15.2-961.1 - Conservation of trees during land development process in localities belonging to a nonattainment area for air quality standards.
§ 15.2-961.1. Conservation of trees during land development process inlocalities belonging to a nonattainment area for air quality standards.
A. For purposes of this section, "tree canopy" or "tree cover" includesall areas of canopy coverage by self-supporting and healthy woody plantmaterial exceeding five feet in height, and the extent of planted tree canopyat 20-years maturity.
B. Any locality within Planning District 8 that meets the population densitycriteria of subsection A of § 15.2-961 and is classified as an eight-hournonattainment area for ozone under the federal Clean Air Act and Amendmentsof 1990, in effect as of July 1, 2008, may adopt an ordinance providing forthe conservation of trees during the land development process pursuant to theprovisions of this section. In no event shall any local tree conservationordinance adopted pursuant to this section also impose the tree replacementprovisions of § 15.2-961.
C. The ordinance shall require that the site plan for any subdivision ordevelopment provide for the preservation or replacement of trees on thedevelopment site such that the minimum tree canopy or tree cover percentage20 years after development is projected to be as follows:
1. Ten percent tree canopy for a site zoned business, commercial, orindustrial;
2. Ten percent tree canopy for a residential site zoned 20 or more units peracre;
3. Fifteen percent tree canopy for a residential site zoned more than eightbut less than 20 units per acre;
4. Twenty percent tree canopy for a residential site zoned more than four butnot more than eight units per acre;
5. Twenty-five percent tree canopy for a residential site zoned more than twobut not more than four units per acre; and
6. Thirty percent tree canopy for a residential site zoned two or fewer unitsper acre.
In meeting these percentages, (i) the ordinance shall first emphasize thepreservation of existing tree canopy where that canopy meets local standardsfor health and structural condition, and where it is feasible to do so withinthe framework of design standards and densities allowed by the local zoningand other development ordinances; and (ii) second, where it is not feasiblein whole or in part for any of the justifications listed in subsection E topreserve existing canopy in the required percentages listed above, theordinance shall provide for the planting of new trees to meet the requiredpercentages.
D. Except as provided in subsection E, the percentage of the site covered bytree canopy at the time of plan submission shall equate to the minimumportion of the requirements identified in subsection C that shall be providedthrough tree preservation. This portion of the canopy requirements shall beidentified as the "tree preservation target" and shall be included in siteplan calculations or narratives demonstrating how the overall requirements ofsubsection C have been met.
E. The ordinance shall provide deviations, in whole or in part, from the treepreservation target defined in subsection D under the following conditions:
1. Meeting the preservation target would prevent the development of uses anddensities otherwise allowed by the locality's zoning or development ordinance.
2. The predevelopment condition of vegetation does not meet the locality'sstandards for health and structural condition.
3. Construction activities could be reasonably expected to impact existingtrees to the extent that they would not likely survive in a healthy andstructurally sound manner. This includes activities that would cause directphysical damage to the trees, including root systems, or cause environmentalchanges that could result in or predispose the trees to structural and healthproblems.
If, in the opinion of the developer, the project cannot meet the treepreservation target due to the conditions described in subdivision 1, 2, or3, the developer may request a deviation from the preservation requirement insubsection D. In the request for deviation, the developer shall provide aletter to the locality that provides justification for the deviation,describes how the deviation is the minimum necessary to afford relief, anddescribes how the requirements of subsection C will be met through treeplanting or a tree canopy bank or fund established by the locality. Proposeddeviations shall be reviewed by the locality's urban forester, arborist, orequivalent in consultation with the locality's land development or licensedprofessional civil engineering review staff. The locality may propose analternative site design based upon adopted land development practices andsound vegetation management practices that take into account the relationshipbetween the cost of conservation and the benefits of the trees to bepreserved as described in ANSI A300 (Part 5) - 2005 Management: Tree, Shrub,and Other Woody Plant Maintenance - Standard Practices, Management of Treesand Shrubs During Site Planning, Site Development, and Construction, Annex A,A-1.5, Cost Benefits Analysis (or the latest version of this standard). Thedeveloper shall consider the alternative and redesign the plan accordingly,or elect to satisfy the unmet portion of the preservation threshold throughon-site tree planting or through the off-site planting mechanisms identifiedin subsection G, so long as the developer provides the locality with anexplanation of why the alternative design recommendations were rejected.Letters of explanation from the developer shall be prepared and certified bya licensed professional engineer as defined in § 54.1-400. If arboriculturalissues are part of explanation then the letter shall be signed by a CertifiedArborist who has taken and passed the certification examination sponsored bythe International Society of Arboriculture and who maintains a validcertification status or by a Registered Consulting Arborist as designated bythe American Society of Consulting Arborists. If arboricultural issues arethe sole subject of the letter of explanation then certification by alicensed professional engineer shall not be required.
