§ 18-61. Landscaping and tree preservation requirements.

(a)

Required landscaping/residential subdivision.

(1)

Each lot shall be provided with a minimum of one deciduous or conifer tree to be placed in the front yard. The type of tree shall be subject to city approval. Coniferous trees must be at least eight feet high and deciduous trees must be at least 2½ inches in diameter at the time of installation. This requirement may be waived by the city where the applicant can demonstrate that a suitable tree having a minimum diameter of 2½ inches for deciduous and eight-foot height for conifers is located in an appropriate location on the lot. The following trees may be used to meet planting requirements:

Scientific Name	Common Name
Overstory Trees
Acer saccharum spp.	Maple, all varieties, except platanoides
Carya ovata	Shagbark Hickory
Celtis occidentalis	Hackberry
Juglans nigra	Black Walnut
Quercus spp.	Oak, all varieties
Aesculus glabra	Ohio Buckeye
Betula nigra	Birch, River
Betula papyrifera	Birch, paper
Catalpa speciosa	Northern Catalpa
Ginkgo biloba	Ginkgo
Gleditsia triacanthos inermis, spp.	Honeylocust, thornless - all varieties
Gymnocladus dioicus	Coffeetree, Kentucky
Tilia spp.	Linden, all varieties
Ulmus spp.	ELM, DED-resistant varieties
Ornamental Trees
Acer ginnala*	Maple, Amur
Amelanchier spp.	Serviceberry or Juneberry
Crataegus spp.	Hawthorn, all varieties
Malus spp.	Crabapple, assorted flowering-Varieties
Ostrya virginiana	Ironwood
Populus tremuloides	Aspen
Sorbus spp.	Ash, Mountain, all varieties
Phellodendron amurense	Amur Corktree
Prunus cerasifera "Newport"	Plum, Newport
Prunus triloba	Plum, flowering or Rose Tree of China
Prunus virginiana "Schubert"	Chokeberry, Schubert
Syringa reticulata	Lilac, Japanese tree
Conifers
Abies balsamea	Fir, Balsam
Abies concolor	Fir, Concolor
Larix laricina	Tamarack
Picea abies	Spruce, Norway
Picea glauca	Spruce, White
Picea glauca densata	Spruce, Black Hills
Pinus nigra	Pine, Austrian
Pinus ponderosa	Pine, Ponderosa
Pinus resinosa	Pine, Norway
Pinus strobus	Pine, White
Pinus sylvestris	Pine, Scotch
Pseudotsuga menziesii	Fir, Douglas
Thuja occidentalis	Arborvitae
Thuja occidentalis "Techny"	Techny Arborvitae

 

* These trees shall be restricted; quantities and location must be approved by the city in a landscape plan.

(2)

The tree(s) must be installed prior to receiving a certificate of occupancy or financial guarantees acceptable to the city must be provided to ensure timely installation.

(3)

All areas disturbed by site grading and/or construction must be seeded or sodded immediately upon completion of work to minimize erosion. When certificates of occupancy are requested prior to the satisfaction of this requirement, financial guarantees acceptable to the city must be provided.

(4)

No dead trees or uprooted stumps shall remain after development. On-site burial or burning is not permitted.

(5)

Landscaped buffers around the exterior of the subdivision shall be required by the city when the plat is contiguous with collector or arterial streets as defined in the comprehensive plan and where the plat is adjacent to more intensive land uses. Required buffering shall consist of berms and landscape material consisting of a mix of trees and shrubs and/or tree preservation areas. No fences will be permitted between the required buffer and the collector or arterial street. Where appropriate, the city may require additional lot depth and area on lots containing the buffer so that it can be adequately accommodated and the homes protected from impacts. Lot depths and areas may be increased by 25 percent over zoning district standards. The landscape plan must be developed with the preliminary and final plat submittals for city approval. Appropriate financial guarantees acceptable to the city shall be required.

(b)

It is the policy of the city to preserve natural woodland areas throughout the city and with respect to specific site development to retain as far as practical, substantial tree stands which can be incorporated into the overall landscape plan.

(c)

No tree removal shall be permitted except as approved in a subdivision, planned unit development or site plan application. Removal of trees prior to city approval will result in the issuance of a citation. The cleared area shall be replanted at a rate of two times the DBH inches (DBH means diameter measured at breast height, 4 5/10 feet above the ground) of trees removed, if known, or one tree per 1,089 square feet of replacement area with the required replacement area calculated at two times the canopy coverage area that was removed. Additionally, the development review process shall be halted and the developer shall be required to resubmit revised existing site condition and tree inventory plans and new landscaping plans incorporating the additional planting requirements.

