Loading...
HomeMy WebLinkAboutMASON STREET INFRASTRUCTURE PROJECT - FDP230016 - SUBMITTAL DOCUMENTS - ROUND 5 - Supporting Documentation Mason Street Infrastructure Native Habitat Buffer Zone Restoration and Annual Monitoring Plan March 2024 PO Box 272150 Fort Collins, CO 80527 i Table of Contents 1.0 Introduction ................................................................................................................................ 1 2.0 Existing Site Conditions ................................................................................................................ 2 3.0 Restoration Plan .......................................................................................................................... 3 3.1 Goals and Objectives .............................................................................................................. 3 3.2 Step-by-Step Approach........................................................................................................... 5 4.0 Annual Monitoring Plan .............................................................................................................. 11 4.1 Schedule ............................................................................................................................. 11 4.2 Permanent Photo-points ....................................................................................................... 11 4.3 Sampling Methodology ......................................................................................................... 12 4.4 Success Criteria ................................................................................................................... 12 5.0 Literature Cited and Data Sources .............................................................................................. 14 1.0 INTRODUCTION North College 1311, LLC has proposed the Mason Street Infrastructure development project (“site”) within 3 lots totaling approximately 13.13 acres. The City of Fort Collins (City) has also proposed a future detention basin (“Hickory Pond”) within portions of Lot 1 and 2 within the site. The site is located within parcels 9702100007 and 9702100918 and is situated between Willox Lane and Hickory Street to the north/south, with Mason Street to the east and railroad to the west. An Ecological Characterization Study (ECS) was performed in September 2022 as required by Article 3, Section 3.4.1 of the City Land Use Code (LUC) (Cedar Creek 2023). The ECS informed the City’s determination that the site contains Dry Creek and will require the implementation of a Natural Habitat Buffer Zone (NHBZ) to mitigate potential impacts from development on ecological character and quality. The proposed Project Development Plan presents the NHBZ delineations on site in accordance with LUC guidelines. Approval of the proposed NHBZ delineation is contingent upon the Applicant completing additional mitigation requirements prescribed by the City’s Environmental Planning Department. This NHBZ Restoration and Annual Monitoring Plan (Plan) presents recommended restoration and monitoring approaches which have been designed to ascertain measurable habitat improvement in the NHBZ. The objective of this Plan is to describe the methods and procedures that will be used to implement restoration, assess establishment and progress of restoration, identify potential issues, and gather information used to inform adaptive management activities. Weed management is discussed within the broader context of our proposed approach in this document and detailed more specifically in a separate Weed Management Plan (Cedar Creek 2024). 2.0 EXISTING SITE CONDITIONS The site primarily consists of upland grassland, containing a mixture of native, invasive, and noxious species, dominated by smooth brome (Bromus inermis). Other species include leafy spurge (Euphorbia esula), Canada thistle (Cirsium arvense), Western wheatgrass (Pascopyrum smithii), orchard grass (Dactylis glomerata), alfalfa (Medicago sativa), and prickly lettuce (Lactuca serriola). Dry Creek traverses the site from the northwest to the southeast. Dry Creek appears to contain no active surface hydrology and shows little signs of conveying ephemeral flow. As such the Dry Creek riparian area is dominated by Siberian elm (Ulmus pumila), crack willow (Salix fragilis), and white poplar (Populus alba), with a herbaceous layer dominated by smooth brome. Other species include showy milkweed (Asclepias speciosa), horse tail (Equisetum sp.), rose (Rosa woodsii), wild licorice (Glycyrrhiza lepidota), and narrowleaf willow (Salix exigua). The southeast portion of Dry Creek (across Mason Street) is dominated by cottonwood (Populus deltoides) and contains no herbaceous layer. Dry Creek is listed as requiring a 100-foot NHBZ in Section 3.4.1 of the City LUC. Given that Dry Creek has not exhibited flowing water for a long time, it is likely that existing vegetation is dependent on shallow ground water. Therefore, the established trees and shrubs within the riparian zone likely will not need supplemental irrigation. However, if additional plant materials are installed supplemental temporary irrigation is warranted. 3.0 RESTORATION PLAN 3.1 Goals and Objectives In accordance with the City LUC 3.4.1 the NHBZ should be managed to: 1. Preserve or enhance the ecological character or function and wildlife use of the natural habitat or feature and to minimize or adequately mitigate the foreseeable impacts of development. 