(1) Purpose. To establish landscaping and tree preservation standards to promote high quality site development, compatibility of uses, biodiversity, tree preservation, and to enhance the health, safety and general welfare of the residents of the community.
(a) Definitions. For the purpose of the landscaping, screening and tree preservation standards, the following definitions shall apply:
BASIC USE AREA. The area necessary for construction of the site's allowed use in accordance with the following:
1. Commercial, industrial, and institutional uses include the area within the footprints of buildings and vehicular hardscape and within 20 feet around those improvements
2. Residential subdivisions include the area within the street right-of-way and that portion of a residential lot between the right-of-way and within 100 feet beyond and parallel to the street right-of-way.
3. Surface water management ponds are not part of the basic use area.
BIODIVERSITY. The variety, distribution and abundance of living organisms in an ecosystem.
DAMAGE. Action or inaction which does not follow good arboriculture practices. Damage may include damage inflicted upon roots by machinery, changing the natural grade above the root system or around the trunk, destruction of the natural shape or any action which causes infection, infestation or decay.
DBH. Diameter at breast height, typically measured at four and one-half feet to six feet above the ground.
DETENTION AREA. Area of a detention pond from the normal water level and up the side slopes to ten feet offset from the high water level.
DISTURBANCE. Any construction, development, removals, earth movement, clearing or other similar activity.
DRIP LINE. Imaginary line on the ground that is extended straight downward from the outermost edge of the canopy.
ENVIRONMENTALLY SENSITIVE AREA (ESA). An area that contains native vegetation, natural features and/or natural resources. These include surface water (rivers, lakes, streams and ditches); shoreland and floodplain areas, especially riparian and wildlife corridors; wetlands, sensitive groundwater (wellhead) protection areas and sensitive geological features; state or federally listed (endangered, threatened or special concern) plant and animal species and their habitat; natural plant communities, including forests, woodlands and prairies, particularly those of high species diversity and other unique and sensitive features. ESA's are categorized as Natural Resource Conservation Areas and Natural Resource Enhancement Area.
FOUNDATION LANDSCAPE ZONE. An area located within fifteen feet of the building.
LARGE SHRUB. Large shrubs have a mature height over six feet.
LARGE TREE. Over story deciduous trees with a mature height of at least 40 feet.
MEDIUM SHRUB. Medium shrubs have a mature height of three to six feet.
MEDIUM TREE. Deciduous trees with a mature height over 18 feet and up to 39 feet.
NATURAL RESOURCE CONSERVATION AREA. An area within the Shoreland District of DNR Public Waters (lakes and creeks), 50 feet of a creek or public ditches, and areas within the Rice Creek Watershed District (RCWD) Wetland Management Corridor (WMC).
NATURAL RESOURCE ENHANCEMENT AREA. Includes wetland areas non-contiguous to the RCWD WMC extending outward from wetland boundary 75 feet for management class A (Preserve), 50 feet for management class B (Manage 1), 30 feet for management class C (Manage 2) and class D (Manage 3); areas located within the 100-year (1% chance) floodplain; and Woodland Preservations Areas.
REMOVAL. Actual removal or effective removal through actions resulting in the death of a tree.
ROOT PROTECTION ZONE. An imaginary circle surrounding the tree trunk with a radius distance of one foot per one inch of tree DBH (e.g., a 20 inch diameter tree has a Root Protection Zone with a radius of 20 feet).
SCREEN. A barrier that hinders sight and, potentially, access.
SMALL SHRUB. Small shrubs have a mature height of less than three feet. Small shrubs are interchangeable with perennials, ornamental grasses and groundcovers to fulfill landscape standards.
SMALL TREE. Understory deciduous trees with a mature height of 18 feet and under.
UNDESIRABLE TREE. Trees that are dead, diseased, structurally weak, invasive or trees that are hazardous to people, infrastructure or buildings.
VEHICULAR HARDSCAPE. Areas covered with hard surface intended for motor vehicles, including but not limited to off-street loading spaces, parking lots, driveway, drop-offs, and drive through facilities.
WETLAND MANAGEMENT CORRIDOR. A contiguous corridor encompassing high priority wetland resources established by the Rice Creek Watershed District.
