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HomeMy WebLinkAboutPATEROS CREEK - PDP - PDP130011 - SUBMITTAL DOCUMENTS - ROUND 1 - ENVIRONMENTAL REPORTREVISED ECOLOGICAL CHARACTERIZATION STUDY REPORT FOR THE PATEROS CREEK PROJECT Prepared by Cedar Creek Associates, Inc. Fort Collins, Colorado Prepared for Bellisimo, Inc. Fort Collins, Colorado March 12, 2013 i TABLE OF CONTENTS Page 1.0 INTRODUCTION AND LOCATION ................................................................................................ 1 2.0 METHODOLOGY ........................................................................................................................... 1 3.0 HABITAT CONDITIONS AND WILDLIFE USE .............................................................................. 3 3.1 Disturbed Areas .......................................................................................................................... 4 3.2 Non-native Grassland ................................................................................................................. 4 3.3 Riparian Woodland, Tree Cluster, and Tree Line ....................................................................... 7 4.0 ECOLOGICAL CHARACTERIZATION STUDY CHECKLIST ...................................................... 12 5.0 POTENTIAL IMPACTS WILDLIFE MITIGATION RECOMMENDATIONS ................................... 14 5.1 Recommended Mitigation Measures ........................................................................................ 18 6.0 REFERENCES CITED ................................................................................................................. 19 APPENDIX A - U.S. Army Corps of Engineers Wetland Approval Letter APPENDIX B - Oversized Figure 2 - Habitat Mapping for the Pateros Creek Property LIST OF FIGURES 1 Location of the Pateros Creek Development Parcel ....................................................................... 2 2 Habitat Mapping for the Pateros Creek Property ......................................... attached in Appendix B 3 Habitat Infringement Comparison ................................................................................................. 16 LIST OF PHOTOS 1 Disturbed/Graded/Debris Pile Area Along the Pateros Creek Northwestern Property Boundary ... 5 2 Residential Area and Bare Ground Along the Pateros Creek Middle North Property Boundary ..... 5 3 Disturbed/Debris Pile Area Along Pateros Creek Northeast Property Boundary ............................ 6 4 Non-native Grassland Area in West Portion of the Pateros Creek Property ................................... 6 5 Non-native Grassland Opening in Undisturbed Riparian Woodland at West End of Pateros Creek Property ................................................................................................................................ 8 6 View of Disturbed Debris Pile Areas at South End of Undisturbed Riparian Woodland .................. 8 7 View of Another Debris Pile at Edge of Riparian Woodland ............................................................ 9 8 View of Small, Isolated Wetland Depression at West Edge of Riparian Woodland ........................ 9 9 View of Wetland at the West End of the Southeast Corner Pond ................................................. 11 10 View of Pond in Southeast Corner of Pateros Creek Property ...................................................... 11 1 DRAFT ECOLOGICAL CHARACTERIZATION STUDY REPORT FOR THE PATEROS CREEK PROPERTY 1.0 INTRODUCTION AND LOCATION This report documents the evaluation of habitat conditions on the proposed Pateros Creek development parcel in Fort Collins, Colorado. The report is provided as a draft at this time since development plans for the property have not been finalized. The report was prepared in accordance with Section 3.4.1 of the Land Use Code of the City of Fort Collins regarding the preparation of an Ecological Characterization Study (ECS) Report. The proposed development site is located in Fort Collins, Colorado in the northeast 1/4 of the southwest 1/4 of Section 2 (T. 7 N. R. 69 W.) at the north termination of Pateros Creek. The property location is shown on Figure 1. 