2. Preserve or enhance the existence of wildlife movement corridors between natural habitats and features, both within and adjacent to the site. 3. Enhance the natural ecological characteristics of the site. If existing landscaping within the NHBZ is determined by the decision maker to be incompatible with the purposes of the buffer zone, then the applicant shall undertake restoration and mitigation measures such as re -grading and/or the replanting of native vegetation. 4. Provide appropriate human access to natural habitats and features and their associated NHBZ’S in order to serve recreation purposes, provided that such access is compatible with the ecological character or wildlife use of the natural habitat or feature. More specific goals have been established through meetings with the City. These general goals are: 1. Control weeds prior to construction throughout the site, including the Dry Creek riparian corridor. 2. Focus on the enhancement of the Dry Creek riparian corridor through potential direction of sheet flow of hydrology on site within Dry Creek and additional herbaceous, shrub, and tree plantings. 3. The future Hickory Pond should resemble a naturalized wetland and shrub plantings around the fringe of the pond should be included. 4. The remaining mitigation area should be established into a higher quality upland grassland than the existing habitat. The restoration approach and monitoring presented in this Plan has been developed to support the meeting of NHBZ goals through evaluation of revegetation establishment and progression. Monitoring results can be used to identify problem areas or potential issues early in the restoration process, inform adaptive management activities (i.e., weed management), and assess progress towards the meeting of success criteria indicative favorable NHBZ restoration and management. 3.2 Responsiblities The applicant shall be responsible for: • Restoration of all upland portions of the NHBZ, including the upland portions of the NHBZ that occur on City of Fort Collins property. The applicant is expected to meet the upland restoration requirements prior to the handoff to City of Fort Collins Utilities. • Preservation and enhancement of the remnant Dry Creek, including establishing site grading to encourage water infiltration within the remnant Dry creek to the maximum extent possible. • Restoration of the Hickory Regional Detention Pond to the interim condition, where the established vegetation will provide soil surface stability until the final design and restoration is completed by the City of Fort Collins Utilities. City of Fort Collins Utilities shall be responsible for: • Ongoing maintenance and weed management of all upland portions of the NHBZ on City of Fort Collins property, after the applicant has met the establishment requirement on the upland portions of the NHBZ. • Final restoration of the Hickory Regional Detention Pond, including installation of naturalized wetland features within the ordinary high-water mark of the detention pond. Hickory Regional Detention Pond shall mimic a heterogeneous natural stream/wetland/floodplain complex as much as site constraints allow. The primary function of the design should attenuate flows and mimic the former Dry Creek riparian complex of riparian corridor, wetlands, and floodplain of the former Dry Creek. o Increase the pervious surface area across the basin’s bottom. o Slow water flow and dissipate flow concentration. o Emphasize sinuous edges and an undulating bottom in order to maximize heterogeneity of edge habitats and provide more resistance to flow through small islands, oxbow channel mimics, and mini floodplains. o Minimize Edge Slope: The terrestrial- facultative plant boundary should have a very gradual slope. o Persistent Emergent Vegetation: Persistent emergent vegetation has stems which persist even after the growing season. This provides year-round resistance to water flow. o Create a heterogeneous moisture regime with hydric, mesic, and upland communities. The design criteria for the Hickory Regional Detention Pond shall include topography to support a variety of hydric conditions, which will result in planned water dependent vegetative communities ranging from emergent / mesic meadow with obligate and facultative wetland species, which will transition to riparian / mesoriparian / xeroriparian habitats where facultative willows and shrubs can be planted. Plant materials, in the form of seeding and planting , will be used to restore habitat features within the detention pond and should target structural and species diversity. 