WOODLAND PRESERVATION AREA. A remnant woodland ecosystem that is generally mapped in the City's Minnesota Land Cover Classification System, and although it may be degraded it generally meets the criteria for one of the following types of ecosystems as reasonably determined by the city: alder, aspen, black ash swamp, deciduous forest, floodplain forest, lowland forest, maple-basswood, mixed hardwood swamp, northern hardwood, oak forest, paper birch, saturated or seasonally flooded deciduous forest, seasonally flooded deciduous forest, tamarack swamp, upland deciduous forest or woodland and willow swamp.
(2) Landscaping standards. New residential platted subdivisions, mixed use, commercial, institutional and industrial uses shall be subject to the landscaping standards unless specifically excepted. The landscape standards have been divided into five categories: canopy cover, foundation landscape, open areas landscape, buffer and screen, and boulevard trees. Projects shall comply with the applicable requirements of all five categories.
(3) Canopy cover standards. The purpose of this requirement is to mitigate the effects of vehicular hardscape by establishing tree canopy cover to intercept rainfall, protect pavement from sun deterioration, reduce the heat island affect, and improve aesthetics. Canopy cover requirements do not apply to single-family residential development, multi-family residential development without surface parking other than individual unit driveways and permitted outdoor storage areas in Industrial Districts.
(a) The required minimum canopy coverage for all uses is 40%.
(b) The following equation shall be used to calculate required canopy coverage:
Vehicular Hardscape (Square Feet) x Canopy Cover Percent = Required Minimum Canopy Cover (Square Feet)
The total of the assigned canopy coverage values for all the trees in or near the vehicular hardscape must be equal or greater than the required minimum. Pervious pavements are considered 50% hardscape.
(c) The assigned canopy coverage value of each tree is based on planting location, tree size and anticipated tree canopy size 15 years after planting. The assigned canopy cover value to each deciduous tree is described in the following table and illustrations:
Table 1
Assigned Canopy Cover Value
|
Assigned Canopy Cover Value
| ||||
Planting Location (for new trees) | Interior parking lot islands | Within less than 7 feet of vehicular hardscape edge | 7 to 12 feet from vehicular hardscape edge | |
Assigned Canopy Coverage Value | 100 percent of the canopy square footage | 50% of the canopy square footage | 25% of the canopy square footage | |
Square feet (SF) of canopy coverage assigned to each deciduous tree | Large Tree | 950 SF (or 1200 SF in islands of 3 or more trees) | 600 SF | 300 SF |
Medium Tree | 500 SF | 250 SF | 125 SF | |
Small Tree | 250 SF | 125 SF | NA | |
Existing Tree: 6 - 12" DBH | 1900 SF | 950 SF | NA | |
Existing Tree: 12+” DBH | 2850 SF | 1425 SF | NA | |
(d) Existing trees may be used to fulfill canopy coverage, as described in division (9) below of this section, when the drip line has proximity to the edge of the hardscape; therefore, existing trees do not need to be within less than seven feet of the vehicular hardscape edge.
(4) Foundation landscape standards. The purpose of these standards is to soften and enhance building architecture, define access points, add color and seasonal interest, and to blend buildings in with the natural environment. Foundation landscaping standards do not apply to single family residential development.
(a) The foundation landscape planting standards are described in the following table:
Table 2
Foundation Landscape Standards
| ||
Per 100 linear feet (LF) of Building* | ||
Location | Trees and Shrubs | |
Front and Public/Private Street | 2 large | 6 large |
(b) Rounded to the nearest tenth, with a minimum factor of one.
(c) Round all calculations to the nearest whole number of plants.
(d) The required plant materials shall be planted in the foundation landscape zone adjacent to the building face where the requirement applies. The city may allow flexible planting locations where service areas or other constraints make the standards difficult to meet.
(e) Existing trees may be used to fulfill the foundation landscape standards as described in division (9) below of this section.
(f) Smaller landscape materials may be substituted at the following rates:
1 Large Tree = 1.5 Medium or 2 Small Trees
1 Large Shrub = 1.5 Medium or 3 Small Shrubs
(g) One large tree may be substituted for every two large shrubs in lieu of the shrub requirement at the discretion of the city.
