New Tree Regulations

In an effort to preserve trees, the City Council approved new tree retention and tree removal permit regulations (Ordinance 2018-19) at the City Council meeting on October 23, 2018 . Ordinance 2018-19 amended Bainbridge Island Municipal Code (BIMC) Section 18.15.010 Landscaping, screening, and tree retention, protection and replacement and repealed and replaced BIMC Chapter 16.18 Land Clearing. This chapter outlines the requirements for Clearing Permits.  The changes come out of a multi-year review of tree and landscaping regulations recommended by the Tree & Low Impact Development Ad Hoc Committee.

The substantive changes to tree regulations fall into two categories: the mechanics of the City's clearing permit process and new tree retention requirements for residential properties in the R-2.9, R-3.5 or R-4.3 zones.

Changes to clearing permits (BIMC Chapter 16.18):


• Permit renamed to Tree Removal/Vegetation Maintenance Permit.

• For properties one acre or less in size: A tree removal permit will be needed to remove four or more significant trees (previously, a permit was required to remove seven or more significant trees).

• For properties greater than one acre in size: A tree removal permit will be needed to remove seven or more significant trees (same threshold).

• No changes in permit thresholds for properties in the Mixed Use Town Center & High School Road Districts- Permit needed to remove any tree 8 inches or greater in size

• Increasing the time-period from 12 months to 36 months related to the removal of significant trees without a permit. For most properties, if the property is more than an acre in size, the owner can only remove up to six significant trees without a permit every three years.

• At this time, a clearing permit (Tree Removal/Vegetation Maintenance Permit) is free.

• NOTE: “Significant tree” means: (a) an evergreen tree 10 inches in diameter or greater, measured four and one-half feet above existing grade; or (b) a deciduous tree 12 inches in diameter or greater, measured four and one-half feet above existing grade; or (c) in the Mixed Use Town Center and High School Road zoning districts, any tree eight inches in diameter or greater, measured four and one-half feet above existing grade; or (d) all trees located within a required critical area buffer as defined in Chapter 16.20 BIMC.

Changes for single family residential properties in the R-2.9, R-3.5 or R-4.3 zones (Winslow Area & Bill Point neighborhood):

The new retention requirement for all single family residential properties in the R-2.9, R-3.5 or R-4.3 zones is 30 tree units per acre (see BIMC Section 18.15.010.G.4.iii ). Under the new regulations, property owners in these zones should check with City staff prior to removing any trees on their property to ensure that they remain in compliance with the new regulations. If trees are removed, replanting may be required. Tree Units are calculated based on the diameter of the tree measured 4 ½ half feet above the ground (diameter breast height, or dbh). See Table Below (BIMC Section 18.15.010.G).

Tree Unit Conversion Table for Preserved Trees [1]

DBH
Tree Units
DBH
Tree Units
DBH
Tree Units
3 - 5
1.0
24 - 26
6.2
39 - 40
10.8
6 - 10
1.2
27 -28
7.0
41 - 42
11.4
11 - 12
1.4
29 - 30
7.8
43 - 44
12.0
13 - 15
2.0
30 - 31
8.4
45 - 46
12.6
16 - 18
3.2
32 - 33
9.0
47 - 48
13.2
19 - 20
3.8
34 - 36
9.6
49+
13.8
21 - 23
 4.6
37 - 38
10.2
   

[1]  For multi-stemmed trees, measure the DBH of each trunk separately, multiply each of these measurements by itself, add up these amounts, and calculate the square root of that total to find the DBH for the tree as a whole.

The ordinance becomes effective on Monday, December 3, 2018.


A public meeting to explain and answer questions about the new regulations is scheduled for the afternoon of Monday, November 19, 2018 at 3:00 PM - 4:30 PM in the Council Chambers. If you have any questions about the new ordinance, please contact Senior Planner Jennifer Sutton at (206) 780-3772 or email pcd@bainbridgewa.gov.