3.3 Step-by-Step Approach The following is a recommended step-by-step process designed to reduce cost, improve the ecological function, and enhance the ecological characteristics of the NHBZ while maintaining flexibility for site-specific conditions. Step 1. Creating Opportunity and Reducing Competition Noxious and invasive species are often non-native, aggressive spreaders, that dominate an ecosystem and outcompete native species. Establishing native species is important for restoration goals and to provide healthy, diverse, and sustainable ecosystem. If noxious and invasive species are left unmanaged, opportunities for native species establishment are greatly reduced. It is recomme nded some method of vegetation control must be utilized to control noxious and invasive species. Vegetation control is implemented via mechanical or chemical controls. Mechanical control entails scraping or plowing to increase bare ground exposure which will serve as a seedbed / planting medium. Chemical control entails the use of herbicide to diminish dominance of undesirable and noxious species . Leafy spurge and Canada thistle the dominant noxious species on the site (see Weed Management Plan; Cedar Creek 2024). The dominant invasive species within the site is smooth brome, an aggressive, non-native, perennial and rhizomatous grass, spread by wind-driven cross-fertilization to produce seeds and propagate vegetatively through tillering and root fragments. While smooth brome can negatively impact biodiversity, it does provide excellent soil stability and forage potential for wildlife. Therefore, a total eradication of this species may not be necessary, but a chemical treatment is highly recommended prior to initiating mechanical manipulation of soil, to reduce competition and encourage the establishment of native vegetation. Step 2. Grading Current development plans propose filling in portions of Dry Creek, though a majority of the channel will remain intact. Grading will be completed to ensure some surface water flows will continue to contribute to the remnant portions of Dry Creek. Grading and design of the future Hickory Pond should follow the City’s standards and guidelines (City of Fort Collins 2009 & 2018). Step 3. Soil Preparation The soil surface should be optimized for seeding or planting. An agronomic assessment is recommended to evaluate the chemical and physical properties of the soil throughout the site, and a required design standard in the location of the proposed Hickory Pond. This information can be used to determine whether soil amendments (i.e. compost) would benefit the establishing plant communities and allow for optimization of the seed mix to soil conditions. Planted areas in Hickory Pond will require topsoil with appropriate levels of organic matter and should receive imported or stockpiled topsoil to a minimum depth of four inches. Sub-grade should be loosened to a depth of 12 inches total (8” existing sub-grade and 4” of new topsoil) in Hickory Pond and 10 inches throughout the remainder of the site. Stones, clods, sticks, rubbish, and other matter large enough to impede planting, seeding, or mowing should be collected and removed from the site. Removed material must be disposed of legally. Cultivation should be repeated in areas where equipment used for hauling and spreading topsoil has recompacted the soil. Disturbed areas should be fine graded to a smooth, uniform surface plane. Prior to seeding, the soil surface should be loose, allowing for good soil/seed contact. Roll and rake, remove ridges, and fill depressions to meet surface grades based on grading plans. Step 3. Seeding and Planting Seeding and planting should occur as soon as possible following final construction and final contouring within a suitable time frame. For seeding, late fall to early spring (October to May) is favorable, with late fall being priority for non-irrigated areas. Woody plantings should occur in late fall (prior to frozen ground) or early spring (October to May) to increase survival success. Woody planting being planted from containers should have the sides and bottom of the root system scarified. Live stakes sho uld be installed to ensure 70 to 80% of the entire live stake is underground. The species used should be native and suitable to the soil and moisture conditions of the NHBZ. Seed mixes should be designed to facilitate growth of appropriate and sustainable species. If changes are to be made to the proposed seed mix based on site conditions, then approval must be provided by a city Environmental Planner. The proposed seed mixes are based on the City’s recommended species, site conditions, and the U.S. Army Corps of Engineers (USACE) Wetland Indicator Status Plant List for the Great Plains Region (USACE 2020). The site contains a high-water table within areas, notably the Dry Creek area. A mixture of upland, facultative-upland, facultative, facultative-wetland, and obligate species were selected to represent varying conditions and slopes. Species were also selected to provide pollinator habitat, with emphasis on milkweed species for the U.S. Fish and Wildlife Service (USFWS) federal listing candidate, the monarch butterfly (Danaus plexippus). See Table 1 for a Proposed Hickory Pond Seed Mix and Table 2 for Proposed Upland Grassland Seed Mix. Seeding can be accomplished using broadcasting and drilling techniques wherever applicable. • For broadcast seeding: the seeding rate should be doubled, seed-to soil contact should be increased immediately through manipulation which will also provide some protection from wind or water erosion and granivores. Manipulation can be accomplished by either a light disc harrowing perpendicular to the flow of energy (wind and/or water) or hand raking around sensitive areas (i.e. willow patches). • For drill seeding, final drilling pass must occur on the contour, to create subtle ridges perpendicular to the flow of energy. Drill seeding should not be conducted in sensitive areas. Appropriate native seeding equipment will be used, which does not include standard turf seeding equipment or agriculture equipment. Drill seed the approved