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HomeMy WebLinkAboutPOWERHOUSE 2 - PDP220006 - SUBMITTAL DOCUMENTS - ROUND 1 - ECS REPORT Prepared for: Powerhouse 2 Development Company Prepared by: Auckland Environmental Consulting February 16, 2022 Powerhouse 2 Ecological Characterization Report Powerhouse 2: ECS Report TOC February 16, 2022 Table of Contents 1.0 Introduction ................................................................................................................................. 2 1.1 Site Location ............................................................................................................................. 2 1.2 Project Background .................................................................................................................. 2 1.3 Project Description ................................................................................................................... 2 2.0 Methodology ................................................................................................................................ 5 3.0 Existing Ecological Conditions ...................................................................................................... 6 3.1 Hydrology and Soils .................................................................................................................. 6 3.2 Existing Development and Vegetation ..................................................................................... 6 3.3 Potential Waters of the US ....................................................................................................... 9 3.4 Threatened and Endangered Species ....................................................................................... 9 4.0 Ecological Characterization and Buffer Zone ............................................................................. 11 4.1 Ecological Characterization Study .......................................................................................... 11 4.2 Buffer Zone Establishment ..................................................................................................... 12 5.0 Impacts ....................................................................................................................................... 13 6.0 Recommendations ..................................................................................................................... 15 7.0 References .................................................................................................................................. 19 Tables and Figures Table 1. Existing and Proposed Cover Types Table 2. Planting Recommendations Figure 1 Project Location Figure 2. Project Vicinity and Parcels Figure 3. Existing Conditions Figure 4. Proposed Condition (Site Plan prepared by BHA) Appendix Appendix A. Photographic Log Powerhouse 2 ECS Report Page 2 of 19 February 16, 2022 1.0 Introduction The Powerhouse 2 Development Company, LLC (Applicant) has contracted with Auckland Environmental Consulting (AEC) to assist in environmental documentation and permitting for the proposed Powerhouse 2 project (Project). This Ecological Characterization Study (ECS) report has been prepared to meet the requirements of the City of Fort Collins’ (City) Land Use Code Section 3.4.1 “Natural Habitats and Features,” subsection (D) “Ecological Characterization and Natural Habitat or Feature Boundary Definition.” This report also addresses possible project impacts to potential Water’s of the US under US Army Corps of Engineers (USACE) jurisdiction or federally-listed threatened and endangered species, so it may be used to support future environmental documentation requirements. 1.1 Site Location The approximately five-acre project site is on the north side of the City of Fort Collins and approximately 400 feet north of the Cache la Poudre River, in Larimer County, Colorado (Figure 1). The Site is bounded by College Avenue (US Highway 287) to the west, East Vine Drive to the south, Jerome Street to the east, and Lake Canal (Canal) to the north (Site). The Site is comprised of three different parcels 700 N College Avenue (Fort Collins Truck Sales), 108 E Vine Drive (Rocky Mountain Automotive) and 202 East Vine Drive (Henry Hersch Trucking), Fort Collins, CO, 80524 (Figure 2). The Site is in the southwest corner of Section 1, Township 7 North, Range 69 West with center coordinates of 40.596439 latitude and -105.075199 longitude (WGS 84 datum). The Site is almost flat and has an average elevation of approximately 4,965 feet. 1.2 Project Background Powerhouse 2 is a public-private partnership that would focus on research and development of climate solutions. It is located within the City’s Innovation Subdistrict of the Downtown District, which already includes the nearby Powerhouse Energy Campus (Powerhouse 1) and the Innosphere technology startup (Figure 2). It is also located near the River Subdistrict. The City requires an Ecological Characterization Study (ECS) because the Site is within 500 feet of known natural habitat, including the Canal with associated riparian forest along the Site’s north edge (City, 2021). The City’s environmental planning contact is Scott Benton. 