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HomeMy WebLinkAboutENGINES & ENERGY CONVERSION LAB - BDR - BDR120006 - REPORTS - ENVIRONMENTAL REPORTMarch 28, 2011 Stuart MacMillan Colorado State University Research Foundation (CSURF) P.O. Box 483 Fort Collins, CO 80522 RE: Ecological Characterization Study (ECS) Report for the Engines & Energy Conversion Lab (EECL) Site Stuart: This letter report is submitted in response to the City of Fort Collinsʼ requirement for an ECS Report summarizing the ecological features of the EECL site, which is proposed for modification and reconstruction of the existing EECL facilities. The EECL project site is located at the southeast corner of the intersection of the Cache la Poudre (Poudre) River and North College Avenue. The property is bounded by the Poudre River to the north, an existing railroad right-of-way to the south and east, and by North College Avenue to the west. This analysis also addresses a strip of undeveloped land between the North Aztlan Community Center and commercial buildings, including the Center for Fin Art Photography, along the east side of College Avenue (see attached Figure 1). This strip of undeveloped land is proposed as additional remote parking to serve the EECL facilities. This 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 ECS Report. I completed a field survey of the project area on March 21, 2011. The field survey was conducted to characterize existing wildlife habitats, as well as identify any unique or sensitive natural resource features. Observations recorded during the wildlife habitat field evaluation included: major vegetation communities/wildlife habitats present within the property, dominant vegetation associated with each community/habitat, and unique habitat features. Existing habitats were also evaluated regarding their ability to support populations of threatened, endangered, and other sensitive plant and wildlife species. The following provides a summary of information required by Fort Collins Land Use Code under 3.4.1 (D) (1) items (a) through (k). ECOLOGICAL STUDY CHARACTERIZATION CHECKLIST (a & i) Nearly the entire north portion of the project site has been cleared of native vegetation by past development, including buildings (currently used as research facilities), parking lots, driveways, City of Fort Collins bike trail, and landscaping. Landscaping and developed portions of the property have minimal to no habitat value for most wildlife species except for a few urban adapted songbirds such as house sparrow and house finch. However, there are a number of significant native and non-native trees growing in the landscaped portions of the north parcel. Based on the current concept plan for the property, trees south of the historic power plant building would need to be removed for proposed development. These include: two blue spruce (Picea pungens,1 ~2.0 feet dbh), two ponderosa pines (Pinus ponderosa, ~2.5 to 3.0 feet dbh), one Rocky Mountain juniper (Sabina scopulorum, ~1.5 feet dbh), one lodgepole pine (Pinus contorta, ~1 foot dbh), and one eastern cottonwood (Populus deltoides, ~2.5 feet dbh). Section 3.2.1 of the Fort Collins Land Use Code would require mitigation tree plantings for the loss of these trees or any other significant trees on the property. 1 Scientific nomenclature for vegetation follows: Weber, W. A. and R. C. Wittmann. 2001. Colorado Flora Eastern Slope, third edition. University Press of Colorado, Niwot, Colorado. 521 pp. S. MacMillan 3/28/11 Page 2 of 4 The only undeveloped portions of the north parcel are a strip of non-native grassland and riparian vegetation located along the edge of the Poudre River, a small pocket of grassland in the northeast corner, and a previously disturbed strip of ground dominated by non-native grasses and annual weeds along the north edge of the railroad right-of-way (see attached Figure 1). Dominant vegetation species recorded adjacent to the railroad right-of-way included kochia (Bassia sieversiana), cheatgrass (Anisantha tectorum), saltgrass (Distichlis stricta), smooth brome (Bromopsis inermis), stinkgrass (Eragrostis cilianensis), and witchgrass (Panicum capillare). The small grassland parcel in the northeast corner of the site supports primarily a native grass, blue grama (Chondrosum gracile), with lesser amounts of smooth brome, saltgrass, and crested wheatgrass (Agropyron cristatum). Dominant grasses in the non-native grass strip adjacent to the river edge are smooth brome and crested wheatgrass. Wildlife habitat value of these undeveloped grass and weed-dominated parcels is minimal because of their small size, lack of any woody vegetation cover, and surrounding development and land uses. The other undeveloped habitats within the north portion of the project area are riparian/disturbed and riparian at the north end of the property. Riparian/disturbed is supported on a steep slope down to the riverʼs edge. This segment of riparian habitat was classified as disturbed because it has been cleared in the past and stabilized with large rock, concrete blocks, and erosion control fabrics. As a result of past