2.0 METHODOLOGY Cedar Creek completed field surveys of the Pateros Creek property in 2011 on October 31 and November 22 and again on January 10, 2012. . The initial field survey on October 31 was completed primarily to delineate the “top of bank line” along the south side of the Cache la Poudre River. The top of bank line was delineated and mapped in the field in consultation with City of Fort Collins staff, Lindsay Ex (Environmental Planner, Current Planning) and Marsha Hilmes-Robinson (Floodplain Administrator). The City of Fort Collins uses the top of bank line for determining buffer setback distances from streams and other water bodies. The second field survey was completed on November 22 to characterize existing wildlife habitats, as well as to identify any unique or sensitive natural resource features. Observations recorded during the field evaluation included major vegetation communities / wildlife habitats present within the property, dominant vegetation associated with each community / habitat, unique habitat features, tree species, and observations of wildlife species and/or definitive sign. Photographs showing representative views of existing habitats were also taken to document site conditions. Wildlife presence and habitat use was based on on-site observations and habitat presence in conjunction with the known habitat requirements of potential wildlife species. Existing habitats were also evaluated regarding their ability to support populations of threatened, endangered, and other sensitive plant and wildlife species. The final survey on January 10, 2012 was completed to delineate and characterize wetlands on the Pateros Creek property. Wetlands on the property were previously reviewed by Terry McKee with the U.S. Army Corps of Engineers (ACOE) on December 30, 2011, and the wetland mapping was approved by the ACOE on January 12, 2012 (see attached letter). 2 3 Natural Resources Conservation Service (formerly SCS) soils mapping (Soil Survey of Larimer County Area, Colorado) was also reviewed to evaluate soils resources regarding potential establishment of native vegetation communities and determine if any known hydric (wetland) soil mapping units are located on the property. 3.0 HABITAT CONDITIONS AND WILDLIFE USE Although the Pateros Creek property is adjacent to and contains portions of the Cache la Poudre River riparian corridor (see Figure 2, at end of report), the ecological function and character of the site have been considerably compromised by existing residential development and the use of portions of the property for refuse disposal and equipment or materials storage. As indicated on Figure 2, there are few portions of the property that have not been impacted by residential development, past disturbance, or refuse disposal. Relatively undisturbed riparian habitat conditions are supported only in the approximate eastern quarter of the proposed development site. The continuity of the site with the existing Cache la Poudre riparian and river corridor is further affected and segregated by the paved Poudre River recreation trail and by a 6-foot chain-link fence along the north and east property boundaries. This fencing continues around the east end of the site and along the southern property boundary as well. Topography of the site is nearly level. Existing land uses within the property consist developed residential, refuse disposal areas, and undeveloped land and wildlife habitat for urban adapted species. Surrounding land uses consist of a mix of residential, commercial, undeveloped land, and river corridor with recreational trail. USDA, Natural Resources Conservation Service (NRCS) soils mapping (2011) indicates that Paoli fine sandy loam and Table Mountain loam are the predominant soils contained within the property boundaries. Paoli fine sand loam occupies approximately two-thirds of the property along its northern and eastern portions. Table Mountain loam comprises the remainder of the southwest portion of the property. Both soils are deep, well-drained soils that formed in alluvium on terraces and floodplains near drainages. Neither is classified as a hydric (wetland) soil, but they can contain hydric inclusions. The Soil Conservation Service (1980) indicates that native vegetation supported by these two soils consists primarily native prairie species including blue grama (Bouteloua gracilis)1, little bluestem (Schizachyrium scoparium), needle-and-thread (Hesperostipa comata), and bluegrasses (Poa spp.) (SCS 1980). Field surveys completed for the Pateros Creek property indicate that Paoli fine sandy loam also supports native riparian woodland dominated by eastern cottonwood (Populus deltoides) and a number of non-native tree species. 1 Scientific nomenclature for vegetation follows: USDA, NRCS PLANTS National Database at: http://plants.usda.gov/java/. 