4595 cordova bay rd, saanich

S

:GiC)

Talbot Mackenzie & AssociatesConsulting Arborists

4595 Cordova Bay Rd, Saanich

Construction Impact Assessment &

Tree Preservation Plan

Noah BorgesISA Certified # PN-8409ATRAQ - Qualified

May 24, 2019

Prepared For:

Prepared By:

Date of Issuance:

Ryan Hoyt Designs Inc.Suite 207, 4475 Viewmont AvenueVictoria, BCV8Z 6L8

Talbot, Mackenzie & Associates

Box 48153 RPO - Uptown Victoria, BC V8Z 7H6Ph: (250) 479-8733Fax: (250) 479-7050

Email: tmtreehelpgmail.com

r:Li)\_,L:: J LtjrN’sl ii )iLI U MAY 2 2rlq LJ

/

_zj= ccb --==-

cJc6

:. • -

Talbot Mackenzie & Associates. . Consulting Arborists

Jobsite Property: 4595 Cordova Bay Rd, Saanich, BC

Date ofSite Visits: May 23, 2019

Site Conditions: No ongoing construction activity.

Summary: One tree, Douglas-fir #0001 (1 13cm DBH) will require removal, as it is within theproposed footprint ofthe driveway to building A.

We recommend the project arborist supervise the removal of the, existing driveway and anyadditional excavation, as roots from municipal trees #0002 and #0004-0008 may be encountered.If possible, we recommend the permeable paving stones be installed overtop the existing baselayers.

The exact location of the underground services to building B and whether the existing services tobuilding A will need to be upgraded has yet to be determined. It is our understanding that, wherepossible, they will be installed within the driveway footprint to mitigate root impacts. The projectarborist should supervise any ‘excavation within the CRZs of the municipal trees. Alternativeexcavation methods will likely be required (e.g. hydro-vac, air-spade, or using an excavator incombination with hand-digging).

Small roots from Douglas-fir #0988 may be encountered during excavation for the rear patio onlot A, but we do not anticipate its health will be significantly impacted as a result.

Scope of Assignment:

. To inventory the existing bylaw protected trees and any trees on municipal or neighbouringproperties that could potentially be impacted by construction or that are within three metres ofthe property line

. Review the proposal to demolish the existing house, subdivide the property into two lots,construct two new houses, and resurface the driveway

. Comment on how construction activity may impact existing trees• Prepare a tree retention and construction damage mitigation plan for those trees deemed

suitable to retain given the proposed impacts

Methodology:

• We visually examined the trees on the property and prepared an inventory in the attached TreeResource Spreadsheet.

• Each by-law protected tree was identified using a numeric metal tag attached to its lower trunk.

4595 Cordova Bay Rd — Tree Preservation Plan Page 1 of6

:--iE=:I--=- - - - :- - -Q C) (‘ ,

: = ---- - Ta1botMacknzie & Associates

. Information such as tree species, DBH (1 .4m), crown spread, critical root zone (CRZ), health,structure, and relative tolerance to construction impacts were included in the inventory.

. The conclusions reached were based on the information provided within the attached plansfrom Ryan Hoyt Designs Inc. (April 2, 2019).

Limitations:

. No exploratory excavations have been conducted and thus the conclusions reached are basedsolely on critical root zone calculations and our best judgement using our experience andexpertise. The location, size and density of roots are often difficult to predict withoutexploratory excavations and therefore the impacts to the trees may be more or less severe thanwe anticipate.

Summary of Tree Resource: Seven trees were inventoried, all of which are by-law protected.There are three trees on the municipal frontage, and an additional two trees under shared ownershipwith the municipality.

Trees to be Removed : One tree will require removal due to construction-related impacts:

. Douglas-fir #0001 (113cm DBH) is within the proposed driveway to building A.

Potential Impacts on Trees to be Retained and Mitigation Measures

. New Driveway: According to the attached plans, the existing driveway will be resurfacedusing permeable paving stones. We recommend the project arborist be on site to superviseremoval of the existing driveway slab, as it overlaps with the CRZs of the municipal trees.Large roots from several ofthese trees may be encountered underneath. There is a large surfaceroot from Douglas-fir #0002 (101cm DBH) growing towards the driveway.

