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3j. Ordinance Amending Chapters 18 & 20 Concerning Trees and LandscapingAt the 4/25/94 City Council meeting, fast i reading was approved with noted strike out changes. A surmary ordinance has been prepared for publications pzposes and is attached. CITY OF CHANHASSEN Approval of the sumrary and second and final CARVER AND HENNEPIN COUNTIES, MINNESOTA reading is recoffw tided. ORDINANCE NO. _ AN ORDINANCE AMENDING CHAPTERS 18 AND 20 OF THE CHANHASSEN CITY CODE CONCERNING TREES AND LANDSCAPING 1 The . City Council of the City of Chanhassen ordains: ' Section 1. Subdivisions: Section 18.61(a)(1) is amended to add the following tree species: 1 Primary Specimen Deciduous Trees Carya ovata ' Juglans nigra Quercus rubra Robinia pseudoacacia I Secondary Deciduous Trees Common Name Shagbark Hickory Black Walnut Oak, Red Black Locust Common Name Aesculus glabra Ohio Buckeye Betula nigra Birch, River Catalpa speciosa Northern Catalpa Ostrya virginiana Ironwood Populus tremuloides Aspen Sorbus spp. Ash, Mountain Ornamental Common Name Crataegus spp. Hawthorne Phellodendron amurense Amur Corktree Conifers Larix laricina Tamarack t Section 2. Subdivisions: Section 18.61(d), Landscaping and tree preservation requirements is amended in its entirety to read as follows : 1 (d) The following standards shall be used in evaluating subdivisions and site plans: 1 1 (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 storm water 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 the 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 significant, special, 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. ' 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 located on site shall be excluded from the calculation of site area in the determination of required 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. 2 Comprehensive Plan Designation Commercial/Industrial/ Institutional High Density Residential Medium Density Residential Low Density Residential Large Lot Residential Base Line Canonv Coverage Per Acre 80-100% 60-79% 40-59% 20-39% 19% or less 28% 25% 20% 14% 10% 35% 30% 25% 20% 15% 40% 35% 30% 25% 20% 55% 46% 35% 30% 25% 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. 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 (10) percent of the canopy retention requirement may be met by an individual tree that is not included within a designated woodland area. 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 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. 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, 3 n 2) tree must be from the approved list of desirable species (preference given for trees designated as native), 3) no more than one -third (' %a) of the trees may be from any one tree species, 4) trees shall average at least 2;6 inch caliper and may be a minimum of U6 inch caliper, 5) not less than twenty percent (20 %) of the trees shall be conifers, 6) conifer trees shall average seven (7) feet and shall be a minimum of six (6) feet in height, 7) plant materials used for the reforestation shall be of a similar species as vegetation found on site, 8) trees shall be used that are appropriate to the soil conditions found on site, and 9) trees shall be from certified nursery stock as defined and controlled by Minnesota Statute Sections 18.44 through 18.61, the Plant Pest Act. (3) To the extent practical, site design shall preserve significant woodland areas and special trees. Special priority for tree preservation shall be given to areas within flood plains, wetlands, stream corridors, wooded slopes, and along collector and arterial roadway corridors. To facilitate this, a woodland management plan, which may include preservation, forestation, and replacement elements, shall be formulated by the developer as one component of the development proposal. The woodland management plan shall be prepared and signed by a registered landscape architect, licensed forester, or other professional approved by the city. This plan shall include the following information: a. Tree survey b. Designated woodland areas C. Location and size of replacement/forestation tree planting areas d. List of all replacement trees including species, caliper, and planting method e. Methods of tree protection f. Location of all protective fencing g. Special construction methods to be utilized h. Location of all retaining walls i. Statement explaining why replacement trees are necessary j. Rationale for selection of replacement/forestation trees (4) In single - family detached residential developments, the applicant must demonstrate that suitable home sites exist on each lot by describing a 60' x 60' building pad (which includes deck area) without intruding into required setbacks and easements. KI (5) 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 street width and right -of -way and increase in street grade up to 10% when the applicant can demonstrate that significant tree ' preservation is directly related to the modification d. use of private drives in lieu of public streets e. variation in street radius and design speed ' E 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 twenty (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. ' (6) 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 must be located at twelve (12) times the tree diameter at DBH from the base of the tree, the critical root zone, and , 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. (7) 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 three hundred (300) I 0 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. Home owners 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 ordinance is permitted within the designated woodland area. (8) During the removal process, trees shall be removed so as to prevent blocking of public rights -of -way or interfering with overhead utility lines. (9) 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. (10) 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 (2) caliper inches per each inch of DBH of the removed, killed, or lost trees. The replacement trees shall be at least two and a half (2 inches caliper and will be species that conform to the List of Desirable Tree Species for Planting in Chanhassen. No more than one -third ( %) 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 1.5 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 one -third ( of trees from any one tree species, average 2;6 inch caliper with a minimum B6 inch caliper, a similar species as vegetation existing on site, and appropriate to the soil conditions. Any replacement trees that cannot be planted on the original site due to space restrictions shall be planted on city property at locations to be determined by the city. (11) Financial guarantees acceptable to the city shall be required to ensure compliance with this section. Section 3. Section 20 -1, Definitions, of the Chanhassen City Code is amended by adding the following definitions: Canopy coverage shall mean the area on a horizontal plane that is located under the crowns of all the trees on the site. 0 Critical root zone means an area twelve (12) times the tree diameter at DBH measured from the base of the tree. DBH means diameter measured at breast height 4.5 feet above the ground). , g ( � . ' ) Designated woodland area means an area within a development that has been ' designated in the woodland management plan as a tree preservation, forestation or replacement planting area. ' Loss of trees means that any of the following may have happened: a. Grade change or land alteration, whether temporary or permanent, of ' greater than one (1) foot, measured vertically from the existing grade, affecting forty (40) percent (as measured on a horizontal plane) or more ' of a tree's critical root zone; or b. Utility construction resulting in the cutting of forty (40) percent or more ' of the tree's roots within the critical root zone; or C. Mechanical injury to the tree trunk causing loss of more than forty (40) I percent of the bark; or d. Compaction to ninety (90) percent of standard proctor to a depth of six ' (6) inches or more of forty (40) percent or more of the surface of the soil within the tree's critical root zone; or e. The pruning of a tree which eliminates forty (40) percent or more of the ' canopy area of a tree; or f. The complete removal of a tree. ' Significant Tree means any healthy tree species measuring twelve (12) inches or more ' DBH; Or any healthy coniferous tree measuring twelve (12) feet in height or more. Special trees mean any large broadleaf trees at least 30 inches DBH, any large conifer ' trees at least 20 inches DBH, any medium broadleaf trees at least 20 inches DBH, any small broadleaf trees at least 12 inches DBH, rare or unusual tree species, or trees of exceptional quality. Tree caliper means diameter of a tree measured at six (6) inches above ground. ' Tree trunk means the stem portion of a tree from the base to the first branch thereof. Woodlands shall mean any groupings of significant trees with a canopy coverage of one (1) acre or more, any groupings of 10 or more significant trees, or any grouping of trees with at least one (1) special tree and where 25 percent or more of other trees are significant trees. Section 4. LANDSCAPING AND TREE REMOVAL: Section 20 -1178 (c) is amended in its entirety to read as follows: (c) The standards in City Code Section 18.61 (d) shall be used in evaluating site plans. Section 5. This ordinance shall be effective immediately upon its passage and publication. PASSED AND ADOPTED this day of , 1994, by the City Council of the City of Chanhassen. ATTEST: Don Ashworth, Clerk/Manager Donald J. Chmiel, Mayor (Published in the Chanhassen Villager on .) 8 l CITY OF CHANHASSEN CARVER AND HENNEPIN COUNTIES, MINNESOTA ORDINANCE SUMMARY Amendment of Landscaping and Tree Preservation ordinances regarding subdivisions ' and site plans. The amendment adds to list of approved trees; expands intent of ordinance regarding benefits of tree protection; requires submittal of tree survey early in the ' development review process; requires determination of existing canopy coverage area of a site; provides criteria for establishing minimum canopy coverage; requires submittal of a woodland management plan; provides guidelines for minimizing tree loss; requires tree ' protection fencing; provides for conservation easements and monumentation; provides penalties for the removal of trees that were designated for preservation; adds definition specifically related to tree protection requirements; and revises site plan landscaping and tree ' removal requirements to reference the subdivision section.