4 Habitats delineated within the property boundaries include disturbed areas (including residential, graded, and refuse disposal sites), non-native grassland, riparian woodlands, wetlands, and a small pond (see Figure 2). The following sections summarize the ecological characteristics of habitats on the Pateros Creek property and wildlife use of the area. 3.1 Disturbed Areas Disturbed areas on the property consist of existing residences, shops and garages, debris or refuse piles, and areas graded to remove debris or for fill placement to elevate areas above the floodplain. These areas are generally devoid of vegetation except where residential landscaping has been established. Some of the trees in the residential areas would be classified as significant by the City of Fort Collins and should be preserved wherever possible. In addition, a few remnant native riparian as well as undesirable, invasive tree species exist along the western half of the north property boundary (see Figure 2). Trees growing in this area are primarily Siberian elms (Ulmus pumila) with a few eastern cottonwoods. Siberian elms are generally considered to be an undesirable, invasive tree species. All trees over 6 inches in diameter have been surveyed, and their locations are plotted on an exhibit in the conceptual review documents submitted to the City of Fort Collins. In the other disturbed, mostly bare areas, annual weeds such as kochia (Bassia scoparia), cheatgrass (Bromus tectorum), western ragweed (Ambrosia psilostachya), redroot amaranth (Amaranthus retroflexus), Canada thistle (Cirsium arvense), and stinkgrass (Eragrostis cilianensis) are the most common species. Photos 1, 2, and 3 provide representative views of disturbed and graded areas on the Pateros Creek property. Because of the disturbed nature of these habitats and human presence and activities, habitat value and wildlife use is limited primarily to urban adapted songbirds use of established landscape and existing trees. 3.2 Non-native Grassland Non-native grassland is dominated primarily by smooth brome (Bromus inermis) with minor amounts of intermediate wheatgrass (Thinopyrum intermedium), crested wheatgrass (Agropyron cristatum), and western wheatgrass (Pascopyrum smithii). The largest non-native grassland parcel is located along the western edge of riparian woodland (see Figure 2). This area of non-native grassland appears to have been subjected to some form of past surface disturbance since the ground surface is uneven and hummocky. Past disturbance in this non-native grassland parcel has also resulted in a greater representation of annual weedy species such as kochia, cheatgrass, Canada thistle, netseed 5 6 7 lambsquarters (Chenopodium berlandieri), and common mullein (Verbascum thapsus). Photos 4 and 5 provide views of non-native grassland/disturbed areas on the property. Habitat value and wildlife use of non-native grassland is limited by the lack of woody vegetation and the relative small size and lack of continuity of these habitat parcels. Where non-native grassland is intermixed with riparian woodland, it provides additional habitat diversity. Mice, voles, and pocket gopher are the only species likely to establish resident populations in non-native grassland habitat. Songbirds such as western meadowlark, Brewer’s blackbird, common grackle, and black-billed magpie may also occasionally use the more open portions of these grassland habitats. Red fox, striped skunk, and raccoon may also forage in this area on occasion. 3.1 Riparian Woodland, Tree Cluster, and Tree Line Riparian woodland is associated with the Cache la Poudre River riparian corridor (see Figure 2). The small tree cluster area is a small pocket of riparian vegetation isolated from the main riparian corridor by past disturbance and vegetation clearing. A number of tree species are supported by these two habitat areas including both relatively young and large, mature eastern cottonwoods (Populus deltoides); crack willows (Salix fragilis); Siberian elms; and a few peachleaf willow (Salix amygdaloides), green ash (Fraxinus pennsylvanica), Russian olive (Elaeagnus angustifolia), and boxelder (Acer negundo) trees. Most of the larger native and desirable non-native trees would be classified as significant by the City of Fort Collins and should be protected, to the extent possible. A non-native grass, smooth brome, dominates the understory. There are locations within and adjacent to riparian woodland where large trash items (e.g. metal tanks, appliances, lumber, furniture, woody slash, etc.) have been dumped. The line of trees growing along the southern property boundary consists of a mix of native riparian, ornamental landscape, and non-native invasive tree species. These trees appear to have developed along an abandoned irrigation ditch that parallels the south property boundary. The principal native species is eastern cottonwood, which range from 3 to 14 inches in diameter. Blue spruce is an ornamental species planted in this area, while Siberian elm, Russian olive, and boxelder are the non- native species growing in this tree line. Photos 5, 6, and 7 provide representative views of riparian woodland. In terms of vegetation and wildlife species diversity, riparian woodland areas represent