disturbance, there is relatively little to no vegetation in the understory, and the tree overstory is dominated primarily by non-native Siberian elms (Ulmus pumila), especially at the east end of this habitat area. However, five large, native peach-leaf willows (Salix amygdaloides) are supported at the west end of this habitat area. The undisturbed riparian area supports a variety of young and mature trees, including peach-leaf willow, Siberian elm, and box elder (Negundo aceroides). This segment of riparian habitat has not been heavily disturbed, but is not continuous with other segments of riparian habitat along the river corridor because of a concrete retaining wall to the east and the North College Avenue bridge to the west. The south portion of the proposed EECL development appears to have been partially cleared or disturbed in the past. It is surrounded by existing development and a railroad right-of-way. Because of past disturbance or clearing, no woody vegetation species are supported in this area. Dominant vegetation supported on this parcel is comprised of remnant, small pockets of native grasses, blue grama, switchgrass (Panicum virgatum), sand dropseed (Sporobolus cryptandrus), and little bluestem (Schizachyrium scoparium) mixed with non-native grasses and annual weeds, including smooth brome, cheatgrass, tall fescue (Festuca arundinacea), kochia, curly dock (Rumex crispus), knotweed (Polygonum arenastrum), field bindweed (Convolvulus arvensis), prostrate vervain (Verbena bracteata), and prickly lettuce (Lactuca serriola). Wildlife habitat value of the south parcel is low because of the lack of any woody cover, prevalence of annual weedy species, small parcel size, and surrounding railroad rights-of-way and development. The river corridor and riparian habitats along the river edge represent the only ecologically important habitats within the property boundaries. However, even the riparian woodlands have been degraded by past slope stabilization measures, and steep slopes and a concrete retaining wall restrict wetland development along the riverʼs edge. Surrounding land uses of highways, railroad tracks, and commercial development further limit habitat value and wildlife use of the river corridor portion of the EECL north parcel. Songbirds, urban adapted mammals (e.g., raccoon, striped skunk, and fox squirrel), and a few water birds such as mallard and Canada goose are wildlife species likely to use the river corridor adjacent to the EECL. Fox squirrel was the only species observed during the field survey of the property. Features of ecological value within 500 feet of the EECL parcels include the Cache la Poudre River corridor and the Gustav Swanson Natural Area. Proposed development within the two EECL parcels would have little impact on these two areas beyond what has already occurred as a result of past developments in the adjacent properties. S. MacMillan 3/28/11 Page 3 of 4 (b) No wetlands are located on the property except at the north edge of the parcel along the edge of the Cache la Poudre River. Because of the very steep slopes from the level edge of the property down to the river and past bank stabilization efforts employing rock placement and concrete retaining wall, wetland vegetation development is restricted to a narrow (1 to 2-foot wide), shoreline strip immediately adjacent to the river in the undisturbed riparian segment at the northwest property corner. The wetlands are jurisdictional but were not mapped since project development would have no impact on the river corridor. (c) The project area does not provide any significant or unobstructed views of natural areas or other important visual features. Views of the Cache la Poudre River corridor from all but the north edge of the property are precluded by the steep drop off from the north edge of the property down to the river. (d) As indicated under (a & i) there are significant native peach-leaf willow trees in the two riparian habitat areas and other significant trees exist in the landscaping around the historic power plant building. Small pockets of remnant, native grasses also are supported in the undeveloped grassland portions of the two development parcels. (e) The only natural drainage in the project area is the Cache la Poudre River. The river corridor is isolated from the majority of the project area by a steep slope and concrete retaining wall at the north edge of the property. (f) Suitable habitat conditions for Prebleʼs meadow jumping mouse (Zapus hudsonius preblei), Ute ladiesʼ-tresses orchid (Spiranthes diluvialis), and Colorado butterfly plant (Gaura neomexicana coloradensis) were judged not to be present within the project area. Slopes down to the river are too steep to support suitable soil moisture conditions for the orchid or butterfly plant, and wetland herbaceous cover preferred by the jumping mouse is absent along the this portion of the river shoreline because of steep slopes, extensive amounts of rock, concrete retaining wall, and scouring by high river. (g) Because of past disturbances and over most portions of the project area, there are no special habitat features present except for the Cache la Poudre River corridor. (h) The Cache la Poudre River provides a movement corridor for urban-adapted wildlife species. The river corridor is isolated from the project area, both physically and visually by the steep slope between the river and the remainder of the property. (j) There are no issues regarding the timing of building construction/removal and ecological features or wildlife use of the project area. 