F. The ordinance shall provide for deviations of the overall canopyrequirements set forth in subsection C to allow for the preservation ofwetlands, the development of farm land or other areas previously devoid ofhealthy and/or suitable tree canopy, or where the strict application of therequirements would result in unnecessary or unreasonable hardship to thedeveloper.
G. The ordinance shall provide for the establishment of a tree canopy bank orfund whereby any portion of the tree canopy requirement that cannot be meton-site may be met through off-site tree preservation or tree plantingefforts. Such provisions may be offered where it can be demonstrated thatapplication of the requirements of subsection C would cause irresolvableconflicts with other local site development requirements, standards, orcomprehensive planning goals, where sites or portions of sites lacksufficient space for future tree growth, where planting spaces will notprovide adequate space for healthy root development, where trees will causeunavoidable conflicts with underground or overhead utilities, or where it canbe demonstrated that trees are likely to cause damage to publicinfrastructure. The ordinance may utilize any of the following off-sitecanopy establishment mechanisms:
1. A tree canopy bank may be established in order for the locality tofacilitate off-site tree preservation, tree planting, stream bank, andriparian restoration projects. Banking efforts shall provide tree canopy thatis preserved in perpetuity through conservation easements, deed restrictions,or similar protective mechanisms acceptable to the locality. Projects used inoff-site banking will meet the same ordinance standards established foron-site tree canopy; however, the locality may also require the submission offive-year management plans and funds to ensure the execution of maintenanceand management obligations identified in those plans. Any such bank shalloccur within the same nonattainment area in which the locality approving thetree banking is situated.
2. A tree canopy fund may be established to act as a fiscal mechanism tocollect, manage, and disburse fees collected from developers that cannotprovide full canopy requirements on-site. The locality may use this funddirectly to plant trees on public property, or the locality may elect todisburse this fund to community-based organizations exempt from taxationunder § 501 (c) (3) of the Internal Revenue Code with tree planting orcommunity beautification missions for tree planting programs that benefit thecommunity at large. For purposes of establishing consistent and predictablefees, the ordinance shall establish cost units that are based on averagecosts to establish 20-year canopy areas using two-inch caliper nursery stocktrees. Any funds collected by localities for these purposes shall be spentwithin a five-year period established by the collection date, or the localityshall return such funds to the original contributor, or legal successor.
H. The following uses shall be exempt from the requirements of any ordinancepromulgated under this section: bona fide silvicultural activity as definedby § 10.1-1181.1 and the areas of sites included in lakes, ponds, and thenormal water elevation area of stormwater retention facilities. The ordinanceshall modify the canopy requirements of dedicated school sites, playingfields, and other nonwooded active recreation areas by allowing these andother facilities and uses of a similar nature to provide 10 percent treecanopy 20 years after development.
I. 1. In recognition of the added benefits of tree preservation, theordinance shall provide for an additional tree canopy credit of up to one andone-quarter times the canopy area at the time of plan submission forindividual trees or the coalesced canopy of forested areas preserved from thepredevelopment tree canopy.
2. The following additional credits may be provided in the ordinance inconnection with tree preservation:
a. The ordinance may provide canopy credits of up to one and one-half timesthe actual canopy area for the preservation of forest communities thatachieve environmental, ecological, and wildlife conservation objectives setby the locality. The ordinance may establish minimal area, dimensional andviability standards as prerequisites for the application of credits. Forestcommunities shall be identified using the nomenclature of either the federalNational Vegetation Classification System (FGDC-STD-005, or latest version)or the Natural Communities of Virginia Classification of Ecological CommunityGroups, Second Approximation (Version 2.2, or latest version).
b. The ordinance may provide canopy credits of up to three times the actualcanopy area of trees that are officially designated for preservation inconjunction with local tree conservation ordinances based on the authoritygranted by § 10.1-1127.1.
J. The following additional credits shall be provided in the ordinance inconnection with tree planting:
1. The ordinance shall provide canopy credits of one and one-half the areanormally projected for trees planted to absorb or intercept air pollutants,tree species that produce lower levels of reactive volatile organiccompounds, or trees that act to reduce air pollution or greenhouse gasemissions by conserving the energy used to cool and heat buildings.
2. The ordinance shall provide canopy credits of one and one-quarter the areanormally projected for trees planted for water quality-related reforestationor afforestation projects, and for trees planted in low-impact developmentand bioretention water quality facilities. The low-impact developmentpractices and designs shall conform to local standards in order for thesesupplemental credits to apply.
3. The ordinance shall provide canopy credits of one and one-half the areanormally projected for native tree species planted to provide food, nesting,habitat, and migration opportunities for wildlife. These canopy credits mayalso apply to cultivars of native species if the locality determines thatsuch a cultivar is capable of providing the same type and extent of wildlifebenefit as the species it is derived from.
4. The ordinance shall provide canopy credits of one and one-half the areanormally projected for use of native tree species that are propagated fromseed or tissue collected within the mid-Atlantic region.