1.3 Project Description The Powerhouse 2 Project would be total redevelopment of a light industrial/commercial area that is currently occupied by scattered buildings and parking lots. The main physical elements of the Powerhouse 2 Project are a large building in the southwest corner, approximately 160 parking spaces, restoration of a riparian buffer along the Canal, stormwater management, and landscaping. The Project includes construction of a trail segment and pedestrian bridge that would pass through a City-owned parcel and cross the Canal. Powerhouse 2 ECS Report Page 3 of 19 February 16, 2022 Figure 1. Project Location Site 2000 Feet Powerhouse 2 ECS Report Page 4 of 19 February 16, 2022 Figure 2. Project Vicinity and Parcels (Source: Fort Collins GIS) Hersch Trucking Rocky Mountain Automotive Fort Collins Truck Sales Powerhouse 2 ECS Report Page 5 of 19 February 16, 2022 2.0 Methodology A desktop review of the Site was completed by reviewing publically available data, including: • Current and historic aerial imagery • United States Geological Survey (USGS) topographic maps • National Resources Conservation Service (NRCS) soil survey data • U.S. Fish and Wildlife Service (USFWS) Information for National Wetland Inventory (NWI) maps and Planning and Conservation (IPaC) data • Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps (FIRM) • City of Fort Collins Geographic Information System (GIS) data • Colorado Oil and Gas Commission (COGCC) GIS data (compiles multiagency data) A site visit and on-site meeting with Scott Benton (City Environmental Planner) were conducted on January 27, 2022 by Julia Auckland of AEC. Ms. Auckland is a wildlife biology and ecology professional with more than 20 years of experience. Her areas of expertise include wetlands, threatened and endangered species, birds, butterflies, the National Environmental Policy Act, habitat mapping, and permitting. She has a bachelor’s degree in Fisheries and Wildlife Science and a Master’s degree in Ecology and Evolutionary Biology. The following were completed during the Site visit; • Take representative photographs (Appendix A), • Document conditions on-Site and in the riparian habitat along Lake Canal, including vegetation, hydrology, and wildlife use, • Noted features per the ECS requirements; • A habitat assessment for federally-listed species with the potential to be impacted by the project based on the United States Fish and Wildlife (USFWS) Information for Planning and Conservation (IPAC) web-based system; and • Evaluation of the Site for potential ecological improvements. Additionally, the riparian vegetation drip line and the top of bank along the south side of the Canal (adjacent to the Site) were mapped using a smart phone GIS application because these two features are used to determine the City’s Natural Habitat Buffer Zones. The City Code Definition states “Top of bank shall mean the topographical break in slope between the bank and the surrounding terrain. When a break in slope cannot be found, the outer limits of riparian vegetation shall demark the top of bank.” Per Scott Benton, the top of bank should be defined as the first topographic break above the Ordinary High Water Mark (OHWM). Potential wetlands along the Canal were mapped based on visible wetland vegetation and hydrology. A delineation of wetlands and/or Waters of the US (WUS) (wetlands) in accordance with U.S. Army Corps of Engineers (USACE) requirements was not completed for several reasons. First, no potential wetlands were present within the construction limits. Second, the City will not accept wetland delineations completed outside the growing season. Third, the ground was frozen and partially covered with snow. Powerhouse 2 ECS Report Page 6 of 19 February 16, 2022 3.0 Existing Ecological Conditions 3.1 Hydrology and Soils Hydrologic sources include precipitation, growing season Canal flows, and groundwater. Based on boring data from January 2022, the depth to ground water is only six to eight feet on the southeast portion of the Site and about ten feet in other areas. Most of the Site and the Canal are within the FEMA mapped 100-year floodplain of the nearby Cache la Poudre River (Poudre River). The hydrology of the Poudre River has been majorly altered by construction of dams and diversions for irrigation. There are three USDA mapped soils on the Site (USDA, 2022). Most of the Site (~68%) is mapped as Table Mountain loam. This series consists of very deep, well-drained soils that formed in thick, calcareous medium textured alluvium. Table Mountain soils are on alluvial fans, terraces and concave drains or old flood plains. There is also Nunn clay loam in the northeast corner (~18%) and Paoli fine sandy loam in the southwest corner (~14%); both of these series types are also very deep, well drained soils that form in alluvium. Based on the draft boring results, four to seven feet of fill material may have been added to the southern half of the Site. This may have been done to reduce flooding risks, fill in depressions, or eliminate muddy conditions and the exact extent of fill material is impossible to determine from seven data points. 