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HomeMy WebLinkAboutTIMBERVINE PDP - PDP140002 - SUBMITTAL DOCUMENTS - ROUND 1 - ENVIRONMENTAL REPORTOctober 10, 2013 Mr. Landon Hoover Summer Park Holdings 1218 W. Ash Street, Suite A Windsor, CO 80550 RE: Characterization Study (ECS) Letter Report for the Timbervine Development Parcel Mr. Hoover: This letter report is submitted to satisfy the requirements of Section 3.4.1 of the Land Use Code of the City of Fort Collins regarding the submittal of an ECS report for proposed development projects. The Timbervine project site is located immediately northwest of the intersection of Munich Way and Zurich Drive in the northwest ¼ of Section 8 and northeast ¼ of Section 7 (Township 7 North, Range 69 West) in Fort Collins, Colorado. Ecological characteristics of the property were reviewed by preliminary reconnaissance on September 25, 2013 with Lindsay Ex (City of Fort Collins Planning Department) and Craig Russell (Russell Mills Studios, Inc.) to determine if any wetlands are present and to review overall site characteristics. A more detailed field survey for the property was completed on October 6, 2013. The following provides a summary of ecological information required by Fort Collins Land Use Code under 3.4.1 (D) (1) items (a) through (k). ECOLOGICAL STUDY CHARACTERIZATION CHECKLIST (a & i) Existing habitats on the project site consist of non-native grassland, weedy areas, and an irrigation ditch (Lake Canal) (see attached Figure 1). The majority of the property’s surface has been cleared of native vegetation and converted to non-native grassland species, presumably for hay production. In the non-native grassland areas, smooth brome (Bromus inermis1), alfalfa (Medicago sativa), and field bindweed (Convolvulus arvensis) are the dominant species, while lesser amounts of tall fescue (Schedonorus arundinaceus), intermediate wheatgrass (Thinopyrum intermedium), Canada thistle (Cirsium arvense), curly dock (Rumex crispus), white prairie aster (Symphyotrichum falcatum), and showy milkweed (Asclepias speciosa) are also present. Canada thistle is listed as a noxious weed by Larimer County. Attached Photos 1 and 2 provide representative views of non-native grassland habitat in the Timbervine project area. Non-native grassland habitat extends up to the base of the Lake Canal embankment, and along many segments of the canal, up to the top of the west bank. Smooth brome is the dominant herbaceous species along the upland portions of the Lake Canal west bank, but pockets of wild licorice (Glycyrrhiza lepidota), smooth horsetail (Equisetum laevigatum), leafy spurge (Euphorbia esula), and asparagus (Asparagus officinalis) are also present. Leafy spurge is listed as a noxious weed by Larimer County. Woody vegetation in non-native grassland habitat is restricted to a few of Russian olive (Elaeagnus angustifolia) trees supported at scattered locations throughout this habitat (see Figure 1). Table 1 provides a listing of the number and sizes of these Russian olives. Russian olives are classified as nuisance species by the City of Fort Collins, but this species does provide some wildlife habitat value in terms of nesting and foraging habitat for songbirds. There is one weed-dominated area on the property. This site is located along the west edge of Lake Canal near the southeast property corner (see Figure 1). The area had been recently disturbed by earth grading activities, and early invader weedy species are dominant here. Common weedy species are kochia (Bassia scoparia), prickly lettuce (Lactuca serriola), and common sunflower (Helianthus annuus). 1 Scientific nomenclature for plants follows USDA, NRCS Plants Database. Available online at: http://plants.usda.gov/java/ L. Hoover 10/10/13 Page 2 of 6 Table 1. Inventory of Tree Species in the Timbervine Project Area Tree Identifier Label on Figure 2 Species, Number, and Sizes Comments Tree A 1 eastern cottonwood - 6-foot diameter partially decadent Tree B 1 large crack willow outside project boundary Trees C 2 crack willows - 18 to 36-inch diameter, multi- trunked Tree Group D 20+ group of narrowleaf cottonwoods - 3 to 14-inch diameter Tree E 1 eastern cottonwood - 4-foot diameter dead; several nest cavity holes Tree Group F 25+ group of narrowleaf cottonwoods - 2 to 14-inch diameter Trees G 2 crack willows - 4 to 6-foot diameter Tree H 1 eastern cottonwood - 6-foot diameter Tree Group I 25+ group of narrowleaf cottonwoods - 2 to 14-inch diameter Tree Group J 10 crack willows - 3 to 14-inch diameter, some multi- trunked 5 narrowleaf cottonwoods - 3 to 10-inch diameter 2 Russian olives - 4 to 6-inch diameter Russian olives are classified as a nuisance tree by City of Fort Collins Tree Group K several large eastern cottonwoods and crack willows outside project boundary Tree Group L 1 Siberian elm - 30-inch diameter 1 crack willow - 8 to 14-inch diameter, multi-trunked Siberian elms are classified as a nuisance tree by City of Fort Collins Tree M 1 eastern cottonwood - 7-foot diameter Tree N 1 Russian olive - 3 to 8-inch diameter, multi-trunked nuisance tree Tree O 1 Russian olive - 6 to 18-inch diameter, multi-trunked nuisance tree Tree P 1 Russian olive - 6 to 18-inch diameter, multi-trunked nuisance tree Tree Q 1 Russian olive - 12-inch diameter nuisance tree Tree R 1 Russian olive - 2 to 6-inch diameter, multi-trunked nuisance tree Tree S 1 Russian olive - 4 to 6-inch diameter, multi-trunked nuisance tree Tree T 3 Russian olives - 1 to 6-inch