We further recommend that the existing base layers underneath the existing driveway be leftin place and the new paving stones be placed on top to minimize root disturbance. Excavatingdown to bearing soil in these areas would likely result in significant health and/or structuralimpacts to the municipal trees. Ifany additional excavation is required within the trees’ CRZs,it must be supervised by the project arborist, and a “floating” driveway will likely have to beconstructed (see attached “floating” driveway specifications).

. Underground Services: The attached plans indicate that the existing water, storm, and sewerservice connections underneath the west driveway entrance will be used to service building A.Based on discussions with the applicant, it is our understanding that it has yet to be determinedwhether these services will need to be upgraded. The attached plans indicate the existingsanitary sewer lateral is within 3m of Douglas-fir #0007 (84cm DBH) and the storm drainlateral is approximately 5m from Big Leaf Maple #0004/0005 (64, 45, 35cm DBH). If anyexcavation is required within the CRZs of trees #0004-0008, we recommend the projectarborist be on site to supervise and that the excavation be completed using a hydro-vac, airspade, or using an excavator in combination with hand-digging. Health impacts could result iflarge roots from these trees are encountered and damaged. It is possible that roots from these

4595 Cordova Bay Rd — Tree Preservation Plan Page 2 of 6

=

C C0 C (,—

Talbot Mackenzie & Associates

trees have already been pruned in these areas, which could limit the potential health impacts ifthey are encountered again.

There is also an existing water service connection underneath the east driveway entrance whichwill service building B. The water service connection is approximately 8.5m from Douglas-fir #0002 (101cm DBH). New storm and sewer service connections are proposed to be installedapproximately 2m east of the water line. We anticipate small roots from #0002 may beencountered, which should be pruned back to sound tissue at the edge of excavation. If anyexcavation occurs within 7m of the tree, we recommend alternative excavation methods beused (e.g. hydro-vac, air-spade, or using an excavator in combination with hand-digging).

Building A Patio: The rear at-grade patio area is proposed to be constructed approximately 6-7m from Douglas-fir #0988 (116cm DBH). This tree is growing in a tree well and is separatedby a second retaining wall between the tree and the proposed building, which may restrict someroot growth in the direction of the area to be excavated. We anticipate small roots from thistree may be encountered and recommend the project arborist supervise any excavation withinthe tree’s CRZ. Any roots severed should be pruned back to sound tissue at the edge ofexcavation to encourage rapid wound compartmentalization and new root growth. Excavationshould not occur more than 50cm outside the patio footprint. We do not anticipate the healthofthis tree will be impacted.

Demolition of the Existing Building: The demolition ofthe existing house and any servicesthat must be removed or abandoned, must take the critical root zone of the trees to be retainedinto account. If any excavation or machine access is required within the critical root zones oftrees to be retained, it must be completed under the supervision and direction of the projectarborist. If temporarily removed for demolition, barrier fencing must be erected immediatelyafter the supervised demolition.

• Arborist Supervision: All excavation occurring within the critical root zones of protectedtrees should be completed under supervision by the project arborist. In particular, the followingactivities should be completed under the direction of the project arborist:

• Removal of the existing driveway slab and construction of the new driveway, where itoccurs within the CRZ of trees #0002-0008

• Installation of any underground services that cross the CRZ of Douglas-fir #0002• Any excavation within the CRZ of Douglas-fir #0988 for construction of the rear patio

area for building A

• Pruning Roots: Any severed roots must be pruned back to sound tissue to reduce woundsurface area and encourage rapid compartmentalization of the wound. Backfilling theexcavated area around the roots should be done as soon as possible to keep the roots moist andaid in root regeneration. Exposed roots should be kept moist until the area is backfilled,especially if excavation occurs during a period of drought. This can be accomplished in anumber of ways, including wrapping the roots in burlap or installing a root curtain of wiremesh lined with burlap, and keeping the area moist throughout the construction process.


