Loading...
HomeMy WebLinkAboutRIDGEWOOD HILLS FIFTH FILING - FDP200024 - SUBMITTAL DOCUMENTS - ROUND 1 - ECS REPORTPreliminary Ecological Characterization Study Triangle Drive Project Prepared for: Goodwin Knight 8605 Explorer Drive, Suite 250 Colorado Springs, CO 80920 Prepared by: Wildland Consultants, Inc. 1001 Jefferson Drive Berthoud, Colorado 80513 October 2019 Table of Contents 1.0 Introduction ………………………………………………………………….. 1 2.0 Vegetation and Wetlands ……………………………………………………. 3 2.1 Rare Plant Species …………………………………………………………… 7 3.0 Wildlife Description …………………………………………………………. 7 3.1 Species and Habitats …………………………………………………………. 7 3.2 Wildlife Corridors ……………………………………………………………. 8 3.3 Rare Wildlife Species ………………………………………………………… 8 4.0 Views …………………………………………………………………………. 9 5.0 Project Impacts ………………………………………………………………. 9 6.0 Conclusions, Proposed Mitigation ……………………………………………. 11 7.0 References …………………………………………………………………….. 12 Attachment A- Site Photographs Attachment B- Preliminary Site Plan 1 Ecological Characterization Study – Triangle Drive Development 1.0 Introduction The Triangle Drive development is located in south Fort Collins, Colorado. The site is bounded on the north by Triangle Drive on the north, and South College Avenue on the east. The proposed residential development is located on a total of approximately 34+- acres. The development includes single family residential, multi-family residential and commercial uses. The proposed development site is surrounded by open land, and existing residential and commercial development. Current land uses on the site include seeded grassland/pasture. Site photos of existing conditions are provided in Attachment A. Natural areas and open space are proposed for stormwater detention areas and a large wetland and adjacent wet meadow in the southern section of the site (Attachment B). The Fort Collins Land Use Code (Section 3.4.1) recommends that an Ecological Characterization Study be completed for projects that are within 500 feet of any natural habitat or feature mapped on the Natural Habitats and Features Inventory Map. The site is adjacent (separated from by South College Avenue) to the Pelican March Natural Area (east site boundary) and the Long View Open Space (south site boundary)(Figure 1). A native upland forest. nonnative grassland, and wet meadow are mapped on the Natural Habitats and Features Inventory Map on the site (Figure 2) (City of Fort Collins 2019). The Ecological Characterization study is also recommended if the site includes areas of unique plant life or wildlife habitat (City of Fort Collins, 2019). 2 Figure 1. Natural Areas near the Triangle Drive Development Site. 3 Figure 2. Natural Habitats and Features Mapped on or near the Triangle Development site (note: these are mapped via aerial photography and are not accurate). The Ecological Characterization study was completed by Mr. Eric Berg of Wildland Consultants, Inc. (WCI). Mr. Berg is a Certified Wildlife Biologist and Certified Professional Wetland Scientist. 2.0 Vegetation and Wetland Description Figure 3, Site Inventory Map shows the major vegetation types occurring on the development site. Site photos of representative vegetation are included in Attachment A. 5 Vegetation on the site is dominated by seeded grassland/pasture. Dominant plants in the seeded grassland areas include: smooth brome grass (Bromus inermis), crested wheatgrass (Agropryon cristatum), alfalfa (Medicago sativa), western tansymustard (Descurania pinnata), sunflower (Helianthus annuus), kochia (Kochia scoparia), field bindweed (Convolvulus arvensis), prickly lettuce (Lactuca serulia), alfalfa (Medicago sativa), and Canada thistle (Cirsium arvensis)(Attachment A Photos 4,5,6,9,11,12,13) Riparian forests were mapped in several areas of the site. A riparian forest (also Wetland 2) dominated by crack willow trees (Salix fragilis) with scatted Siberian elm (Ulmus parvifolia), and an understory of reed canarygrass (Phalaris arundinaceae) and stinging nettle (Urtica dioca) occurs along a drainage channel that drains to Roberts Lake (Attachment A Photos 9,11) . A wooded area dominated by mature plains cottonwood (Populus deltoides) occurs just south of the adjacent community park (Attachment A, Photo 6,8 ). A riparian forest of plains cottonwood trees (smaller 15-20 foot tall trees) occurs just west of the North Louden Ditch in the south section of the site (Attachment A, Photos 1,3). Wetlands are located in several areas of the site (Figure 3 and 4). WCI completed a formal wetland delineation on the site according