
80 inches.No 3.9 2.2
73 - Nunn clay loam, 0-1%
slopes Well-drained clay loam; depth to water table more than 80 inches.No 1.4 0.8
74 - Nunn clay loam, 1-3%
slopes Well-drained clay loam; depth to water table more than 80 inches.No 0.6 0.3
76 - Nunn clay loam, wet,
1-3% slopes
Somewhat poorly drained clay loam and clay; depth to water table
more than 80 inches.No 88.0 49.3
98 - Santanta Variant clay
loam, 0-3% slopes
Somewhat poorly drained clay loam; depth to water table more
than 80 inches.No 49.1 27.5
Total 178.5 100.0
1Web Soil Survey (WSS), Natural Resources Conservation Service
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4.3 Top of Bank Delineation
Top of bank of Boxelder Creek, Dry Creek, and Lake Canal is displayed in Map 1. Boxelder Creek
displayed an incised channel along much of its length, where the bankfull stage is at a lower elevation
than the top of either stream bank, but not in the northeastern stretch from Northern Colorado
Motorsports to I-25. Flood events allow Boxelder Creek to access to the adjacent floodplain in flow events
with more than 1.5 year intervals in both the northeastern stretch and the stormwater easement at the
extreme southern reach on Site, but not adjacent to the agricultural fields.
The top of bank of Dry Creek and Lake Canal, both maintained irrigation ditches, is clear and obvious.
Both Dry Creek and Lake Canal pass underground at their eastern extremes on Site but also have
overflow structures that occasionally convey water to Boxelder Creek at times of high flow. Lake Canal
intersects with Boxelder Creek in the extreme northeast corner of the Site at I-25; Dry Creek intersects
with Boxelder Creek immediately west of Northern Colorado Motorsports (Map 1 and 2).
4.4 Wildlife
Wildlife observations were conducted during both March and May 2020 field surveys. These included
raptor nest observations, incidental wildlife observations, and prairie dog surveys. The greater habitat
diversity found along Boxelder Creek, the wetlands, and the perennial water present in Dry Creek and
Lake Canal supports a greater number of wildlife species, however habitat quality of Boxelder Creek is
lowered by the presence of noxious weeds, urban location, and proximity to the I-25 corridor.
4.4.1 Big Game
Three big game animals could potentially frequent the property and adjacent area year round –
pronghorn antelope (Antilocapra americana), white tailed deer (Odocoileus virginianus), and mule deer
(Odocoileus hemionus). The value of the Site and adjacent areas to big game is low due to the urban
location and proximity to the I-25 corridor, and will continue to decline as urban development increases.
No crucial big game habitats are recognized on Site. Boxelder Creek, Dry Creek, and Lake Canal could
provide some marginal cover/shelter for big game, and the agricultural fields could provide some cover
and/or feed when crops are mature.
4.4.2 Predators
Mid-sized predators including red fox (Vulpes vulpes) and coyote (Canis latrans) would be expected to
occasionally frequent the Site and adjacent properties. Mink (Neovison vison), long-tailed weasel (Mustela
frenata), and badger (Taxidea taxus) would be less common visitors. Despite supporting prey species on
the Site (prairie dogs and voles, Section 4.6 and 4.4.3, respectively), the value to predators is still
relatively low due to the urban location and proximity to the I-25 corridor, and will continue to decline as
urban development increases.
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4.4.3 Other Mammals
A total of 11.6 acres of active black-tailed prairie dog colonies were delineated (Map 1 and 2). The results
of prairie dog surveys are detailed in Section 4.6. Other mammal observations in March and May 2020
include indirect sign of raccoons (Procyon lotor) in the form of scat and tracks along the water bodies, as
well as direct observation of field voles (Microtus sp.).