(h) The design of landscaping for ground areas under the building roof overhang must take into account the potential effects of runoff from the roof edge.
(i) Trees planted within 30 feet of the building shall be considered within the foundation landscape zone.
(5) Open areas landscape standards. The purpose of these standards is to provide general site beautification and high aesthetic quality with a mix of plant materials in open areas. Open areas include disturbed site areas, that are not located within the foundation landscape zone, vehicular hardscape area or the building footprint and include cul-de-sac islands, boulevard medians, storm water management areas, and common areas in multifamily sites that are not for recreation facilities. Open area landscaping standards do not apply to single family residential lots. Open areas landscaping shall meet the following standards.
(a) The open areas planting standards are described in the following table:
Table 3
Open Areas Landscape Standards
| ||
Per 2500 SF* | Trees and Shrubs | |
1 large | 2 large | |
*Rounded to the nearest tenth, with a minimum factor of one. | ||
(b) Round all calculations to the nearest whole number of plants.
(c) Only land above the normal water level shall be included in the open area calculation for storm water detention areas. Planting shall be located above the normal water level in detention areas. The city may require specific tree species in locations where water levels vary.
(d) Existing trees may be used to fulfill open areas landscape standards as described in division (9) below of this section.
(e) Smaller landscape materials may be substituted at the following rates:
1 Large Tree = 1.5 Medium or 2 Small Trees
2 Large Shrub = 1.5 Medium or 3 Small Shrubs
(f) One large tree may be substituted for every two large shrubs in lieu of the shrub requirement at the discretion of the city.
(g) Areas that are included in a project-specific natural resource management plan that addresses vegetation are not subject to the open areas landscaping standards.
(6) Buffer and screen standards. The purpose of this requirement is to separate and buffer different land use types, screen roads and parking, and screen utility and loading areas. The location of buffers and screens are listed below, while the width of the buffer yard can be found in the respective zoning districts. Buffers and screens shall meet the following standards:
(a) Required screen location, height, and materials are described in the following table:
Table 4
Landscape Screen Location, Height and Materials
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Location | Required Screen Height | Required Screen Materials |
Between a parking lot and public right of way or sidewalk where parking projects toward the public right-of-way or sidewalk | 30 inches | • Planting screen in compliance with paragraph (f)2. Or • A combination of berm and screen in compliance with division (6)(b) below. |
Between residential uses and arterial or collector street | 6 feet | • Planting screen in compliance with (6)(b). Or • Wall or fence and plantings shall provide shrub cover for 50% of the wall or fence on the exterior side. Or • A combination of berm and screen in compliance with division (6)(b). |
Between any development and adjacent, less intense, residential land uses (this includes across a street from residential), but not on the side of a use considered to be the front (as determined by the Zoning Administrator) | ||
Between loading/service area and public view | ||
Outdoor Storage Yards | 10 feet | • A wall or fence of permanent materials and planting shall provide shrub cover for 50% of the wall or fence on the exterior side. At its discretion, the City Council may approve a modification or waiver from these standards where the affected lot line adjoins another industrial property. |
(b) All planting screens shall require at a minimum a double row of plants with triangulated spacing (See illustration). Planting plans shall include species which are sized to appropriately screen visibility within five years of planting. Small shrubs shall be a planted at a maximum interval of three feet on center; medium shrubs shall be planted at a maximum interval of four feet on center; and large shrubs shall be planted at a maximum interval of six feet on center unless; otherwise authorized by the city.
(c) A wall or fence intended to provide a continuous year round screen shall block visibility completely.
(d) In addition to the shrub cover required in the table above, all screens shall be planted with large trees every 50 LF, medium trees every 35 LF, small trees every 25 LF, or some combination thereof, along the length of the screen.
(e) Existing vegetative screens should be left in place unless composed of invasive species or otherwise directed by the city. Existing screens may be enhanced with new plantings to comply with the requirements.
(f) Berms shall be irrigated, have maximum side slopes of 3:1, and have no less than four inches of topsoil.
(g) Permanent walls and fences shall be offset by a minimum of two feet at intervals of 75 feet maximum length for stability and visual relief (See illustration).