to Army Corps of Engineers (ACOE) guidelines (Wildland Consultants, Inc. 2019). A total of 102,660 square feet of wetlands were delineated on site. Wetland boundaries are shown on Figure 4. Wetlands were delineated in 5 areas within the site. These included:  Wetland 1 (Attachment A Photo 10), isolated wetland on a seep (Data points W1, U1)(2,908 Square Feet in size)  Wetland 2 (Attachment A Photos 9,11), wetland along a channel that drains to Roberts Lake (Data Points W2, U2)(11,136 square feet in size)  Wetland 3 (Attachment A- Photos 2,7,8) wetland fringe and ordinary high water mark along the North Louden Ditch (Data Points W3, U3)(13,137 square feet in the OHWM, 7,926 square feet in wetland fringe)  Wetland 4 (Attachment A Photos 1,3), wetland in a swale to west of North Louden Ditch (Data Points W4, U4)(66,907 square feet in size)  Wetland 5, wetland in a large swale south and east of the North Louden Ditch (below the ditch in elevation)(Data Points W5,U5)(616 square feet in size). Wetland 1 (2,908 square feet) supports stands of coyote willow (Salix exigua), cattail (Typha latifolia) and stinging nettle. Wetland hydrology is present including standing water and saturated soils. Wetland soils are present. This wetland is located approximately 100 feet downslope of Wetland 2 and appears to be an isolated seep. Wetland 2 (11,136 square feet) supports an overstory of crack willow and plains cottonwood. The understory is dominated by reed canarygrass. Wetland hydrology is present including running and standing water. Wetland soils are present. The channel looks to be manmade and connects/runs to Roberts Lake (600 feet east). The channel appears to have perennial standing water but also receives flood overflows from the North Louden Ditch. 6 Figure 4. Wetland Delineation, Triangle Drive Site. Wetland 3 (North Louden Ditch)( 13,137 square feet in the OHWM, 7,926 square feet in wetland fringe) supports a 3-4 foot wide flowing water channel and a wetland fringe. The wetland fringe is dominated by Emory sedge (Carex emoryi) and reed canarygrass. Wetland hydrology is evident with running and standing water, wetland soils are present. Wetland 4 (66,907 square feet) is located in a large swale located below (down elevation from) the North Louden Ditch. This large wetland is dominated by reed canarygrass, 7 American threesquare (Schoenplectus pungens) and Baltic rush (Juncus balticus). The wetland fringe contains Canada thistle (Cirsium arvensis) and meadow fescue (Festuca prantensis). Wetland hydrology is present (saturated soils, standing water in pits). The North Louden Ditch likely helps support wetland hydrology, the wetland is located below the ditch and the ditch is an earthen ditch. Wetland 5 (616 square feet) is located in a small swale to the west of the North Louden Ditch. Reed canarygrass is the dominant plant. Wetland hydrology and soils are present. This small wetland is located slightly below the waterline of the North Louden Ditch. A Wetland Delineation report has been submitted to the Army Corps of Engineers (ACOE) for approval along with a request to determine what wetlands on the site are under ACOE jurisdiction. Disturbance/fill of ACOE jurisdictional wetlands will require a permit under Section 404 of the Clean Water Act. 2.1 Rare Plant Species The wetlands on the site provide marginal potential habitat for the Ute ladies’ tresses orchid (Spiranthes diluvialis) and Colorado butterfly plant (Guara neomexicana). The orchid has been documented in areas with seasonally wet soils and wet meadows near springs, lakes, or perennial streams and their associated flood plains below 6,500 feet above sea level in the South Platte River Drainage (U.S. Fish and Wildlife Service 1992). The Colorado butterfly plant typically grows on sub-irrigated alluvial soils in floodplains and drainage bottoms and in depressions along slow-moving streams (Fertig 2000, O’Kane 1988). Because the wetland vegetation has been controlled (by mowing or herbicides) in the past it is unlikely that either rare plant species is present. In addition, there are no known populations of these plants located nearby within the City of Fort Collins. WCI did not observe these species on the site when completing field reviews and the wetland delineation. 