-- z _

c5:i c:

c;Jz-z:-:E:::::

Talbot Mackenzie & Associates

Barrier Fencing: The areas surrounding the trees to be retained should be isolated from the. .“.- - - : . construction activi by erecting protective barrier fencing. Where possible, the fencing should

. . . be erected at the perimeter of the critical root zones.

The barrier fencing must be a minimum of 4 feet in height, of solid frame construction that isattached to wooden or metal posts. A solid board or rail must run between the posts at the topand the bottom ofthe fencing. This solid frame can then be covered with plywood, or flexiblesnow fencing. 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 theproject. Signs should be posted around the protection zone to declare it off limits to allconstruction related activity. The project arborist must be consulted before this fencing isremoved or moved for any purpose.

Minimizing Soil Compaction: In areas where construction traffic must encroach into thecritical root zones oftrees to be retained, efforts must be made to reduce soil compaction wherepossible by displacing the weight of machinery and foot traffic. This can be achieved by oneofthe following methods:

. Installing a layer of hog fuel or coarse wood chips at least 20 cm in depth andmaintaining it in good condition until construction is complete.

. Placing medium weight geotextile cloth over the area to be used and installing a layerof crushed rock to a depth of 1 5 cm over top.

. Placing two layers of 19mm plywood.

. Placing steel plates.

Mulching: Mulching can be an important proactive step in maintaining the health oftrees andmitigating construction related impacts and overall stress. Mulch should be made from anatural material such as wood chips or bark pieces and be 5-8cm deep. No mulch should betouching the trunk of the tree. See “methods to avoid soil compaction” if the area is to haveheavy traffic.

Blasting: If required, care must be taken to ensure that the area of blasting does not extendbeyond the necessary footprints and into the critical root zones of surrounding trees. The useof small low-concussion charges and multiple small charges designed to pre-shear the rockface will reduce fracturing, ground vibration, and overall impact on the surroundingenvironment. Only explosives of low phytotoxicity and techniques that minimize tree damageshould be used. Provisions must be made to ensure that blasted rock and debris are stored awayfrom the critical root zones of trees.

Scaffolding: This assessment has not included impacts from potential scaffolding includingcanopy clearance pruning requirements. If scaffolding is necessary and this will requireclearance pruning of retained trees, the project arborist should be consulted. Depending on theextent of pruning required, the project arborist may recommend that alternatives to fullscaffolding be considered such as hydraulic lifts, ladders or platforms. Methods to avoid soilcompaction may also be recommended (see “Minimizing Soil Compaction” section).


_c C“ . . ...-... .: • •

:: TalbotMackenzie&Associates

. Landscaping and Irrigation Systems: The planting of new trees and shrubs should notdamage the roots of retained trees. The installation of any in-ground irrigation system musttake into account the critical root zones of the trees to be retained. Prior to installation, werecommend the irrigation technician consult with the project arborist about the most suitablelocations for the irrigation lines and how best to mitigate the impacts on the trees to be retained.This may require the project arborist supervise the excavations associated with installing theirrigation system. Excessive frequent irrigation and irrigation which wets the trunks of treescan have a detrimental impact on tree health and can lead to root and trunk decay.

. Arborist Role: It is the responsibility of the client or his/her representative to contact theproject

arborist for the purpose of:

. Locating the barrier fencing

. Reviewing the report with the project foreman or site supervisor

. Locating work zones, where required

. Supervising any excavation within the critical root zones oftrees to be retained

. Reviewing and advising of any pruning requirements for machine clearances

. Review and Site Meeting: Once the project receives approval, it is important that the projectarborist meet with the principals involved in the project to review the information containedherein. It is also important that the arborist meet with the site foreman or supervisor before anysite clearing, tree removal, demolition, or other construction activity occurs and to confirm thelocations ofthe tree protection barrier fencing.

Please do not hesitate to call us at (250) 479-8733 should you have any further questions.