3.2 Existing Development and Vegetation Most of the Site consists of parking lots that have been covered with asphalt, cement, or gravel. The western quarter of the Site consists of two lots that are semi-joined by an overlapping building (Figure 2). The northernmost lot slightly overlaps the Canal (Appendix A, Photo 7). Farther south, there is small building on the southwest corner that has signs for cell phone repair and a larger building with an attached automobile shop that is occupied by Fort Collins Truck Sales and Rocky Mountain Automotive (Appendix A, Photos 8 and 9). The large eastern portion of the Site is a 3.81-acre lot occupied by Hersch Trucking (Appendix A, Photos 1-4 and 10). Their facilities include extensive truck parking lots, an office building/single bay semi-truck garage, a small concrete building, and some concrete pads. There is a six-foot tall chain link fence along the north side and a six-foot tall wooden privacy fence along the east side of the lot. The northern fence is constructed five to ten feet south of the actual Property line. Between the north fence and the Canal top of bank there is a one- to three-foot tall berm of fill material, possibly left behind from grading the parking lot (Appendix A, Photo 4). There is also some scattered concrete debris. Based on the north bank elevation and steepness, additional fill material was likely placed here much longer ago and is now vegetated with mature trees. This could have happened during Canal construction or maintenance, or be material that was dumped here for other reasons. Powerhouse 2 ECS Report Page 7 of 19 February 16, 2022 3.2 Existing Development and Vegetation (continued) There are three main vegetation types: • Streetscaping (0.14 acre) along College Avenue and the western portion of Vine Street consists of a row of non-native black locust (Robinia pseudoacacia) trees, low juniper bushes (Juniperus sp.) and mowed grass (Figure 3). • In developed areas (5.12 acre), herbaceous vegetation is all non-native and limited to small, weedy, mowed areas around the western buildings, plus some sparse (five to 20% cover) vegetation on the edges of the eastern truck parking lot. Smooth brome (Bromus inermis) is the most common species. Other species include diffuse knapweed (Centuarea diffusa) cheatgrass (Bromus tectorum), kochia (Bassia scoparia), and prickly lettuce (Lactuca serriola). There are also scattered large trees, approximately five Siberian elms (Ulmus pumila) and a single sugar maple (Acer saccharum). • Riparian forest (0.13 acre on-Site) is located along the Canal and north of the Property line except for a narrow strip north of the fence and one section that juts out over the Canal (Appendix A, Photos 4 and 7). The entire riparian area along the south bank of the Canal is described. The eastern third is vegetated with dense native plains cottonwood (Populus deltoides ssp. monilifera). The rest of the riparian area is more diverse, but with many non-native species. Native trees include plains cottonwoods, lanceleaf cottonwoods (Populus x acuminata) and box elders (Acer negundo) (~20%). Non-native trees include Siberian elm (~50% total cover) with lesser cover of crack willows (Salix fragilis) and Russian olive (Elaeagnus angustifolia). In the shrub layer there are patches of native common snowberry (Symphoricarpos albus) (~5% cover), a couple of small native juniper trees (Juniperus scopulorum), and small Russian olives (~10% cover) (non- native). Herbaceous cover is approximately 80%, weedy, and densest along the fence/on-Site. The dominant species is smooth brome (~60% cover). Other non-native species include the Canada thistle (Cirsium arvense), perennial pepperweed (Lepidium latifolium), common mullein (Verbascum thapsus), and curly dock (Rumex crispus). The only native herbaceous species observed was showy milkweed (Asclepias speciosa). Non-vegetated areas (~20%) are the dirt piles along the fence and leaf litter under the trees. Powerhouse 2 ECS Report Page 8 of 19 February 16, 2022 Figure 3. Existing Conditions Powerhouse 2 ECS Report Page 9 of 19 February 16, 2022 3.3 Potential Waters of the US Per Section 404 of the Clean Water Act (CWA), Waters of the US (WUS) are regulated by the USACE. Waters of the US include wetlands and other waters that have a surface connection to other downstream wetlands. Other waters may include streams, irrigation ditches, and ponds with permanent or seasonal flows. Wetlands are defined as areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions (i.e. hydrophytic vegetation). The only potential WUS are along the Canal; they include open waters along the main channel up to the Ordinary High Water Mark (OHWM) and the adjacent wetland vegetation (Figure 3). Potential WUS/wetlands were mapped along the Canal where it overlaps the northernmost portion of the Site (Figures 3 and 4). Wetland vegetation along this portion of the Canal consists of a dense band of herbaceous vegetation along the lower banks and the dominant species is non-native reed canary grass (Phalaris arundinacaea). Additional WUS are expected to occur along the full length of the Canal. All other areas of the Site were confirmed to be uplands. An initial assessment was completed by reviewing NWI maps, aerial photographs, and topography. Based on vegetation color and proximity to the Canal, one area of possible wetlands was identified in the northwest corner. During the Site visit, upland conditions were present in this corner as evidenced by the presence of upland vegetation species such as diffuse knapweed, smooth brome, and cheat grass and an absence of wetland plant species. 