The findings of the Board of Trustees adopted in ordinance no. 05-2-2, on February 1, 2005, are re-stated as subsections A through D of this section, and the Board of Trustees further adopts the findings in subsections E, F and G of this section. The terms "native trees" and "native woodlands", when used in these findings, shall have the meanings given in section 9-6-5 of this chapter.
A. The Plan Commission of the Village of Riverwoods on June 3, 2004 conducted a public hearing on the question of adopting a zoning text amendment under this title for the purpose of protecting woodlands and submitted its report to the Board of Trustees recommending that a woodland protection ordinance be considered to protect woodland areas in the Village.
B. The Board of Trustees conducted a public hearing and town meeting on December 7, 2004, and received testimony at that time from Mr. Charles Stewart, President, Urban Forest Management, Inc., who served as Village Forester beginning in 1976; Dr. George Ware, Ph.D., Dendrologist Emeritus at the Morton Arboretum; Mr. Steve Swanson, Director of the Kennecott Grove National Historic Area in Glenview, Illinois; Mr. Mark O'Leary, M.S., Senior Ecologist with Applied Ecological Services, Inc., an ecological consulting, contracting and restoration firm; and Mr. Patrick Glenn, P.E., Gewalt Hamilton Associates, Inc. ("GHA"), the engineering firm serving as Village Engineer. At such town meeting, GHA presented its report entitled "Report on Woodland/Turfgrass Hydrology, Using NRCC TR-55 Hydrological Methods", dated December 2004, prepared by GHA (the "GHA Report").
C. The Urban Forest Research Unit of the USDA Forest Service, Northeastern Research Station in Syracuse, New York, was established in 1978, to investigate the effects of urban forests and their management on human health and environmental quality, and it has developed the urban forest effects (UFORE) model, which model is used to quantify the following:
1. Urban forest structure by land use type (e.g., species composition, tree density, tree health, leaf area, leaf and tree biomass, species diversity, etc.);
2. Hourly amount of pollution removed by the urban forest, and its associated percent air quality improvement throughout a year. Pollution removal is calculated for ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide and particulate matter (<10 microns);
3. Hourly urban forest volatile organic compound emissions and the relative impact of tree species on net ozone and carbon monoxide formation throughout the year;
4. Total carbon stored and net carbon annually sequestered by the urban forest;
5. Effects of trees on building energy use and consequent effects on carbon dioxide emissions from power plants;
6. Compensatory value of the forest, as well as the value of air pollution removal and carbon storage and sequestration;
7. Tree pollen allergenicity index;
8. Potential impact of gypsy moth and Asian longhorned beetle infestation;
9. Tree transpiration.
The Urban Forest Research Unit of the USDA Forest Service, Northeastern Research Station in Syracuse, New York, has modeled numerous cities in the United States and published its results quantifying the direct, favorable ecological and financial benefits of maintaining urban forests.
D. After reviewing the expert testimony and reports presented to the Board of Trustees and the published research available to quantify the economic benefits of urban forests, the Board of Trustees adopts the following findings as the basis for adoption of this chapter and intends that this chapter be interpreted in the light of such findings:
1. Approximately ninety percent (90%) of the areas within the Village's R-1, R-2 and R-3 Single-Family Residential Zoning Districts (excluding subdivisions developed as planned unit developments) are located within the mixed-hardwood forest and woodland landscape that is the characteristic natural ecological system in the Village.
2. In the Village's woodland ecosystem, the canopy, understory and ground plane (herbaceous) levels each have characteristic species.
3. The natural woodland ecology in the Village is modified and pressured by human activity and development, the presence of deer herds, in particular, and other wildlife and insect populations, and the proliferation of non-native, invasive species, such as buckthorn and garlic mustard. Human activity in the form of replacing native understory and ground plane plants with turfgrass is also a negative factor in the maintenance of healthy woodlands because each of the three (3) native components of the woodlands - the canopy, understory and ground plane - is necessary for the continued regeneration of native trees and plants.
4. Since 1976, the Village's woodlands have diminished in quantity and in the quality of the plant community as a result of the pressure factors that are described above. As a result, the Village's woodlands have become more fragmented and have suffered a loss in the ability to regenerate the more desirable species of trees and plants of the native landscape.
5. For the natural woodland ecology in the Village to remain self-sustaining, it is necessary to take steps to reduce the further loss and fragmentation of woodland areas resulting from human activity in order that the woodland trees and plants can more readily resist the pressure factors resulting from non-human factors.
6. The Village should continue to monitor the work of the Lake County Forest Preserve District in maintaining the deer population at a level that can be supported by the environment; the Village should continue to work with other governmental units to minimize and control infestations of gypsy moth, Asian longhorned beetles and similar pests; and the Village should continue to support woodland restoration by educational efforts and by providing assistance to residents seeking to eliminate non-native, invasive species from their properties. The actions referred to in this section should be coordinated with the provisions in this chapter regulating the removal of native trees and woodlands to establish the best possible conditions for the health of the woodlands.
