16.33.050 General landscaping requirements and standards

16.33.050 General landscaping requirements and standards.

A. Minimum Lot Area to Be Landscaped. A minimum of 15 percent of the total lot area must be covered with landscaping. The landscaped areas required in this chapter apply to the minimum lot area to be landscaped. All other disturbed areas on the site that are not part of the required landscaped areas must be planted with grass or a similar ground cover to create a lawn. However, the planting of grass and annual flowers alone does not constitute landscaping in the context of this chapter.

B. Clearing Restrictions. No lot may be cleared of native vegetation prior to issuance of a permit for a use of a lot under this title.

1. Exemptions. After approval of a preliminary plat for a subdivision, vegetation may be cleared in the following areas as shown on the preliminary plat:

a. Roads and rights-of-way;

b. Water, sewer, and utility easements; and/or

c. Drainage and/or storm water facilities.

1. Existing Trees and Forested Areas. Existing healthy trees must be preserved to the greatest extent practical to sustain an age-diverse urban forest and to minimize tree canopy cover losses.

2. Shoreline Protection Area. The purpose of the shoreline protection area is to preserve and enhance the important hydrologic, ecological, and aesthetic functions provided by wetlands, water bodies, and water courses. Water bodies and courses include, but are not limited to, lakes, streams, creeks, and rivers. This section applies to all zoning districts and all developments within the city limits. This section does not repeal or supersede any existing federal, state, or local laws. When this subsection imposes a higher or more restrictive standard, this subsection shall apply.

a. Clearing. Native vegetation shall be preserved and there shall be no clearcutting in any area of a lot that is within 75 feet of the mean high-water mark of any body of water, including a lake, stream, creek, or river. However, minimal areas may be cleared to allow access to docks, boathouses, water’s edge, and other similar uses with approval of an administrative approval land use permit.

b. Maintenance. Maintenance, modification, or removal of vegetation within the shoreline protection area is permitted as follows:

i. Pruning for the health of existing vegetation is allowed but may not remove more than 25 percent of the living crown of a tree or jeopardize the health and natural shape of a tree or shrub;

ii. Removal of trees and shrubs that are dead, a safety hazard to person, property, or public, or diseased is permitted;

iii. The use of herbicides for control/removal of vegetation is prohibited; and

iv. The placement of fertilizer is prohibited.

c. Legally Established Uses. See WMC 16.24.030(C)(3) for provisions relating to nonconforming setbacks.

d. Other Regulatory Agencies. The lot owner must obtain the appropriate permit/approval from the federal, state, or local agencies having jurisdiction within this area prior to any activity within the shoreline protection area.

3. Existing Native Vegetation. Existing native vegetation that is sufficient to meet the intent of the standards set out in this chapter may be retained in place of all or part of any required landscaping. Existing trees may be credited toward the landscape requirements on a 3:1 basis for a coniferous tree 10 feet or more in height or a 3:1 basis for a deciduous tree six inches or greater caliper.

4. Individual Trees. The following protection requirements must be met:

a. Critical Root Zone. The critical root zone (CRZ) is, and will remain, substantially undisturbed. The CRZ is represented by a circle, centered on the tree trunk and having a radius of one and one-half feet for each one inch of trunk diameter measured at four and one-half feet above ground level. Although an undisturbed circular area centered on the tree generally assures less critical root loss, modifications to the CRZ perimeters resulting in nonconcentric, irregular, and/or smaller areas are acceptable for tree preservation if either of the following conditions are met:

b. Maximum Disturbance. The modified root zone includes at least 50 percent of the concentric CRZ, contains no less total contiguous area than the concentric CRZ, and includes no disturbance or encroachments by improvements within the structural root plate area.

c. Existing Conditions. The tree has demonstrated long-term viability within the same substandard root zone and that area will not be further reduced or adversely impacted. In some cases, a certified arborist may be required to delineate the functioning root zone and confirm avoidance of further impacts.

d. Structural Root Plate. The structural root plate is represented by a circle, centered on the tree trunk and having a radius of one-half foot for each inch of trunk diameter measured at four and one-half feet above ground level, but no less than six feet and no more than 10 feet.

e. Tree Crown. No more than 25 percent of the crown has been or will be removed and the pruning is done according to American National Standards Institute (ANSI) standards (A300).

f. Protective Barriers. Trees designated for preservation must be protected from all potentially harmful activity during development by the temporary installation of protective barriers. Barriers must be constructed of chain link fence, orange laminated plastic fencing, or wood posts and rails, consistent with professional arboricultural practices and must be installed along the perimeter of all required preserve areas prior to any land clearing, demolition, grading, or construction. No potentially harmful activity may take place within the protective barrier, including, but not limited to, grade change, trenching, compaction, grubbing, piling of debris or materials, snow storage, or root raking.