diameter, multi-trunked nuisance tree Tree U 2 Russian olives - bushes nuisance tree, mostly to partially decadent Tree V 1 Russian olive - 1 to 4-inch diameter, multi-trunked nuisance tree, partially decadent Tree W 2 Russian olives - 1 to 6-inch diameter, multi-trunked nuisance tree, partially decadent Tree X 1 Russian olive - 3 to 6-inch diameter, multi-trunked nuisance tree Tree Y 1 Russian olive - 4 to 8-inch diameter, multi-trunked nuisance tree Lake Canal supports non-continuous strips of wetlands inside the ditch embankments. The canal wetlands are supported as bands along the lower, inside edges of the embankments, especially where portions of the banks have slumped off to form lower benches within the canal. These are the only wetlands supported on the project area. Additional information on Lake Canal wetlands is provided under the subsequent Section (b). Attached Photo 3 provides a representative view of wetlands supported along one the lower bench areas within the canal banks. Lake Canal also supports non-continuous strips of riparian woodland vegetation. Locations of tree stands are depicted on Figure 1, and tree label locations on Figure 1 are keyed to descriptions of tree species, sizes, and numbers in Table 1. Dominant tree species along Lake Canal consist primarily of narrowleaf cottonwood L. Hoover 10/10/13 Page 3 of 6 (Populus angustifolia), eastern cottonwood (Populus deltoides), and crack willow (Salix fragilis). A few Russian olive and Siberian elm (Ulmus pumila) trees are also present. Both of these species are classified as nuisance species by the City of Fort Collins, although they do provide perching, foraging, and nesting habitat value for songbirds. Narrowleaf cottonwood and eastern cottonwood are native species. The others are introduced, non- native species. The USDA, Natural Resources Conservation Service (NRCS) classifies narrowleaf cottonwood, eastern cottonwood, and crack willow as wetland species. Trees 6 inches in diameter or larger and may be classified by the City Forester as significant based on the Fort Collins Land Use Code. The City Forester or a private arborist will need to evaluate the health of these trees in order for their significance status to be determined. Attached Photos 4 and 5 show views of riparian woodlands along Lake Canal. Section 3.4.1 of the Fort Collins Land Use Code calls for a 50-foot no development buffer for isolated patches of native upland or riparian forest. Based on the current development plan for Timbervine, an approximate 50-foot buffer would be maintained between the proposed development and Lake Canal riparian woodlands, except for a recreation trail. Section 3.4.1 of the Land Use Code indicates that trails are permitted features within buffer zones. In addition to wetland and riparian habitats, Lake Canal also creates a seasonal strip of open water (aquatic) habitat during the growing season. Lake Canal wetlands and riparian woodlands are the only areas of native vegetation or unique habitat features supported within the project area. Non-native grassland and weedy areas have been cleared of native vegetation and woody species, and as a result, support no natural habitat features and have low ecological and wildlife habitat value. Seasonal mowing of the non-native grassland further reduces overall habitat value by reducing vegetation cover. Canada geese grass may occasionally graze or rest in non-native grassland areas. Likely resident wildlife species in non-native grassland include western meadowlark, horned lark, prairie vole, and deer mouse. Riparian woodlands on the property may be used year round and/or seasonally for perching, foraging, and nesting by a variety of songbird and other avian species, including great horned owl, eastern screech owl, downy woodpecker, western kingbird, black-capped chickadee, house wren, American robin, northern flicker, mourning dove, yellow warbler, house finch, American goldfinch, and Bullock’s oriole, among others. The one dead eastern cottonwood tree in riparian woodlands (see Table 1) exhibited several nest cavity holes that likely provide for nesting habitat for woodpeckers and other cavity nesting species. Due to the late season timing of the field surveys, the only avian species observed on the property were northern flicker, Eurasian collared-dove, house finch, and American goldfinch. Trees in the riparian corridor may also be used for perching and nesting by open-country raptors such as Swainson’s hawk and red-tailed hawk, but the presence of the adjacent trailer park residential area likely precludes nesting use by these two species. No raptor nests were located in trees on the property during the October 6, 2013 field survey. Mammalian wildlife species likely to use Lake Canal wetland and riparian woodland habitats include to urban adapted species such as coyote, red fox, raccoon, fox squirrel, striped skunk, mule deer, and white-tailed deer. These species may also occasionally wander out into the more open, non-native grassland habitat areas to forage. (b) City of Fort Collins Natural Areas mapping show much of the Timbervine project area supporting wet meadow habitat, and according to NRCS soils mapping for the project area (obtained from: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx), more than half of the Timbervine project area is underlain by a hydric (wetland) soil, Loveland Clay Loam. However, as indicated in the previous section, the only wetlands on the project area are those supported within the