TREE CONSERVATION REPORT Carleton University Parking Facility

Transcription

1 TREE CONSERVATION REPORT Carleton University Parking Facility 3/21/ Hunt Club Road, Suite 300 Ottawa, ON K1V 0Y3 t: f:

2 TABLE OF CONTENTS Introduction... 1 General Overview... 1 University Property... 1 O-Train Corridor... 1 Field Observations... 2 Method of Evaluation... 2 Assessment... 2 Recommendations... 2 Municipal By-laws / Permits... 3 City of Ottawa By-law No D-03-08: Phytosanitary Requirements to Prevent the Introduction Into and Spread Within Canada of the Emerald Ash Borer, Agrilus planipennis (Fairmaire)... 3 Vegetation Summary and Recommendations... 3 Compensation... 4 Preservation and Protection Recommendations... 5 General Recommendations... 5 Pruning Practices... 6 Establishment of a Tree Protection Zone (TPZ)... 7 Tree Protection Fencing... 7 Temporary Tree Protection Measures... 7 Construction Implementation... 7 Pre-Construction... 7 Construction... 8 Post-Construction... 8 Conclusion... 8 Limitations of Assessment... 8

3 APPENDIX A... I Definitions... I APPENDIX B... II Existing Site Photos... II APPENDIX C... III Current Vegetation Plan... III APPENDIX D... IV Proposed Development and Conserved Vegetation Plan... IV

4 Introduction This report has been prepared taking into consideration Carleton University s plan to construct a parking facility north of Campus Avenue above the existing O-Train line (City of Ottawa property). This proposed construction will require an air rights agreement from the City of Ottawa. Proposed construction will require the removal of trees (on City of Ottawa property and Carleton University property) over 10cm in diameter. Due to restricted access to the City of Ottawa s property, this report is a preliminary inventory and visual assessment of trees and landscape communities within the limits of the proposed construction site. Characterization of vegetation within the rail corridor was undertaken through observation from the adjacent University property. This progress report will be amended as a finalized report post completion of the site survey and site access permission. Recommendations are provided for tree protection and tree removals based on the limits of grading and construction. This report is to be read in conjunction with: Definitions (APPENDIX A) Existing Site Photos (APPENDIX B) Current Vegetation Map (APPENDIX C) Proposed Development and Conserved Vegetation Map (APPENDIX D) General Overview University Property The subject lands are zoned as I2A F(1.5) Institutional Major. The owner of the land is Carleton University located at 1125 Colonel By Drive, Ottawa Ontario, K1S 5B6 (tel: ). The subject lands are part of Lot L Concession B (Rideau Front) Geographic township of Nepean, now City of Ottawa. This report represents the only known application affecting the land and, to the best knowledge of the consultant, no other applications exist which would affect this part of the site. The subject lands are located north of campus Avenue and between Campus parking lot P7 to the east and P6 to the west. The proposed construction site encompasses both Carleton University property and City of Ottawa property. The terrain immediately adjacent to both parking areas slopes towards the centre of the site and is generally void of trees and shrubs. The majority of the terrain of the site is made up of two steep embankments leading down from the existing parking areas to the existing O-Train rail line. The steep embankments are the result of the lowering of the CPR Prescott railway line in the 1960s. Just north of the site the rail line enters a tunnel under Dow s Lake. Both of the embankments are heavily vegetated with a mix of trees and medium to tall understory shrub growth. O-Train Corridor Carleton University proposes to construct a parking structure over the existing O-Train line. This will involve the removal of existing trees, asphalt, bases and curbs as part of the proposed realignment of Campus Avenue and existing parking areas P6 and P7. It is understood that construction will begin as soon as possible while respecting various regulations and site specific restrictions. The anticipated construction start date is May 1 st to coincide with the end of the nesting season. The majority of vegetation on site is dense forest cover found within the O-train corridor. The forest cover is a mixture of hardwood (deciduous) and softwood (coniferous) species with a predominantly deciduous shrub understory. The coniferous trees are located within approximately 20 metres of the Campus Avenue bridge over the rail line. All trees to the north of this grouping are deciduous trees. Preliminary 1