3.4 Threatened and Endangered Species The project area was specifically assessed for nine federally-listed threatened and endangered species with potential to occur in, or be impacted by, the project per the United States Fish and Wildlife Service’s (USFWS) Information, Planning, and Conservation System website. The Project is expected to have no impact on these species. There is low quality habitat for only one species, the Preble’s meadow jumping mouse (Zapus hudsonius preblei). However, it is not expected to occur because the closest known occupied habitat is 4.7 miles northwest of the Site and the closest USFWS designated Critical Habitat is 10 miles southwest. Habitat improvements along the Poudre River floodplain should benefit this species because it inhabits healthy, shrub-dominated riparian habitat near water and relatively undisturbed uplands where they can hibernate above typical flood levels. Four species are listed because they occur downstream of the project area and could be impacted by projects that would result in water depletions to the South Platte River; piping plover (Charadrius melodus), whooping crane (Grus americana), pallid sturgeon (Scaphirhynchus albus), and western prairie fringed orchid (Platanthera praeclara). The proposed project is not expected to alter downstream flows to the South Platte River. Thus there is no potential to impact these species. Powerhouse 2 ECS Report Page 10 of 19 February 16, 2022 3.4 Threatened and Endangered Species (Continued) There is no suitable habitat within the project area for the four other species, nor are they known to occur nearby. Canada lynx (Lynx canadensis) occurs in isolated mountains. Eastern black rail (Laterallus jaimaicensis ssp. jamaicensis) occupies large marshes. Greenback cutthroat trout (Oncorhynchus clarkii stomias) occur in streams. The Ute-ladies’ tresses orchid (ULTO) (Spiranthes diluvialis) grow in mesic meadows within the transitional hydrologic zone between wetlands and uplands, including old floodplain scars. The IPAC also included one candidate species, the monarch butterfly (Danaus plexippus). Monarchs occur throughout the United States and are declining for multiple reasons including habitat loss, more intensive agriculture, and increased pesticide use. This highly mobile species could pass through much of Colorado, including the Site. However, the Site currently provides low quality habitat with minimal nectar or larval hostplants (milkweed). The proposed Project would improve monarch butterfly habitat by increasing nectar and possibly milkweed. Powerhouse 2 ECS Report Page 11 of 19 February 16, 2022 4.0 Ecological Characterization and Buffer Zone 4.1 Ecological Characterization Study The following sections address the specific details required for the Ecological Characterization Study per City Code Section 3.4.1 (D) (1) and are lettered accordingly. (a) The developed portions of the Site are low quality wildlife habitat with the greatest value being the scattered non-native trees that provide some connection for birds between the riparian forest along the Canal and the Poudre River. The Canal riparian forest is moderate quality habitat for wildlife because it provides cover and nesting habitat for numerous small species; however, the small on-Site portion is low quality habitat consisting mostly of weeds growing on piles of fill. Both areas are valuable habitat for migratory birds, especially the structurally diverse riparian forest. The existing chain link and privacy fences are major barriers to use by large mammals. The following signs of wildlife were seen; fox squirrel (Sciurus niger) nests, eastern cottontail (Sylvilagus floridanus) track in fresh snow, and a couple of cavities in dead trees that could be used by multiple species of nesting birds. Four species of birds were seen; red- tailed hawk (Buteo jamaicensis), northern flicker (Colaptes auratus), downy woodpecker (Dryobates pubescens), and European starlings (Sturnus vulgaris). (b) Wetlands occur along the short section of Lake Canal that overlaps the Site. They are limited to a narrow strip of non-native reed canary grass growing on steep slopes. Thus, they are of very low quality with their primary value being erosion control, but this condition is typical along maintained irrigation ditches. (c) The Site is flat and there are no prominent views from or across the Site. However, there are good views of riparian forest from within the Site. (d) Native vegetation is limited to riparian forest habitat that is mostly north of the Site. The portion of the riparian