mix in two passes, each at a right angles to the other and using half the seed in each pass. Seed should be drilled at the specified application rate and to a depth of no greater than ½ inch. If areas are too wet or steep to drill seed, broadcast seed in opposite directions at twice the application rate used for drill seeding. Restore fine grade after seeding, and cover seed to a depth of ¼ of an inch by raking or dragging. Firm seeded areas with a roller weighing a maximum of 100 lbs. per foot of width. Woody plantings of trees and shrubs along Dry Creek and the fringe of Hickory Pond are also proposed to provide structural diversity and meet restoration goals. Species to be used should be approved by a City Environmental Planner. Woody plantings should be planted using industry Best Management Practices. The following native trees are recommended for planting: • Cottonwood (Populus deltoides). This species is present within portions of Dry Creek, except in areas where non-native or noxious species such as Siberian elm and crack willow are present. Cottonwood should be planted along Dry Creek where possible. • Peachleaf willow (Salix amygdaloides). This species may be planted along Dry Creek and along the fringe of Hickory Pond. The following upland native shrubs are recommended for planting along the fringe of Hickory Pond or other upland areas: • Rubber Rabbitbrush (Ericameria nauseosa var. nauseosa) • Winterfat (Krascheninnikovia lanata) • Broom snakeweed (Gutierrezia sarothrae) • Fourwing Saltbush (Atriplex canescens) • Snowberry (Symphoricarpos occidentalis) The following mesic to wetland native shrubs are recommended for planting within Hickory Pond or along Dry Creek, where the water table may be high and surface water may be present after rain events: • Redosier dogwood (Cornus sericea) • Coyote willow (Salix exigua) • Waterbirch (Betula occidentalis) • Wild black currant (Ribes americanum) Plantings and/or plugs of wetland species is recommended in Hickory Pond or Dry Creek if inundation or saturation precludes seeding. If necessary, these plantings should be concentrated in areas with high risk of erosion to minimize the risk of soil loss. Planting should also be concentrated where favorable moisture zones are likely to exist. Planting small plugs in the fall is not desirable due to the loss of plants to Canada geese (Branta canadensis). Subsequent plantings are recommended after initial establishment and when weeds are controlled (2-5 growing seasons after initial construction). These plantings can be concentrated in areas needing additional erosion control protection and/or bare areas. Supplemental temporary irrigation should be used to aid in establishing newly installed plant materials. Step 4. Maintenance and Management Maintenance and management activities should be implemented to ensure success of the ecological restoration project. After seeding, the area shall be covered with crimped straw, jute mesh, or other appropriate soil surface stabilization methods. Straw mulch should be certified weed-free hay or certified weed-free straw with no seed heads. In the stormwater drainage area, natural fiber blankets are recommended, as synthetic blankets can entangle reptiles and amphibians in aquatic habitats. Routine inspections for erosion should be performed during the time between seeding and vegetation establishment to assure no excessive erosion features form on the project area. Restoration goals can be achieved without the use of supplemental water if planting plans correspond to local climatic patterns for native seeding, late fall or early spring. However, temporary supplemental irrigation is planned within the upland restoration areas in the NHBZ to ensure more reliable establishment in a variety of potential climatic conditions. Temporary supplemental irrigation will be used in a manner to provide no more than 150% of normal precipitation for the area and will be removed at least one growing season prior to measurement of the success criteria presented in Section 4.4. The Weed Management Plan (Cedar Creek 2024) provided for the site will be implemented to ensure that weeds are properly managed before, during, and after seeding activities. Overall, the contractor shall monitor seeded area for erosion control, germination, and reseeding as needed to establish cover. 4.0 ANNUAL MONITORING PLAN The applicant will be responsible for ensuring execution of the monitoring and reporting protocol described below. 4.1 Schedule The NHBZ will be surveyed twice a year on the following schedule: 1. In the spring, a qualified ecologist will traverse the entirety of the site to assess noxious weed populations prior to implementation of management strategies. This effort will result in optimized and targeted weed control efforts and provide sufficient time to manage weeds prior to seed production. 2. At the peak of growing season, a qualified ecologist will implement the quantitative procedure described in section 4.2 to measure ground cover within the NHBZ. The ecologist will also traverse the entirety of the site to identify potential problems or issues with restoration. During these traverses, the observer will take note of areas of poor seedling emergence, indicators of soil fertility problems, noxious weeds or invasive plant infestation , expectations for noxious weed seeding/flowering, excessive erosion, and any other similar revegetation / restoration related issues (if observed). Annual monitoring will continue for a total of three years following restoration of the NHBZ. A brief memo containing survey findings and recommendations will be provided to the City by October 31st of each year. This will give the City and the applicant ample time to discuss and implement adaptive management to address any underperforming areas prior to when on-the-ground treatment implementation would be needed, if determined necessary. 