5 field visual observations note that a majority of the deciduous and coniferous tree species have a diameter at breast height (DBH-1.3m above ground) of over 20cm. Left relatively untouched, the embankments have naturalized over time. However, the coniferous trees located within the first 20 metres, north of Campus Avenue, were most likely planted at a later date. This is assumed because the trees planted by the University to the South of Campus Avenue and adjacent to University Drive are the same species and general size. The majority of the deciduous tree species consist of White Ash (Fraxinus americana) and Trembling Aspen (Populus tremuloides). The coniferous tree species are Scots Pine (Pinus sylvestris). Field Observations The field observations were conducted on March 18 th, 2013 at the Carleton University site at 1125 Colonel By Drive, Ottawa Ontario. Due to restricted access to the City of Ottawa s property a site survey report has yet to be completed. As such, individual tree locations and detailed identification/classification has not been undertaken. This report will be amended as a finalized report post completion of the site survey and site access permission. APPENDIX A includes photos of existing conditions (March 2013) as well as summer photos (source- Google images). Method of Evaluation Assessment: Vegetation is assessed based on a visual inspection of the trunk and branch condition, structure, foliage condition, and evidence of abiotic (environmental, mechanical and physical damage) and biotic (insects and disease) stressors. Trunk Integrity: Assessment of the trunk for any defects Canopy Structure: Assessment of the scaffold branches and canopy of the tree Canopy Vigor: Assessment of the amount of deadwood versus live growth in the tree crown, also consider size, colour and amount of foliage. As tree health is best judged in late summer when tree stress is reflected by foliage condition, the condition of deciduous trees was not able to be accurately determined. Since the inventory was conducted in winter during the dormant season, vegetation was assessed based on stability, structure, branch attachment, deadwood, and trunk defects. Evaluations were given based on the above attributes. Recommendations: Recommendations are a declaration of future action to be taken upon assessment of the current state of the plant and future context within which it will be located. Vegetation recommended to be Retained is deemed to be minimally affected by development and/ or outside of the limits of construction. This designation may also be applied to trees that are in excellent, good or fair conditions and species at risk. Vegetation recommended to be Removed are deemed to be within development/construction limits and would not be able to withstand construction related activities or changes to grading. This designation also may be applied to trees that are dead, in poor condition or trees that could pose future safety concerns. 2

6 Vegetation recommended to be Transplanted are deemed to be within development/construction limits, in good condition and typically under 30cm caliper. Transplantation of trees is dependent on available space on site. Municipal By-laws / Permits City of Ottawa By-law No The proposed construction site is within the City of Ottawa. Furthermore, the proposed site is greater than one hectare in area. Any removal of trees 10cm diameter at breast height (DBH) and above are subject to the City of Ottawa s Urban Tree Conservation By-law. The site work area is subject to this Bylaw and a tree clearing work permit will be required from the City of Ottawa prior to commencement of removals. Additionally, tree protection measures identified in the approved tree conservation report must be implemented. D-03-08: Phytosanitary Requirements to Prevent the Introduction Into and Spread Within Canada of the Emerald Ash Borer, Agrilus planipennis (Fairmaire) The Canadian Food Inspection Agency issues a prohibition of movement where the emerald ash borer (EAB) has been confirmed. The subject is property is within identified areas prohibiting the movement of regulated materials (including but not limited to ash wood or bark and ash wood chips or bark chips) from the specific property. EAB regulated articles moving out of a regulated area must be accompanied by a Movement Certificate issued by the CFIA. Vegetation Summary and Recommendations At the time this report was prepared, a site plan showing the proposed development was made available to the Landscape Architect. Determinations were made with respect to tree survival based on their proximity to the proposed development. There is an approximate 2:1 sloped embankment down to the O-Train rail corridor (City of Ottawa property). A majority of the trees on the site cover the two embankments. Existing stormwater drainage on the site is down the embankments. The tree canopy is dominated by White Ash (Fraxinus americana) and Poplar (Populous tremuloides) with a scattered mix of Manitoba Maple (Acer negundo), Serviceberry (Amelanchier laevis), and Hackberry (Celtis occidentalis). A large number of the Ash trees (Fraxinus americana) within this community are showing signs of stress and the presence of the Emerald Ash Borer is strongly suspected. There is a small pocket of coniferous trees located within approximately twenty (20) metres of the area just north of the Campus Avenue bridge. There are approximately nine (9) Scots Pines (Pinus sylvestris) in this area. There are very few trees within the site which exist on Carleton University property. A majority of the vegetation within University property is medium-tall vegetated understory/naturalized hedge row. This vegetation community is dominated by varieties of Sumac (Rhus) and Buckthorn (Rhamnus) shrubs with pockets of poplar (Populous tremuloides) saplings. The proposed construction of a parking structure over the embankments will have a large impact on the trees within the site and require many removals. A majority of the required tree removals will be on City of Ottawa property. A greater part of these removals will be Ash trees (Fraxinus americana). The pockets 3

