[CANUFNET] tree protection

Mon Jan 16 16:30:27 EST 2017

Good afternoon,

The process of tree protection on development sites is simple;  don't encroach within the Critical Root Zone of the tree.   That said, the only way to ensure this happens is to neuter development.    Defining the CRZ is discretionary and based upon conflicting information.  The Canadian Landscape Standard, based upon the BC Landscape Standard,  states that the CRZ is based on a factor of 8x dbh of a tree.   This information can be found in Section 3.2.3; Table T-3.1.   Other references will state CRZ is between 6x -12x dbh with factors all the way up to 18x for Western Red Cedar.   One must take into account; species, age, health, site factors etc. to determine a more accurate definition of a trees CRZ.    I have found that species and their tolerance for disturbance is the most critical factor of those stated.  Which side of the tree are you impacting; tension or compression?  Age and health will help to determine if it is worth the fight to protect a tree.  Historically, I have always worked off of the "no more than 30%" rule for root intrusion.

The bigger issue on in-fill building is zoning bylaws.  If you are allowing the construction of a building with a side yard variance of 1.5m, how can you expect to protect trees at property line on an adjacent lot?   A tree protection bylaw may state that you are not to encroach within the CRZ (as does ours), but is this reality?     When this becomes a civil issue between adjacent property owners, the question becomes; which bylaw supersedes the other?  Does the zoning bylaw and the right to build on "my" property supersede the need for protection of "your" tree under the Tree Protection Bylaw?   Or does "your" tree have the ability to cause me economic hardship by not allowing me to obtain the full use and enjoyment of my property as defined under the zoning bylaw?    This question then falls under the Community Charter s. 50(2) (a) and (b) which basically states that if a bylaw would have an effect on a parcel of land (a) preventing all uses permitted under the applicable zoning bylaw and (b) preventing the development to the density permitted under the applicable bylaw, the bylaw (Tree Protection Bylaw) does not apply.   But.... if there is an avenue for alteration of the development that would still allow for density to be achieved, the Tree Protection Bylaw would apply.  It would become incumbent upon your municipality to provide support for the enforcement of the Tree Protection Bylaw and make said developer aware of the fact that he must alter his plan to take the tree into account and provide protection.   I repeat...you must have support from your municipality when you make the developer aware that he will be encumbered with additional costs to ensure protection of the tree.

When it comes to protection of City owned trees,  unless it is for the installation of City infrastructure or franchise utilities (Right to Power Act etc.), we make the decision at the time of application as to whether the tree is worth fighting for.  Not all trees are worth protecting.  I have been to many municipalities and seen the failed efforts to protect large trees on development sites.    Often times, all things were done correctly within the CRZ, but the change in hydrology off of the adjacent lot puts the tree into a slow decline.  Off-site impacts affect trees due to development as well.  Exposure to winds caused a failure of large firs on a property across the street from a cleared lot.

As a municipality, we have a mandate to protect the assets (trees) that are on City property.  We use all avenues available to ensure compliance up too, and including fines and compensation.  We would much rather use education to seek compliance before they have the ability to "say sorry".    Trees on private property are protected (as defined) under the Tree Protection Bylaw.   As stated earlier, the biggest issue here lies with the Zoning Bylaw and the definition of permitted uses and density on the adjacent properties.

My two bits....

Ken Snowden
BCMA
Assistant Manager, Parks Services
Parks, Recreation & Culture
Tel: 604-853 5485 ext. 5886
[Operations Yard]

From: CANUFNET [mailto:canufnet-bounces at list.web.net] On Behalf Of Chartier, Michelle (CY - Parks) via CANUFNET
Sent: Monday, January 16, 2017 11:48 AM
To: 'canufnet at list.web.net'
Subject: [CANUFNET] tree protection

Hi all,

I'm trying to track down samples of city policies or bylaws related to tree protection that effectively balance the protection of established trees and new in-fill building. Saskatoon is currently seeing several large building projects and homes being built in established neighbourhoods where the work site is surrounded by large valuable City trees. We currently have a City Council policy in place that provide Urban Forestry with direction related to tree protection. As part of this policy we do not remove large (>15cm" diameter) healthy trees for development. However we are finding ourselves in a difficult position of attempting to work with construction companies hired to build what does not reasonably allow for preservation or protection of the existing tree(s). In some cases the building footprint requires excavation that will result in ~40%-50% root removal. Often the damage is done on the private property side when our City trees are close to property lines or in some cases straddle property lines (funny how tree roots just don't respect property lines).

I know there are several cities that have tree protection bylaws and some also protect private trees. I'm wondering if anyone knows of a really good example that might include standards that include what can and can't be done on private property adjacent to City trees. I'd also like to know if anyone can share their experience or views (what has worked and what hasn't worked) with existing Bylaw or policies.

Thanks,

Michelle Chartier
City of Saskatoon
Community Services, Parks Division
Superintendent - Urban Forestry/Pest Management
Ph: 306.975-2537  Fax: 306.975.3034
michelle.chartier at saskatoon.ca<mailto:michelle.chartier at saskatoon.ca>
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