(d)

The following standards shall be used in evaluating subdivisions and site plans:

(1)

It is a policy of the City of Chanhassen to protect the integrity of the natural environment through the preservation, protection, and planting of trees. The city finds that trees provide many benefits including: stabilization of the soil by the prevention of erosion and sedimentation, reduction of stormwater runoff and the costs associated therewith, improvement of air quality, reduction of noise pollution, control of urban heat island effect, protection and increase of property values, protection of privacy, energy conservation through natural insulation, control of drainage and restoration of denuded soil subsequent to construction and grading, protection from severe weather, providing habitat for birds and other wildlife, conservation and enhancement of city's physical and aesthetic environment, reforestation of open lands, and general protection and enhancement of the quality of life and general welfare of the city. It is therefore the purpose of this section to provide regulations related to the cutting, removal, or killing of trees on construction and development sites and to ensure the protection and preservation of the natural environment and beauty of the City of Chanhassen.

(2)

Prior to the submittal of development plans, a tree survey of the site shall be prepared by a registered landscape architect, licensed forester, or other professional approved by the city. This survey shall include the species, DBH size, condition, location of all trees over ten inches in diameter and any damaged or diseased trees on site. All significant special, damaged or diseased trees shall be tagged and identified by number on the survey. A delineation of the existing canopy coverage area(s) which outlines all areas covered by tree canopy shall be included as part of the survey. Additionally, all damaged and diseased trees shall be cataloged with the nature and extent of any damage or disease specified.

a.

Based on this survey and either site observation and measurement or a current aerial photograph (taken within one year of the date of plan submittal) interpretation, the following shall be calculated:

1.

Base line canopy coverage.

2.

Minimum canopy coverage requirements.

b.

The following table shall be used to determine the minimum amount of canopy coverage that must be maintained or provided on-site as part of the development. It shall represent the minimum canopy coverage, consisting of existing tree canopy and/or additional trees required for the site. Existing wetland areas, bluff areas, and dedicated park land located on site shall be excluded from the calculation of site area in the determination of site coverage. If a forested area is to be dedicated to the city for park land, then this area shall not be included in the base line canopy coverage area calculation nor shall it count towards the minimum canopy coverage for the site.

	Base Line Canopy Coverage Per Acre
Comprehensive Plan Designation	80—100%	60—79%	40—59%	20—39%	19% or less
Commercial/industrial/institutional	28%	25%	20%	14%	10%
High density residential	35%	30%	25%	20%	15%
Medium density residential	40%	35%	30%	25%	20%
Low density residential	55%	46%	35%	30%	25%
Large lot residential	68%	56%	43%	35%	25%

 

Base line canopy coverage is the canopy coverage existing at the time the development application is filed with the city. Minimum canopy coverage is determined by using the matrix.

c.

Priority shall be given to retaining stands of trees and undisturbed wooded lands over individual specimen trees that will be incorporated into the development. No more than ten percent of the canopy retention requirement may be met by an individual tree that is not included within a designated woodland area.

d.

For developments that do not meet the minimum canopy coverage, the developer shall be required to develop a forestation plan to bring the total canopy coverage up to the minimum requirement. Where existing woodlands are removed or there is a loss of trees that would otherwise be used to meet the canopy coverage retention requirement, the developer shall develop a woodland replacement plan. The replacement plan must designate an area at least one and two-tenths (1.2) times the removed canopy coverage area that shall be planted with replacement trees for those removed. These plans shall locate additional trees either as a continuation of existing stands of trees that are to be preserved or create new stands of trees in desirable locations such as along roadway corridors, on the north and west perimeters of the development, in common open areas, or adjacent to park facilities.

e.

The following criteria shall be followed in establishing minimum canopy coverage:

1.

When planting trees, one tree shall be deemed to provide 1,089 square feet of required canopy coverage;

2.

Trees must be from the approved list of desirable species (preference given for trees designated as native);

3.

No more than ten percent of the trees may be from any one tree species and no more than 20 percent of the trees may be from any one genus;

4.

Overstory trees shall be at least 2½-inch caliper and understory trees shall be a minimum of 1½-inch caliper;

5.

Conifer trees shall be a minimum of six feet in height;

6.

Plant materials used for the reforestation shall be of a similar species as vegetation found on-site;

7.

Trees shall be used that are appropriate to the soil conditions found on site;

8.

Trees shall be from certified nursery stock as defined and controlled by M.S. §§ 18.44 through 18.61, the Plant Pest Act; and

9.

Not less than 75 percent of the total trees required shall be overstory species.