7 of scots Pines (Pinus sylvestris) have been identified as valuable trees and are recommended for protection in conjunction with the current planned location of the proposed parking structure. Compensation The development of the proposed parking facility will impact vegetation along the majority of the rail embankment within the site area. It is estimated at this time that there will be eighty trees above 10cm DBH removed to facilitate the construction of the parking facility. Tree planting is recommended where possible within the limits of construction or within available space elsewhere on the University Campus to mitigate the overall loss of vegetation and to contribute to the City of Ottawa forest cover target. Given the limited space available within the immediate vicinity of the subject construction site it is recommended that Carleton University supplement the removed trees at suitable sites within the campus. The proposed planting design is summarized into three main categories: 1. Preservation of existing deciduous and coniferous trees for a distance of approximately twenty metres from the edge of the existing Campus Avenue bridge to act as a vegetated visual buffer to the new structured parking facility. 2. Street trees along the western edge of the proposed structure (future Campus Avenue access to Colonel By Drive). 3. Vegetated mix of deciduous and coniferous trees at pedestrian entry/exit locations into the parking facility at the southwest and northeast corners of the proposed structure Tree species recommended to be planted within restoration and landscape open space areas are to be urban tolerant and similar species that currently exist on the site. A selection of recommended tree species includes: English Oak Fastigiata (Quercus robur Fastigiata ) o planted as a street tree in areas of restricted space White Spruce (Picea glauca) o Planted in open space areas White Pine (Pinus strobus) o Planted in open space areas Red Maple (Acer rubrum) o Planted in open space areas Yellow Birch (Betula alleghaniesis) o Planted in open space areas A selection of recommended shrub species, groundcover and ornamental grasses include: Canadian serviceberry (Amelanchier canadensis) Red Osier Dogwood (Cornus sercia) Smooth Sumac (Rhus glabra) Common Snowberry (Symphoricarpos albus) Common Periwinkle (Vinca minor) Feather Reed Grass (Calamagrostis acutifolia Karl Foerster ) 4

8 Note: 1. No single species should exceed 30% of the total restoration planting total. 2. All proposed plantings are recommended to be planted in keeping with the principles of CPTED (Crime Prevention through Environmental Design) Preservation and Protection Recommendations The survival rates for trees, which are in proximity to construction, are dependent on the resultant changes to a variety of environmental and anthropogenic factors. These construction activities bring about changes to a variety of environmental features including the existing microclimate including winds, temperature, soil moisture, amount of available sunlight, soil quality, and the level of the water table. Increased human activities may also damage the structure and/or physiological activities of the trees. The full effects of the damage may not appear until several years after its occurrence. It is essential that both vegetative clearing and preservation methods follow the guidelines below and those generally accepted as keeping with good horticultural and construction practices. The guidelines are subject to adjustments deemed reasonable and appropriate considering the proximity and number of trees involved and the sitespecific servicing requirements. Upon review of the proposed parking structure design, the first 20 metres of embankment immediately North of Campus Avenue can be maintained. General Recommendations The following is a list of practical considerations for the construction phase of the project that applies to all trees that may be impacted by the construction: Prior to the commencement of tree removals, all limits of the locations of the tree preservation fencing must be clearly staked in the field and approved by the contract administrator. All trees within the tree preservation zone must be left standing. The tree removals must be coordinated to be completed outside of the nesting season May 1 to August 8; All removals must be felled into the work area to ensure that damage does not occur to the trees within the tree preservation zone; Upon completion of the tree removals, all felled trees are to be removed from the site, and all brush chipped. However, as mandated by the Canadian Food Inspection Agency a prohibition of movement will be issued for properties where the emerald ash borer (EAB) has been confirmed. This measure prohibits the movement of regulated materials from the specific property. Regulated materials include: ash trees (whole or parts), ash nursery stock, ash logs and branches, ash lumber, wood, packaging materials with an ash component, ash wood or bark, ash wood chips or bark chips, firewood from all tree species. EAB regulated articles moving out of a regulated area must be accompanied by a Movement Certificate issued by the CFIA. All vehicles used to transport regulated articles must be cleaned of debris prior to loading at origin and prior to departure from the receiving facility. The required treatment will depend upon the regulated article transported, but may include sweeping or power washing. For more information about transporting regulated articles, contact your local CFIA office; All brush, roots and wood debris must be shredded into pieces that are smaller than 25 mm in size to ensure that any insect pests that could be present within the wood are destroyed. This work must be completed outside of the nesting season, May 1 to August 8; 5

