This site is in beta — data may be incomplete and features are still being added.
Council Meeting/Documents/Arborists' Report Original - Lake View Village Residential Development
Appendix

Arborists' Report Original - Lake View Village Residential Development

July 5, 2016Pages 111–1228 sections

Initial baseline assessment of trees on the Nursery Hill site from 2011.

8.1.e) Form and Character Development Permit with Variances No. 2016/02 - 301 Nursery Hill Drive - "Lillian Gate"
October 31, 2011Includes tree retention plans and protection fencing details

October 31, 2011

Seven Valleys Development LTD 725 Caleb Pike Road Victoria, BC V9B6G5

Attn: Tony Akhavan

Page 111–122

Re: Lake View Village – Residential Development Proposal

Assignment: Prepare a tree retention plan to be used during the proposed construction of a mixed-use townhouse/condominium development on Lot C, Nursery Hill Drive.

Methodology: Each tree was identified onsite using its existing numeric tag number. Information such as tree species, size(dbh), critical root zone, health and structural condition, relative tolerance to construction impacts and general remarks and recommendations was recorded in the attached tree resource spreadsheet.

Potential impacts: We anticipate that the highest onsite impacts will occur during excavation, blasting and rock removal to create the footprint for the proposed townhouses, condos, parking areas and driveways.

Observations: At the time of our site visit all of the trees had been removed and a portion of the blasting work had been completed in the center of the property, leaving the trees along the back and sides of the property that have the best opportunity for retention given the proposed development plans. The ability to retain these perimeter trees will depend on their current health and structural condition and any impacts that are proposed for within their critical root zones. Douglas fir trees numbered 629 to 635 are located where they potentially could be retained given the proposed building and parking design. This group of trees is showing decline symptoms in the form of large deadwood, epicormic growth, limb failure and reduced annual shoot growth, likely due to impacts from the recent construction that has taken place on the neighboring lot and over all changes in hydrology and drainage patterns from the surrounding development. It is likely that these trees will continue to decline, regardless of the changes that are to occur on lot C and as they decline it will increase the risk of limb failure and eventually whole tree failure. In our opinion, given their existing health and structure, the impacts that are going to occur from the development on lot C and the introduction of new targets, it would be wise to remove these trees prior to construction and use this area to replant with healthy young native trees that can better adapt to these growing conditions.

Page 111–122

Mitigation of impacts:

Barrier Fencing:

Areas, surrounding the trees to be retained, should be isolated from the construction activity by erecting protective barrier fencing. Where possible, the fencing should be erected at the perimeter of the critical root zones. The barrier fencing to be erected must be a minimum of 4 feet in height and constructed of solid material or flexible safety fencing that is attached to wooden or metal posts. If a flexible fencing material is used, the top and bottom of the fencing must be secured to the posts by a wire or board that runs between these posts. The fencing must be erected prior to the start of any construction activity on site (i.e. demolition, excavation, construction), and remain in place through completion of the project. Signs should be posted around the protection zone to declare it off limits to all construction related activity. The project arborist must be consulted before this fencing is removed or moved for any purpose. Solid hording material may also be required to protect the trunks of trees from mechanical injury if vehicles or machinery are permitted close to tree trunks and where blasting is required.

Blasting and rock removal:

We anticipate that further blasting will be required, in addition to blasting that has already taken place. Blasting to create the required grades for the condominium and townhouse units may necessitate the removal of bylaw-protected trees. Once the scope of the blast is defined, we can comment further on the potential impacts to the tree resource. If areas of bedrock are encountered, the blasting to level these rock areas should be sensitive to the root zones located at the edge of the rock. Care must be taken to assure that the area of blasting does not extend into the critical root zones beyond the building and road footprints. The use of small low-concussion charges, and multiple small charges will reduce fracturing, ground vibration, and reduce the impact on the surrounding environment. Only explosives of low phytotoxicity, and techniques that minimize tree damage, are to be used. Provisions must be made to store blast rock, and other construction materials and debris away from critical tree root zones. Should bedrock be encountered within service trenches that are located within the critical root zones of trees that are to be retained, alternate methods of removal that do not include explosive charges may be required.

Building footprint:

Excavation for the proposed townhouse footprints will likely necessitate the removal of trees on the Southern side of the property. Trees that appear to be located within the building footprints according to the plans supplied include: 607, 609, 610, 611, 612, 613, 614, 615, 616, 622, 623, 625, 624, 626, 637, 638, 636, 640.

The following trees are located outside of the building footprints, but will be impacted; and in our opinion will be unsuitable to retain in a high target area: 634, 633, 632, 631, 635, 630, 629, 627, 619.

Trees that may be possible to retain providing that the critical root zones can be adequately protected: 646, 647, 628, 513, 606, 604, 608, 621, 620, 648, 605, 603, 602, 601, 617, 618.