(h) Approved permanent wall/fence materials shall include wood, metal, masonry, concrete stone, or other prefabricated and/or sustainable materials. Non-decorative concrete block is prohibited for screening walls. Rock face block or other decorative material is required for masonry walls. Chain link fences with slats are prohibited for screening walls.
(i) Maintenance of the required buffer strip planting and/or fence shall be the responsibility of the individual property owners or, if applicable, the homeowners association.
(7) Boulevard tree standards.
(a) Boulevard trees shall be required in all new residential subdivisions.
(b) Boulevard trees are required at the rate of one tree per lot frontage for single family and two-family lots. Townhome and multi-family properties shall provide boulevard trees at a rate of one tree per 70 linear feet of street frontage where property fronts any public street.
(c) Boulevard trees shall be planted within 14 feet of the curb line or as otherwise determined by the City Forester.
(d) Existing trees may be used to fulfill boulevard tree standards at the city's discretion.
(e) The city may, at its discretion, purchase and install the required boulevard trees. In such case, the city shall collect a standard fee per tree. Said fee shall be established by the City Council and based on the estimated market rate cost to purchase and install trees within the development site.
(8) Sod and ground cover. All areas not otherwise improved in compliance with the approved site plans shall have a minimum depth of four inches of topsoil and be sodded including boulevard areas. Exceptions to these criteria may be approved by the Zoning Administrator as follows:
(a) Seed may be provided in lieu of sod in any of the following cases:
1. Where the seed is applied to future expansion areas as shown on the approved plans, or
2. Where the seed is applied adjacent to natural areas or wetlands. Seed mixture shall be approved by the city, or
3. For single family and two family residential properties, proper erosion control measures shall be implemented and maintained until vegetation is established. Sod may be required in areas subject to erosion as determined by the Building Official or City Engineer.
(b) Undisturbed areas containing existing viable natural vegetation which can be maintained free of foreign and noxious plant materials.
(c) Areas designated as open space or future expansion areas properly planted and maintained with native grasses or wild flowers indigenous to Minnesota. Seed mixture shall be approved by the city.
(d) Use of mulch materials such as bark, wood chips, and decorative rock in support of shrubs and foundation plantings.
(e) Natural prairie restoration areas. Native grasses and wild flowers indigenous to Minnesota, planted and maintained on any occupied lot or parcel of land, setback a minimum of 20 feet from the front lot line and/or side lot line abutting a public street, as part of a garden or landscape treatment.
(9) General landscaping standards.
(a) All lot areas not used for off-street parking, off-street loading, sidewalks, driveways, building sites, or other requirements shall be landscaped with grass, shrubs, trees or other acceptable vegetation, or treatment as required by this chapter prior to issuance of a certificate of occupancy. Exceptions to this requirement are listed in division (15) below of this section.
(b) Commercial, industrial, public/semi-public, institutional, and multi-family residential uses shall be required to submit a site landscape plan, in compliance with § 1007.020, Site and Building Plan Review, of this chapter, for approval by the city prior to issuance of a building permit.
(c) Desirable existing trees may be used to fulfill canopy cover, foundation landscape, and open areas landscape standards if applicable by placement. Desirable existing trees are valued according to the following table:
Table 5
Existing Tree Value | |||
Tree Size | deciduous trees under 6 inches DBH or evergreen trees under 12 feet tall | deciduous trees between 6 to 12 inches DBH or evergreen trees between 12 to 20 feet tall | deciduous trees over 12 inches DBH or evergreen trees over 20 feet tall. |
Tree Value | 1 large tree | 2 large trees | large trees |
(d) Plantings may be grouped if part of an approved landscape plan.
(e) Standards may be met with different sizes of trees and shrubs.
(f) New trees may fulfill canopy coverage, foundation landscape, landscape screen, and open space standards simultaneously if applicable by location.
(g) An existing tree is considered to be removed if the tree trunk is damaged or if more than 30% of the root protection zone area is disturbed during the construction process.
(h) The city may allow flexibility in landscape standards if there are conflicts with solar power, wind power, water harvesting, food production, or other innovative measures proposed for the site.
(i) The landscape plan shall be compared to all applicable CPTED (Crime Prevention Through Environmental Design) standards and reviewed by the Police Department.
