13.09.030 Shoreline vegetation conservation.
A. Vegetation conservation standards shall not apply retroactively to existing uses and developments. Vegetation associated with existing structures, uses and developments may be maintained within shoreline jurisdiction as stipulated in the approval documents for the development.
B. Regulations specifying establishment and management of shoreline buffers are located in BMC 13.13.010 and 13.13.060. Vegetation within shoreline buffers, other stream buffers, and wetlands and wetland buffers shall be managed consistent with Chapter 13.13 BMC, Critical Areas in Shoreline Jurisdiction.
C. Vegetation outside of shoreline buffers, other stream buffers, and wetlands and wetland buffers and within shoreline jurisdiction shall be managed according to this section, BMC 13.09.020, Environmental protection, and any other regulations specific to vegetation management contained in other chapters of this SMP.
D. Vegetation clearing outside of wetlands and buffers shall be limited to the minimum necessary to accommodate approved shoreline development that is consistent with all other provisions of this SMP. Mitigation sequencing shall be applied so that the design and location of the structure or development minimizes native vegetation removal. Development or uses that require vegetation clearing shall be designed to avoid the following in the order indicated below, with 1. being the most desirable vegetation to retain:
1. Native significant trees.
2. Nonnative significant trees.
3. Native nonsignificant trees.
4. Other native vegetation.
5. Other nonnative vegetation.
E. Significant trees located in shoreline jurisdiction outside of wetlands and wetland, stream or shoreline buffers shall be retained using the preferences specified in subsection D of this section as a guide and consistent with the percent of the total in diameter inches of the significant trees located within the net buildable area of the subject property provided in Table 13.09.030-1; significant trees shall mean existing trees over eight inches in caliper as measured four feet above grade.
|
Shoreline Water Body |
Natural |
Urban Conservancy |
Shoreline Residential |
High Intensity/High Intensity-Park or Marina |
|---|---|---|---|---|
|
Sammamish River |
NA |
65 |
20 |
20 |
|
North Creek |
90 |
65 |
35 |
35 |
|
Swamp Creek |
NA |
65 |
35 |
35 |
F. The city may approve modifications or require minor site plan alterations to achieve maximum tree retention. A tree retention plan may provide for the retention of fewer significant trees than required in subsection E of this section only if the trees to be removed are replaced at a ratio of three to one. The size of said replacement trees shall be in accordance with the requirements of this chapter.
G. All proposed developments shall include a tree retention plan for the entire subject property within shoreline jurisdiction except identified areas in which existing vegetation would not be disturbed in any manner. If any significant trees within such undisturbed area(s) outside of critical areas and their buffers are to be counted toward the percent significant tree retention required by subsection E of this section, the location of such trees shall be indicated on a plan, but other tree retention plan requirements shall not apply to the undisturbed area or areas. The tree retention plan shall include the following:
1. Location, size, species and driplines of all existing healthy trees over eight inches in caliper measured four feet above grade;
2. Proposed and existing contours;
3. Trees and other vegetation to be retained; and
4. A description of protection techniques to be utilized during construction, including but not limited to five-foot-high chainlink or plastic-net fencing around tree driplines, tunneling instead of trenching, stump grinding instead of stump pulling, and routing of traffic to prevent excessive soil compaction.
H. A disturbance-free area beyond the tree dripline shall be indicated. A tree designated for retention shall not have the soil grade altered within its dripline or within 15 feet of its trunk, whichever is greater, unless an alternative tree retention method is submitted by a tree specialist acceptable to the city, and said alternative method is approved by the city.