4.2 Permanent Photo-points Eight permanent photo-points (marked with GPS coordinates) on the site will be established to visually catalog vegetation progress, including, 4 along the Dry Creek riparian corridor, 2 within Hickory Pond, and 2 within surrounding upland grassland area. Photo-points should be determined in the field at a location representative of the NHBZ area, each location marked with GPS coordinates, and each designated with a number which will remain consistent throughout the 3-year monitoring period. Each photo-point should be documented during the summer evaluation at the peak of the growing season, for each of the annual monitoring efforts that will follow restoration. At each point, four photos will be collected, one each in a cardinal compass direction (N-E-S-W), using a photo board that is visible in each frame to indicate the photo-point number. 4.3 Sampling Methodology Cover sampling will be conducted at a minimum of 15 sample points in the reclaimed areas of the NHBZ to assess progress towards standards. A minimum of 5 sample points each should be located in the Dry Creek riparian corridor and within Hickory Pond (10 total). At each sample point, ground cover will be measured using ocular estimates in a 1 meter by 1 meter quadrat. Sample locations will be determined randomly prior to field evaluation. Upon reaching the sample point, the quadrat will be placed on the ground and the ecologist will estimate and record vegetative ground cover by species to the nearest 1%. All species, including noxious and invasive species, and their respective percent ground cover will be recorded. In addition, percent cover of litter, rock, and b are ground exposure will be estimated and recorded; when summed with vegetation estimates, these will produce 100% coverage of ground cover at each sample point. 4.4 Success Criteria Total vegetative ground cover and diversity standards will be determined using a reference area approach, where the reference areas are representative of the target vegetative community and are selected by the City Environmental Planner. The total vegetative ground cover of the applicable reference area(s) will be measured by the City annually at the end of the growing season (late summer to early fall) to the point of demonstrating sample adequacy in order to provide an accurate level of vegetative cover r eflective of local climatic conditions. The areas of the Development that are planned to be NHBZ mitigation areas shall be inspected jointly by the Developer and the Environmental Planner at specified intervals for a minimum of three (3) growing seasons or until determined by the Planner to be well established in accordance with the coverage specifications of this paragraph, whichever occurs first. The NHBZ success criteria are as follows: (1) The total vegetative ground cover contributed by all desirable plant species (excepting mature trees) is equal to or greater than the desirable vegetative cover of the applicable reference area(s) from that calendar year, (2) No more than five percent (5%) of the species noted on the site may be weedy or noxious species as defined by City Code Section §20-41 and Colorado Department of Agriculture’s Noxious Weed List as defined by the Colorado Noxious Weed Act §§35-5.5, (3) The development site shall display no evidence of detrimental erosion due to rills, gullies or excessive bare spots of ground, (4) Survival rate of all planted shrubs and trees is equal to or greater than eighty percent (80%), and (5) Any diversity standards applied according to the City Environmental Planner’s discretion. Diversity standards should be reflective of the reference area or target habitat conditions provided by the City. by the City Environmental Planning Department and Utility Services Department. The City Environmental Planning Department has the authority to deem revegetation established in lieu of meeting success criteria, as well as withhold approval despite meeting success criteria, if they so choose . If final stabilization is not achieved to the satisfaction of the agency, the developer and/or landscape contractor shall be responsible for additional corrective measures to satisfy final vegetative requirements for closeout. 5.0 LITERATURE CITED AND DATA SOURCES Cedar Creek Associates, Inc. 2024. Mason Street Development Weed Management Plan. January 2024. _____. 2023. 1311 North College Ecological Characterization Study. February 2023. City of Fort Collins. 2021. Land Use Code. March 5, 2021. _____. 2018. Stormwater Criteria Manual. December 2018. _____. 2009. Landscape Design Standards and Guidelines for Stormwater and Detention Facilities. November 2009. U.S. Army Corps of Engineers. 2020. National Wetland Plant List – Great Plains Region. http://rsgisias.crrel.usace.army.mil/NWPL/index.html United States Forest Service (USFS). 1984. Brown, D.; Hallman, R.G. Reclaiming Disturbed Lands.