(j) Trees and shrubs shall not be planted in the right-of-way without city authorization and shall not be planted in easements without authorization from the holder of the easement.
(k) Turf slopes in excess of three to one (3:1) are prohibited.
(l) Commercial, industrial, multi-family, public/semi-public, and institutional uses shall install irrigation systems to ensure survivability of landscape materials.
(10) Tree preservation and mitigation standards. The purpose of these standards is to protect valuable trees and stands of vegetation, while not interfering with landowners' reasonable use and development of property. The goal is to minimize unnecessary loss of habitat, biodiversity and forest resources, and to replace removed trees in areas where tree cover is most critical. Unless specifically excepted, tree preservation and mitigation standards apply to all plats, site plans, conditional use permits, interim use permits, grading, building, and other activity that requires a city permit or approval.
(a) Tree preservation and mitigation standards are described in the following table:
Table 6
Tree Preservation and Mitigation Standards
| |||
Environmentally Sensitive Area (ESA) Category | Tree Location: within Basic Use Area | Tree Location: not within Basic Use Area | |
deciduous trees 6 inches DBH and over or evergreen trees between 12 to 20 feet tall | deciduous trees 6-12 inches DBH or evergreen trees between 12 and 20 feet tall | deciduous trees over 12 inches DBH or evergreen trees over 20 feet tall | |
Non-ESA | no mitigation required | provide one tree per tree removed | provide two trees per tree removed |
Natural Resource Conservation Area | provide one tree per four trees removed | provide two trees per tree removed | provide three trees per tree removed |
Natural Resource Protected Area | provide one tree per two trees removed | provide two trees per tree removed | provide three trees per tree removed |
(b) Trees used for mitigation may also fulfill the open areas landscape standards at the discretion of the city.
(c) Trees with 30% of the roots damaged are considered to be removed and must be mitigated for at the applicable rates.
(d) Undesirable trees are not subject to the tree preservation and mitigation standards.
(e) Areas where trees are being removed for ecological restoration in accordance with a city approved restoration plan are not subject to the tree preservation and mitigation.
(f) On existing lots with existing buildings where no building or development activity that requires a permit or approval from the city is occurring, the removal of trees is not subject to tree preservation and mitigation standards.
(g) Replacement trees shall be planted on site.
(h) The applicant may request to pay a fee per tree in lieu of some or all of the trees required for mitigation. At the city's discretion, the city may accept the fee for planting trees within the general area of the development project. The city shall maintain a standard fee per tree based on the estimated market rate cost to purchase and install trees.
(11) Landscaping guidelines and technical specifications. The selection, installation, and maintenance of all planting materials shall be in compliance with the City's Landscaping Guidelines and Technical Specifications Manual.
(12) Tree survey.
(a) A tree survey is required for all property that contains a significant tree.
(b) The tree survey shall be the basis for the tree preservation plan, tree mitigation standards, and the use of existing trees to fulfill landscape standards.
(c) The tree survey shall provide the following information:
1. In the basic use area and other areas where tree removal is proposed, for all significant trees:
a. Tree species
b. Size
c. Location
d. Root protection zone
e. Tree condition
2. The location of the combined root protection zones of all tree stands designated for preservation on the development property.
3. On adjacent properties, the root protection zone of significant tree where the root protection zone is within five feet of the development property.
(d) For a new plat or new planned unit development, the tree survey shall be one plan sheet and the tree preservation plan shall be a separate plan sheet.
(e) For a building permit for a new structure on an existing lot, the tree survey and preservation information may be included on the lot survey typically required for a building permit instead of on a separate document. For a building permit for an addition to an existing structure, the tree survey information may be provided in an informal medium that sufficiently conveys the information.
(f) At the city's discretion, the tree survey requirement may be waived under the following circumstances:
1. Significant trees will not be removed and are not likely to be impacted by construction.
2. Significant trees will only be removed within the basic use area and the basic use area is not an ESA.
(13) Tree preservation plan.
(a) A tree preservation plan shall be required for all soil disturbance activities where tree preservation and mitigation standards apply. A tree preservation plan shows how the tree preservation and mitigation standards will be met and how preserved trees will be protected during construction and other potentially harmful activities.
(b) The tree preservation plan shall be based on the tree survey.