3.0 Wildlife Description 3.1 Species and Habitat The project area provides habitat to wildlife species adapted to seeded pasture/grasslands, ditch corridors and riparian/wetland areas. Wildlife species likely to use the area periodically include: red fox, coyote, raccoon, striped skunk; mule deer, a variety of small mammals (deer mouse, meadow vole, house mouse, cottontail rabbit); a variety of birds (meadow lark, mourning dove, American robin, common grackle, common flicker, yellow warbler, house finch, English sparrow, black-billed magpie, starling, American kestrel, great horned owl, red-tailed hawk, great blue heron, and many others); a few reptiles (western terrestrial garter snake, gopher snake) and amphibians (leopard frog, tiger salamander, plains spadefoot toad) (Andrews and Righter 1994, Colorado Division of Parks and Wildlife 2011, Fitzgerald et al. 1998, Hammerson 1999). The site does not include any mapped key or important wildlife habitats (Colorado Division of Parks and Wildlife 2019). There are no great blue heron rookeries, waterfowl/waterbird 8 concentration areas, black-tailed prairie dog colonies on the site. The most valuable wildlife habitats on the site include wetlands and riparian forest areas. The forest areas provide nesting habitat to a variety of neotropical migrating passerine bird species. Wildlife species or signs of species observed on the site during a summer 2019 field reviews included: English sparrow, meadowlark, robin, yellow warbler, American goldfinch, common flicker, black-capped chickadee, starling, magpie, mourning dove, great blue heron, American kestrel, red-tailed hawk, great-horned owl, Swainson’s hawk, deer mouse, meadow vole, raccoon, striped skunk, cottontail rabbit, red fox, and coyote. There are no black-tailed prairie dog colonies on the site. There is an American kestrel nest in a cavity of a large plains cottonwood tree just south of adjacent community park (Figure 3). There are no other known raptor nests on the development site or adjacent areas. Note: WCI did site reviews when trees had leaf cover, it is possible that raptor nest was present but not observed, WCI will complete another site visit after leaf drop to determine if any nests were missed. Raptors have been observed foraging, and roosting on the site (American kestrel, red-tailed hawk, Swainson’s hawk). There are no great blue heron rookeries or other important waterbird or waterfowl use areas on the site. Great blue herons and other waterbirds/waterfowl may forage occasionally along the North Louden Ditch. 3.2 Wildlife Corridors Wildlife can currently move freely through the site. The North Louden Ditch provides a minor and narrow wildlife movement corridor through the site. There is no thick riparian shrub cover along Ditch on the site. The Ditch is narrow and supports a very narrow wetland fringe (15-20 feet total for ditch and fringe). Portions of the Ditch corridor within the City of Fort Collins upstream of the site have been heavily altered by previous developments. Raccoons, skunks, muskrat and other urban adapted species use the ditch to move through the site. The ditch is not expected to provide a movement corridor for wildlife species that are sensitive to human presence (big game animals, large predators). 3.3 Rare Wildlife Species The site provides poor potential habitat to Federally Listed Preble’s meadow jumping mouse (Zapus hudsonius preblei). Preferred habitat for the Preble’s meadow jumping mouse includes thick shrubby riparian habitat along area streams and rivers (Armstrong et al. 1997). The riparian habitat areas within the development site are small and isolated (not connected) to other riparian zones. There is little chance that the Preble’s meadow jumping mouse is present on the site. The nearest quality potential habitat is present along the Cache la Poudre River approximately 5 miles to the northeast of the site (note: this area does not support a population of Preble’s mice). The nearest occupied habitat for the Preble’s mouse is along the Cache la Poudre River upstream of LaPorte. This area is approximately 12 miles northwest of the proposed project area. Numerous trapping efforts have resulted in no Preble’s captures in good potential habitat areas along the Cache la Poudre River, adjacent tributaries and canals (including Fossil Creek, Spring 9 Creek, Box Elder Creek). Because of past negative trapping efforts along the Cache la Poudre River in Fort Collins and in adjacent areas there is little likelihood that the rare mouse is present along the North Louden Ditch and the isolated riparian zones on the Triangle Drive site. Bald eagles (delisted but protected by the Bald Eagle Protection Act) may be present foraging on the site especially during the winter periods. Bald eagles may also be seen day roosting in large trees on the site occasionally during the winter. The development area (just like most of Larimer County) is mapped as part of overall bald eagle winter range (Colorado Division of Wildlife 2019). There are no nests or bald eagle communal winter roost sites on or near the proposed development. 