Phillip Rodbell and Tom Perry
1 0 March, 1988
Intent
To establish procedures and practices which will govern the removal,
protection, installation, and long-term management of trees, soils,
vegetation, wildlife and other landscape elements within the planning jurisdiction
of Chapel Hill.
Land development is a complex and often hectic series of events. The changes that take place in the existing land contours and the ecology of a development site are considerable. The scraping and compacting that commonly occurs during construction destroys the absorption and life-sustaining capabilities of the soil. The resulting "non-soil" will erode, undermine concrete, clog drainage systems and associated trees and other plants will decline in health and die. Chapel Hill will inherit the problem; the taxpayer will pay the price. In order to minimize this disturbance, a complete site analysis should be done early in the concept stages of the design process.
The Town cannot force a developer to design with nature, however, through the development review process it can direct a developer to incorporate certain protective, corrective and maintenance measures into the design in order to protect the health, safety and welfare of its citizens. These measures should be incorporated into the site development plan and directed toward the stabilization and management of soil, trees and other natural resources. If the plan is not adhered to, the certificate of occupancy may be withheld until the developer replaces or enhances resulting "non-soil" and dead or dying trees and other plants. Further, the certificate should be revoked at any time during the life of the project if the developer does not maintain plants in a vigorous and healthy state.
A videotaped
TREE PROTECTION SEMINAR should be given to developers, architects,
builders and contractors, and town employees involved in the development
process. The Developer must acquire a certificate of completion before
acceptance of a development application by the Town. The seminar
should focus on practical methods of soil and plant management before during
and after construction, project evaluation, timing, maintenance requirements
and landscape budgeting, and a detailed session on developing a low maintenance
Tree Protection plan.
Overview of Tree Protection Ordinance.
Continued: - 2
THE TREE PROTECTION PLAN should consist of existing and proposed landscape elements including:
1. Their location, species, and size;
2. Identification and specific location of specimen trees;
3. The location, grade and dimensions of planting areas, street lawns, vehicular surface areas and buffers;
4. The location and description of barriers to be erected to protect trees and soils from damage both during and after construction as now required;
5. Provisions for temporary irrigation and drainage, soil enhancement
and stabilization, plant protection, maintenance access and construction
worker areas, and storage areas for topsoils and transplanted landscape
elements;
1
6. All existing or proposed land uses adjoining or adjacent to the
site;
7. A description of a proposed schedule of maintenance activities (now required in a maintenance plan) for soils and trees including thinning and replacement for the life of the design:
8. A zoning compliance permit should not be granted until the resource management plan is approved and an individual is assigned by the developer to assure that the plan is honored.
A
qualified individual, preferably a member of Town Staff, must
review the Tree Protection plans as they effect soil structure, trees
and other natural resources. The plans must be examined for pre-
and post-construction measures for tree preservation, landscape maintenance
requirements and proposed landscape budgeting. The individual on
Staff (an Urban Forester) must also act as Inspector and visit the site
to assure that the contractor conforms to the approved plan. The
urban forester will develop standards or guidelines which developers must
follow in order to conform with this ordinance.
Overview of Tree Protection Ordinance.
Continued: - 3 -
Draft Provisions
The following administrative provisions will prescribe specific site development
and maintenance practices that should be incorporated into the town's
development review system:
1.0 PRE-CONSTRUCTION:
1.1 Roads, utilities and structural layout shall be designed to minimize soil displacement and take advantage of natural drainage patterns. As a minimum distance, trenching should be kept outside the dripline (perimeter of crown) of trees to be saved. Where possible, several utilities should be placed in one trench, preferably below driveways, etc., in order to minimize damage resulting from several trenches crisscrossing the root zone. If this is not feasible, the developer will enhance soils to a depth of 16 inches, provide for water and drainage, and replace all harmed trees and other plants before a certificate of occupancy is issued.
1.2 When developing dense forestland, the forest shall be thinned to remove hazardous, damaged, and insect or disease infested trees; favor young and vigorous trees; strive for diversity. Native shrubs can be as valuable as trees and also deserve protection.