Lake Canal embankments. Field surveys found no evidence of areas dominated by wetland or wet meadow vegetation within non-native grassland habitat. Additionally, four test pits located during the field surveys in non-native grassland habitat indicated groundwater levels well below the depth required to support wetland vegetation. These test pits had been dug by a backhoe and were 5 to 6 feet deep. Field survey observations indicted the test pits were either dry or only contained water within the lower foot of the pits. Groundwater needs to be at least within 16 inches of the surface during the growing season to support wetland vegetation. Photo 6 provides a view of one of the four test pits located in non-native grassland habitat. L. Hoover 10/10/13 Page 4 of 6 Wetlands supported along Lake Canal occur as non-continuous strips, primarily along the west side of the canals and are typical of wetlands supported along larger irrigation ditches in the Fort Collins area. Wetlands were most extensive along portions of the ditch where the ditch embankment had slumped to form a lower bench within the ditch. Wetlands were less developed or absent along segments of the ditch where the inside banks were near vertical. Dominant herbaceous wetland species along Lake Canal consist primarily of Indian hemp (Apocynum cannabinum) and Emory sedge (Carex emoryii). Sandbar willow (Salix exigua), narrowleaf cottonwood, eastern cottonwood, and crack willow are the dominant woody wetland species. Lake Canal wetlands were not formally delineated since project development would have no impact on the irrigation canal or associated wetlands. However, the overall length (1,400 feet) and average width (8 feet) of the canal segments supporting wetlands were estimated in the field, indicating the total acreage of Lake Canal wetlands to be less than 0.3 acre. Two other wetlands are located within 500 feet of the Timbervine development parcel. The north end of the closest wetland is depicted on Figure 1. This wetland is approximately 80 feet south of the Timbervine south property line. The size of this wetland was estimated from aerial photography, and was determined to be approximately 0.8 acre. Dominant species supported in the wetland are sandbar willow, crack willow, eastern cottonwood, and Russian olive. A similar wetland is located approximately 360 feet south of the Timbervine project area (not depicted on Figure 1). This wetland is supported along most of the western side of Munich Way south of Zurich Drive and was estimated to be approximately 1.0 acre in size. The wetland and seasonal aquatic habitats supported by Lake Canal are valuable habitats in that they typically support a greater diversity of plants and animals than that found in adjacent dryland habitats in urban areas. Wildlife species from adjacent upland habitats rely on wetland habitats for obtaining food, cover, and water on a regular or intermittent basis and will use the canal for a movement corridor through grassland habitats and developed urban areas. Wetlands and seasonal aquatic habitats also provide foraging and resting habitats, and movement corridors for waterfowl and other urban-adapted waterbirds. Other species potentially present in canal wetland and aquatic habitats include Woodhouse’s toad, chorus frog, and wandering terrestrial garter snake. Section 3.4.1 of the Fort Collins Land Use Code calls for a 50-foot no development buffer for wetlands less than 0.3 acre in size and for a 100-foot buffer for wetlands greater than 0.3 acre. Based on the current development plan for Timbervine, an approximate 50-foot buffer would be maintained between the proposed development and Lake Canal wetlands, except for a recreation trail. Section 3.4.1 of the Land Use Code indicates that trails are permitted features within buffer zones. The proposed development areas would be well over 100 feet from the two wetland areas identified south of the Timbervine project area. (c) Portions of the project area provide partial, but not prominent, views of the Front Range foothills. (d) As indicated under (a & i) the project area supports little native vegetation, and significant trees are restricted to the Lake Canal corridor. Trees growing along Lake Canal are itemized in Table 1 and their distribution is depicted on Figure 1. (e) There are no natural drainages on or within 500 feet of the project area. (f) There is no suitable habitat for any threatened, endangered, or other sensitive species on or adjacent to the project area. No other sensitive or ecologically important species are likely to use the property since the majority of its surface has been converted from native habitats to non-native grassland. (g) Past removal of native habitat has eliminated the potential for any special habitat features on the property other than significant trees, wetlands, and the movement corridor along the Lake Canal corridor. (h) Lake Canal represents the only wildlife movement corridor on or near the project area. The canal originates at the Cache la Poudre River just west of College Avenue and proceeds eastward past the Timbervine project area through mostly open space and agricultural lands east of I-25 until it terminates in uplands in an area south L. Hoover 10/10/13 Page 5 of 6 of the Windsor Reservoir. Section 3.4.1 of the Fort Collins Land Use Code calls for a 50-foot no development buffer for irrigation canals that serve as wildlife movement corridors. Based on the current development plan for Timbervine, an