Driveway/parking areas:

The following trees will likely require removal for the proposed driveway/parking areas: 641, 642, 643, 644, 645. Floating driveway specifications are recommended for any paved surfaces within the critical root zone of Garry oak #647. Approximately 90 percent of the critical root zone of this tree has been backfilled previously. If this backfill required removal for driveway construction, we recommend it be removed under the supervision of the project arborist. We recommend that if retained, this tree be examined more closely by an ISA certified arborist to determine if it a good specimen to retain in a high target area.

Servicing:

From our discussions, it is our understanding that all servicing will come in off of Nursery Hill Drive, outside of the critical root zones of bylaw-protected trees. If proposed services encroach critical root zones of bylaw-protected trees, their locations must first be reviewed with the project arborist. Any excavation within the critical root zones of bylaw-protected trees must be performed under the supervision of the project arborist.

Stump removal:

If stumps require removal within critical root zones of bylaw-protected trees, they must be removed under the supervision of the project arborist, or ground in place using a stump grinder.

Building/canopy conflicts:

Once detailed building plans and elevations are made available, we can comment on pruning specifics. An ISA Certified arborist must complete the pruning of any bylaw-protected trees.

Lot D:

During our site visit, it was noted that there have been tree failures throughout lot D. We recommend that trees within striking distance of the proposed development be examined for any evidence of wood decay pathogens. We also recommend that they be examined during high wind conditions for any evidence of root plate instability.

Work area and Material Storage:

On restricted sites such as this, it may be difficult to find sufficient space for soil and material storage onsite without using portions of the defined critical root zone. If access within the critical root zone area is required for construction or material storage, the project arborist must be contacted to propose appropriate mitigation measures based on the degree of encroachment required.

Review and Site Meeting:

Once the building permit is approved, it is important that the project arborist meet with the principals involved in the project to review the information contained herein. It is also important that the arborist meet with the site foreman or supervisor before any site clearing or other construction activity occurs.

Arborists Role:

It is the responsibility of the client or his/her representative to contact the project arborist for the purpose of:

  • Locating the barrier fencing or hording for tree protection
  • Reviewing the report with the project foreman or site supervisor
  • Locating work zones, where required
  • Supervising excavation for the driveway and sidewalk footprints, and service corridor

Please do not hesitate to call us at 479-8733 should you have any further questions. Thank You.

Yours truly, Talbot Mackenzie & Associates

Tom Talbot & Graham Mackenzie ISA Certified, & Consulting Arborists Encl. – Tree Resource Spreadsheet, Barrier Fencing Specifications, Floating Driveway Specifications

Disclosure Statement

Arborists are professionals who examine trees and use their training, knowledge and experience to recommend techniques and procedures that will improve their health and structure or to mitigate associated risks.

Trees are living organisms, whose health and structure change, and are influenced by age, continued growth, climate, weather conditions, and insect and disease pathogens. Indicators of structural weakness and disease are often hidden within the tree structure or beneath the ground. It is not possible for an Arborist to identify every flaw or condition that could result in failure or can he/she guarantee that the tree will remain healthy and free of risk.

Remedial care and mitigation measures recommended are based on the visible and detectable indicators present at the time of the examination and cannot be guaranteed to alleviate all symptoms or to mitigate all risk posed.