(c) If a tree survey shows that no significant trees are on the development property or adjacent properties are near the construction area, the city may waive the tree preservation plan requirement.
(d) A tree preservation plan shall identify:
1. The basic use area and environmentally sensitive areas.
2. The disturbance area.
3. Tree size (DBH), species, condition, location, and root protection zone for all significant trees to be preserved, or;
4. The combined root protection zone of all stands of trees designated for preservation, whichever is applicable.
5. Location and type of tree protection fence.
6. Staging areas.
7. Temporary construction access routes when temporary site access is necessary within root protection zone of any tree or tree stand designated for preservation.
a. Temporary access shall be routed in a manner that is least disruptive to the tree or tree stand per the approval of the City Forester.
b. Temporary access roads shall not exceed 25 feet in width and shall be delineated by snow fencing or safety fencing.
c. An eight-inch deep cover of wood chip mulch shall be placed over the temporary access route to cushion the root protection zones from compaction.
9. Existing and proposed grading.
10. The plan shall show directional felling and trenching to separate root systems prior to bulldozing trees or stumps if necessary to avoid damage to adjacent trees.
11. The plan shall be coordinated with utility planning so that utilities are installed in a manner that protects trees intended to be saved.
(e) Trees to be preserved shall be tagged in the field and keyed to the tree preservation plan. The city may inspect the trees to verify compliance with the preservation plan at any time during construction.
(f) If a natural resource management plan has been approved for the site, the tree preservation plan shall be in compliance with said plan.
(g) The following shall occur prior to soil disturbance:
1. The tree preservation plan shall be approved by the city.
2. Fencing and all tree protection measures shall be installed and inspected by the city.
3. Erosion control measures shall be installed and inspected by the city.
4. All required financial securities have been submitted.
5. Any required development agreement has been approved.
(14) Tree preservation during construction. Trees that are to be preserved must be protected by the following methods unless otherwise approved by the city.
(a) Before land clearing, grading, or construction begins, the city approved tree protection fencing or other method shall be installed and maintained around the root protection zone of the trees to be protected. Fencing shall be a minimum of four feet high and of a highly visible material, such as snow fence or polyethylene laminar safety netting, and must be standing throughout the construction process. Cut roots with clean, pruning cuts at the fence line prior to fence installation to avoid later tearing of the roots. Signage shall be installed to instruct workers to stay out of the root protection zone.
(b) Areas where development must encroach upon the root protection zone must be identified on the tree preservation plan in which case the fencing shall be installed at that edge.
(c) No actions that may harm the health of the tree; including but not limited to construction, traffic, compaction, storage of equipment or materials including soil, grading, or concrete washout areas; may occur in the root protection zone.
(d) Trees damaged by construction, or with more than 30% of the roots disturbed, shall be counted as removed and mitigated at applicable rates.
(e) Tree protection measures shall remain in place until all grading and construction activity is terminated.
(15) Final inspection. Prior to the issuance of a certificate of occupancy, the project developer, builder, or representative shall certify in writing to the city that all elements of the tree preservation plan and landscaping plan were completed. These must be confirmed by the city. However, the city may issue a certificate of occupancy prior to completion of landscaping in the following situations:
(a) If winter weather will prevent healthy planting practices, a security shall be posted to ensure the remaining planting is accomplished and all planting must be installed by June 15 the following spring.
(b) A certificate of occupancy may be issued by the city on residential lots prior to lawn seeding or sod, provided an escrow security is submitted sufficient to ensure that the work will be completed and the date of completion is specified.
(16) Non-compliance. If the city finds that the property is not in compliance with the approved landscaping plan or tree preservation plan, it shall inform the property owner or, if applicable, the homeowners association, regarding the non-compliance and describe, in writing, the steps needed to bring the property into compliance within a reasonable timeframe, not to exceed 60 calendar days.
(17) Performance security. The city may require performance security to ensure compliance with the requirements of this chapter.
(a) The performance security shall extend for two years from the date of planting. The form of the security (cash, letter of credit, or other form) shall be determined by the city.
(b) If after notification of non-compliance the property owner or, if applicable, the homeowners association, fails to achieve the compliance within 60 calendar days, the city may exercise its authority to use the performance security to address compliance.