(3)

In order to calculate the tree removal area of the single-family detached development the applicant must include the front 105 feet of each lot within the tree removal area of the development. If a front setback variance is approved as part of the subdivision review process, the depth of the area calculated for tree removal on the lot may be reduced by the amount of the front yard setback variance.

(4)

Minimizing the tree loss should be achieved by any combination of the following:

a.

Realignment of streets, utilities and lot lines.

b.

Consideration of alternative utility configurations such as the use of ejector pumps, force mains, or revised home elevations to minimize grading.

c.

Reductions in roadway width and right-of-way and increase in street grade up to ten percent when the applicant can demonstrate that significant tree preservation is directly related to the modification.

d.

Use of private streets in lieu of public streets.

e.

Variation in street radius and design speed.

f.

Modified grading plans.

g.

Within PUDs, the city council may consider waiving minimum lot area requirements and/or density transfers as long as it can be demonstrated by the applicant that tree preservation can be enhanced. In no case shall overall project densities exceed what is allowed by the comprehensive plan. The greater the level of preservation, the greater flexibility will be considered by the city.

h.

Within PUDs, variations to building setback lines, provided a minimum 20-foot building separation is maintained between buildings on adjacent lots. The setback variations shall be established and recorded as part of the plat approval.

(5)

Trees designated for preservation shall be protected by snow fences with clearly marked signage specifying that the area is off limits for construction activities, or other means acceptable to the city, prior to land preparation or construction activities. Protective barriers in locations determined by the city must remain in place until all construction activities are terminated. No equipment, chemicals, soil deposits, or construction materials shall be placed within the protective barriers. All understory trees and natural vegetation should be preserved within the boundaries of the protective areas. Where this protection area cannot be maintained or would otherwise render lots undevelopable, an alternate protection, mitigation or tree replacement plan may be considered and approved by the city. This plan may include the use of retaining walls, installation of aeration systems, requirement for post-construction deep root fertilization and soil aeration, or construction vehicle ramp systems.

(6)

At the city's discretion, conservation easements may be required to protect designated tree preservation areas. Such easements shall be permanently marked and signed as a conservation area with low profile monumentation acceptable to the city. A monument is required for each 300 linear feet of tree conservation area. Within designated woodland areas, the city shall encourage the use of indigenous grasses and plant species to more closely resemble a natural area. Homeowners associations shall be responsible for the maintenance of vegetation in common areas. Individual property owners shall be responsible for the maintenance of vegetation on their property. The planting of trees in excess of those required by this section is permitted within the designated woodland area.

(7)

During the removal process, trees shall be removed so as to prevent blocking of public rights-of-way or interfering with overhead utility lines.

(8)

The removal of diseased and damaged trees is permissible only if they cannot be saved. These trees shall not be counted when computing the base line tree canopy coverage.

(9)

If any protected significant trees are removed or killed or there is a loss of trees as the result of construction activities, the city requires replacement at the rate of two diameter inches per each inch of DBH of the removed, killed, or lost trees. The replacement trees shall be at least 2½ inches in diameter and will be species that conform to the "list of desirable tree species" for Planting in Chanhassen. No more than ten percent of the trees may be from any one tree species. Other species or sizes may be used as replacement trees subject to approval by the city. Alternately, at the city's discretion, if a developer removes trees within a protected area, the canopy coverage area shall be calculated for that area and a replacement area two times the canopy coverage area that was removed shall be planted. One tree shall be planted for each 1,089 square feet of required replacement area. Trees shall be from the list of desirable tree species, no more than ten percent of trees from any one tree species, average 2½-inch diameter, a similar species as vegetation existing on-site, and appropriate to the soil conditions. For any replacement trees that cannot be planted on the original site due to space restrictions, the developer shall pay the city the value of the trees, including material and installation, in to the community tree planting fund.

(10)

Financial guarantees acceptable to the city shall be required to ensure satisfactory installation of landscaping requirements.

(Ord. No. 33-D, § 6.6, 2-25-85; Ord. No. 153, § 2, 11-4-91; Ord. No. 204, §§ 1, 2, 5-9-94; Ord. No. 240, § 7, 7-24-95; Ord. No. 250, § 1, 4-8-96; Ord. No. 255, § 1, 7-22-96; Ord. No. 324, § 19, 7-9-01; Ord. No. 378, § 1, 5-24-04; Ord. No. 395, § 6, 5-9-05; Ord. No. 410, § 8, 1-23-06; Ord. No. 432, § 6, 9-25-06; Ord. No. 458, §§ 1—3, 9-24-07; Ord. No. 595, §§ 3—5, 5-12-14)

Cross reference

Landscaping and tree removal, § 20-1176 et seq.