Thank you,

Noah BorgesISA Certified #PN-8409ATRAQ — Qualified .

Talbot Mackenzie & AssociatesISA Certified Consulting Arborists

End. 1-page tree resource spreadsheet, 1 6-page site and building plans, 1-page floating drivewayspecifications, 1-page barrier fencing specifications, 2-page tree resource spreadsheetmethodology and definitions

Disclosure Statement

The tree inventory attached to the Tree Preservation Plan can be characterized as a limited visual assessment from the ground and should not beinterpreted as a risk assessment” of the trees included.

4595 Cordova Bay Rd — Tree Preservation Plan S Page 5 of 6

z:z_:: :-

c)

:__

-‘-

_

: -Talbot Mackenzie & Associates

Arborists are professionals who examine trees and use their training, knowledge and experience to recommend techniques and procedures that willimprove 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 insectand disease pathogens. Indicators of structural weakness and disease are often hidden within the tree structure or beneath the ground. It is notpossible 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 andfree of risk.

Remedial care and mitigation measures recommended are based on the visible and detectable indicators present at the time of the examination andcannot be guaranteed to alleviate all symptoms or to mitigate all risk posed.


Ct

VS

Q

CU

In

C’

CsC

t

0_C“0

U“0

Q

cooz

000

PROPOSED SUBDIVISION:

4595 Cordova Bay RoadSAANICH, BC

PROJECT INFORMATION:

SITE ADDRESS: 45O5YORD&!ABAYROAD

LAND DISTRT 62

SCOPE OF WORK;

SHEET INDEX; PROJECT DIRECTORY:

DESIGNER RYAN HOYT DESIGNS IAC.

[email protected]

AO.O COVRRSI-IEET

61.5 EGRTWIGSITEPHOTOSA1.S DEVELOPMENT ELEHATIGNS

I.1

H

Ccc0a:>-cc0C00

(I,

C)

0U,

LI.C)

.

__

__

_

IIII1I

Lfl3

-

I

DRAWING SCALE: 1I4 1-0” ALL MEASUREMENTSARE IN FEET

543210 5 10 15 20

iihuIu

j

II1LIIL___I

LL

J[

HILLId

I

II

6

II

L

Ii

qH r

9

,

..1

[

e

DRAWING SCALE: 114 . 1-Q ALL MEASUREMENTS ARE W FEET

1Q5

1

. I, .

I

10 15 20

1 •

tj—t—

——

i1j•t——

::-i“1’

H141

6

‘III

g

i’

‘I

••j:••••

•••

Diagram — Site Specific Floating Driveway, Parking and Walkway Areas

Surfacingmaterial I

Base layer

cloth layer

ordrainrocklayer .

Felted Geotextile fabric (Nilex 4535,or similar) Covered by a layer of .

.

woven Tensar BX 1200 or Amoco2002.

Specifications for Floating Driveway, Parking and Walkway Areas:

1 . Excavation for construction of the driveway/parking/walkway areas must remove the sod layer only, where they encroach on the root zones of the

protected trees

2. A layer ofmedium weight felted Geotextile fabric (Nilex 4535, or similar) is to be installed over the entire area ofthe critical root zone that is to be

covered by the driveway Cover this Geotextile fabric with a layer of woven Amoco 2002 or Tensar BX 1200 Each piece of fabric must overlap flthe adjoining piece by approximately 30-cm.

3. A 10cm layer of torpedo rock, or 20-mm clean crushed drain rock, is to be used to cover the Geotextile fabric.

4. A layer of felted filter fabric is to be installed over the crushed rock layer to prevent fine particles of sand and soil from infiltrating this layer.

5. The bedding or base layer and permeable surfacing can be installed directly on top of the Geotextile fabric.

00,..

TREE PROTECTION FENCING

NOTES:

I . 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 WOODFRAME WITH “ZIP” TIES OR GALVANZIED STAPLES.

2. ATTACH A 500mm x 500mm SIGN WITH THE FOLLOWING WORDING:WARNING-HABiTAT PROTECTION AREA. THIS SIGN MUST BE AFFIXEDON EVERY FENCE FACE OR AT LEAST EVERY 10 LINEAR METRES.