habitat that overlaps the Site is mostly the non-native herbaceous edge. See description in Section 3.2. (e) Non-native vegetation is dominant, primarily consists of trees, and is described in Section 3.2. The scattered non-native trees provide some shade, cooling, visual improvement, and wildlife habitat value. However, their overall value is negative because they can spread into and degrade adjacent riparian habitat. (f) The Canal top of bank was initially mapped by the surveyors, but with some concerns about accuracy. During the Site visit, the top of bank was ground-truthed by AEC and determined to be several feet lower in most areas based the location of the first topographic break above the ordinary high water mark of the ditch. However, defining the top of bank was problematic because the Canal is an artificial waterway with a north bank elevated by at least one or two layers of fill material. Powerhouse 2 ECS Report Page 12 of 19 February 16, 2022 4.1 Ecological Characterization Study (Continued) (g) Sensitive and Specially Valued Species with potential to occur in Fort Collins were identified based on the City’s 2017 Wildlife Conservation Guidelines and Larimer County species ranked as Critically Imperiled (1), Imperiled (2), or Vulnerable to Extirpation (3) by CNHP (CNHP, 2022). More than 100 wildlife and 75 plant species were reviewed and none are expected to inhabit or frequently use the Site. However, the Site’s scattered proximity to riparian habitat means that the weedy edges and scattered non-native trees could be used by some of the birds listed as City Species of Interest, especially during spring and fall migration. (h) There are no special habitat features, per the Buffer Zone table (City Code 3.4.1). (i) The Site currently has limited potential for use a wildlife corridor because the developed area has no cover and is confined by a ten-foot tall chain link along the north and east sides. Any wildlife attempting to move through the riparian habitat along the north edge of the property would be confined between the fence and the steep bank down to the Canal. Wildlife would typically prefer to move through the off-site portions of the Canal (north side and bottom when dry) because they provide alternative routes with more cover and no fences. (j) The general ecological functions of the Site are mostly negative. The natural floodplain has been altered by clearing, filling, grading, fencing, and ongoing light industrial uses. Vegetation is sparse and consists almost entirely of non-native plants that can spread into adjacent areas. The main positive function of the Site it that it provides some cover and possible nesting habitat for birds attracted to the area due to the surrounding riparian habitat. (k) The main timing issue to consider during development is that any tree clearing or work in the riparian habitat should be done outside of the songbird nesting season (April 1 to August 31). A second concern is that weeds may increase on-Site, especially if properties are vacated by the current tenants ahead of construction. (l) Mitigation recommendations are described in Section 6.0. 4.2 Buffer Zone Establishment A natural habitat buffer zone (NHBZ) has been established for the riparian forest per the Buffer Zone table (City Code 3.4.1) (Figure 4). The riparian forest drip line extends beyond the Canal top of bank. Thus, the drip line was used to establish a 50-foot wide riparian forest buffer. The buffer zone is approximately 0.90 acre and comprised entirely of parking lots and weedy areas. Per City Code 3.4.1(E), “The purpose of the buffer zones is to protect the ecological character of natural habitats and features from the impacts of the ongoing activity associated with the development.” The riparian vegetation to be protected is located off-Site except for the weedy southern edge adjacent to the on-Site parking lots. The Site is currently developed and lacks native vegetation. Thus, the Project would not negatively impact the riparian forest and any increase in native vegetation would meet the City’s buffer zone performance standards. Powerhouse 2 ECS Report Page 13 of 19 February 16, 2022 5.0 Impacts Based on the Site Plan and the abysmal existing conditions, the Project would have an overall positive impact. A minimum of 1.15 acre and 21% of the Site would consist of native riparian vegetation, an increase of over one acre (Table 1). The existing 0.11-acre of riparian vegetation would be restored/enhanced since it is a narrow, weedy strip of mostly herbaceous vegetation mixed with fill material. New riparian habitat would be created by restoring the existing developed floodplain areas (parking lots and buildings) including the northern parking lot beneath the tree drip line (0.14 acre), a 25- to 45-foot wide buffer beyond the drip line (0.57 acre), and a stormwater detention pond in the southeast corner of the Site (0.33 acre) (Table 1). Additionally, the project would add 0.64 acre of landscaping and 0.45 acre of streetscaping. The only negative ecological impact would be removal of scattered non-native trees, approximately five Siberian elms and a single