4.0 Views The development site lies on a small rise above South College Avenue. Views across the site from South College Avenue don’t include prominent mountain views because of the higher elevation of the development site. From Triangle Drive views extend to the south over the site towards Loveland. Because of the higher elevation there are prominent mountain and plains views present from the middle of the development site in all directions. The areas to the west, north and east of the site area already heavily developed with commercial and residential properties. Because the development sits on a higher rise proposed development will be visible from many surrounding roads. 5.0 Project Impacts Project construction would result in the conversion of approximately 25 acres of seeded grassland/pasture,1.13 acres of riparian forest, and 0.665 acres of wetlands to urban uses. Approximately 1,376 feet of the North Louden Ditch would removed and placed in an underground pipe. Open space/natural areas would include stormwater detention areas, and an open space area in the south section of the site. Approximately 5.8 acres of the site would remain as open space/natural area. Attachment B- Preliminary Development Plan shows the current proposed development design. Wetlands and Riparian Zones- Project construction would result in loss of approximately 0.656 acres of wetlands (Wetlands 1, 2 and parts of Wetland 3), 1.13 acres of riparian forest and 1,376 feet of the North Louden Ditch. Appropriate permits would be obtained from the ACOE prior to construction and final City of Fort Collins development approval for fill of any jurisdictional wetlands. The majority of the North Louden Ditch upslope of the large southern wetland area (Wetland 4) would remain undisturbed (approximately 300 feet of the Ditch just north of Wetland 4 would be placed in a pipe, approximately 510 feet of the Ditch in this area 10 would remain undisturbed). The hydrology (water source) of Wetland 4 likely is supported by seepage from the North Louden Ditch. Wetland mitigation is proposed to create new wetlands to mitigate for wetland losses and loss of wetland buffer areas. Wildlife- Project construction would result in the conversion of approximately 25 acres of seeded grassland/pasture habitat, 1.13 riparian forest habitat, and 0.665 of wetland habitat to urban uses. Approximately 1,376 feet of the North Louden Ditch would removed and placed in an underground pipe. Open space/natural areas would include stormwater detention areas, and an open space area in the south section of the site. Approximately 5.8 acres of the site would remain as open space/natural area. Wildlife species using these habitat areas would be displaced. The narrow wildlife movement corridor associated with the North Louden Ditch would be removed. Note: this is not a major urban wildlife movement corridor within the City of Fort Collins. Direct impacts to nesting migratory birds would be minimized by completing tree and shrub removal outside the nesting season. Habitat loss of riparian and wetland habitat areas would remove some nesting habitat for a variety of passerine bird species. Open space areas would continue to provide habitat to urban adapted wildlife species. Proposed mitigation and enhancement measures (wetland mitigation, tree plantings, native shrub and grass plantings, replacement of lost wetland buffers in the open space acreage) would help to mitigate losses of wildlife habitat. Rare Species- Past negative trapping along the Cache la Poudre River and adjacent perennial tributaries in Fort Collins indicates that the Preble’s meadow jumping mouse is not present within the City. Wooded riparian habitat on the project area is isolated and not connected with other large offsite wooded riparian zones. It is highly unlikely that the Preble’s mouse is present on or near the site. Therefore, trapping for the Preble’s meadow jumping mouse is not recommended for the site. Impacts are not expected to occur to the Preble’s meadow jumping mouse with project construction. No impacts to the Ute ladies’ tresses orchid and Colorado butterfly plant are expected to occur with project construction. These species were not observed on the site during flowering periods of 2019. No nearby locations for these species are present. 