* IN ROCKY AREAS, METAL POSTS (T-BAR OR REBAR) DRILLED INTO ROCKWILL BE ACCEPTED

I DATE: March/08

I DRAWN: DM

I APP’D.SCALE: N.T.S.

2.4M MAXIMUM SPAN

DETAIL NAME: TREE PROTECTION FENCINGH:\shared\parks\Tree Protection Fencing.pdf

cPS? ZZJ •

Talbot Mackenzie & AssociatesConsulting Arborists

Box 48153 RPO - Uptown Victoria, BC V8Z 7H6Ph: (250) 479-8733Fax: (250) 479-7050

Email: tmtreehelpgmail.com

Tree Resource Spreadsheet Methodology and Definitions

jig: Tree identification number on a metal tag attached to tree with nail or wire, generally at eyelevel. Trees on municipal or neighboring properties are not tagged.

NT: No tag due to inaccessibility or ownership by municipality or neighbour.

DBH: Diameter at breast height — diameter of trunk, measured in centimetres at 1 .4m aboveground level. For trees on a slope, it is taken at the average point between the high and low side ofthe slope.* Measured over ivy, Approximate due to inaccessibility or on neighbouring property

Crown Spread: Indicates the diameter ofthe crown spread measured in metres to the dripline ofthe longest limbs.

Relative Tolerance Rating: Relative tolerance ofthe tree species to construction related impactssuch as root pruning, crown pruning, soil compaction, hydrology changes, grade changes, andother soil disturbance. This rating does not take into account individual tree characteristics, suchas health and vigour. Three ratings are assigned based on our knowledge and experience with thetree species: Poor (P), Moderate (M) or Good (G).

Critical Root Zone: A calculated radial measurement in metres from the trunk ofthe tree. It is theoptimal size oftree protection zone and is calculated by multiplying the DBH ofthe tree by 10, 12or 1 5 depending on the tree’s Relative Tolerance Rating. This methodology is based on themethodology used by Nelda Matheny and James R. Clark in their book “Trees and Development:A Technical Guide to Preservation ofTrees During Land Development.”

. 1 5 x DBH = Poor Tolerance of Construction

. 12 x DBH = Moderate

. 1OxDBH=Good

To calculate the critical root zone, the DBH of multiple stems is considered the sum of 100% ofthe diameter of the largest stem and 60% of the diameter of the next two largest stems. It shouldbe noted that these measures are solely mathematical calculations that do not consider factors suchas restricted root growth, limited soil volumes, age, crown spread, health, or structure (such as alean).

Spreadsheet Methodology & Defmitions Page 1 of 2

00D ()Ci0Talbot Mackenzie & Associates

Health Condition:

. Poor - significant signs of visible stress and/or decline that threaten the long-term survivalofthe specimen

. Fair - signs of stress

. Good - no visible signs of significant stress and/or only minor aesthetic issues

Structural Condition:

. Poor - Structural defects that have been in place for a long period oftime to the point thatmitigation measures are limited

. Fair - Structural concerns that are possible to mitigate through pruning

. Good - No visible or only minor structural flaws that require no to very little pruning

Retention Status:

. x - Not possible to retain given proposed construction plans

. Retain - It is possible to retain this tree in the long-term given the proposed plans andinformation available. This is assuming our recommended mitigation measures arefollowed

. Retain - See report for more information regarding potential impacts

• TBD (To Be Determined) - The impacts on the tree could be significant. However, in theabsence of exploratory excavations and in an effort to retain as many trees as possible, werecommend that the final determination be made by the supervising project arborist at thetime of excavation. The tree might be possible to retain depending on the location of rootsand the resulting impacts, but concerned parties should be aware that the tree may requireremoval.

• NS - Not suitable to retain due to health or structural concerns

Spreadsheet Methodology & Definitions Page 2 of 2

4595 cordova bay rd, saanich

Documents