approximate 50-foot buffer would be maintained between the proposed development and Lake Canal, except for a recreation trail. Section 3.4.1 of the Land Use Code indicates that trails are permitted features within buffer zones. (j) There is one issue regarding the timing of property development and ecological features or wildlife use of the project area. If the development proposal includes removal of any trees on the property or if construction occurs near an occupied bird nest during the songbird nesting season (February through July), these activities could result in the loss or abandonment of a nest and would be in violation of the federal Migratory Bird Treaty Act. (k) Since most of the project area has been converted from native habitats to non-native grassland, project development would have no impact on natural habitats or important habitat features, other than existing trees on the property. The Lake Canal movement corridor, riparian habitat, and wetlands would remain intact, and the Land Use Code prescribed buffer of 50 feet would protect these features. The current development plan would result in the removal of Russian olive trees supported in non-native grassland. Although these trees are considered nuisance species, they do provide some wildlife habitat value for songbird perching, foraging, and possibly nesting. Because tree removal or construction near trees during the nesting season could result in the loss or abandonment of a nest, it is recommended that tree removal or construction near songbird nests occur outside of the nesting season (February 1 – July 31), or trees on or near the project area be surveyed to ensure lack of nesting prior to removal or construction activities during the nesting season. The same mitigation recommendation applies to construction near Lake Canal riparian habitat during the nesting season. This mitigation recommendation would preclude the possible incidental take or disturbance of active songbird or raptor nests. Wildlife habitat quality in the buffer zone along the west side of Lake Canal should be enhanced by control/removal of weedy species, particularly leafy spurge and Canada thistle, and plantings of suitable native shrub and tree species. Native woody plantings would expand the existing riparian corridor and provide additional visual screening between the proposed development and wildlife use of existing Lake Canal riparian and wetland habitats. The buffer zone should be planted with an upland riparian vegetation mix, including shrubs and trees, to create a zone of native riparian vegetation. Plantings of trees should also be used mitigate the removal of Russian olive trees that currently provide some wildlife habitat value in non-native grassland habitat. The goal of plantings in the buffer zone should be to create a self-sustaining, native vegetation community to stabilize soils and enhance wildlife habitat. Buffer zone enhancement and planting plans should be coordinated with City Planning and Natural Resources staff. Any additional woody species plantings would also need to be in compliance with the ditch companies’ maintenance requirements for Lake Canal. It is not the intention of the buffer zone enhancement recommendations to convert areas currently supporting stable non-native grass cover to be converted to native grassland species. Conversion of stable non-native grass areas to native grassland is not recommended for three reasons. First, although the majority of existing grass cover is non-native, non-native grassland on the property is well established and meets the general intent of the City’s buffer zone performance standards. Soils are stable in the non-native grassland areas and non- native grass (primarily smooth brome), when not mowed, provides adequate wildlife cover adjacent to riparian habitat. Finally, any attempt to convert well-established non-native grassland habitat to native grassland are likely to fail without intensive management efforts, and converted areas are most likely to be dominated by aggressive, undesirable weedy species such as cheatgrass (Bromus tectorum) and kochia. Habitat enhancement plantings would likely require soil treatment to relieve compaction (ripping) and improve fertility (fertilizer amendments). Supplemental irrigation may be required for initial establishment of shrubs, trees and herbaceous species. A weed management plan should be developed in concert with habitat enhancement plantings to minimize the development of non-desirable, invasive species in the buffer zone enhancement areas. L. Hoover 10/10/13 Page 6 of 6 Loss of trees classified as significant would need to be mitigated with replacement trees as per Section 3.2.1 (F) of the Land Use Code. All residential trash should be contained within animal proof containers or enclosures to minimize the risk of human conflicts with species such as raccoon, skunk, red fox, and coyote. The intensity of night lighting from the sides of houses facing the Lake Canal buffer zone and designated open space habitat should be shielded or directed to minimize the intrusion of artificial nighttime light into these areas. This concludes Cedar Creek Associates, Inc.’s evaluation of the Timbervine project area. If you have any questions or require additional information regarding my evaluation, please give me a call. Sincerely, INC. T. Michael Phelan Principal Senior Wildlife Biologist attachments: Figure 1, Habitat Mapping for the Timbervine Project Area Photos of the Timbervine Project Area