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HomeMy WebLinkAboutTHE GROVE AT FORT COLLINS - PDP - 16-10B - REPORTS - ENVIRONMENTAL REPORTL. Ripley 11/30/10 Page 4 of 4 sites by the adults, and nearby construction after this period is less likely to compromise their successful rearing. If the site is developed it is uncertain if red fox will continue to use the general area for hunting, breeding, and parturition. However, given the adaptability of red fox in urban areas, the maintenance of natural buffer zones along the wetland drainage and Larimer Canal No. 2, and the preservation of what appears to be the primary natal den adjacent to Larimer Canal No. 2, red fox may well continue to reside in the area, especially as long as the land between Larimer Canal No. 2 and the New Mercer Ditch remains undeveloped. Although continued fox use of the project area will provide wildlife viewing opportunities for existing residents and future residents of the Grove development, fox use of this area is not ideal from a wildlife management perspective and a fox health standpoint. Fox presence in what will become a more highly developed area increases the risk for vehicle/fox collisions as well as fox/human/human pet conflicts. In addition, foxes raised in this type of urban setting may become habituated to foraging in trash containers or relying on human handouts. Wild foxes can also be carriers for rabies and distemper, which may be passed on to unvaccinated pets. Because of this, the Colorado Division of Wildlife (CDOW) typically recommends that fox use of den sites in urban areas be discouraged during the non -breeding season to reduce potential conflicts with foxes and humans. The other advantage of discouraging fox use of den burrows during the non -breeding season is, that if efforts are successful, there would be no need to preclude construction activities at or near the burrow sites during the parturition and early rearing period (March through May). Based on informal conversations with the CDOW, it is recommended that the existing fox burrows be permanently closed and plugged with non-excavatable material during the fall/early winter period to discourage their use of the project area. Linda, this concludes my revisions for the ECSR for the Grove Project. Please let me know if you have any questions or require further assistance. Sincerely, CEDAR CREEK ASSOCIATES, INC. . C�r S"'ti T. Michael Phelan Principal and Senior Wildlife Biologist L. Ripley 11/30/10 Page 3 of 4 intermixed with lesser amounts of Baltic rush and Nebraska sedge. Reed canarygrass is considered and exotic and invasive wetland species. Any disturbance requiring the placement of fill in over 0.1 acre of jurisdictional wetlands in the project area will require 404 permit coordination with the U.S. Army Corps of Engineers. Since wetland impacts would be less than 0.1 acre, wetland disturbance would be covered under the U.S. Army Corps of Engineers' existing Nationwide Permit, and the U.S. Army Corps of Engineers would not require any wetland mitigation for the project. Wetland mapping completed for project area by Cedar Creek Associates, Inc. (Cedar Creek) has been previously approved by the U.S. Army Corps of Engineers. Once the Concept Plan is finalized, Cedar Creek will submit a brief report to the U.S. Army Corps of Engineers confirming that wetland impacts would be less than 0.1. acre. The City will require mitigation for wetland loss, and Cedar Creek will prepare a formal wetland mitigation plan that will provide mitigation, management, monitoring, and site maintenance specifications to address the City's requirements for mitigation of project development wetland losses. It is assumed the City will require wetland mitigation in a 1 for 1 replacement ratio of wetland area constructed to wetland area impacted. The site for the compensatory wetland will be selected based on the potential for adequate hydrologic support. Given the wetland mitigation area will be in an upland area immediately adjacent to the existing wetlands, it is believed that existing groundwater levels will serve as a sub -irrigation support source. This assumption is based on groundwater levels measured in observation wells (B-2, B-3 and B-4) in 2009 as a part of the drilling/monitoring activities conducted on site. These levels range from 2.0 to 3.0 feet 24 hours following drilling to 0.5 to 3.0 feet during July and November 2009. Further, a clay stone layer is present at a depth from 7.0 to 8.0 feet in wells B-3 and B-4, indicting a potential for perching groundwater inputs in the upper soil profile at the selected wetland mitigation site. In addition, this site could take advantage of any flood flows emanating from the unnamed drainage, should flooding occur. Surface drainage flows from the development will also be directed, in part, to the mitigation site and will provide an additional source of hydrologic support. Lastly, incident precipitation will also add, to a limited degree, to the hydrologic input to the mitigation site. Soil material will be excavated down to the