the most valuable and diverse wildlife habitat within or near the project area. However, dominance by smooth brome in the understory and refuse piles somewhat reduce the overall habitat value of riparian woodland in the project area. Several of the trees are large enough to be suitable as raptor nest sites, but no raptor nests were located on or near the property. The proximity of nearby developments and recreational use 8 9 10 of the Poudre River trail reduce the likelihood of any future raptor nesting use of the property by most raptors except perhaps by great horned owl and American kestrel. Larger trees and snags in riparian habitats provide important foraging and/or nesting habitat for woodpeckers, a variety of songbirds, and, possibly, American kestrel. Because of the fall season timing (October and November) of the field survey, observations of songbirds and other avian species were limited. Northern flicker, dark-eyed junco, and blue jay were the only bird species observed on the property, but spring and summer avian use of the property is likely to be much more diverse. Other wildlife species documented using riparian woodland on the Pateros Creek property were mule deer, red fox, raccoon, mink, and fox squirrel. Apparently, the 6-foot chain-link fence along the north, east, and south property boundaries does not prevent larger mammals such as mule deer, red fox, and raccoon from moving in and out of project area riparian habitats. 3.4 Wetlands and Pond Wetlands exist on the property as four isolated depressions in riparian habitat, six small wetland pockets on a remnant irrigation ditch along the southwest property line, and two slightly larger wetlands on the remnant irrigation ditch along the southeast property line. The only other project area wetland is associated with the pond perimeter at the southeast property corner (see Figure 2). The dominant wetland herbaceous species in all but the pond wetland is reed canarygrass (Phalaris arundinacea). Small stands of coyote willow (Salix exigua) are also present in the two of the four riparian woodland wetland depressions as well as in the largest of the southern property line wetlands. The wetland area around the pond perimeter is dominated by reed canarygrass with crack willow in the overstory, but the west, and apparently drier, end of this wetland supports primarily smartweed (Polygonum sp.) and sedge (Carex sp.). Photos 8, 9, and 10 provide representative views of wetland areas and the pond on the Pateros Creek property. The ACOE has not provided an jurisdictional determination for the project area wetlands, but all of the wetlands except for the southeast corner pond/wetland area would likely be classified as non-jurisdictional since they have no wetland or channel connection to other Waters of the U.S. (i.e. the Poudre River). The pond and associated wetland in the southeast property corner would likely be classified as jurisdictional since the outflow channel from the pond flows into the Poudre River. All wetlands are under ¼ acre in size, but riparian and pond wetlands provide additional habitat diversity within riparian woodland and may provide spring breeding habitat for local amphibian populations such as northern chorus frog and Woodhouse’s toad. The small pond was observed being used by a mink during the second field survey and may also serve as resting, loafing, feeding habitat by puddle ducks such as mallard and green- winged teal. The six small pocket wetlands along the southwest property line have developed in a remnant irrigation lateral that is no longer functioning, and these wetlands may not persist into the future. 11 12 These wetland pockets no longer provide a water quality function, and their value as wildlife habitat is negligible because by their small, isolated nature and single-species dominance by reed canarygrass. Coyote willow in the largest south boundary wetland may provide some additional songbird-nesting habitat. 1.0 ECOLOGICAL CHARACTERIZATION STUDY CHECKLIST The following provides a summary of information required by Fort Collins Land Use Code under 3.4.1 (D) (1) items (a) through (i). Items (j) and (k) are addressed under the next section, 5.0 Potential Impacts and Wildlife Mitigation Recommendations. (a and i) Wildlife use and general ecological functions of the Pateros Creek property are described in the preceding Section 3.0. (b) Wetlands on the property are described in Section 3.4. (c) The project area provides significant and relatively unobstructed views of the Cache la Poudre River and the riparian corridor, although these views are compromised somewhat by existing 6-foot chain-link fencing and the paved Poudre River recreation trail. (d) As indicated in Sections 3.1 and 3.3 a number of significant trees existing within the disturbed areas and in riparian woodland. Trees 6 inches or greater in diameter on the property may be classified as significant trees by the City’s Land Use Code. All trees over 6 inches in diameter have been surveyed, and their locations are plotted on an exhibit in the conceptual review documents submitted to the City of Fort Collins. The applicant is in the process of having the health status determined for all inventoried trees. 