Chapter 21A.37
DEVELOPMENT STANDARDS – TREES

Sections:

21A.37.200    Purpose.

21A.37.210    Approval required.

21A.37.215    Calculations – Rounding.

21A.37.220    Evaluation required.

21A.37.230    Exemptions.

21A.37.240    Removal standards.

21A.37.250    Retention standards.

21A.37.260    Variances.

21A.37.270    Tree protection standards.

21A.37.280    Tree replacement standards.

21A.37.290    Violation – Criminal penalties.

21A.37.200 Purpose.

(1) The purpose of this chapter is to:

(a) Avoid the removal of significant trees, including heritage trees and landmark trees, in order to maintain the quality of Sammamish’s urban environment;

(b) Protect significant trees, heritage trees and landmark trees to the maximum extent possible in the design of new development proposals including, but not limited to, buildings, roadways, and utilities;

(c) Mitigate the environmental and aesthetic consequences of tree removal through on-site and off-site tree replacement to achieve a goal of no net loss of canopy throughout Sammamish;

(d) Provide measures to protect trees that may be impacted during construction;

(e) Maintain and protect the public health, safety, and general welfare; and

(f) Preserve the aesthetic, ecological, and economic benefits of forests and tree-covered areas in Sammamish, which include:

(i) Providing varied and rich habitats for wildlife;

(ii) Absorbing greenhouse gas emissions;

(iii) Moderating the effects of winds and temperatures;

(iv) Stabilizing and enriching the soil;

(v) Slowing runoff from precipitation and reducing soil erosion;

(vi) Improving air quality;

(vii) Improving water quality;

(viii) Masking unwanted sound;

(ix) Providing visual relief and screening buffers;

(x) Providing recreational benefits;

(xi) Enhancing the economic value of developments; and

(xii) Providing a valuable asset to the community as a whole. (Ord. O2015-395 § 3 (Att. A))

21A.37.210 Approval required.

(1) Approval Required. Except as provided in SMC 21A.37.230, Exemptions, any person who desires to cut down or remove any significant tree or who desires to conduct grading activities on a site that will result in the removal of any significant tree, must first obtain approval as required in this chapter. Approval may take the form of a tree removal permit or it may be included in conjunction with another land use approval such as a preliminary plat grading permit.

(2) Forest Practices Permittees. Permittees under Class IV – General forest practice permits issued by the Washington State Department of Natural Resources (DNR) for the conversion of forested lots to developed lots are also required to obtain approval under subsection (1) of this section. For all other forest practice permits (Class II, III, IV – special permit) issued by DNR for the purpose of commercial timber operations, no approval is required but no land use permits will be issued for six years following tree removal. (Ord. O2015-395 § 3 (Att. A))

21A.37.215 Calculations – Rounding.

(1) When calculations result in a fraction, the fraction shall be rounded to the nearest whole number as follows:

(a) Fractions of 0.50 or above shall be rounded up; and

(b) Fractions below 0.50 shall be rounded down. (Ord. O2015-395 § 3 (Att. A))

21A.37.220 Evaluation required.

(1) Professional Evaluation. In determining whether an approval shall be granted, the submittal of a professional evaluation and/or a tree protection plan prepared by a Certified Arborist may be required when the City deems such services are necessary to demonstrate compliance with the standards of this chapter. Such professional evaluation(s) and services may include:

(a) Providing a written evaluation of the anticipated effects of proposed construction on the viability of trees on a site;

(b) Providing a hazardous tree assessment;

(c) Providing a written evaluation of heritage trees and/or landmark trees, as well as significant trees, near environmentally critical areas and associated buffers;

(d) Developing plans for tree protection or replacement, including supervising and/or monitoring implementation of any such plans; and/or

(e) Conducting a post-construction site inspection and evaluation. (Ord. O2015-395 § 3 (Att. A))

21A.37.230 Exemptions.

(1) Removal Exemptions. The following actions are exempt from obtaining approval as required in this chapter:

(a) Emergency removal of any significant tree necessary to remedy an imminent danger as defined in SMC 16.25.190;

(b) Removal of any significant tree in public easements and public rights-of-way; and

Documentation of significant tree removal under this section shall be provided to the City within 21 days of removal.