1.3 Guidelines should be developed for the installation of protective fences, and temporary drainage and irrigation for trees and other plants to be preserved. The Developer must establish transplant and holding areas for valuable native shrubs and topsoils, and a place to hold construction spoil. Construction limits must be established by ordinance as well as material storage areas and parking facilities for workmen, construction trailer and port-a-johns.
1.4 When a natural buffer or tree is to be preserved, its habitat shall
be clearly delineated and the developer shall designate an individual,
answerable to the inspector and supervisor during construction, who will
assure that the contractor honors all barriers. If this is not feasible
or neglect is evident, a stop work order will be issued andpenalties
or terms of compensation determined (by ordinance) before construction
is resumed.
Overview of Tree Protection Ordinance. Continued: - 4
1.5 If it is necessary to compact soil or significantly damage tree root systems, the tree shall be removed, or given extra water and special care (defined by ordinance), to prevent susceptibility to attack by insects and plant diseases.
1.6 Avoid grade changes or undermining root systems; soil compaction should be kept to a minimum. These could be tied to existing grading ordinances.
1.7 Design should include provisions for minimizing damage to roots and providing for sufficient space for root growth. Guidelines should be developed for enclosing tree trunks within roof lines or decking, or for the encasement or burial of tree roots.
1.8 When designing the placement of leach lines and septic tanks, consider the effects of root severance, soil saturation and salt accumulation on nearby trees and down-slope vegetation.
1.9 All contractors and subcontractors must acquire a certificate of completion of the Resource Protection Seminar before working on the site.
2.0 CONSTRUCTION:
2.1 A zoning compliance permit shall not be issued until the Tree Protection Plan is approved.
2.2 Avoid back-filling or undermining root systems; soil compaction should be kept to a minimum. Build retaining walls where grades have been lowered around trees to minimize future erosion in the root zone of remaining trees. Standards or guidelines need to be developed for all of the above.
2.3 Guidelines need to be established for the disposal of material (excess cement, paint cans, plastic, etc.). Trees and other plants must be considered when establishing a waste water management program; excess water from washing cement and cleaning brickwork is toxic to plants.
2.4 If limbing becomes necessary, do not remove more than one half of
the live crown of trees and if possible do the work prior to construction.
Overview of Tree Protection Ordinance. Continued: - 5 -
2.5 The "instant landscape" for opening ceremonies should be avoided; too many dead or non-functional plants result from installation during the summer months. Perennial landscapes shall be installed in the proper season. Sensible alternatives should be negotiated with the Town; a certificate of occupancy shall not be issued before: a) the proper installation of all required materials; b) a landscape maintenance association is established; or c) a triple bond is established for later plantings; etc.
3.0 POST-CONSTRUCTION:
3.1 Guidelines must be developed for the provision of extra water, fertilizer, insect and disease control for plant materials during two growing seasons. Injured trees must be pruned and stumps poisoned.
3.2 Favorable soil conditions must be established in areas of disturbance. Guidelines must be developed for soil enhancement.
3.3 Adequate root space must be provided and intensive horticultural practices avoided under the drip line of established trees. Avoid the establishment of dense grass, or ground covers which compete for oxygen and other resources vital to the tree. Use bark chips or other mulches.
3.4 For long-lived and low maintenance landscape elements use native trees or trees of proven performance in the Chapel Hill Region (seed sources should be genetically adapted to the soils and climate of the region). Exotic trees and shrubs selected for special effects in the landscape are often short-lived and require special care. When exotics are used, the landscape plan should include specific plans for their maintenance. Guidelines must be developed for the selection of landscape materials. All landscaping shall be inspected before a Certificate of Occupancy is issued.
3.5 Remove temporary fences and irrigations systems. Plan for
growth and maintenance of plants.
Overview of Tree Protection Ordinance.