depth necessary to access groundwater during the growing season at the proposed mitigation site. The exact excavation depth has yet to be determined. The site will then be over excavated by approximately 1.0 foot. Soils salvaged from the wetlands to be impacted will be spread over the mitigation site to a depth of approximately 1.0 foot bringing the finished grade to a design elevation reflecting a saturated, but not flooded, soil moisture regime. Soil samples will then be taken to determine the chemical and fertility status of the applied wetland soil and the sub -grade material underlying the applied wetland soils. Following the receipt of laboratory data, fertilizer will be added as per laboratory recommendations. The seedbed will then be prepared and the mitigation site seeded with a wetland seed mixture. If appropriate given soil chemistry constraints, willow cuttings will be planted around the compensatory mitigation site to enhance the wildlife habitat value of the mitigation feature. Given the overall mitigation approach, the form, values, and function of the impacted wetlands are anticipated to be re-established to higher quality levels than those currently supported at the wetland impact areas. Red Fox Dens Project development would result in the loss of all the fox burrows in and near the project area except for the one burrow complex closest to the Larimer No. 2 Canal (see Figure 2). Field surveys and observations by adjacent neighbors indicate fairly consistent fox use of the project area for hunting, breeding, and rearing of young. In order to avoid the potential loss of fox young from site development, it is recommended that construction in the project area occur outside of the parturition and early rearing period (March through May) unless surveys can demonstrate a lack of den occupation during the breeding season. Young are typically born in March through early April and remain in the den their first month of lifel. Once the young begin to venture out of the den, they are often moved to alternative den 1 Fitzgerald, J.P., C.A. Meaney, D.A. Armstrong. 1994. Mammals of Colorado. Denver Museum of Natural History and University Press of Colorado, Niwot, Colorado. 467 pp L. Ripley 11/30/10 Page 2 of 4 confirm the presence or absence of raptor nesting activity. If an active raptor nest is discovered, a buffer zone setback, as prescribed in Section 3.4.1 of the Fort Collins Land Use Code, should be maintained during the breeding, nesting, and nestling rearing period. The City buffer zone standard for wetlands, greater than 0.3 acre without significant waterfowl use, is 100 feet. This would apply to the wetlands along the northern property edge. A 100-foot setback along the north edge wetlands would also protect the potential wildlife movement corridor along this drainage. These buffer zone standards can be modified by the decision maker as long as overall project design meets the performance standards described under Section 3.4.1(E)(1) of the Land Use Code. Generally, a buffer standard less than 80 percent of the minimum distance specified under Section 3.4.1 (E) of the Land Use Code would require project review though Planning and Zoning Board Review as defined under Section 2.1.1 of the Land Use Code. Based on the current site plan, a 100-foot setback will not be maintained along some portions of the wetland drainage, and there would bean encroachment of a total of less than 0.1 acre of development into two wetland areas associated with the north drainage. The remainder of the north edge of the proposed development would maintain an overall average buffer width slightly less than 100 feet overall because of project design constraints. A 100-foot buffer would have created a buffer area of 5.22 acres. With the slightly reduced buffer, a buffer area of 5.02 acres would be created. The south edge of the site would maintain an average buffer width of greater than 50 feet from the Larimer No. 2 Canal, but there would be a buffer width of less than 50 feet along a few segments of the south edge of the development. A constant 50-foot buffer would have created a buffer area of 2.07 acres. With the current proposal and an average buffer width of greater than 50 feet, a buffer area of 2.29 acres would be created. Proposed buffer areas are depicted on PDP submittal Sheet S-2. Buffer segments with less than optimal buffer widths will be mitigated and other buffer segments will be enhanced by plantings of native shrubs and trees to create additional habitat and vegetation structural diversity as well as natural visual shielding between the proposed development and the interior portions of the buffers. Native shrub and tree cover is essentially lacking in the proposed buffer areas, and plantings of native woody species would provide considerable habitat enhancement for these areas beyond their existing conditions. In addition, plantings of native woody species to enhance habitat and provide visual shielding is consistent with the performance standards described under Section 3.4.1(E)(1) of the Land Use Code and would