D. Plant Materials. Plant material must be true to name, variety, and size and must conform to all applicable provisions of the American Standards for Nursery Stock, latest edition, and meet the following:

a. Shrubs planted in required perimeter landscape areas must be a minimum of 24 inches in height at time of planting. Shrubs planted in other required landscape areas must be a minimum of 18 inches at time of planting, except as specifically required in this chapter.

b. Deciduous trees must be a minimum of eight feet in height or a minimum of two-inch caliper, whichever is taller, at time of planting, except as specifically required in this chapter.

c. Evergreen trees (nondeciduous) must be a minimum of six feet in height at time of planting and the ratio of height to spread should not be less than 5:3, except as specifically required in this chapter. Height measurement is taken at the midpoint between the uppermost whorl(s) and the tip of the leader.

2. Quality. All plant material must be healthy, of a suitable type for the site conditions being used in, and hardy to the project area.

3. Species. All landscaping shall utilize native plant species or other vegetation that is appropriate for the area.

4. Diversity. The diversity of any trees required to be planted on a site shall comply with the following limits to avoid uniform site tree decline from pests or disease and to increase the aesthetic appeal:

Number of new trees planted on site	Maximum percentage of any one species planted
5 – 19	65%
20 – 49	40%
50 or more	30%

5. Installation. All required landscaping must be installed in a sound manner utilizing established professional standards and consistent with the requirements in this chapter.

6. Ground Covers and Mulch. All ground cover around vegetation in required planting beds must consist of mulch, as defined in this title, or a product with similar appearance and functionality. Alternatives that may be approved in place of mulch include products with a similar appearance to mulch, evergreen ground cover, low-lying perennial plants, perennial ornamental grasses, or other similar plants, as approved by the city planner. Industrially zoned lots may utilize landscape quality rock, gravel, evergreen ground cover, or grass with mulch around base of plants as ground cover/mulch in required planting beds when lot frontage is on roadway(s) classified as “local” roads in the City of Wasilla Official Streets and Highways Plan. When plants are used for ground cover instead of mulch, placement and quantity must be in a manner that continuous ground cover will be achieved within two years.

1. Placement. Installation of plants in appropriate locations is essential to long-term survival. Locations should match mature plant size to available soil volume and other conditions necessary for healthy growth. Appropriate separation must be provided from pavement, structures, streets, driveways, curbs, sidewalks, signs, lights, and utilities.

2. Vehicle Overhang. All required landscape planting beds must be protected from vehicular damage. Vehicular use areas shall provide raised curbs, wheel stops, bollards, or other effective means to permanently protect landscape areas from damage by vehicle encroachment. Vehicles may not overhang into landscape areas beyond the designed boundaries of vehicular use areas.

a. Only plants that will not create persistent utility maintenance or interference problems may be installed where overhead utilities exist.

b. Trees may not be planted directly below power lines to prevent them from being energized or disrupting service.

c. Trees and vegetation within a utility easement may not achieve heights greater than 10 feet or intrude from the side closer than 15 feet to power lines, or exceed clearances otherwise required by applicable ANSI and/or National Electric Safety Code (NESC) standards, whichever is greater.

d. Tree species with a large mature crown must be planted a minimum of 30 feet from power lines or exceed clearances otherwise required by applicable ANSI and/or NESC standards, whichever is greater.

4. Visibility Clearance Areas/Sight Distance. Landscaping within the sight distance/sight triangle areas must be designed, installed, and maintained to allow visibility between three feet and nine feet above grade. The trunks of mature trees trimmed of foliage to nine feet and newly planted trees with immature crown development allowing visibility are generally acceptable within this area.

1. Timing. All landscaping structural requirements (e.g., drainage, grading, concrete, rock or keystone bed structures, curbs, sidewalks) must be in place prior to occupancy. If occupancy occurs outside the planting season, all landscaping must be in place no later than June 30 of the following year. Topsoil addition and final grading, seeding, and plantings must be in place within 12 months of occupancy, or within the first growing season after occupancy, whichever comes first.

a. Tree Roots. In addition to the minimum areas required by this chapter for planted and preserved trees, curbs, sidewalks, and other concrete around trees must be minimized and more flexible materials utilized to accommodate tree roots (e.g., crushed rock, porous pavers).

G. Guaranty. The granting of an application for a use with a structure having a gross floor area greater than or equal to 5,000 square feet shall be conditioned upon the applicant furnishing a guaranty for the provision of any required landscaping. An itemized estimate of the required landscaping must be submitted with the guaranty. The guaranty must be equal in amount to the estimated cost of the required landscaping, be held in trust or payable to the city and released to the city if the city certifies that the applicant has not completed the required landscaping, may not be released or cancelled without approval from the city, and be in one of the following forms:

1. A cash deposit in escrow with a responsible financial institution authorized to do such business in the state, under an escrow agreement that provides the deposit will be held in trust for the benefit of the city and will not be used as security for any other obligation.

2. A surety bond from a company authorized to do such business in the state and posted either by the applicant or a contractor obligated by written contract to the applicant for installation of all of the required landscaping.

3. An irrevocable letter of credit with a responsible financial institution authorized to do such business in the state; provided, that the letter of credit will be held in trust for the benefit of the city and will not be used as security for any other obligation. (Ord. 22-03 § 7, 2022; Ord. 17-18(AM) § 2, 2017)