7. The woodlands in the Village, as demonstrated in the GHA Report, significantly reduce the volume and rate of stormwater runoff produced under various land use conditions in the Village in comparison to the volume and rate of stormwater runoff in turfgrass lawn areas. The GHA Report is incorporated in this chapter as if fully set forth herein. Lessening the removal of herbaceous plants and understory trees and the substitution of turfgrass in place thereof will reduce stormwater runoff and lessen the severity of local flooding in the Village.
8. The maintenance of a healthy woodland environment in the Village provides the following benefits: shade and cooling; control of erosion; filtering of water pollutants from stormwater; recharging of aquifers used by residents for drinking water; replenishment of the groundwater table; maintenance of flows into wetlands and streams; cleansing of air of pollutants; mitigation of global warming by absorbing greenhouse gases; and promotion of a biologically diverse community of micro-organisms, plants and animals, protecting some species from extinction while preserving genetic diversity. The urban forest effects (UFORE) model developed by the Urban Forest Research Unit of the USDA Forest Service, Northeastern Research Station in Syracuse, New York, has been used to quantify the dollar benefits of urban forests, and such models indicate that there is a significant quantifiable benefit from woodlands in respect of the benefits described above, and such findings demonstrate that the Village's urban forest cover produces significant quantifiable benefits.
9. The regulations proposed in this chapter, in the severest case of applicability, nevertheless will allow for a building envelope which is sufficient for the construction of a main dwelling and multiple combinations of accessory uses (such as a tennis court and swimming pool and an accessory building) that, in size and extent, would be comparable to intensely developed, existing residential properties in the Village except in the degree to which woodlands have been removed. The protection of woodlands will promote higher property values for woodland areas in the Village. The regulations proposed in this chapter will not unreasonably restrict development nor constitute an arbitrary and capricious exercise of Municipal powers.
10. The preservation of woodland areas in the Village will provide many essential benefits to the community as a whole, as described in the foregoing sections, and, accordingly, the adoption of a long-term policy of preserving woodland areas is necessary to safeguard, protect and promote the health, safety and welfare of the current and future inhabitants of the Village and surrounding areas.
E. The protection of native woodlands depends especially on the adoption of a long-term policy of promoting the regeneration of native trees which populated the native woodlands once prevalent throughout the Village. In particular, the preservation and regeneration of native trees in the Village will promote the repair of ecologically disturbed areas and the gradual restoration of native woodlands. The adoption of these regulations, while still allowing for the reasonable improvement of land within the Village, is intended to accomplish, where possible, the following specific objectives:
1. To protect native trees as an important public resource enhancing the quality of life and the general welfare of the Village and enhancing its unique character and physical, historical, and aesthetic environment;
2. To protect, maintain, and enhance the ecological quality and long-term viability of native woodlands and the essential character of those areas throughout the community;
3. To enhance and preserve the air quality of the Village through the filtering effect of trees on air pollutants;
4. To reduce noise within the Village through the baffle and barrier effect of trees on the spread of noise;
5. To reduce topsoil erosion through the soil retention effect of tree roots;
6. To reduce energy consumption through the wind break and shade effects of trees when they are properly preserved on the lot;
7. To preserve and enhance nesting areas for birds and other wildlife which in turn assist in the control of insects;
8. To reduce stormwater runoff and the costs associated therewith and replenish ground water supplies; and
9. To protect and increase property values.
F. Applied Ecological Services, Inc. (AES), as Village Ecologist, has advised the Village on the general location of native woodland communities. In 2015 - 2016, the Village Ecologist conducted various types of inventories of the vegetation communities within the Village to map vegetation community boundaries, such as native woodlands (mesic savanna, northern flatwoods, mesic woodland, dry-mesic woodland, and floodplain forest), wet prairie and marsh complexes.
1. The Village Ecologist has prepared a report dated May 2016, summarizing these inventories, the historic and current ecological conditions of each vegetation community and to the extent possible, floristic quality of these areas, and developed a summary of recommended management tasks for managing the vegetation communities imperiled by various ecological and human induced factors (the "Natural Community and Green Infrastructure Report").
2. The Village has adopted voluntary ecological cost-share programs whereby the stewardship and management activities of residents in woodland areas are eligible to be partially reimbursed by the Village in furtherance of the recommended goals set forth described in the Natural Community and Green Infrastructure Report.
G. The Village caused multi-spectral aerial imaging of the entire Village to be performed on April 8, 2017, in accordance with technical specifications relied upon by restoration ecologists. The Village Ecologist applied such imaging to delineate the boundaries of native woodlands on parcels throughout the Village and to generate an individual woodland delineation parcel map for each parcel, each dated April 8, 2017, indicating the parcel acreage, woodland acreage, and percent woodland cover for such parcel (a "woodland delineation parcel map"). (Ord. 18-03-05, 3-6-2018)