(2) Retention Exemptions. The following conditions are exempt from retention calculation as required in this chapter:

(a) Significant trees determined to present an imminent danger; or

(b) Significant trees located in public utility easements and public rights-of-way. (Ord. O2015-395 § 3 (Att. A))

21A.37.240 Removal standards.

(1) R-1, R-4 and R-6 Zoned Lots. A lot as defined in SMC 21A.15.725 zoned R-1, R-4 or R-6 as of the effective date of this chapter must obtain a tree removal permit prior to removing any significant tree located on the lot. This requirement does not apply to rights vested to prior land use regulations.

(a) A permit shall be granted for the removal of significant trees as shown in the following table. The number of significant trees allowed for removal shall be limited by the lesser of the percentage column or cumulative number column:

Lot Size

Percent of significant trees allowed to be removed per 10 years

Number of significant trees allowed to be removed per year

Cumulative number of significant trees allowed to be removed per rolling 10-year period

< 1/4 ac

50

2

6

1/4 ac – 1/2 ac

40

4

12

1/2 ac – 1 ac

30

6

18

1 ac – 2 ac

20

8

24

> 2 ac

10

10

30

(b) Within environmentally critical areas and associated buffers, significant trees and other vegetation shall be retained subject to the requirements of Chapter 21A.50 SMC.

(c) Replacement trees shall be planted as provided in SMC 21A.37.280, Tree replacement standards.

(d) An application that seeks to remove trees in excess of the limits specified in subsection (1)(a) of this section may be granted at the discretion of the director subject to double the tree replacement requirements in SMC 21A.37.280. Director approval may be granted for one of the following reasons:

(i) Thinning a heavily wooded area where remaining trees may benefit from the thinning and the lot’s forested look, value, or function is maintained;

(ii) Maintaining the lot’s landscaped areas;

(iii) Building a new structure, excluding a new primary residence, or adding onto an additional structure such as an existing residence, ADU, garage or shed; or

(iv) Installing or maintaining utilities or sources of renewable energy, such as solar panels.

(2) R-8, R-12, R-18, O, NB and CB Zoned Lots. A lot as defined in SMC 21A.15.725 zoned R-8, R-12, R-18, O, NB or CB as of the effective date of this chapter must obtain a tree removal permit prior to removing any significant tree located on the lot. This requirement does not apply to rights vested to prior land use regulations. Permit approval will be based on the following criteria:

(a) A permit shall be granted for the removal of not more than four significant trees per year with a limit of eight significant trees every five years.

(b) Within environmentally critical areas and associated buffers, significant trees and other vegetation shall be retained subject to the requirements of Chapter 21A.50 SMC.

(c) Replacement trees shall be planted as provided in SMC 21A.37.280, Tree replacement standards.

(d) An application that seeks to remove trees in excess of the limits specified in subsection (2)(a) of this section may be authorized at the discretion of the director. Director approval may be granted for one of the following reasons:

(i) Thinning a heavily wooded area where remaining trees may benefit from the thinning and the lot’s forested look, value, or function is maintained;

(ii) Maintaining the lot’s landscaped areas; or

(iii) Installing or maintaining utilities or sources of renewable energy, such as solar panels. (Ord. O2015-395 § 3 (Att. A))

21A.37.250 Retention standards.

(1) Development Proposals on R-1, R-4 and R-6 Zoned Lots. A new primary residence or a type 2, 3 or 4 development proposal on R-1, R-4 and R-6 zoned lots must obtain a land use permit or approval prior to removing any significant tree located on the lot.

(a) Regardless of the zoning designation, erosion hazard areas and areas within the erosion hazards near sensitive water bodies overlay that drain to the no-disturbance area, as well as Pine Lake and Beaver Lake drainage sub-basins as depicted on maps created and maintained by the City shall retain 50 percent of the significant trees within areas unconstrained by wetlands, streams, landslide hazard areas, and associated buffers.

(b) R-1 Zoned Lots. A minimum of 50 percent of the significant trees shall be retained within areas unconstrained by wetlands, streams, landslide hazard areas, and associated buffers.

(c) R-4 and R-6 Zoned Lots. A minimum of 35 percent of the significant trees shall be retained within areas unconstrained by environmentally critical areas and associated buffers.

(d) Replacement trees shall be planted as provided in SMC 21A.37.280, Tree replacement standards.