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. (e) The only natural drainage in the project area is the Cache la Poudre River. The top of bank of the river and 300-foot buffer from the top of bank is depicted on project survey maps provided in the conceptual review submittal documents. (f) The project area was evaluated with regards to potential habitat for state and federal listed threatened and endangered species. The Cache la Poudre River corridor and adjacent wetland and riparian habitats could possibly provide suitable habitat for three federal listed threatened species, Preble’s meadow jumping mouse (Zapus hudsonius preblei), Colorado butterfly plant (Gaura neomexicana coloradensis), and Ute ladies’-tresses orchid (Spiranthes diluvialis). An evaluation of their potential presence is provided in the following paragraphs. 13 Preble’s meadow jumping mouse. Suitable habitat for the jumping mouse is provided by low undergrowth consisting of grasses, forbs, or both in open wet meadows and riparian corridors or where tall shrubs and low trees provide adequate cover. Potential habitat includes wet meadow habitats, native hayfields, stream channels (perennial and intermittent), riparian habitats, or floodplains below 7,600 feet elevation in Colorado. Saturated wetlands supporting dense stands of cattail or bulrush do not provide suitable habitat conditions for the jumping mouse (U.S. Fish and Wildlife Service 1999; Armstrong et al. 1997). Potentially suitable wetland herbaceous and woody cover for Preble’s meadow jumping mouse may be supported in the riparian and pond/wetland areas at the east end of the property, but no populations of jumping mouse are known to exist along the Poudre River downstream of the Watson Lake area. Colorado butterfly plant. The Colorado butterfly plant is a short-lived, perennial herb endemic to moist soils in mesic or wet meadows of floodplain areas in southeastern Wyoming, north-central Colorado, and extreme western Nebraska. This early to mid-seral stage species occurs primarily in habitats created and maintained by streams active within their floodplains with vegetation that is relatively open and not overly dense or overgrown. It is found on subirrigated, alluvial soils of drainage bottoms surrounded by mixed grass prairie at elevations of 5,000 to 6,400 feet (Spackman et al. 1997, Federal Register 1998). Populations of this species are often found in low depressions or along bends in wide, active, meandering stream channels a short distance upslope of the actual channel. The plant requires early to mid-seral riparian habitats. Typical habitat is relatively open without dense or overgrown vegetation. It commonly occurs in communities dominated by redtop (Agrostis stolonifera) and Kentucky bluegrass on wetter sites and by wild licorice (Glycyrrhiza lepidota), Flodman's thistle (Cirsium flodmanii), curlycup gumweed (Grindelia squarrosa), and smooth scouring rush (Hippochaete laevigata) on drier sites. These areas are usually intermediate in moisture between wet, streamside communities dominated by sedges, rushes, and cattails, and dry shortgrass prairie (Federal Register 1998). Suitable streamside habitats for Colorado butterfly plant do no exist on the Pateros Creek property. Ute ladies’-tresses orchid. Habitat for the Ute ladies'-tresses orchid typically consists of seasonally moist soils and wet meadows near lakes, springs, or perennial streams and their associated floodplains below 6,500 feet. Associated vegetation species typically include those with a "FACW" Corps of Engineers classification (Equisetum, Asclepias, Calamagrostis, Solidago, etc. genera) occurring in relatively open and not overly dense, overgrown, or over-grazed areas. This species prefers comparatively well-drained, high moisture content wetland soils that are not strongly anaerobic or composed of heavy clays. Conversely, sites consisting entirely of dense stands of reed canarygrass, those characterized by standing water including monocultures of cattails or three-square, dense clayey soils, or highly saline soils supporting a dense community of inland saltgrass (Distichlis stricta) are not 14 considered to be habitat for this species (U. S. Fish and Wildlife Service memorandum: Plants - Spiranthes diluvialis, Ute ladies'-tresses