maintain the effectiveness of the buffer areas even where the buffer distance would be less than the City buffer zone standards. Details of native species to be planted as well as the locations, configurations, and density of native shrub and tree plantings are shown on the landscape site plan sheet (L-1) provided in the PDP submittal package. Trees Two mature cottonwood trees would be lost to development at the proposed intersection of realigned Rolland Moore Drive and Centre Avenue. One of these trees was determined to be hazardous and one was determined to be cotton bearing by the City Forester, and the.City will not require mitigation for these two native trees. Additionally, two boxelder trees growing along the Larimer No. 2 Canal, determined to be hazardous by the City Forester, will be removed by development and not replaced with mitigation trees. Russian olive trees, classified as nuisance trees in the northern buffer zone, will also be removed without mitigation. The City will require mitigation tree planting for only one tree, a small mulberry (Morus sp.) that would be lost to development. Wetland Mitigation Development of the current site plan would result in the loss of less than 0.1 acre of wetland through the direct placement of fill. This is a significant reduction from the 0.49 acre of wetland impact that would have occurred with the former Concept Plan for The Grove. The areas of wetlands to be impacted are the lowest quality and least diverse wetland community, in terms of vegetation structural and species diversity, in comparison to the main body of wetlands along the northern property boundary. Wetlands to be impacted are characterized by a dense grass/forb community dominated primarily by reed canarygrass CMAE CC;MW.Z _ ASSOCCA7MP INC. 4t6 Wn 4 A%*. Fon 401n#. CO 0=1 • (970) 4QA4X4 November 30, 2010 Linda Ripley VF Ripley Associates 401 W. Mountain Ave., Suite 200 Fort Collins, CO 80521 RE: ESCR Update for The Grove 11/29/10 Concept Plan Linda: This letter report is submitted to address the recent changes in The Grove Concept Plan regarding environmental impacts and mitigation required by Section 3.4.1 of the City of Fort Collins Land Use Code. Baseline conditions of the project area have not changed since the submittal of the May 6, 2010 ECSR prepared for the project area. However, Section 5.0 of the May 6, 2010 ECSR needs to be revised based on the new Concept Plan. The following text provides an up-to-date assessment of project impacts and required mitigation based on the 11/29/10 Concept Plan for The Grove and should be used to replace Section 5.0 of the.May 6, 2010 ECSR. 5.0 WILDLIFE AND NATURAL AREAS MITIGATION 5.1 Proiect Backaround and Imoacts Development planning for the project area had a number of physical and infrastructure constraints to accommodate, and the current site plan has evolved over a period of several months involving interaction between the Project Applicant, Design Team, CSURF, City of Fort Collins (City) staff from various departments, and surrounding neighbors. A summary of the evolution of the site plan development process is attached to the Ripley Design, Inc. Planning Objectives letter provided with the PDP submittal. Development considerations and constraints affecting site plan design included, but are not limited to, the non-standard shape of the development parcel, the presence of wetlands on the north and Larimer Canal No. 2 to the south, the extension of Rolland Moore Drive to connect between Centre Avenue and Shields Street, FEMA floodway mapping, and project design objectives. The current site plan has attempted to minimize impacts to natural areas (wetlands in particular) and meet City natural area buffer standards, to the extent possible, given the identified development constraints. The following sections summarize natural areas impacts associated with the proposed Grove Project and mitigation measures developed by the design team and Cedar Creek Associates, Inc. to minimize impacts and.enhance natural areas buffers to compensate for unavoidable adverse effects to natural areas. General mitigation recommendations provided in this section are based on existing habitat conditions and current City of Fort Collins guidelines provided in Section 3.4.1 of the Land Use Code Buffer Standards. As indicated in Section 4.0, the only special habitat features present are wetlands along the north property edge and mature eastern cottonwoods along the Larimer No. 2 Canal. Both the Larimer No. 2 Canal and the wetland drainage represent potential movement corridors for urban -adapted wildlife species. The City buffer zone standard for wildlife movement corridors is 50 feet, which would apply to the Larimer No. 2 Canal and the wetland drainage. This setback from the Larimer No. 2 Canal would also protect most of the mature eastern cottonwood trees growing along the canal. Because large cottonwood trees provide potential raptor nesting habitat, these trees should be surveyed again prior to any construction activities during the breeding, nesting, and nestling rearing periods to