I. The shoreline administrator shall require that a maintenance bond or other surety be submitted to the city of Bothell to ensure retention of existing trees and plant material during construction. In the event any trees designated by the city to be retained are removed, the city shall have the option of enforcing any bond posted. Each tree identified for retention shall be bonded pursuant to Table 13.09.030-2:
|
Tree Diameter |
Amount |
|---|---|
|
8 – 12 inches |
$2,000 |
|
Larger than 12 – 16 inches |
$4,000 |
|
Larger than 16 – 20 inches |
$8,000 |
|
Larger than 20 – 24 inches |
$12,000 |
|
Larger than 24 – 28 inches |
$16,000 |
|
Larger than 28 inches |
$20,000 |
J. In the event that existing significant trees or vegetation which are designated to be retained die or are damaged or removed as a result of development activity, prior to issuance of occupancy permits, or release of any tree retention bonds required pursuant to subsection I of this section, a restoration plan shall be prepared and submitted to the shoreline administrator for approval. The plan shall provide for replacement of plants in the following manner:
1. Each such significant tree shall be replaced by a mixture of three native deciduous and/or native coniferous trees. For each additional two inches of caliper over eight inches on the dead, damaged or removed tree, one new tree shall be planted. Particular species shall be approved by the city, with all native trees removed required to be replaced with native trees. Replacement trees shall conform to required plant sizes in accordance with the requirements of this section, and may be placed in other locations on the property than where the replaced trees were located. Where conditions allow, native replacement trees should be placed in on-site wetlands or wetland, stream or shoreline buffers if doing so would improve function of the critical area or its buffers.
2. Shrubs and ground cover shall be replaced in all disturbed areas by a mixture of indigenous shrubs, groundcovers and other plant material to provide 85 percent surface coverage within two years from planting.
3. The restoration shall be in addition to the revocation of the tree bond.
K. Where vegetation removal conducted consistent with this section results in adverse impacts to shoreline ecological function, new developments or site alterations shall be required to develop and implement a supplemental mitigation plan. Adverse impacts are assumed to result from removal of native shrubs and groundcovers not otherwise regulated under the significant tree provisions, or when allowed removal of the significant trees disrupts an existing vegetation corridor connecting the property to other critical areas or buffers. Mitigation plans shall be prepared by a qualified professional and shall contain information required in BMC 13.09.020(G). Mitigation measures shall be maintained over the life of the use and/or development.
L. Where native shoreline vegetation must be removed to accommodate a temporary staging area necessary to implement an allowed use, the area must be immediately stabilized and restored with native vegetation once construction is complete.
M. Selective pruning of trees for safety or view protection is allowed. Where trees pose a significant safety hazard as indicated in a written report by a certified arborist or other qualified professional, they may be removed or converted to wildlife snags if the hazard cannot be eliminated by pruning, crown thinning or other technique that maintains some habitat function.
N. Trees that are part of a grouping or that otherwise provide mutual support during strong winds shall be preserved to prevent blow down of on- and off-site trees with particular emphasis on trees that support adjacent wildlife habitat areas.
O. Vegetation removal conducted without city authorization requires the submittal and approval of a restoration plan prepared by a qualified professional as defined in Chapter 13.03 BMC. The mitigation plan must utilize only native vegetation, and should be designed to compensate for temporal loss of function and address the specific functions adversely impacted by the unauthorized vegetation removal.
P. With the exception of hand removal or spot-spraying of invasive or noxious weeds on shorelands, the determination of whether nonnative vegetation removal may be allowed in shoreline jurisdiction must be evaluated in conformance with this section, BMC 13.09.020, Environmental protection, and Chapter 13.13 BMC, Critical Areas in Shoreline Jurisdiction. Such removal of noxious weeds and/or invasive species shall be incorporated in mitigation plans, as necessary, to prevent erosion and facilitate establishment of a stable community of native plants.
Q. Aquatic weed control shall only be permitted where the presence of aquatic weeds will adversely affect native plant communities, fish and wildlife habitats, or an existing water-dependent recreational use. Aquatic weed control efforts shall comply with all applicable laws and standards. Removal using mechanical methods is preferred over chemical methods. (Ord. 2280 § 5, 2019; Ord. 2112 § 3 (Exh. C), 2013).