Page 111–122

TREE RESOURCE for Lot C, Nursery Hill Drive

Tree # d.b.h. (cm) CRZ Species Condition Health Condition Structure Relative Tolerance Remarks / Recommendations
647 22 2.0 Garry oak Fair Fair Good Backfill around trunk, trunk wound. May be possible to retain providing critical root zone can be adequately protected. Recommend removal of backfill around base. Floating driveway specifications recommended for paved areas within crz.
646 94 9.5 Garry oak Fair Fair/poor Good Backfill around trunk, history of large limb failure, large deadwood. May be possible to retain providing critical root zone can be adequately protected. Recommend removal of backfill around base. Floating driveway specifications recommended for paved areas within crz. Structural prune, deadwood prune, closer exam. recommended if retained.
645 29 3.0 Garry oak Fair Fair Good Corrected lean, backfill around base, epicormic growth, small deadwood. In footprint of parking area. Removal.
644 60 9.0 Douglas-fir Fair Fair Poor Small deadwood, basal wound, suppressed, backfill around base. In footprint of parking area. Removal.
643 46 7.0 arbutus Fair Fair Poor Canker, trunk wounds, backfill around base, dieback. In building footprint. Removal.
642 147 22.0 Douglas-fir Dead Dead Poor Dead tree. Remove.
641 53 8.0 arbutus Fair Fair Poor Small deadwood. In building footprint. Removal.
640 40 6.0 Douglas-fir Fair Fair Poor Ivy covered, backfill around base. In building footprint. Remove.
639 43 6.5 Douglas-fir Fair Fair Poor Low live crown ratio, corrected lean. In building footprint. Remove.
638 54 8.1 Douglas-fir Fair Fair Poor Low live crown ratio. In building footprint. Remove.
Tree Resource table page 1
Tree Resource table page 1
Tree # d.b.h. (cm) CRZ Species Condition Health Condition Structure Relative Tolerance Remarks / Recommendations
637 49 7.4 Douglas-fir Fair Fair Poor Low live crown ratio, corrected lean, epicormic growth. In building footprint. Remove.
636 40 6.0 Douglas-fir Fair Fair Poor Suppressed. In building footprint. Remove.
635 72 11.0 Douglas-fir Fair Fair Poor Live stump at base, surface rooted, epicormic growth, low live crown ratio. Unlikely to survive impacts. Removal recommended.
634 72 11.0 Douglas-fir Fair Fair Poor Health stress, sparse, hangers. Unlikely to survive impacts. Removal recommended.
633 61 9.0 Douglas-fir Poor Fair Poor Backfill around base, health stress. Unlikely to survive impacts. Removal recommended.
632 64 9.5 Douglas-fir Fair Fair Poor Live stump at base, surface rooted, health stress. Unlikely to survive impacts. Removal recommended.
631 60 9.0 Douglas-fir Fair Fair Poor Phellinus pini fruiting body in old branch stub. Unlikely to survive impacts. Removal recommended.
630 88 13.0 Douglas-fir Fair Fair Poor Deadwood, end-weighted, surface rooted, one-sided form, epicormic growth, history of limb failure. Unlikely to survive impacts. Removal recommended.
629 147 22.0 Douglas-fir Fair Fair/poor Poor Large deadwood, hangers, sparse, epicormic growth, declining. Unlikely to survive impacts. Removal recommended.
628 40 4.0 Garry oak Good Fair Good Leans away from proposal. May be possible to retain providing critical root zone can be adequately protected.
627 95 14.5 Douglas-fir Fair Fair Poor Girdling root, pitch flow, possible internal crack, one-sided form. Unlikely to survive impacts. Removal recommended.
Tree Resource table page 2
Tree Resource table page 2
Tree # d.b.h. (cm) CRZ Species Condition Health Condition Structure Relative Tolerance Remarks / Recommendations
626 70 10.5 arbutus Fair Poor Poor Corrected lean, lower trunk cavity, history of limb failure. Located in building footprint. Removal.
625 32 5.0 Douglas-fir Fair Fair Poor Ivy covered. Located in building footprint. Removal.
624 49 7.5 Douglas-fir Fair Fair Poor Ivy covered, small needle size. Located in building footprint. Removal.
623 90 13.5 Douglas-fir Fair Fair Poor Corrected lean, large deadwood, history of large limb failure. Located in building footprint. Removal.
622 67 10.0 Douglas-fir Fair Fair Poor Corrected lean, hangers, deadwood, grows at edge of cut. Located in building footprint. Removal.
621 94 14.0 Douglas-fir Fair Fair Poor Large deadwood, history of limb failure. May be possible to retain providing critical root zone can be adequately protected.
620 10 1.0 Garry oak Fair Fair Good Grows horizontally. May be possible to retain providing critical root zone can be adequately protected.
648 48 5.0 Garry oak Poor Poor Good Dead/decayed central leader, poor specimen. May be possible to retain providing critical root zone can be adequately protected.
603 10 1.0 Garry oak Fair Fair Good May be possible to retain providing critical root zone can be adequately protected.
604 12 1.0 Garry oak Fair Fair Good May be possible to retain providing critical root zone can be adequately protected.
605 4 1.0 Garry oak Fair Fair Good Short juvenile tree, approximately 2 meters tall. May be possible to retain providing critical root zone can be adequately protected.
Tree Resource table page 3
Tree Resource table page 3
Tree # d.b.h. (cm) CRZ Species Condition Health Condition Structure Relative Tolerance Remarks / Recommendations
608 21 2.0 Garry oak Fair/poor Fair Good Health stress, declining. May be possible to retain providing critical root zone can be adequately protected.
606 12 1.0 Garry oak Fair Fair Good Located next to building corner. May be possible to retain providing critical root zone can be adequately protected.
602 17 2.0 Garry oak Fair Fair Good May be possible to retain providing critical root zone can be adequately protected.
601 8 1.0 Garry oak Fair Fair Good May be possible to retain providing critical root zone can be adequately protected.
607 10 1.0 Garry oak Fair Fair Good Rooted in rock. Located in building footprint. Removal.
513 17 2.0 Garry oak Fair Fair Good No tag. May be possible to retain providing critical root zone can be adequately protected.
511 4 1.0 Garry oak Poor Poor Good No tag, decayed. May be possible to retain providing critical root zone can be adequately protected.
510 65 6.5 arbutus Poor Poor Poor Hollow/decayed. Poor specimen to retain in high target area. Recommend removal if new targets are introduced.
619 46 7.0 Douglas-fir Fair/poor Fair Poor Was co-dominant, smaller stem removed historically, sparse, low live crown ratio. Will be impacted, poor specimen to retain in high target area. May be better to re-plant with a more suitable species.
617 15 1.5 Garry oak Fair Fair Good Juvenile tree. Possible to retain providing the critical root zone can be adequately protected.
616 5 1.0 Garry oak Fair Fair Good Juvenile tree. Possible to retain providing the critical root zone can be adequately protected.
Tree Resource table page 4
Tree Resource table page 4
Page 111–122
Tree # d.b.h. (cm) CRZ Species Condition Health Condition Structure Relative Tolerance Remarks / Recommendations
618 10, 10 1.5 Garry oak Fair Fair Good Juvenile tree. Will be impacted. Field decision based on extent of blasting/excavation.
615 10 1.0 Garry oak Fair Fair Good Juvenile tree. Located in building footprint. Removal.
614 5 1.0 Garry oak Fair Fair Good Juvenile tree. Located in building footprint. Removal.
613 20 2.0 Garry oak Fair Fair Good Juvenile tree. Will be impacted. Field decision based on extent of blasting/excavation.
612 10 1.0 Garry oak Fair Fair Good Juvenile tree. Will be impacted. Field decision based on extent of blasting/excavation.
611 10, 10 1.5 Garry oak Fair Fair Good Juvenile tree. Will be impacted. Field decision based on extent of blasting/excavation.
610 20 2.0 Garry oak Fair Fair Good Juvenile tree. Located in building footprint. Removal.
609 10 1.0 Garry oak Fair Fair Good Juvenile tree. Located in building footprint. Removal.
Tree Resource table page 5
Tree Resource table page 5
Page 111–122