Prairie dog burrows provide valuable habitat and prey base for a variety invertebrates, raptors, reptiles,
and other mammals. A variety of small and medium sized mammal species are known to occur locally,
although not observed during field surveys, including various small rodents including mice, rats, ground
squirrels, and chipmunks. Eastern cottontail (Sylvilagus floridanus) was observed during May 2020 field
surveys. Such prey species are cyclically common, widespread throughout the region, and are important
food sources for raptors and other predators. Striped skunks (Mephitis mephitis) thrive in urban areas
and semi-urban areas. Muskrat (Ondatra zibethicus) and beaver (Castor canadensis) could potentially
utilize Boxelder Creek, but the likelihood is low. Various bats could also frequent adjacent Boxelder Creek,
Dry Creek, and Lake Canal. Two common bat species that are consistently found in Fort Collins and roost
primarily in trees are hoary bats (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans).
4.4.4 Raptors
A red-tailed hawk (Buteo jamaicensis) and American kestrel (Falco sparverius) were observed on Site
during field efforts. No nests were observed on Site or in trees adjacent to site (nest survey was
completed prior to leaf-out). The presence of prairie dogs provides potential burrowing owl (Athene
cunicularia) habitat, however none were observed during incidental wildlife surveying or during prairie
dog surveys conducted in May 2020.
Raptor species known to occur in the region include turkey vulture (Cathartes aura), bald eagle
(Haleaeetus leucocephalus), golden eagle (Aquila chrysateos), ferruginous hawk (Buteo regalis),
Swainson’s hawk (Buteo swainsoni), northern harrier (Circus cyaneus), rough-legged hawk (Buteo
lagopus), and prairie falcon (Falco mexicanus). Some of these species are year round residents, some are
seasonal visitors, and some are migrants. Additional owl species which could potentially frequent the
property include the barn owl (Tyto alba), great horned owl (Bubo virginianus), long-eared owl (Asio
otus), and short-eared owl (Asio flammeus). There is no suitable habitat for the northern goshawk
(Accipiter gentilis), screech owl (Megascops spp.), or peregrine falcon (Falco peregrinus). There is no
suitable bald eagle winter roost habitat.
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4.4.5 Upland Game Birds
Four species of upland game birds have the potential to occur on Site – mourning doves (Zenaida
macroura), wild turkey (Meleagris gallopavo), gray (or Hungarian) partridge (Perdix perdix), and ring-
necked pheasant (Phasianellus colchicus).
4.4.6 Waterfowl and Shorebirds
Mallards (Anas platyrhynchos) and killdeer (Charadrius vociferus) were observed utilizing Dry Creek,
Boxelder Creek, and upland areas in March 2020. A great blue heron (Ardea herodias) was observed in
May 2020.
The Site provides some value to resident or water-obligate migratory stopovers, waterfowl, and
shorebirds in the form of cover and food sources provided by perennial/semi-perennial waterbodies
(Boxelder Creek, Dry Creek, Lake Canal, wetlands). Such species include American wigeon (Anas
Americana), wood duck (Aix sponsa), gulls, belted kingfisher (Megaceryle alcyon), swifts, and swallows.
The Site and adjacent areas is not a concentration area for migratory or nesting waterfowl or shorebirds,
however Canada geese (Branta canadensis) could occasionally glean agricultural leftovers from the
cultivated fields in large numbers.
4.4.7 Migratory Songbirds
Red-winged blackbird (Agelaius phoeniceus), barn swallow (Hirundo rustica), Brewer’s blackbird
(Euphagus cyanocephalus), cliff swallow (Petrochelidon pyrrhonota), Bullock’s oriole (Icterus bullockii),
western kingbird (Tyrannus verticalis), house finch (Haemorhous mexicanus), and American goldfinch
(Spinus tristis) were observed on Site in May 2020.
Nesting activity, whether on the ground or in trees/shrubs, is likely to be limited to portions of the
Boxelder Creek corridor, trees on the Site perimeter, and the less disturbed areas between Dry Creek and
Lake Canal. Foraging grounds and cover for a number of species, including woodpeckers, sparrows, and
black-capped chickadee (Poecile atricapillus), are possible in the same areas.
4.4.8 Amphibians, Reptiles, and Aquatic Species
A bullsnake (Pituophis catenifer sayi) was observed on Site during May 2020 field surveys. No
amphibians, aquatic species, or other reptiles were observed in March or May 2020.