sugar maple. This would have a short-term negative impact on wildlife and shade, but would be mitigated by planting native species in other parts of the Site. Removing the non-native trees will have a positive impact on surrounding vegetation. No impacts to the potential WUS associated with the Canal are expected (Figures 3 and 4). The Site Plan shows a new trail and pedestrian bridge. The illustrated alignment would avoid any WUS impacts by crossing the Canal at a point where there is a gap in riparian and wetland vegetation because tall concrete walls have been built on either side of the ditch. The uplands adjacent to the walls are vegetated with non-native smooth brome grass. A full WUS/wetland delineation per USACE criteria was not completed because the City will not accept delineations complete in the winter and no impacts to potential WUS are expected. If the Project might impact the mapped potential WUS or other sections of the Canal, then a full WUS/wetland delineation should be completed, unless the USACE determines the Canal is not a WUS. Table 1. Existing and Proposed Cover Types Cover Type Current Proposed Area (Acres) Percent of Area Area (Acres) Percent of Area Streetscaping (Sidewalk and Trees) 0.14 2.6% 0.59 10.9% Developed (Buildings and Parking Lots) 5.14 95.4% 3.01 55.9% Riparian Forest including Buffer and Native Stormwater Basin 0.11 2.0% 1.15 21.2% Other Landscaping 0 0% 0.64 11.9% Total 5.39 100% 5.39 100% *Numbers are estimates based on the vegetation mapping and Site Plan. Powerhouse 2 ECS Report Page 14 of 19 February 16, 2022 Figure 4. Proposed Condition (Site Plan prepared by BHA) Powerhouse 2 ECS Report Page 15 of 19 February 16, 2022 6.0 Recommendations The Project is an opportunity to restore more than an acre of the Poudre River floodplain. Flood waters deposit sediment, shift channels, and create marshy scour channels parallel to rivers. Thus, natural floodplains are typically wide, flat cottonwood forests interspersed with higher uplands and lower wetlands. Most of the following recommendations are based on mimicking these conditions in order benefit from the associated ecological values such as increasing flood capacity, slowing down runoff, increasing plant diversity, and providing wildlife habitat. Recommendations are generally consistent with City policies, but may need to be adapted to meet design requirements, especially those relating to floodplain modifications, stormwater management, or installation of solar panels in the parking lot. Recommendations: 1. On the north and east sides of the Site mimic a natural floodplain with 30 to 60% cover of large cottonwood trees interspersed with different topography/vegetation types including wetlands, shrubs, smaller trees, and grassy areas. This supports the City’s Innovation Subdistrict development standards of incorporating natural characteristics of the river landscape and using plants native to the river corridor. 2. Cottonwoods are a key riparian species that support numerous species of wildlife. They are not included on the City’s approved street tree list (nor are any other native trees). However, the use of native landscaping is encouraged in the Innovation Subdistrict and by the 2015 “Nature in the City Strategic Plan”. If needed, a City forestry waiver should be obtained for at least the minimum recommended cover (Table 2) and to plant both male and female trees. 3. Plant large, native trees along Vine Street, Jerome Street, and within the Site’s landscaped areas per Table 2. This will restore a more contiguous tree canopy across the floodplain and is the most ecologically effective use of these narrow spaces. May plant other native trees or shrubs below the large trees. 4. The southeast detention basin is a potential wetland habitat creation area. Use an extended release stormwater outlet with the maximum release time. Create gradual, irregular slopes to mimic a natural depression and a large flat area in the bottom surrounded by a slightly higher mesic planting area. If possible, the bottom elevation should be within one to two feet of the water table. Adjust the final planting plan based on the expected hydrology. 5. In the riparian buffer, use runoff from the parking lot and roof to create mesic swales (~20 – 40% of the area depending on hydrology) and possibly some small wetland areas. 6. Use the low-impact development techniques to mimic a natural floodplain and support native vegetation, including: a. Buffer zone: rain gardens and bioswales. b. Vine Street and Jerome Street: rain gardens, bioswales, or planter boxes. 7. Grade the parking lots so that surface flow goes into the riparian buffer and detention pond. Use low impact development (LID) techniques to direct flows into these areas. Powerhouse 2 ECS Report Page 16 of 19 February 16, 2022 8. Surface flow should be spread out and slowed down. Within detention basins and swales, use natural bottoms that allow infiltration. If needed, use extended release outlets. Along swales, use low check structures so that more water is available to plants, infiltrates into the ground, and runoff decreases. Low, wide berms are best as they will also increase vegetation diversity, but artificial structures (concrete, metal) can be used instead. 