5. The ordinance shall provide canopy credits of one and one-quarter the areanormally projected for the use of cultivars or varieties that developdesirable growth and structural patterns, resist decay organisms and thedevelopment of cavities, show high levels of resistance to disease or insectinfestations, or exhibit high survival rates in harsh urban environments.
K. Tree preservation areas and individual trees may not receive more than oneapplication of additional canopy credits provided in subsection I. Individualtrees planted to meet these requirements may not receive more than twocategories of additional canopy credits provided in subsection J. Canopycredits will only be given to trees with trunks that are fully located on thedevelopment site, or in the case of tree banking projects only to trees withtrunks located fully within easements or other areas protected by deedrestrictions listed in subsection G.
L. All trees planted for tree cover credits shall meet the specifications ofthe American Association of Nurserymen and shall be planted in accordancewith the publication entitled "Tree and Shrub Planting Guidelines,"published by the Virginia Cooperative Extension.
M. In order to provide higher levels of biodiversity and to minimize thespread of pests and diseases, or to limit the use of species that causenegative impacts to native plant communities, cause damage to nearbystructures, or possess inherent physiological traits that prone trees tostructural failure, the ordinance may designate species that cannot be usedto meet tree canopy requirements or designate species that will only receivepartial 20-year tree canopy credits.
N. The locality may allow the use of tree seedlings for meeting tree canopyrequirements in large open spaces, low-density residential settings, or inlow-impact development reforestation/afforestation projects. In these cases,the ordinance shall allow the ground surface area of seedling planting areasto equate to a 20-year canopy credit area. Tree seedling plantings will becomprised of native species and will be planted in densities that equate to400 seedlings per acre, or in densities specified by low-impact developmentdesigns approved by the locality. The locality may set standards for seedlingmortality rates and replacement procedures if unacceptable rates of mortalityoccur. The locality may elect to allow native woody shrubs or native woodyseed mix to substitute for tree species as long as these treatments do notexceed 33 percent of the overall seedling planting area. The number of asingle species may not exceed 10 percent of the overall number of trees orshrubs planted to meet the provisions of this subsection.
O. The following process shall be used to demonstrate achievement of therequired percentage of tree canopy listed in subsection C:
1. The site plan shall graphically delineate the edges of predevelopment treecanopy, the proposed limits of disturbance on grading or erosion andsedimentation control plans, and the location of tree protective fencing orother tree protective devices allowed in the Virginia Erosion and SedimentControl Handbook.
2. Site plans proposing modification to tree canopy requirements or claimingsupplemental tree canopy credits will require a text narrative.
3. The site plan shall include the 20-year tree canopy calculations on aworksheet provided by the locality.
4. Site plans requiring tree planting shall provide a planting schedule thatprovides botanical and common names of trees, the number of trees beingplanted, the total of tree canopy area given to each species, variety orcultivars planted, total of tree canopy area that will be provided by alltrees, planting sizes, and associated planting specifications. The site planwill also provide a landscape plan that delineates where the trees shall beplanted.
P. The ordinance shall provide a list of commercially available tree species,varieties, and cultivars that are capable of thriving in the locality'sclimate and ranges of planting environments. The ordinance will also providea 20-year tree canopy area credit for each tree. The amount of tree canopyarea credited to individual tree species, varieties, and cultivars 20 yearsafter they are planted shall be based on references published or endorsed byVirginia academic institutions such as the Virginia Polytechnic Institute andState University and accepted by urban foresters, arborists, andhorticulturalists as being accurate for the growing conditions and climate ofthe locality.
Q. The ordinance shall establish standards of health and structural conditionof existing trees and associated plant communities to be preserved. Theordinance may also identify standards for removal of trees or portions oftrees that are dead, dying, or hazardous due to construction impacts. Suchremoval standards may allow for the retention of trunk snags where thelocality determines that these may provide habitat or other wildlife benefitsand do not represent a hazardous condition. In the event that existing treecanopy proposed to be preserved for tree canopy credits dies or must beremoved because it represents a hazard, the locality may require thedeveloper to remove the tree, or a portion of the tree and to replace themissing canopy area by the planting of nursery stock trees, or if a viablealternative, by tree seedlings. Existing trees that have been granted creditswill be replaced with canopy area determined using the same supplementalcredit multipliers as originally granted for that canopy area.
R. Penalties for violation of ordinances adopted pursuant to this sectionshall be the same as those applicable to violations of zoning ordinances ofthe locality.
S. In no event shall any local tree conservation ordinance adopted pursuantto this section exceed the requirements set forth herein; however, any localordinance adopted pursuant to the provisions of § 15.2-961 prior to July 1,1990, may adopt the tree conservation provisions of this section based on10-year minimum tree canopy requirements.
T. Nothing in this section shall invalidate any local ordinance adoptedpursuant to § 15.2-961.
(2008, cc. 333, 711.)