Boxelder Creek, Dry Creek, and Lake Canal provides some marginal perennial aquatic habitat, suitable for
species like crayfish. The lack of deep water limits the presence and diversity of fish and
macroinvertebrates. The wetlands and stormwater easement on-Site and adjacent to the Site provide
potential habitat for locally common riparian amphibian and reptiles, including the western chorus frog
(Pseudacris triseriata), bullfrogs (Lithobates catesbeianus), plains spadefood (Spea bombifrons),
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Woodhouse’s toad (Bufo woodhousei), and tiger salamander (Ambystoma tigrinum). Less common
riparian species include the common garter snake (Thamnophis sirtalis), wandering (terrestrial)
gartersnake (Thamnophis elegans vagrans), western painted turtle (Chrysemsys picta bellii), eastern
snapping turtle (Chelydra serpentina serpentina), and ornate box turtle (Terrapene ornata ornata). The
presence of small mammals provides suitable prey base for other common upland reptile species,
including the prairie rattlesnake (Crotalus viridis), eastern yellow-bellied racer (Coluber constrictor
flaviventris), and plains hog-nosed snake (Heterodon nasicus).
4.5 Prominent Views
Views across the Site to the east are immediately met with the I-25 corridor, to the north views are met
with industrial use, and to the south views across the Site views are dominated by Prospect Road. The
prominent view across the Site to the west is the foothills of the Rocky Mountains.
4.6 Sensitive and Specially Valued Species
A current list of federally threatened, endangered, proposed, and candidate species, and designated
critical habitat that may occur within the boundary of the Site and/or may be affected by the proposed
development was obtained from the USFWS IPaC website (2020). Table 2 lists the species and their
designated and proposed critical habitats. No USFWS designated critical habitat occurs in or near the Site.
Suitable habitat for CPW, Larimer County, and City species of concern/interest is limited due to the
habitat alteration resulting from current land uses, including the Preble’s meadow jumping mouse (Zapus
hudsonius preblei).
The black-tailed prairie dog is listed as a Species of Concern by CPW and as a Species of Interest by the
City. Prairie dogs are present on Site as discussed prior, which also allows for the potential use of
burrows by the burrowing owl (Athene cunicularia), considered Threatened by CPW and a Species of
Interest by the City. The maximum count during prairie dog surveys was 30 individuals. The total number
of prairie dogs seen was 52 individuals. The results of the prairie dog survey likely correspond with a
population estimate that is lower than the true population at the Site due to trail use and the presence of
an off-leash dog during the time of the survey. No burrowing owls were observed during prairie dog
surveys.
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Table 2 Gateway at Prospect - Special Status Species with Potential to Occur on the Site
Species Federal
Status1 Habitat Habitat
Present?Determination
North Platte, South Platte, and Laramie River Basin Species
Least Tern
Sterna antillarum
Piping Plover
Charadrius melodus
Whooping Crane
Grus americana
Pallid Sturgeon
Scaphirhynchus albus
Western Prairie Fringed Orchid
Platanthera praeclara
Mammals
Canada Lynx
Lynx canadensis
North American Wolverine
Gulo gulo luscus
Preble's Meadow Jumping Mouse
Zapus hudsonius preblei
Birds
Mexican Spotted Owl
Stri occidentalis lucida
Fish
Greenback Cutthroat Trout
Oncorhynchus clarkii stomias
Insects
Arapahoe Snowfly
Arsapnia arapahoe
Flowering Plants
Colorado Butterfly Plant
Gaura neomexicana v. coloradensis
North Park Phacelia
Phacelia formosula
Ute Ladies'-tresses
Spiranthes diluvialis
Source: USFWS 2018
1DL = Delisted, E = Federally Endangered, T = Federally Threatened, PT = Proposed Threatened, C = Candidate
T This species inhabits cold water streams and lakes with
adequate stream spawning habitat during spring.No No Effect
No EffectNoStoneflies are primarily associated with clean, cool,
running waters.C
PT Deep, persistent, and reliable snow cover.No No Effect
No EffectNoSeasonally moist soils and wet meadows of drainages
below 7000' elevation.T
E
The species is limited to eroded soil outcrops composed of
barren exposures of the Coalmont Formation, a coal-
bearing substrate in North Park CO.