orchid, dated November 23, 1992). No suitable wetland habitat for Ute ladies’-tresses orchid exists on the Pateros Creek property. (g) Because of past disturbances over most portions of the project area, the only special habitat features on the property are the pond, wetlands, and relatively undisturbed riparian woodland habitat parcels in the eastern quarter of the property. The Cache la Poudre River corridor immediately north of the property and the pond immediately south of the property also represent special habitat features. (h) The Cache la Poudre River corridor along the north and east property boundaries represents a wildlife movement corridor primarily for songbirds and urban-adapted water birds and other terrestrial species (e.g. striped skunk, raccoon, red fox, fox squirrel, and mule deer). The river corridor is partially isolated from the project area by the existing paved recreation trail and a 6-foot chain-link fence. 2.0 POTENTIAL IMPACTS WILDLIFE MITIGATION RECOMMENDATIONS The remaining Items, (j) and (k) of the ECS Checklist, are addressed in this section. (j) There is only one issue regarding the timing of building construction/removal and ecological features or wildlife use of the project area. If existing trees or shrubs require removal for project development, they should be cut down outside of the songbird-nesting season (April-July) to avoid any potential loss of active nests with young, which would be a violation of the Migratory Bird Treaty Act (MBTA). In lieu of a timing restriction for removal, trees and shrubs could be removed during the nesting season if nest surveys confirm a lack of nests. None of the trees on or near the property exhibited any evidence of raptor nesting activity, and it is unlikely any raptors would nest near the property because of the intensity of human activities within and surrounding the area. (k) Re-development of the Pateros Creek parcel and removal of some existing disturbances would create few additional impacts to the Cache la Poudre River corridor beyond those that currently exist with existing development and disturbance. However, the physical configuration, important natural resource features, and City of Fort Collins buffer requirements regarding these natural resources put some constraints on re-development of the Pateros Creek property. Habitats of greatest value on or near the property are the riparian woodlands and wetlands in the eastern quarter of the site and the Cache la Poudre River corridor, along with associated riparian woodlands, to the north and east of the property. The primary City of Fort Collins Land Use Code buffer zone and other environmental standards (Section 3.4.1) that apply to the Pateros Creek property are as follows. • 300-foot development buffer from the top of bank of the Cache la Poudre River 15 • 50-foot development buffer from the edge of isolated patches of native riparian forest and from wetlands less than 1/3 acre in size • Preserve significant trees wherever possible; mitigation will be required for loss of any significant trees The existing condition of the property is not in compliance with the 300-foot Poudre River buffer. In addition, many of the undeveloped portions of the property within the 300-foot buffer have been significantly disturbed by vegetation removal, dumping of debris, and equipment and materials storage, even where development has not occurred. The Pateros Creek property is currently outside City Limits, and the majority of the site was developed and disturbed before City buffer standards were promulgated. However, once the property is annexed by Fort Collins, City Land Use Code buffer standards would apply. The design team for the Pateros Creek property has developed three different scenarios based on buffer standards, as well as other City of Fort Collins development requirements (see Figure 3). These design scenarios are provided in the conceptual review documents submitted to the City. Relative habitat quality rankings provided in the conceptual review documents were based on the habitat mapping provided in Figure 2 of this report. This ECS Report evaluates the three development scenarios solely on environmental and habitat quality considerations, while conceptual review documents evaluate the three scenarios on a variety of planning and development considerations. Table 1 provides a summary comparison of the principal environmental considerations for the three development scenario alternatives. Based on this comparison, Alternative C appears to be the most environmentally appropriate alternative for a number of reasons. First and foremost, there would be no encroachment into higher quality riparian habitat with this alternative, and the river buffer would exceed 300 feet in the area