11 6.0 Conclusion, Proposed Mitigation Project construction would result in the conversion of approximately 25 acres of seeded grassland/pasture, 1.13 acres of riparian forest, and 0.665 acres of wetlands to urban uses. Approximately 1,376 feet of the North Louden Ditch would removed and placed in an underground pipe. Open space/natural areas would include stormwater detention areas, and an open space area in the south section of the site. Approximately 5.8 acres of the site would remain as open space/natural area. Attachment B- Preliminary Development Plan shows the current proposed development design. The minor wildlife movement corridor associated with the North Louden Ditch would be removed. A small acreage (1.78 acres) of good passerine bird nesting habitat would be removed (riparian zones and wetland area that are removed)). No impacts to rare/special status wildlife or plant species are anticipated with project development. Proposed mitigation measures are designed to meet City of Fort Collins requirements (based on the City code, and City of Fort Collins Planner comments). Wetland mitigation will also meet the requirements of the ACOE. Mitigation measures are designed to offset project impacts to wetlands, riparian zones/trees, and other important habitat areas.  A formal Wetland Delineation Report and Approved Jurisdictional Determination have been submitted to the ACOE. Appropriate permits will be obtained from the ACOE for any disturbance/loss of jurisdictional wetlands. Wetland mitigation (either onsite construction of wetlands or purchase of mitigation credits from an approved mitigation bank) will be completed for ACOE jurisdictional wetlands.  The City of Fort Collins will require mitigation of all wetlands (both ACOE jurisdictional and non-jurisdictional wetlands). Based on current project design a total of 0.656 acres of wetlands would be lost to development activities. Wetland mitigation is proposed to create an additional 0.656 of wetlands in the south section of the project. The proposed wetland mitigation area would be adjacent to the existing large wetland area south of the North Louden Ditch (Attachment B Preliminary Site Plan). New wetlands would be created in this area by excavation of existing vegetation/soils to a depth where saturated soils are present (saturated during the growing season within 12-inches of the ground surface). This area would be planted/seeded with wetland plant species. More details of proposed mitigation site hydrology (depth to groundwater) will be gathered by placing monitoring wells in the proposed mitigation area.  The Fort Collins City Code recommends buffer zones of 50 feet for major irrigation canals, 50 feet for wetlands less than 0.3 acres and 100 feet for wetland greater than 0.3 acres. The City of Fort Collins has commented that mitigation would be required for lost buffer zones (City of Fort Collins 2019). Project development would result in the loss of Wetlands 1, 2 and portions of 3 (North Louden Ditch) these disturbed areas would not be buffered from development. However, lost buffer zones would be included in acreage of proposed open space. Because portions of the North Louden Ditch (approximately 1,376 feet of the 12 Ditch will be placed underground) and Wetland 2 will be removed the City will require as mitigation the dedication of 4.28 acres of natural area/open space to replace this lost buffer area. (Approximately 1,376 feet of Louden Ditch (Wetland 3) X 100 feet (50 feet on either side of ditch)=137,600 square feet (3.16 acres). A 50 foot buffer area around Wetland 2 is approximately 1.12 acres.)  Tree mitigation will be completed according to a Tree Mitigation plan developed in consultation with the City of Fort Collins forester. Tree mitigation will be designed to replace trees removed due to site development with appropriate native tree species. Riparian forest areas (approximately 1.13 acres) lost to development will be replanted in open space areas in the south section of the site and along stormwater detention areas.  Tree and shrub removal associated with site development would be completed outside of the nesting season for migratory bird species. Tree and shrub removal would be completed between August 15 and March 31.  If nesting raptors are located on the site prior to development, consultation would occur with the City of Fort Collins and the Colorado Division of Parks and Wildlife prior to removal of any nest trees.  