No No Effect
No EffectNo
An early successional plant (although probably not a
pioneer) adapted to use stream channel sites that are
periodically disturbed. It occurs on subirrigated, alluvial
soils on level or slightly sloping floodplains and drainage
channels.
T
No EffectNo
Nesting/roosting habitat typically occurs either in well-
structured forests with high canopy cover, large trees, and
other late seral characteristics, or in steep and narrow
rocky canyons formed by parallel cliffs with numerous
caves and/or ledges within specific geological formations.
T
No EffectNoLush vegetation along watercourses or herbaceous
understories in wooded areas near water.T
T
No EffectNoMoist boreal/subalpine forests in the W. US with cold,
snowy winters and a high-density snowshoe hare prey
base.
T
No water
depletion No Effect
No EffectNo water
depletion
Sandy beaches, sandflats, dredge islands, and drained
river floodplains.
2The bald eagle was removed from the fedarl list of T&E species in 2007, but it continues to enjoy protection under the Migratory Bird Treaty Act (MBTA)and Bald
and Golden Eagle Portection Act (BGEPA).
Sparsely vegetated sandbars on large rivers and
sand/gravel pits.No EffectNo water
depletionE
No EffectNo water
depletion
Tall grass prairie on unplowed, calcareous prairies, and
sedge meadows. Upstream depletions to the Platte River
system in Wyoming may affect the species in NE.
T
No EffectNo water
depletion
Large, free-flowing, warm-water, and turbid rivers with a
diverse assemblage of physical habitats.E
E Wetlands, inland marshes, lakes, ponds, wet meadows
and rivers, and agricultural fields.
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4.7 Wildlife Migration Corridors
The Site is located in mostly developed areas of the City and surrounded by commercial and residential
development, the I-25 corridor, and active agricultural fields. It is highly unlikely that the Site serves as a
significant migration corridor for sensitive, unique, or regionally protected wildlife. However, Boxelder
Creek, Lake Canal, and Dry Creek provide some migratory benefit to resident urban-adapted wildlife such
as red foxes, raccoons, coyotes, and skunks, and provides temporary stopover habitat for migrating
birds. Canada geese likely glean agricultural remains in the crop fields. Resulting changes to wildlife
corridor quality should be minimal because the property is located in a developed area where wildlife are
already accustomed to structures, roads, bridges, fences, buildings, and other habitat modifications.
4.8 General Ecological Functions
The general ecological functions provided by the Site have been reduced by multiple human-induced
stressors including agricultural production, adjacent residential development, and commercial
development. The minor riparian habitat supported by Boxelder Creek, the wetlands on- and off-Site, and
the stormwater easement along the southern border provide some degree of shading, cover, and nesting
opportunity for a variety of wildlife species (particularly amphibians), flood abatement, water infiltration,
and aesthetic appeal.
4.9 Timing of Development in Relation to Ecological Character
The MBTA specifically protects migratory birds and their nests from possession, sale, purchase, barter,
transport, import, export, and take. The regulatory definition of take (50 CFR 10.12) means to pursue,
hunt, shoot, wound, kill, trap, capture, or collect, or to attempt these actions. Burrowing owls, a
migratory species, have the potential to nest on-site given the presence of black-tailed prairie dogs and is
a species protected by federal, state, county, and City statutes.
It is recommended that ground-disturbing activities be conducted from late summer to late winter to
avoid the avian nesting and breeding season. If that is not compatible with construction schedules,
additional surveys are recommended prior to commencement of ground-disturbing activities to insure
compliance with the MBTA.