supporting the highest value riparian habitat. A development buffer of 80 to 200 feet would be maintained in the areas currently supporting the most degraded or non-existent riparian habitat on the development site. There would also be no loss of native riparian tree or other vegetation with this alternative. Although the 300-foot Poudre River buffer would be reduced by Alternative C (average 18% reduction over 55% of buffer zone length), proposed buffer habitat conditions would be considerably enhanced over existing conditions. In addition, reduction of the buffer in existing, lower quality habitat areas permits total preservation of higher quality riparian habitats and an expanded buffer from the river in these areas. As indicated in Section 3.0, much of the property has been degraded by past disturbances and land use practices. Areas to remain as open space and be landscaped within the Poudre River buffer zone would be considerably enhanced, over existing conditions. Enhancement would occur by the conversion of areas dominated by bare ground, debris piles, and/or mostly weedy and non-native grass 16 17 Table 1. Environmental Comparison of Alternative Development Scenarios Design Alternative Compliance with 300-foot Poudre River Buffer1 Compliance with 50-foot Riparian Woodland and Wetland Buffer1 Compliance with Significant Tree Preservation Clean Up and Removal of Debris Piles, Scrap Equipment, and Materials from Open Space Alternative A Yes No Plan would result in encroachment into higher quality (relatively undisturbed) riparian habitat. A 50 -foot buffer would be maintained for the riparian and pond wetlands, but all other south property boundary wetlands would be lost to development A. Yes There would be some loss of significant landscape trees, as well as native riparian trees. Losses of significant trees would be mitigated with tree plantings in the buffer zone. Yes Alternative B Yes No Same as Alternative A Yes Same as Alternative A, except there would be a greater loss of existing significant landscape trees. Yes Alternative C No 300-foot buffer would be reduced by ~ 25 to 70 feet (avg. ~ 18% reduction) over 18 species to areas revegetated by native riparian, perennial woody and herbaceous species. With these enhancement measures and extensive plantings of native vegetation, buffer zone performance standards specified in Section 3.4.1 of the Land Use Code would be met, even with some reduction in the buffer zone standard. Another consideration regarding a reduction in the 300-foot buffer is the existing Poudre River recreation trail along the northern boundary of the Wood Street property. This existing, paved trail is within the 300- foot buffer (near its outer edge), and the considerable recreational use it receives has compromised and will continue to compromise the environmental benefit of a 300-foot buffer. Alternative A and B would have greater impacts to wetlands and would not maintain a 50-foot buffer from existing riparian habitat. Alternatives A and B would result in the loss of all wetlands along the southern property line except for the pond/wetland complex in the southeast property corner. Alternative C would maintain a 50-foot buffer from existing riparian habitat and all wetlands except the seven western-most southern boundary wetlands, a total of 3,315 square feet (< 0.08 acre), which would be lost to development. No ACOE permit would be required for theses wetland impacts since wetland loss would be under 0.1 acre. The wetland losses would be mitigated by the development of higher quality and more diverse wetlands in the proposed wetland forebay area and by expansion of the pond/wetland area complex. The size of the proposed forebay wetland would be 5,740 square feet (0.13 acre and the expanded pond area would create an additional undetermined amount of wetlands around the expanded pond perimeter. 2.1 Recommended Mitigation Measures Regardless of which development alternative is selected, a number of wildlife and habitat mitigation recommendations would apply to development of the Pateros Creek property. 1. Remove all trash and debris piles from riparian woodland and reclaim the existing dirt road in this area with native riparian species. 2. Existing native cottonwood and willow trees and significant non-native trees should be preserved unless they pose a human safety risk. 3. The currently disturbed portions of the buffer zone between proposed development and existing riparian areas should be planted with an upland riparian vegetation mix, including shrubs and trees, to create a zone of native riparian vegetation. The goal of these plantings should be to create a self-sustaining, native vegetation community to stabilize soils and enhance wildlife habitat. Plantings of native shrubs and trees should be completed along the buffer zone to provide further visual screening between development sites and important habitat areas. Buffer zone enhancement and planting plans should be coordinated with City Planning and Natural Resources staff. 