(e) Trees previously designated for protection or located within a designated open space tract or environmentally critical area tract may not be removed unless they are determined to be hazardous. Any trees qualifying for an exemption under SMC 21A.37.230 are not included in the limits established by this section.

(2) Development Proposals on R-8, R-12, R-18, O, NB and CB Zoned Lots. A new primary residence or a type 2, 3 or 4 development proposal on R-8, R-12, R-18, O, NB and CB zoned lots must obtain a land use permit or approval prior to removing any significant tree located on the lot.

(a) Regardless of the zoning designation, erosion hazard areas and areas within the erosion hazards near sensitive water bodies overlay that drain to the no-disturbance area, as well as Pine Lake and Beaver Lake drainage sub-basins as depicted on maps created and maintained by the City shall retain 50 percent of the significant trees within areas unconstrained by wetlands, streams, landslide hazard areas, and associated buffers.

(b) A minimum of 25 percent of the significant trees shall be retained within R-8, R-12 and R-18 zoned lots in areas unconstrained by environmentally critical areas and associated buffers.

(c) There is no minimum retention requirement for significant trees located within O, NB, and CB zoned lots in areas unconstrained by environmentally sensitive areas and associated buffers.

(d) Replacement trees shall be planted as provided in SMC 21A.37.280, Tree replacement standards, except the replanting requirement shall be doubled for development proposals in the O, NB, and CB zones where tree retention is less than 25 percent.

(e) Trees previously designated for protection or located within a designated open space tract or environmentally critical area tract may not be removed unless they are determined to be hazardous. Any trees qualifying for an exemption under SMC 21A.37.230 are not included in the limits established by this section. (Ord. O2015-395 § 3 (Att. A))

21A.37.260 Variances.

(1) Variances. Where conditions exist that prevent full compliance with this chapter, the applicant may request a variance pursuant to SMC 20.05.020 and the decision criteria as described for such in SMC 21A.110.030. (Ord. O2015-395 § 3 (Att. A))

21A.37.270 Tree protection standards.

(1) Priority. Significant trees identified for retention pursuant to SMC 21A.37.250 shall be selected, to the extent feasible, subject to the following order of priority from most important to least important:

(a) Significant trees part of a continuous canopy adjacent to an environmentally critical area and associated buffer;

(b) Significant trees part of a continuous canopy adjacent to a public park and/or other protected open space;

(c) Significant trees part of any other on-site and/or off-site continuous canopy;

(d) Significant trees providing relief from identified environmental impacts;

(e) Significant trees providing perimeter connectivity and/or off-site screening;

(f) Significant trees able to be incorporated into required landscaping;

(g) An isolated cluster of significant trees;

(h) Individual significant trees.

(2) Designation. Any applicable application and/or plan required for new development shall show all significant trees designated for protection. These areas may be shown by labeling them as “Protected Significant Trees” or such other designation as approved by the director. Protected vegetation, including protected trees, shall not be modified, harmed, or removed except as provided in this section.

(3) Preservation. An approval for new development may require the significant trees to be retained are permanently preserved within a tract, easement or other permanent protective mechanism. When required, the location, purpose, and restrictions of these protected areas shall be shown on the face of the deed, plat, binding site plan, covenant or similar document, and shall be recorded with the King County department of records and elections or its successor. The recorded document shall include the requirement that the protected areas shall not be removed, amended, or modified without the written approval of the City of Sammamish.  

(4) Incentives. The following incentives are available for higher levels of landmark, heritage and significant tree preservation:

(a) Landmark Trees. The permanent preservation of a landmark tree in conjunction with subsection (1) of this section shall receive retention credit as follows:

(i) Two hundred percent credit in conjunction with subsections (1)(a) through (c) of this section.

(ii) One hundred fifty percent credit in conjunction with subsections (1)(d) through (f) of this section.

To qualify for this incentive, all landmark trees proposed for permanent preservation shall be outside of any environmentally critical area and associated buffer.

(b) Heritage Trees: The permanent preservation of a heritage tree in conjunction with subsection (1) of this section shall receive retention credit as follows:

(i) One hundred seventy-five percent credit in conjunction with subsections (1)(a) through (c) of this section.

(ii) One hundred twenty-five percent credit in conjunction with subsections (1)(d) through (f) of this section.