Lighting adjacent to open space areas will be as wildlife friendly as possible. Lighting will follow the principals: low (lights mounted as low as possible) and wattage as low as possible, shielded (fixture will shield bulb/lens from Spring Creek), long (only long wave length light (560nm or longer)) bulbs (Florida Fish and Wildlife Conservation Commission 2019).  To mitigate for lost wetlands and riparian forest areas additional enhancements of site open space will be required. Enhancements will include plantings of native trees, shrubs, forbs and grasses designed to provide high quality wildlife habitat areas within open space areas and detention areas. Detention areas would also serve as natural areas/open space. The Landscape/Enhancemtn plan to be developed for the project would provide details of plantings proposed for open space, natural areas and proposed mitigation areas (areas designed to mitigate lost wetlands and lost buffer zones to wetlands). 7.0 References Andrews, R. and R. Righter. 1992. Colorado Birds. Museum of Natural History, Denver, CO. 442pp. Armstrong, D.M., M.E. Bakeman, N.W. Clippinger, A. Deans, M. Marguiles, C.A. Meaney, C. Miller, M. O’Shea-Stone, T.R. Ryon, and M. Sanders. 1987. Report on Habitat Findings of the Preble’s Meadow Jumping Mouse. Presented to the U.S. Fish and Wildlife Service, and Colorado Division of Wildlife. City of Fort Collins. 2019. City of Fort Collins Natural Habitats & Features Inventory Map. GIS Data City of Fort Collins. 2019. City Code Section 3.4.1. 13 City of Fort Collins. 2019. Comments from Stephanie Blochowiak, Comment Letter from the City of Fort Collins 8/13/19. Colorado Division of Parks and Wildlife. 2019. GIS Data. Fertig, W. 2000. Status Review of the Colorado butterfly plant (Gaura neomexicana ssp. coloradensis). Report prepared for the Wyoming Cooperative Fish and Wildlife Unit, U.S. Fish and Wildlife Service, and Wyoming Game and Fish Department by the Wyoming Natural Diversity Database, Laramie, WY. Fitzgerald, J.P., C.A. Meaney, D.M. Armstrong. 1994. Mammals of Colorado. Denver Museum of Natural History and University Press of Colorado. 467pp. Florida Fish and Wildlife Conservation Commission. 2019. Wildlife Lighting Criteria. Hammerson, G.A. 1999. Amphibians and Reptiles in Colorado. Colorado Division of Wildlife. Denver, CO. 130pp. National Wetland Inventory Mapping. 2019. U.S. Fish and Wildlife Service, NWI GIS Data. O’Kane, S.L. 1988. Colorado’s rare flora. Great Basin Naturalist 48(4):434-484. Spackman, S., B. Jennings, J. Coles, C. Dawson, M. Minton, A. Kratz, and C. Spurries. 1997. Colorado Rare Plant Field Guide. Colorado Natural Heritage Program. Wildland Consultants, Inc. 2019. Wetland Delineation Report, Triangle Drive Project. Attachment A- Site Photos Photo 1. View to northwest across Wetland 4, from the south site boundary, cottonwood riparian forest along North Louden Ditch. Photo 2. View to the north along the North Louden Ditch from the south site boundary Photo 3. View to west across Wetland 4, riparian forest area is located just west of the North Louden Ditch Photo 4. View to north along center of site, seeded grassland. Photo 5. View to south from center of the site, seeded grassland. Photo 6. Plains cottonwood trees, just south of adjacent community park, North Louden Ditch at left photo margin. Photo 7. View to north along the North Louden Ditch, historic barn on adjacent community park. Flowing water, narrow fringe of wetland vegetation. Photo 8. View to the north along the North Louden Ditch, north end of site, small stand of mixed plains cottonwood, Russian olive along ditch in background. Photo 9. View to east from high point near northeast site boundary, Triangle Drive. Seeded grassland, crack willow dominated riparian forest (Wetland 2) on right photo margin, Russian olive trees in middle. Photo 9. View of Wetland 2, riparian forest dominated by crack willow trees. Photo 10. View to north of Wetland 1, coyote willow, cattail dominated. Wetland appears associated with a small seep/groundwater expression. Photo 11. View to south (east site boundary) along South College Avenue from near north end of site. Wetland 4 (riparian forest) in background, seeded grassland, Photo 12. Representative view to west from east site boundary, north central portion of site, seeded grassland. Photo 13. View to south from Center of site. Large cottonwood trees in center of photo are on the adjacent Long View Open Space, seeded grassland. 100' WETLAND BUFFER 100' WETLAND BUFFER WETLAND DETENTION MITIGATION AREA DETENTION DETENTION MITIGATED WETLAND MITIGATED WETLAND N O R T H