River s Crossing Significant Tree Overview Assessment 18 June 2012

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1 ` River s Crossing Significant Tree Overview Assessment Prepared For: Tinney & Associates Land Planning & Design PO Box Fairfield Road Victoria, BC V8S 1G0 Prepared By: LANDECA Services Inc Bay Street Victoria, BC V8T 1S8!

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3 Introduction LANDECA Services Inc. has been engaged to assist with a focused review of a select number of identified trees of interest on the River s Crossing site. The objective is to provide professional advice on the viability of preserving the limited number of identified mature tree specimens and to generally outline recommended best practices in tree preservation for the project. LANDECA s Certified Arborist, horticultural technicians and landscape designers, under the direction of a Member of the Canadian Institute of Planners, completed the initial assessment of the existing trees of interest on the property. It is important to note that the observations and recommendations outlined in this report are intended to provide an overview of the select trees of interest based on the comprehensive tree survey; the lot plan overlay; and the cut and fill road plan; compiled by JE Anderson and Associates. This letter is not intended to capture a complete analysis of the current state of the trees on the entire property. Where appropriate and to provide background, the findings of the comprehensive Aqua-Tex Scientific Consulting Ltd. report, Riparian Management Zones Lot alignment, RAR and SWM Pursuant to Rezoning Application RZ Bear Mountain Parkway, have been referenced. Background As noted in the Aqua-Tex report, much of the landscape in the area proposed for residential development has been previously disturbed, with an internal road system, two existing buildings, and on-site stormwater and wastewater treatment infrastructure. The site has experienced significant tree canopy loss due to blow down, leaving the forest edge vulnerable to further wind disturbance. Virtually all the existing disturbed areas are proposed for re-development. The proposed residential concept of a clustered, conservation-style subdivision is envisioned to reflect the semi-rural character of the District of Highlands, with the surrounding forest to be preserved in perpetuity. Adopting a landscape strategy that focuses on the use of indigenous and drought-tolerant species plant species within the residential neighbourhood will contribute to the continuity of character for the property and will reflect principles of sustainable development, inherent in the project s design. This conservation subdivision design plan conserves natural landscapes by concentrating density on a very small proportion of the property (17%). This results in the development being less landconsumptive, ensuring that the majority of the land is permanently protected (under Covenant), contributing to an interconnected network of functional green spaces and connecting corridors sustained, living semi-rural landscapes. Site Conditions The site is characteristic of a Douglas fir forest, with rocky outcroppings supportive of stands of Arbutus trees. As the subject area has previously been disturbed, the forest is not mature and has suffered from loss of trees along the edges of the property adjacent to the Bear Mountain Parkway and from the existing development. The objective of the tree assessment is to identify the tree species that are present and outline the steps required before any development takes place on the property. It is recognized that many of the existing trees will need to be removed at time of development. However, where possible, opportunities to retain 3!

4 ! existing trees should be considered. The focus of our analysis has been on the existing trees of significance as identified through the tree survey/site plan overlay. The significant tree species that are present on the property include six mature Douglas firs, one mature Western Red Cedar, and a number of Arbutus clusters as highlighted on the attached plans. Pseudotsuga menziesii (Douglas fir) The largest of the identified Dougas fir specimens (1.4 m Fir) is located along proposed Road B near the intersection with proposed Road A. This tree is presently at risk as a result of the tree s form being compromised, with a topped leader, likely the result of storm damage, and a significantly leaning growth habit. This tree cannot be retained and should be removed as it poses a risk to future use and development of the property. 4!

5 There may be opportunities to consider the creative use of the timber resulting from the harvesting of the tree in the construction/development of the site. It is also recommended that replacement Douglas fir specimens (proposed ratio of 3:1) be planted elsewhere on the property in a more suitable long-term location. A second Douglas fir specimen (1.2 m Fir) is located at the centre of the proposed new Road B providing access to Phase Two of the project and adjacent to a portion of the site where blasting to normalize the topography is proposed. It is unlikely that the road could be realigned to avoid the tree due to the constraint of the existing lot boundary/covenant area boundary and the topography of the site. It would appear that this tree has been damaged by human activity, as there is evidence of fire/burn damage and cut holes. 5!

6 ! It is recommended that this tree be safely removed with an approved permit. There may be opportunities to consider the creative use of the timber resulting from the harvesting of the tree in the construction/development of the site. It is also recommended that replacement Douglas fir specimens (proposed ratio of 3:1) be planted elsewhere on the property in a more suitable long-term location. There is an additional Douglas fir specimen (1.0 m Fir) located on proposed Lot 27, which is in an area where the topography will be cut. The tree cannot be retained and therefore should be removed with permit. Again, there may be opportunities to consider the use of timber from the significant trees in the development of the site. The final Douglas fir specimens (1.0 m Fir at the southeast corner of proposed Lot 27; 0.9 m Fir at the junction of proposed Lots 15 and 16; and 1.0 m Fir adjacent to the proposed Green Space in the northeast corner of the site) appear to be candidates for retention, subject to detailed analysis at time of development. Arbutus menziesii (Pacific Madrone) The Arbutus stands located near the existing Treehouse building should be retained and a tree protection perimeter set up around the trees to keep all development activity outside of the trees drip line. Similarly, efforts should be made to preserve the existing Arbutus stands on the proposed residential lots where possible and not impacted by proposed road cut/fill, with the siting of buildings respecting the trees drip lines. Our team has studied Lot 21, for example, to demonstrate a conceptual building siting and design that respects the preservation of the Arbutus tree grove (Arbutus Cluster) and features the retained tree in the architectural design of the residence. 6!

7 The layout for proposed Lots 7 and 8 includes panhandle connections for driveways to the road turnaround and it may be possible to align the driveways at the development stage to preserve the Arbutus clusters. Thuja plicata (Wester Red Cedar) The leader of the existing mature Western Red Cedar (1.1 m Cedar - mis-labeled as 1.1 m Fir) located on proposed Lot 17 has a split high up in the canopy, compromising the integrity of the tree at a critical height. While it may be possible to support the tree through the installation of a cable system, the longterm viability of the tree cannot be guaranteed. However, as the crown is in reasonable condition, efforts should be made to attempt to retain the tree. A cable system, if considered, could be installed between the major limbs of the tree, greatly reducing strain and helping to support the tree. 7!

8 ! Tree Preservation Planning It is recommended that all development on the proposed lots be assessed on a lot-by-lot basis through the completion of individual tree surveys and tree preservation plans that are respectful of the regulations set out in the Highlands Tree Management Bylaw No.10,1994. The Bylaw states that any blasting or excavating is considered tree damaging activity; therefore, regardless of the size of the tree, permits and development of a tree protection plan would be required. Efforts to preserve and retain as many trees as possible and feasible should be considered at the Building Permit stage of development through the Building Scheme guidelines. LANDECA is pleased to be part of the project team at this stage and will continue to provide professional Arborist and landscape direction to the development as the project advances. Lisa James, Certified Arborist LANDECA Services Inc. Jennifer Kay, MCIP LANDECA Services Inc. 8!