To qualify for this incentive, all heritage trees proposed for permanent preservation shall be outside of any environmentally critical area and associated buffer.

(c) New subdivisions and short plats proposing a minimum 45 percent permanent preservation of significant trees in conjunction with subsections (1)(a) through (c) of this section shall receive a 50 percent reduction of required on-site recreation space. To qualify for this incentive, all significant trees proposed for permanent preservation shall be outside of any environmentally critical area and associated buffer.

(d) New subdivisions and short plats proposing a minimum 40 percent permanent preservation of significant trees in conjunction with subsections (1)(a) through (c) of this section shall receive a 25 percent reduction of required on-site recreation space. To qualify for this incentive, all significant trees proposed for permanent preservation shall be outside of any environmentally critical area and associated buffer.

(5) Protection Measures. To ensure long-term viability of trees identified for protection, permit plans and construction activities shall comply with the following minimum required tree protection:

(a) All minimum required tree protection measures shall be shown on the tree protection and replacement plan.

(b) Tree protection barriers shall be installed five feet beyond the drip line of significant trees to be protected prior to any land disturbance.

(c) Tree protection barriers shall be a minimum of four feet high, constructed of chain link, or polyethylene laminar safety fencing or other material, subject to approval by the director. On large or multiple-project sites, the director may also require that signs requesting subcontractor cooperation and compliance with tree protection standards be posted at site entrances.

(d) Where tree protection areas are remote from areas of land disturbance, and where approved by the director, alternative forms of tree protection may be used in lieu of tree protection barriers, provided that protected trees are completely surrounded with continuous rope or flagging and are accompanied by “Tree Save Area – Keep Out” signs.

(e) Native understory trees, shrubs and other vegetation shall be protected within the designated tree protection area.

(6) Preventative Measures. In addition to the above minimum protection measures, the applicant shall support the protection measures by employing, as appropriate, the following preventative measures, consistent with best management practices for maintaining the health of the tree:

(a) Significant trees shall not be topped;

(b) Excessive pruning shall not be allowed unless necessary to protect life and property;

(c) Visible deadwood on trees to be protected or relocated shall be pruned;

(d) Fertilizer shall be applied to enhance the vigor of stressed trees;

(e) Use soil amendments and soil aeration in planting areas;

(f) Apply mulch over tree drip line areas; and

(g) Ensuring proper water availability before, during and after construction.

(7) Alternative Methods. The director may approve the use of alternative tree protection and/or preventative techniques if a protected tree will be protected to an equal or greater degree than through the techniques listed above. (Ord. O2015-395 § 3 (Att. A))

21A.37.280 Tree replacement standards.

(1) Replacement Required. Any significant tree lawfully removed pursuant to SMC 21A.37.240, Removal standards, or SMC 21A.37.250, Retention standards, shall be subject to the following replacement requirements:

(a) Each landmark tree shall be replaced by three new trees;

(b) Each heritage tree shall be replaced by two new trees;

(c) Each significant tree shall be replaced by one new tree;

(d) Replacement coniferous trees shall be at least eight feet in height;

(e) Replacement deciduous trees shall be at least two and one-half inches in diameter (DBH);

(f) Replacement trees shall be primarily native species to Washington in order to restore and enhance a site as nearly as practicable to its pre-removal character and function;

(g) Nonnative replacement trees shall be recommended by a Certified Arborist as having characteristics suitable to the proposed location of planting, or as otherwise approved by the City;

(h) The condition of replacement trees shall meet or exceed current American Nursery and Landscape Association or equivalent organization’s standards for nursery stock;

(i) Financial guarantees for replacement trees may be required consistent with the provisions of SMC Title 27A;

(j) Installation of required replacement trees shall be in accordance with the International Society of Arboriculture’s best management practices for arboriculture including, but not limited to, soil assessment, sampling, amendments and conservation, which ensure the tree’s long-term health and survival; and

(k) The director may consider smaller-sized replacement trees if the applicant can demonstrate that smaller trees are more suited to the species, the site conditions, and the purposes of this section, and that such trees will be planted in sufficient quantities to meet the intent of this section.

(2) Location for Tree Replacement – On Site. Unless approved for one or more of the alternatives set forth in subsection (3) of this section, replacement trees shall be planted on the site from which significant trees are removed and may be approved for the following areas on site:

(a) On-site replacement trees approved to be located in environmentally critical areas and associated buffers shall receive a 125 percent credit toward the tree replacement requirement.