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 in and surrounding the area. (k) Additional development of the EECL parcel and removal of some existing development would create no additional impacts to the Cache la Poudre River corridor beyond those that currently exist with current development and surrounding commercial and roadway land uses. The current Fort Collins Land Use Code buffer standard for this segment of the Poudre River is 200 feet (Section 3.4.1 of the Land Use Code). However, the majority of the EECL project area was developed long before this buffer standard was instituted. Based on the most recent concept plan for the proposed development, the historic power plant building and existing City bike trail would remain within the 200-foot buffer zone, but much of the existing ancillary buildings (Solix Biofuels) and paved parking areas east of the power plant building would be removed and shifted to areas south of the 200-foot buffer and the historic power plant building. This plan indicates approximately 1.0 acre of development (buildings and paved parking lots) would be removed from the Poudre River 200-foot buffer. Any conversion of developed land to more natural habitats within the 200-foot buffer would improve overall habitat conditions along the Poudre River. However these improvements would be relatively small (~1.0 acre) and isolated due to surrounding developments, railroad right-of-way, bike trail, and roadways within the 200-foot buffer. In addition, the S. MacMillan 3/28/11 Page 4 of 4 quality of the riparian corridor, adjacent to the river and the parcel where development would be removed, has been degraded by past bank and river stabilization activities. As indicated under the discussion for Checklist Items (a & i), rock and concrete retaining wall placement and scouring river flows have prevented the development of understory and wetland vegetation, and overstory trees along this portion of the river are dominated by non-native Siberian elms, which are classified as a nuisance species by the City of Fort Collins. Even prior to development occurring on the EECL property, the riparian corridor along this portion of the Poudre River was probably not very extensive because of the cutting nature of the river along this section of shoreline and the relatively steep slope transition from adjacent uplands down to the waterʼs edge. A review of Natural Resources Conservation Service (NRCS, formerly SCS) soils mapping for the EECL project area indicates the Paoli fine sandy loam soil-mapping unit underlies the entire site up to the river embankment. This is an upland soil that, in an undisturbed state, supports native short-grass prairie species such as blue grama, little bluestem, and needlegrass (Nasella viridula)2. As indicated under the discussion for Checklist Items (a & i), remnant pockets of blue grama and/or little bluestem still are present in the northeast corner of the north EECL parcel and throughout the undeveloped EECL south parcel. Based on the extent of current development within the 200-foot buffer and surrounding developments, railroad rights-of-way, and roadways, I do not believe that any habitat enhancement or mitigation measures are appropriate for the buffer and remaining portions of the two development parcels except for returning the 1.0-acre area of development removal to its former native prairie condition. Plantings of native shrubs and trees along the northern edge of the 1.0-acre parcel would create increased habitat diversity primarily for songbirds adjacent to the river corridor and provide additional visual screening between proposed and existing development and the edge of the river corridor. Any habitat enhancement plantings would likely require soil treatment to relieve compaction (ripping) and improve fertility (fertilizer amendments). Selection of species to be used for revegetation should focus on dryland drought tolerant species since the buffer area is elevated well above the river corridor. Even with the use of drought tolerant species, supplemental irrigation would likely be required for initial establishment of shrubs and trees. Stuart, this concludes my evaluation of the EECL project area. If you have any questions or require additional input regarding my evaluation, please give me a call. Sincerely, CEDAR CREEK ASSOCIATES, INC. T. Michael Phelan Principal attachment pc: Nick Haws, Northern Engineering w/ attachment 2 Soil Conservation Service. 1980. Soil survey of Larimer County area, Colorado. USDA, SCS, and Forest Service in cooperation with Colorado Agricultural Experiment Station. U.S. Government Printing Office, Washington, D.C. 174 pp. + maps.