Diagram- Driveway or sidewalk with pavers crossing over Critical Root Zone

Diagram of driveway or sidewalk with pavers crossing over Critical Root Zone
Diagram of driveway or sidewalk with pavers crossing over Critical Root Zone

Specifications for driveway or sidewalk crossing over critical root zone

  1. Excavate to a 6-8 inch depth, for the required driveway surface, under the supervision of an ISA Certified Arborist.
  2. Excavation for area around structural roots with an Airspade or by Hydro Excavation to bearing layer of soil.
  3. Backfill area around roots with coarse sand or a structural soil mix.
  4. A layer of medium weight woven Geotextile fabric (Amoco 2002 or similar) is to be installed over the backfilled area of the driveway.
  5. Construct base layer and pavers or other porous surfacing material over Geotextile layer to required grade.

Diagram labels:

  • Sand base layer and permeable paving materials.
  • Woven Geotextile fabric (Amoco 2002 or similar)
  • Roots
  • Airspade or hydro excavated area around structural roots, backfilled with coarse sand or Structural soil.
Page 111–122

TREE PROTECTION FENCING

Detail drawing E105 - Tree Protection Fencing
Detail drawing E105 - Tree Protection Fencing

TREE PROTECTION FENCING FENCE WILL BE CONTRUCTED USING 38 X 89 mm (2"X4") WOOD FRAME: TOP, BOTTOM AND POSTS. * USE ORANGE SNOW-FENCING MESH AND SECURE TO THE WOOD FRAME WITH "ZIP" TIES OR GALVANZIED STAPLES

  • IN ROCKY AREAS, METAL POSTS (T-BAR OR REBAR) DRILLED INTO ROCK WILL BE ACCEPTED

Drawing details:

  • 2.4M MAXIMUM SPAN
  • 38 x 89mm TOP RAIL
  • 38 x 89 mm BOTTOM RAIL
  • 38 x 89mm POST
  • TIES OR STAPLES TO SECURE MESH
  • Height above grade: 1.20
  • Post depth below grade: 600
DETAIL NAME: DATE: Oct 30/07
DRAWN: DM
TREE PROTECTION FENCING APP'D. RR
SCALE: N.T.S.
E105 DRAWING
Page 111–122

Key to Headings in Resource Table

d.b.h. – diameter at breast height - diameter of trunk, measured in centimetres at 1.5 metres above ground level

CRZ – critical root zone - estimated optimal size of tree protection zone based on tree species, condition and age of specimen and the species tolerance to root disturbance. Indicates the radial distance from the trunk, measured in metres.

Condition health/structure –

  • Good – no visible or minor health or structural flaw
  • Fair – health or structural flaw present that can be corrected through normal arboricultural or horticultural care.
  • Poor – significant health or structural defects that compromise the long-term survival or retention of the specimen.

Relative Tolerance – relative tolerance of the selected species to development impacts.

Page 111–122
Extracted from: 2016 07 05 Council Agenda - Pdf