(b) Each required street tree planted on site shall receive a 50 percent credit and each street tree planted on site in excess of the minimum requirement shall receive a 100 percent credit toward the tree replacement requirement, subject to director approval.

(c) On-site replacement trees approved to be located within the perimeter of a stormwater facility shall receive a 100 percent credit toward the tree replacement requirement.

(d) On-site replacement trees approved to be located in places other than subsections (2)(a) through (c) of this section shall receive a 100 percent credit toward the tree replacement requirement.

(3) Location for Tree Replacement – Alternatives. When on-site replacement cannot be completely achieved, the following alternatives may be considered:

(a) Off-Site Tree Replacement.

(i) The number of replacement trees shall be the same as described in subsection (1) of this section. Replacement costs (material plus labor) shall be at the applicant’s expense.

(ii) Allowable sites for receiving off-site replacement plantings may include public lands, open space areas, open space tracts, delineated environmentally critical areas and associated buffers. A receiving site shall be within the Sammamish City limits or within land owned by the City.

(b) Landscape Restoration. Where appropriate, other measures designed to mitigate the loss of trees by restoring all or parts of the forest landscape and its associated benefits may be considered. Measures, as determined by the director, may include, but are not limited to:

(i) Creation of wildlife snags from trees which would otherwise be removed;

(ii) Replacement of certain ornamental trees with native shrubs and groundcover;

(iii) Replacement of hazardous or short-lived trees with healthy new trees that have a greater chance of long-term survival;

(iv) Daylighting and restoration of stream corridors with native vegetation; and

(v) Protection of nonsignificant trees to provide for the successional stages of forest development.

(4) Tree Replacement Guidelines and Requirements. The following provisions shall be considered for tree replacement:

(a) Replacement trees should be planted to reestablish or enhance tree clusters where they previously existed;

(b) Where possible, replacement trees should be planted within environmentally critical areas and associated buffers. Replacement trees may be planted within a designated open space tract or environmentally critical area tract, where it is determined that such planting enhances and complements existing vegetation and environmental functions;

(c) Replacement trees shall be planted in locations appropriate to the species’ growth habit and horticultural requirements;

(d) Replacement trees shall be located away from areas where damage is likely;

(e) Replacement trees shall be located to provide screening of the development from adjacent properties, where appropriate;

(f) Replacement trees shall be planted in areas that connect or are adjacent to a designated open space tract or environmentally critical area tract or other open space, where appropriate;

(g) Replacement trees shall be integrated into the required landscape plans, if any, for a development; and

(h) Replacement trees to be planted next to or under power lines shall be selected with consideration of the trees’ maturation and maintenance requirements.

(5) Tree Maintenance. All required replacement trees and relocated trees shown on an approved permit, whether located on site or off site, shall be maintained in healthy condition by the applicant throughout the life of the project, unless otherwise approved by the director in a subsequent permit or approval. Healthy condition can be achieved by employing, as appropriate, the following preventative measures, consistent with best management practices for maintaining the health of the tree:

(a) Trees shall not be topped;

(b) Excessive pruning shall not be allowed unless necessary to protect life and property;

(c) Visible deadwood on trees to be protected or relocated shall be pruned;

(d) Fertilizer shall be applied to enhance the vigor of stressed trees;

(e) Use soil amendments and soil aeration in tree protection and planting areas;

(f) Apply mulch over tree drip line areas; and

(g) Ensuring proper water availability during and immediately after construction. (Ord. O2015-395 § 3 (Att. A))

21A.37.290 Violation – Criminal penalties.

(1) Criminal Conduct. Any person who violates the provisions of this chapter or fails to comply with any of the requirements shall be guilty of a gross misdemeanor and subject to the penalties set forth in SMC 1.10.010. In keeping with the City’s concern regarding protection of the environment, the court should consider the imposition of a maximum fine of no more than $5,000 per occurrence and imprisonment not to exceed one year. Each day such violation continues shall be considered a separate, distinct offense.

As a supplement or alternative to the remedies set forth in this section, the code administrator shall have the authority to seek civil penalties for violation of the provisions of this chapter as provided for in SMC 23.100.010. (Ord. O2015-395 § 3 (Att. A))