4. It is not the intention of the mitigation recommendations to convert areas currently supporting stable non-native grass cover to be converted to native grassland species. Conversion of stable 19 non-native grass areas to native grassland is not recommended for three principal 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 three objectives listed in the third recommended mitigation measure. 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 and kochia. 5. Browse cages may need to be installed around planted young shrubs and trees for several years to prevent their loss from deer, beaver and other wildlife species feeding on these young plants. 6. 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 habitat enhancement areas. 7. 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. 8. It is recommended that if trees require removal, they should be cut outside of the songbird nesting season to avoid any potential loss of active nests with young, which would be in violation of the Migratory Bird Treaty Act (MBTA). In lieu of a timing restriction for removal, trees and shrubs could be removed during the nesting season if nest surveys confirm a lack of nests. 9. 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. 10. Free-roaming cats and dogs should be prohibited to protect wildlife from harassment by domestic pets and to protect predation of domestic pets by wildlife. 11. The intensity of night lighting from the sides of houses facing buffer zones, riparian habitat, and designated open space habitat should be shielded or directed to minimize the intrusion of artificial nighttime light into these areas. 12. A split rail or similar type open-rail fencing should be used as a replacement for the existing 6-foot chain-link fence along the north and east edge of the property to permit greater ease of wildlife movement between riparian areas on the Pateros Creek property and existing riparian woodlands along the Cache la Poudre River. 3.0 REFERENCES CITED Armstrong, D.M., M.E. Bakeman, N.W. Clippinger, A. Deans, M. Margulies, C.A. Meaney, C. Miller, M. O’Shea-Stone, T.R. Ryon, and M. Sanders. 1997. Report on habitat findings of the Preble’s meadow jumping mouse. Edited by M.E. Bakeman. Report presented to the U.S. Fish and Wildlife Service and the Colorado Division of Wildlife. 91 pp. Federal Register. 1998. Endangered and threatened wildlife and plants: proposed threatened status for the plant, Gaura neomexicana ssp. coloradensis. Federal Register: March 24, 1998 (Volume 63, Number 56) pp.14060-14065. Spackman, S., B. Jennings, J. Coles, C. Dawson, M. Minton, A. Kratz, and C. Spurrier. 1997. Colorado rare plant field guide. Prepared for the Bureau of Land Management, the U.S. Forest Service, and the U.S. Fish and Wildlife Service by the Colorado Natural Heritage Program, Fort Collins, Colorado. 20 Soil Conservation Service (SCS). 1980. Soil Survey of Larimer County Area, Colorado. Natural Resources Conservation Service (formerly Soil Conservation Service). U. S. Government Printing Office. Washington, D. C.174 pp. + maps. USDA, NRCS. 2011. Web Soil Survey. Available at: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx. Soil mapping for the Pateros Creek property accessed December 28, 2011. U.S. Fish and Wildlife Service. 1999. Interim survey guidelines for Preble’s meadow jumping mouse. U.S. Fish and Wildlife Service, May 19, 1999 Appendix A U.S. Army Corps of Engineers Wetland Approval Letter Appendix B Oversized Figure 2 - Habitat Mapping for the Pateros Creek Property 55% of buffer length. Average buffer width would be ~ 355 feet due to extensive buffer at east end of site. All areas of higher quality riparian habitat would be preserved. Yes With one exception. Buffer from higher quality riparian habitat would be maintained in excess of 50 feet at ~ 80 to 200 feet. A 50-foot buffer would be maintained for all wetlands except the 7 low quality, remnant ditch wetlands would be lost to development. Wetland losses would be mitigated by development of the forebay wetland and expansion of the wetland pond complex at the southeast property corner. Yes Loss of significant landscape trees would be similar to Alternative A. No native riparian trees would be lost. Losses of significant trees would be mitigated with tree plantings in the buffer zone. Yes 1 The decision maker can modify the buffer zone standards as long as overall project design meets the performance standards described under Section 3.4.1(E)(1) of the Land Use Code.