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5.0 MITIGATION MEASURES AND RECOMMENDATIONS
Table 3 (below) outlines potential mitigation measures and standards as defined by LUC 3.4.1 and CPW
recommendations. A 50 foot buffer is applied to the top of bank of Lake Canal. A 100 foot buffer is
applied to the top of bank of both Boxelder Creek and Dry Creek. A 100 foot buffer is applied to the
wetlands associated with Boxelder Creek. The small wetlands currently found in Lower Cooper Slough are
more than likely a result of near surface groundwater conditions, and not connected hydrologically to the
Upper Cooper Slough, which stipulates a 300 foot buffer. Considering the lower-elevation of the swale
relative to the surrounding area, the recorded groundwater depths from August 2000 soil sampling
(Gateway Soils Report, 2000) would suggest water is within 2-4 feet of the ground surface, which is
sufficiently near surface to support wetland vegetation. It would be expected than in the spring, or
following large rain/melt events, that local groundwater levels would be elevated above the levels
measured in late summer, further supporting that local conditions are most likely leading to the current
wetland communities. Additionally, the Lower Cooper’s Slough likely collects some run-off, particularly
from the immediately adjacent urban development up-gradient from the swale. For these reasons, a 100-
foot buffer was determined appropriate for the greater than 1/3 acre wetlands associated with Lower
Cooper’s Slough immediately adjacent to the Site. A 50 foot buffer was applied to the non-jurisdictional
wetlands associated with the stormwater easement.
Potential mitigation measures include maintaining the overall buffer zone acreage requirements, shifting
lot locations away from natural features, and placement of open space, recreational areas, or other areas
acceptable to the City within the buffer zone. Planting of native trees, shrubs, and vegetative
communities in the buffer zones is recommended according to a natural habitat buffer zone plan, as well
as noxious weed control through the development of a weed management plan.
The presence of black-tailed prairie dogs necessitates the creation of a mitigation plan to map out the
removal or relocation of potentially impacted individuals and prevent re-colonization at a later time (LUC
3.4.1 (A)(2)(j)). Buffer distances around colonies are by site analysis. Additional burrowing owl surveys
are required if ground disturbance and/or prairie dog control occurs March 15 – October 31. If burrowing
owls are observed on Site, CPW recommends a 150’ buffer around the utilized burrows.
Light spillage is a potential impact to the natural resources on Site, as per LUC 3.2.4(D)(6).
15
Table 3 Gateway at Prospect - Potentially Applicable Buffers1
Natural Habitat or Feature Buffer Zone Standard
Irrigation ditches that serve as wildlife corridors 50 feet
Wetlands < 1/3 acre in size 50 feet
Wetlands > 1/3 acre in size, without significant use by waterfowl 100 feet
Boxelder Creek 100 feet
Cooper Slough 300 feet
Dry Creek 100 feet
Prairie dog colonies Site Analysis
Burrowing Owl-occupied burrows 150 feet2
1Buffer Zone Table, Land Use Code 3.4.1(E)(2)(c)
2Colorado Parks and Wildlife recommendations
Isolated Areas
Stream Corridors
Special Habitat Features / Resources of Special Concern
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6.0 LITERATURE CITED AND DATA SOURCES
City of Fort Collins – Natural Areas Department. 2016. Restoration Plan 2016-2025.
City of Fort Collins. 2000. Natural Habitat and Features Inventory Map.
Colorado Department of Public Health and Environment (CDPHE). 2012. Colorado Nonpoint Source
Program 2012 Management Plan, Appendix G.
Colorado Parks and Wildlife (CPW). Threatened and Endangered Species List.
https://cpw.state.co.us/learn/Pages/SOC-ThreatenedEndangeredList.aspx. Accessed 3/10/2020.
Colorado Natural Heritage Program. Colorado Wetland Inventory.
https://csurams.maps.arcgis.com/apps/webappviewer/index.html?id=a8e43760cb934a5084e89e
46922580cc. Accessed 3/10/2020.
Earth Engineering Consultants. 2000. Preliminary Subsurface Exploration Report – Interstate Land Parcel,
Prospect Road and I-25.
Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web
Soil Survey. Available online at https://websoilsurvey.sc.egov.usda.gov/. Accessed 3/10/2020.
USACE. 1987. Corps of Engineers Wetland Delineation Manual.
USACE. 2010. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Great Plains
(Version 2.0).
US Fish and Wildlife Service. Information, Planning, and Conservation System (IPaC).
https://ecos.fws.gov/ipac/. Accessed 3/10/2020.
US Fish and Wildlife Service. National Wetlands Inventory (NWI) Wetlands Mapper.
https://www.fws.gov/wetlands/. Accessed 3/10/2020.
Appendix A
NRCS Web Soil Survey Soil Map
Appendix B
Wetland Datasheets