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Tree Ordinance Guidelines
Ordinance
provisions for specific goals (Provisions 16-25)
Provisions from this category should be selected on the basis of whether
they are appropriate to your community and consistent with your management
goals. It is neither necessary nor desirable that every community adopt
each of these provisions. In assembling your ordinance, you should consider
those provisions that correspond to the specific goals you have established.
The goal-oriented provisions are numbered 15 through 37 in the table below.
Each of these provisions is related to one or more the nine management
goals discussed under Goals for Community Forest
Programs and can be accessed from the links on that page. Many of these
management goals are interrelated, so some provisions are referenced to
several different goals. Many of the basic provisions
(e.g., Provision 15, Designate
administrative responsibilities) are directly related to many of the
listed goals and should be included in most ordinances.
| Number |
Provision |
Goals |
| 16 |
Establish a tree
board or commission |
6,8 |
| 17 |
Specify
cooperation between departments and agencies |
6,7 |
| 18 |
Develop a comprehensive
management plan |
1,2,3,4,5,7 |
| 19 |
Resolution
of conflicts between trees and structures |
1,2,4 |
| 20 |
Exemption from
Solar Shade Control Act (California) |
1 |
|
21 |
Responsibilities
of property owners |
5 |
| 22 |
Help for
citizens performing tree maintenance |
2,8 |
| 23 |
Topping prohibited |
2 |
| 24 |
Permit
required for planting trees in the public right-of-way |
5 |
| 25 |
Planting requirements |
1,2,3,4,5 |
| 26 |
Situations
which are declared to be public nuisances |
2 |
| 27 |
Abatement
of hazards and public nuisances |
2 |
| 28 |
Licensing
of private tree care firms |
2 |
| 29 |
Harming public
trees forbidden |
2 |
| 30 |
Permit
required for activities that may damage city owned trees |
1,2,4,5 |
| 31 |
Permit
required for activities that may damage protected private trees |
1,2,4 |
| 32 |
Conservation
of forest and woodland resources during development |
1,3,4 |
| 33 |
Procedures
to be followed in resolving tree disputes |
9 |
| 34 |
Standards
for resolution of tree disputes |
9 |
| 35 |
Apportionment
of tree dispute resolution costs |
9 |
| 36 |
Recording
for notification of future owners |
9 |
| 37 |
Enforcement
of tree dispute resolutions |
9 |
16.
Establish a tree board or commission
Purpose: To establish a citizen advisory board, commission, or
committee.
Key elements:
Notes: Tree boards provide a means to involve the public in urban
forestry management. Tree boards can promote new and existing tree programs
by motivating both local government and the public to support urban forest
management. Typical functions of the tree board are described in provision
15 (Designate
administrative responsibilities), and will vary with the community.
Sometimes city staff members are included on the tree board.
| There is hereby created a City Tree Advisory
Board which shall consist of five members....The members shall be lay citizens
and others with established professional competence in a pertinent discipline,
and the following characteristics or attributes may serve as guidelines
in making appointments to the Board:
1. Members of the public interested in trees
as a major component of Carpinteria's physical and aesthetic environment.
2. Arborists, ornamental horticulturists, and
landscape architects and designers, or those with a technical background
in a related field. At least two members of the Board shall have such a
professional
background....
[Carpinteria, CA: City Code Section
12.28.080]
There shall be a beautification or tree commission in the city consisting
of 7 members, appointed by the mayor, subject to approval of the city
council. Their terms of office shall be 3 years and until their successors
are appointed and qualified... The members shall serve without compensation,
but all necessary expenses shall be paid by appropriate council action.
The city council may remove any appointed member
of said commission from office prior to the expiration of their term, with
or without cause by an affirmative vote of not less than three-fifths of
the members of the city council. Vacancies on the commission, ... , shall
be filled by appointment by the mayor, subject to approval of the city
council.
The commission shall hold regular meetings
at least once each month, and may hold such addition meetings as it deems
necessary. A majority of the commission shall constitute a quorum for the
purpose of transacting the business of the commission. The commission shall,
as soon as practical after the time of the annual appointment of a member
to the commission, elect a chairman, vice-chairman, and a secretary thereof...
The secretary of the commission shall keep
a record of all proceedings, resolutions, findings, determinations and
transactions of the commission, which records shall be a public record,
and a copy of which record shall be filed with the city clerk as clerk
of the city council...
[Burlingame, CA: City Code Chapter
3.28]
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17.
Specify cooperation between departments and agencies
Purpose: To require cooperation between municipal departments
in matters pertaining to tree resources.
Key elements:
- List of activities that require consultation between departments
- Responsibilities of municipal departments to coordinate activities
Notes: Urban trees are subjected to wide variety of potentially
damaging impacts from municipal departments, utility companies, and private
contractors. Maintenance of above- and below-ground utilities and other
infrastructure may lead to serious tree damage or tree death. Adverse impacts
can often be minimized or avoided but only if the the input of tree professionals
is obtained before damage is inflicted. The urban forester or tree program
manager should be given the responsibility and authority to require modifications
to various activities that may adversely impact city trees (see provision
15 - Designate
administrative responsibilities). Even if the tree program manager
has this authority, it may be helpful to include this additional provision
to explicitly require that departments, agencies, utilities, and others
communicate and cooperate with the community forest program when they conduct
operations that can affect trees.
| A. The Public Works Department shall notify
the Parks and Recreation Department of any applications for new curb, gutter,
sidewalks or driveway installations, or other improvements which might
require the removal of or cause injury to any street tree, or interfere
with the fulfillment of the street tree plan.
B. Any public utility maintaining any overhead
wires or underground pipes or conduits shall obtain permission from the
Director before performing any maintenance work on the wires, pipes, or
conduits which would cause injury to street trees. The public utility shall
in no way injure, deface, prune, or scar any street tree until their plans
and procedures have been approved by the Director...