9. Cluster mesic shrubs and trees in areas with more water due to shallow groundwater or runoff (for ex. near curb cuts or on the upstream side of berms). 10. Allow water to flood natural areas before it moves off the Site. Use grading, culverts, and trench drains to spread runoff throughout the Site. 11. In all areas that would be planted, remove a minimum of six inches of surface material to reduce the amount of weed seeds and all fill material that is unsuitable for plant growth. 12. In the vegetated riparian areas behind the fence, remove at least twelve inches of topsoil to reduce non-native smooth brome and Canada thistle. Limit soil removal if it would damage native tree roots. 13. Weedy, invasive species are prevalent north of the Site, especially smooth brome. During the on-Site meeting, Scott Benton requested that non-native species south of the Canal be controlled to prevent them from spreading into native planting areas on-Site and that efforts to coordinate with adjacent property owners be documented. Herbicide could harm native trees, so the recommended approach is to include this area with the other restoration activities or during construction of the trail/bridge. Remove 12” of smooth brome infested topsoil, fill material, and concrete debris to the extent possible and without damaging native trees. Kill non-native trees, but leave large trunks standing to provide nesting habitat for cavity nesting birds. 14. To the extent possible, remove all fill material and lower the grade in new natural vegetation areas so the ground surface is one to three feet above the water table. 15. If contamination is a concern, test soils prior to preparing them for planting. 16. The alluvial soils several feet beneath Site surface may contain a viable native seed bank. In deeper excavation areas, save/stockpile enough of this material to spread it six inches deep within each of the native revegetation areas. 17. If the native alluvial soils are not suitable for planting, they may be mixed with up to 70% imported weed free topsoil and soil amendments. 18. Salvaged alluvial soils may be tested for seed bank viability. If they are extremely rocky, sieves may be used to remove the largest rocks. 19. Use at least temporary irrigation in the natural areas until all vegetation is established (typically 2 to 3 years, with the most watering during the first year). 20. Develop and implement a plan to manage noxious and non-native plant species. Include this in the long-term Site maintenance costs. 21. Around the building, continue to use native plants and low impact development techniques to reduce the need for irrigation. 22. Plant diverse flowering species around the building to provide nectar for pollinators. Consider using hemp dogbane (Apocynum cannabinum) as a dense, native groundcover preferred by pollinators in mid-summer. Develop an annual maintenance plan that leaves at least some dead annual plant material and fallen leaves in place until the following July. Powerhouse 2 ECS Report Page 17 of 19 February 16, 2022 23. Design the building, windows, and adjacent plantings to minimize bird strikes. This is extremely important because so many migrant birds use riparian habitat. The National Audubon Society estimates that window kill millions of birds each year. They, and other organizations, provide detailed guidance to minimize bird strikes. 24. REMOVE THE CHAINLINK AND PRIVACY FENCES. If any future fences are needed, follow City guidelines for wildlife friendly fences. 25. Any tree clearing or work in the riparian habitat should be done outside of the songbird nesting season (April 1 to August 31). If these activities must occur during the nesting season, then pre-construction surveys for nesting birds should be conducted by a qualified wildlife biologist and any active nests protected per the requirements of the City and the Migratory Bird Treaty Act. 26. Weedy, vegetated areas should be routinely mowed to prevent non-native plants and noxious weeds from going to seed. This can end once the Site is developed and re- vegetated with native species. If the any portions of the Site will be vacant for extended portions of the growing period, consider adding a temporary cover seed mix. Powerhouse 2 ECS Report Page 18 of 19 February 16, 2022 Table 2. Natural Habitat Planting Recommendations Large Native Trees Mimic natural floodplain tree canopy throughout the Site and along the side street (excluding around the building). Plan for 40 to 70% mature tree cover with at least 30% cottonwood cover consisting of plains cottonwood (at least 25% cover), narrowleaf cottonwood (Populus angustifolia), or lanceleaf cottonwood (Populus x acuminata). The following additional species may be used; box elders, netleaf hackberry (Celtis reticulate), or ponderosa pines (Pinus ponderosa). Wetlands Mesic Areas Uplands Seed Mix: Wetland or Detention Basin (depending on hydrology). Add showy or swamp milkweed (Asclepias speciosa or A. incarnata) (1 lb/acre) On the wetland edge of the detention pond, plant three peach leaf willows (Salix amygdaloides) (5 gallon) and 40 sandbar willow cutting (Salix exigua). If hydrology is not suitable for willows, substitute with similar size native trees and shrubs. Seed Mix: Mesic. Add hemp dogbane (Apocynum cannabinum) (0.3 pound/acre) (If not available, sub showy milkweed at 1 lb/acre). 