Continued: - 6
Recommendations for Tree Protection
General
A successful
Tree Protection Program must consist of the following four elements:
1 . A Resource Inventory;
2. A Street Tree Plan;
3. A Tree Protection Ordinance;
4. Sufficient resources to do the job.
--support by concerned citizens and the development community is as
vital a resource as adequate funds and manpower provided through the Town
Government. A program of education will be an essential part of the
Tree Protection program.
THE
RESOURCE INVENTORY is a computerized resource management system in
which trees are a major element; open space, soils, shrubs, wildlife
habitat and recreation potential should also be part of the inventory.
Data regarding the location, species, age, size, condition and maintenance
requirements of each tree owned by the city or encroaching upon rights-of-way
will be kept current in the data base, , data regarding the location of
each property owned or maintained by the city and each property ripe for
development is also recorded. This information is used to prepare
longrange development and maintenance plans and to determine requirements
for equipment, materials and monies.
THE STREET TREE PLAN is a written document defining the planting, pruning
and removal policies of the Town. It will include specifications
to assure that the right tree is planted in the appropriate site.
Included here is an inventory of potential planting spaces (including soil
conditions) along streets or within "entry-way" areas in the town, a species
specific planting and pruning schedule, and cost predictions for a continuing
program of street tree management.
Overview of Tree Protection Ordinance.
Continued: - 7 -
THE TREE PROTECTION ORDINANCE will be designed to regulate the effects of development activities on trees, soils, vegetation and wildlife. The Ordinance customarily establishes:
1. Permits for the private planting and removal of trees on city rights-of-way, and any penalties relating to the above;
2. Standards for the protection, maintenance and preservation of trees on public properties and developing lands;
3. A Resource or Tree commission to lobby for funds, provide for citizen involvement, organize community groups and events, and educate the public as to the need to protect and preserve the natural resources of the town.
4. An Administrator
who issues permits and reviews development plans.
RESOURCES would include staff, facilities, equipment, vehicles and a
budget for plant materials, landscape designs, contract work and
community education. All these needs should be spelled out in
the Street Tree Plan.
Overview of Tree Protection Ordinance.
Continued: - 8
Specific
A
Resource Manager (Urban Forester) on the planning staff should be responsible
for site plan review and follow-up while also developing the Street Tree
Plan. The Ordinance and the required budget requests should be managed
by the Public Works Director of the Town. However, the implementation
of the Street Tree Plan, Inventory and permit inspections and approval
should be accomplished by an Arborist on the Public Works Staff, who will
work with the Urban Forester in the Planning Department. The Arborist
will have counterparts in Duke Power, OWASA and other utility companies,
and will provide technical assistance to the Park and Recreation Department.
Position of Arborist will be a "field position" under the General Services
Division of Public Works; if two positions are not desirable, the Arborist's
duties may be handled by some other department (after special training
of the personnel involved).
TREE
WORK PERMITS allowing private citizens to plant, remove, or maintain
trees in the public rights-of-way should be established by Ordinance.
The Public Works Department will be able to use the Tree Work Permits to
control species selection, location, planting, removal and severe pruning
of trees on the town rights-of-way. Allowing adjoining property owners
to maintain trees via Permit will save the Town manpower and funds for
other projects. Utility companies should also be required to apply
for a blanket or yearly permit or a system should be developed whereby
Public Works is aware of activities by franchised companies.
The Ordinance will establish legal authority for the town to prune or remove trees on public or private property. The cost will be billed to the adjoining resident when such trees are a hazard to public safety and when adequate opportunity for appeal is provided. The permits will further establish that trees planted by citizens will be maintained by citizens or the cost will be billed to them. All fees collected through the permit process may be considered tax-deductible contributions to the town with all monies applied toward the purchase of plant materials.
The Ordinance will require developers to attend a Tree Protection Seminar
and submit a Tree Protection Plan before a Zoning Compliance Permit is
issued. The Developer will further be required to assign an individual
on site to assure that barriers are maintained and the Plan adhered to;
a stop work order will be issued at any point of unauthorized departure
from the Plan and a system
of fines will be developed to cover costs of soil enhancement and tree
replacement, if "damage" (soil compaction, root severance, decline in vigor,
etc.) occurs.
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