9 Tree protection fencing must be constructed and installed. Upon installation of the fencing, the contractor will contact the consulting arborist to review and approve the fencing and its location prior to commencement of any grading work; Areas within the tree preservation zone are not to be used for any type of storage (e.g. storage of debris, construction material, surplus soils, and construction equipment). No trenching or tunneling for underground services shall be located within the tree protection zone or dripline of trees designated for preservation within or adjacent to the construction zone; No grade changes shall occur within tree preservation zone unless approved as part of this report. In the event that any grade changes may occur, either as a cut or fill situation, the consulting arborist must be notified prior to such work occurring to ensure that all precautions to preserve the tree can be made; Trees shall not have any rigging cables or hardware of any sort attached or wrapped around them, nor shall any contaminants be dumped within the protective areas. Further, no contaminants shall be dumped or flushed where they may come into contact with the feeder roots of the trees; In the event that it is necessary to remove additional limbs or portions of trees, after construction has commenced, to accommodate construction, the consulting arborist is to be informed and under their direction the removal is to be executed carefully and in full accordance with arboricultural techniques, by a certified arborist. Pruning Practices All limbs damaged or broken during the course of construction should be pruned cleanly, utilizing by-pass secateurs in accordance with approved horticultural practices. Should there be a potential risk of transfer of disease from infected to non-infected trees; tools must be disinfected after pruning each tree by dipping in methyl hydrate. This practice is particularly important during periods of tree stress and when pruning many members of the same genera, within which a disease could be spread quickly; During excavation operations in which the root area is affected, the contractor is to prune all exposed roots cleanly. Pruned root ends are to be neatly and squarely trimmed and the area is to be backfilled with clean native fill as soon as possible to prevent desiccation and promote root growth. The exposed roots should not be allowed to dry out, and the contractor shall discuss watering of the roots with the consulting arborist so that the roots shall maintain optimum soil moisture during construction and backfilling operations, yet so not to interfere with construction operations. Backfilling must be with clean uncontaminated topsoil from an approved source. Texture must be coarser than existing soils, and to come into clean contact with existing soils (remove air pockets, sod, etc.); All pruning cuts should be made to a growing point such as a bud, twig or branch, cut just outside the branch collar (the swollen area at the base of the branch that sometimes has a bark ridge), and perpendicular to the branch being pruned rather than as close to the trunk as possible. This minimizes the site of the wound. No stubs should be left. Poor cut location, poor cut angle and torn cuts are not acceptable; Tree roots should not be excavated within the critical structural rooting area. This is the minimum area of the root system necessary to maintain vitality or stability of the tree. Typically this area extends to the dripline of the tree. The severing of one root can cause approximately 5-20% loss of the root system. A reduction of this area by greater than 30% can pose stability concerns for the tree; Extensive pruning is best completed before plants break dormancy. Pruning should be limited to the removal of no more than one third (1/3) of the total bud and leaf bearing branches. Pruning should include the careful removal of: o deadwood, 6

10 o branches that are weak, damaged, diseased and those which will interfere with construction activity, o secondary leaders of conifers, o trunk and root suckers, o trunk waterspouts, and o tight V-shaped or weak crotches (included unions). The Contractor must report immediately any damage to trees such as broken limbs, damage to roots, or wounds to the main trunk or stem systems so that the damage can be assessed immediately; The tree protection fencing will be maintained until all construction is completed, soils are stabilized and all of the equipment has been removed from the site. Establishment of a Tree Protection Zone (TPZ) Tree preservation measures, including the establishment of Tree Protection Zone (TPZ) shall apply to the individual trees denoted for preservation on the Proposed Development and Conserved Vegetation Plan (APPENDIX ) as well as all vegetated areas noted for retention; Trees located within the project area that are to be preserved will have tree protection fencing installed at the dripline plus 1 metre to establish a tree protection zone. All trees located on adjacent properties shall be preserved unless otherwise stated in this report; No grade changes shall occur within tree protection zone. In the advent that grade changes occur either as a cut or fill situation, the consulting arborist must be notified so that precautions to preserve the tree can be determined prior to the placement of fill or excavation activities; Every precaution must be taken to prevent damage to trees and root systems from damage, compaction and contamination resulting from the construction to the satisfaction of the consulting arborist; Trees that require pruning to permit construction activities have been identified in the Arborist report. In the event that it is necessary to remove additional limbs or portions of trees, after construction has commenced, to accommodate construction, the consulting arborist is to be informed and under their direction the removal is to be executed carefully and in full accordance with arboricultural techniques, by a certified arborist; Any damage to trees such as broken limbs, damage to roots, or wounds to the main trunk or stem systems are to be reported to the consulting arborist so that the damage can be assessed immediately and mitigation can be promptly implemented. Tree Protection Fencing The Tree Protection Zone (TPZ) shall be established by the installation of tree protection fencing. Temporary Tree Protection Measures Protection of retained trees will be provided by the installation of temporary protective fencing; All of the tree protection measures are to be installed and approved prior to commencement of site grading. Periodic inspection and maintenance of the tree protection measures will be required throughout construction. Construction Implementation Pre-Construction A site meeting will be held with Contractor and Contract Administrator to review the clearing limits and confirm the installation location for the temporary tree protection fence; 7