20 to 30% cover of small trees and shrubs. At least 2% cover of each of the following per typical minimum spacing; common snowberry, Wood’s rose (Rosa woodsii), golden currant (Ribes aureum), chokecherry (Prunus virginiana), American plum (Prunus americana) Rocky mountain juniper (Juniperus scopulorum), and box elder. May add additional native species. Seed Mix: Upland. Approximately 5% cover of rubber rabbitbrush (Chrysothamnus nauseosus). At least 15 each of skunkbrush (Rhus trilobata var. trilobata) and whitestem gooseberry (Ribes inerme). If these cannot be found, substitute other native upland shrubs. Notes: 1. Use City of Fort Collins Native Seed Mixes (https://www.fcgov.com/developmentreview/pdf/seed-mixes.pdf 2. For additional native plant species, refer to the City’s Recommended Plant List database at https://www.fcgov.com/vegetation/ and the Natural Areas Department’s Native Plants document: http://www.fcgov.com/naturalareas/pdf/nativeplants2013.pdf. 3. Plant each species in areas with appropriate soils and hydrology. Powerhouse 2 ECS Report Page 19 of 19 February 16, 2022 7.0 References Ackerfield, Jennifer A. 2015. Flora of Colorado. Brit Press. City. 2022. City of Fort Collins Native Seed Mixes. Available at https://www.fcgov.com/developmentreview/pdf/seed-mixes.pdf City. 2017. Wildlife Conservation Guidelines. City of Fort Collins, Natural Areas Department. July 11, 2017. Available at https://www.fcgov.com/naturalareas/pdf/wm- guidelines17.pdf?1504276461. City. 2018. City of Fort Collins Natural Habitat and Features GIS Data. Updated April 24, 2018. Download February 1, 2022. City. 2020. City of Fort Collins Natural Area Map. Dated May 2020. https://www.fcgov.com/naturalareas/pdf/natural-areas-map.pdf. City. 2021. City Preliminary Development Review Draft comments for E Vine Dr & N College Ave Powerhouse 2, PDR210021 addressed to Roger Sherman, BHA Design. October 19, 2021 Colorado Natural Heritage Program (CNHP). 2022. Custom Tracking Lists. Available at: https://cnhp.colostate.edu/ourdata/trackinglist/custom-tracking/. Larimer County data. Downloaded February 2022. NRCS (Natural Resources Conservation Service). 2022. Web Soil Survey. Available at: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx. Accessed January 2022. Taylor, Jennifer L. 2001. Populus deltoides. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Accessed February 2, 2022. Available at: https://www.fs.fed.us/database/feis/plants/tree/popdel/all.html [2022, February 2]. POWERHOUSE 2 JANUARY 27, 2022 APPENDIX A Ecological Characterization Report SITE PHOTOGRAPHS Page 1 of 5 1. Facing west from southeast corner, along Vine Street and towards the Hersch Trucking office/garage that is surrounded by parking lots. Several large Siberian elms are visible along the south side of the Site (photo left). 2. Facing north from southeast corner, across Hersch Trucking lot with Jerome Street on photo right and plains cottonwood trees in the background. POWERHOUSE 2 JANUARY 27, 2022 APPENDIX A Ecological Characterization Report SITE PHOTOGRAPHS Page 2 of 5 3. North side of Site, facing west along the northern Property edge. The Property line is approximately five feet behind the fence. The tree drip line extends over the parking lot. 4. Facing east along the northern Property edge. Note the berm of dirt that appears to have been pushed here from past parking lot grading (before the fence was built). This extends along much of the fence. POWERHOUSE 2 JANUARY 27, 2022 APPENDIX A Ecological Characterization Report SITE PHOTOGRAPHS Page 3 of 5 5. Off-site photograph taken from just north of the Property. Facing northeast across Lake Canal and along the pedestrian bridge alignment over the concrete walls. Thus, no wetlands would be impacted. 6. Off-site photograph taken from the existing College Avenue pedestrian bridge and facing east along Lake Canal. There are probable wetlands along the lower banks of the Canal, as evidenced by dense reed canary grass. POWERHOUSE 2 JANUARY 27, 2022 APPENDIX A Ecological Characterization Report SITE PHOTOGRAPHS Page 4 of 5 7. Facing west across the small section of the Property that juts out to the north and overlaps Lake Canal. The upland riparian habitat here is vegetated with Siberian elm, box elder, and smooth brome. 8. Southwest corner, facing north along College Avenue. Streetscaping consists of black locust trees and juniper bushes. Truck sales lot is on photo right. POWERHOUSE 2 JANUARY 27, 2022 APPENDIX A Ecological Characterization Report SITE PHOTOGRAPHS Page 5 of 5 9. Photo taken from near southwest corner, facing east along the south edge of the Site and Vine Drive. Rocky Mountain Automotive sign is visible. Additional sidewalks and streetscaping would be added along Vine Drive. 10. Photo taken from south side of the Site, facing north across truck parking area.