11 The tree removals must be coordinated to be completed outside of the nesting season; May 1 to August 8, or a visual survey must be undertaken by an ornithologist to ascertain that there are no nests present within the nesting season; Tree removal along the tree retention limit must be carefully felled away from the tree retention limit and into the construction / development area. Stumps adjacent to trees identified for retention are to be flush cut and not chipped or grubbed in order to avoid impacts to retained trees. Construction Periodic inspections will be undertaken by the site supervisor to ensure that the mitigation measures are being maintained during construction; The temporary protection fence is to be maintained throughout the entire construction period. No equipment storage, flushing of fuel, washing of construction equipment, and storage of spoil or construction debris is to occur behind the temporary protection fence; To avoid root zone impacts on trees to be retained, excavated material will not be stored against the tree protection barrier; Where the root system of trees to be preserved are exposed or damaged through construction activities, the cut ends are to be neatly and squarely trimmed back to the limits of disturbance and the area is to be backfilled with clean native fill as soon as possible to prevent desiccation and promote root growth. Proportional selective thinning of the canopy is not recommended as canopy pruning is only recommended in the event that the health of the tree declines. Post-Construction The temporary protection fence will be removed last after all of the construction has ended, soils are stabilized and all of the equipment has been removed. Conclusion Minimal tree removals are required on Carleton University property to construct the subject parking facility. Substantial tree removals are required within the City of Ottawa s O-Train corridor. An effort to preserve existing vegetation, where possible, is proposed. It is recommended, as a result of this report, that replacement tree plantings be undertaken within the immediate vicinity of the proposed structure. Furthermore, it is recommended that trees be planted across the University Campus where applicable and appropriate to the University s long-term campus and landscape planning strategy. Limitations of Assessment This report represents a preliminary inventory and visual assessment of trees and landscape communities within limits of impact of the proposed construction. Due to absence of site access permission to date, all subject inventories and reporting has been undertaken on and from Carleton University property only. Detailed tree inventory and reporting will be conducted as an extension of this report post permission to access the O-Train corridor and in-parallel with updates to site surveying. 8

12 MMM GROUP LIMITED Jonathan Loschmann, OALA, CSLA, LEED AP Senior Landscape Architect 9

13 APPENDIX A Definitions Species DBH Trunk Integrity (T.I.) Canopy Structure (C.S) Canopy Vigor (C.V.) Good Tree Condition Fair Tree Condition Poor Tree Condition Tree Protection Zone Critical Root Zone CPTED The botanical and common names are provided for each tree. The diameter (in centimetres) at breast height and is measured at 1.3 m above the ground for each tree. An assessment of the trunk for any defects or weaknesses measured on a scale of poor, fair, good. An assessment of the scaffold branches, unions and the canopy of the tree, measured on a scale of poor-fair-good. An assessment of the health of the tree and the amount of deadwood and live growth in the crown as compared to a 100% healthy tree. The size, colour and amount of foliage are also considered in this category. The assessment is based on a scale of poor-fair-good. Tree displays less than 15% deficiency/defect within the given tree assessment criteria (TI, CS, CV). Tree displays 15%-40% deficiency/defect within the given tree assessment criteria (TI, CS, CV). Tree displays greater than 40% deficiency/defect within the given tree assessment criteria (TI, CS, CV). The preservation area of the tree to be protected with tree protection measures. No construction activities are to be undertaken within this zone. Established as being 10 centimetres from the trunk of a tree for every centimetre of trunk diameter. The trunk diameter is measured at a height of 1.2m for trees of 15cm diameter and greater and at a height of 0.3m for trees less than 15cm in diameter (Per City of Ottawa Tree Protection Guidelines). Crime Prevention through Environmental Design I

14 APPENDIX B Existing Site Photos II

15 APPENDIX C Current Vegetation Plan III

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17 APPENDIX D Proposed Development and Conserved Vegetation Plan IV

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