[Modesto, CA: City Code Section
12-5.08]
In order to provide for coordination and the maximum feasible use of all
public lands, areas and funds, plans and specifications for city street
and public area planting proposed by the landscape supervisor shall be
submitted to the city engineer, traffic engineer, planning director, and
where appropriate, special district directors and managers, for their
recommendations, and such recommendations shall be made within thirty
days after receipt of such plans and specifications. To facilitate the
planting and maintenance of trees in new subdivisions, developments, streets
and public areas, the planning director shall advise and cooperate with
the landscape supervisor in carrying out the provisions of this chapter.
[Camarillo, CA: City Code 13.12.080]
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18.
Develop a comprehensive management plan
Purpose: To develop an integrated management plan for the urban
forest.
Key elements:
- Responsibility for developing and updating the comprehensive management plan
(if not defined in provision 15 -Designate
administrative responsibilities)
- Method by which the plan is to be adopted and revised
- List of elements to be included in the plan
Notes: The comprehensive tree management plan is the keystone of
any tree program, because it lays out the framework for tree management
in the community. Much of the work needed to develop the comprehensive
plan will already be completed if you have followed the process discussed
under Developing a Community Forest Management Strategy.
Throughout the entire management planning process, public input and public
education should be given high priority. Authority for developing and implementing
the plan should be assigned.
Some elements to be considered in the management plan include:
- inventory of existing trees;
- identification of planting sites;
- prioritized planting plan;
- standards for tree selection, siting, planting, and pruning;
- scheduled maintenance for new and established trees;
- inspection program for tree-related problems and hazards;
- guidelines for protecting existing trees from construction-related damage;
- integrated disease and pest management strategies;
- reforestation plans that allow for phased removal and replacement as trees
become a liability;
- plans for utilization of waste wood.
| Within three years of the adoption of this
Ordinance, the Director with the advice and participation of the Tree Board
shall adopt an Urban Forest Management Plan. The Division thereafter shall
use its best efforts to insure that activities of the Division are guided
by such plan. The plan shall incorporate the following elements:
(a) A clear, concise, and comprehensive Statement
of Policies and Objectives for urban forestry management in the City, which
statement is to be developed by the Director with the advice and participation
of the Tree Board through a process of at least three public hearings;
(b) A designation of proposed urban forestry
treatments for major traffic routes and districts within the City consistent
with the City's Master Plan, together with a program, schedule, and suggested
budget for implementing such treatments;
(c) An inventory of every street tree and any
other trees deemed necessary by the Division, which inventory shall include,
as appropriate, species, age, condition, maintenance records, names of
adjacent property owners, record of fees and fines, and any other information
necessary or usable in the long-range planning or day-to-day planting and
maintenance of the City's urban forest;
(d) A Street-Tree Renewal Plan, based on an
evaluation of species characteristics and performance as recorded in the
inventory, providing for rotational reforestation of diseased or declining
trees and break-up of potentially problematic monocultures;
(e) A set of Standards for the Division, and
the public for street-tree installation, landscape-tree installation, pruning
and maintenance, acceptable tree species and any other standards, criteria,
or administrative procedures deemed necessary to carry out the purposes
of this Ordinance and the Urban Forest Management Plan;
(f) A process for continual update and improvement
of the Urban Forest Management Plan elements.
[San Francisco, CA: Public Works Code Section
806]
Management program. In consultation
with the parks commission, planning commission and public works department,
the director of parks and recreation or his/her designee, shall develop
and implement a public tree policy consistent with other city regulations
designed to provide an orderly program of tree management. Such program
shall include all public property and rights-of-way including parks,
public greenbelts and other city-owned property except Lake Chaplain.
The development of such a program include the following objectives:
A. The setting of standards for the planting, maintenance, protection,
preservation, removal and replacement of existing trees;
B. Planning and planting of trees for future benefit of the citizens
of Everett;
C. Approval of all tree plantings, maintenance, and removal of trees
on city-owned property and rights-of-way; and
D. In the short term, no net loss of forest canopy cover on city-owned
public lands and right-of-way; in the long term, measurable gain.
[Everett, WA: City Code
Section 8.40.040]
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19.
Resolution of conflicts between trees and structures
Purpose: To set priorities for solving conflicts between trees
and street improvements.
Key elements:
- Priority of trees over street improvements (hardscape)
- Responsibility for approving corrective measures
Notes: Tree-related damage to street improvements is common in many
communities. Although tree roots are blamed for the cracking concrete and
invading sewer lines, it is equally valid to point out that these structures
fail because they have not been properly engineered to function in a landscape
that contains growing trees and their roots. Unfortunately, the approach
in too many cities has been to remove trees rather than to find a way to
redesign structures to be compatible with trees. This provision can be
used to establish the priority of trees over hardscape. Individual property
owners normally do not have the resources or expertise to develop satisfactory
solutions to tree- hardscape conflicts on their own. Therefore, the responsibility
for correcting conflicts between trees and street improvements should not
be assigned to the property owner. However, if the conflict results from
actions by a property owner which violate municipal tree planting standards,
the city may require the property owner to bear some or all of the cost
of corrective action.
A. When roots of a tree planted within the
planting area damage city curbs, gutters and sidewalks (including driveway
ramps), the city shall be responsible for appropriate corrective measures
which are least damaging to the tree.
[San Luis Obispo, CA: City
Code Section 12.24.150]
Where sidewalk or curb damage due to tree roots
occurs, every effort shall be made to correct the problem without removing
or damaging the tree. The city forester shall be responsible for developing
or approving corrective measures in consultation with the city engineer.
[Example code by the authors]
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20.
Exemption from Solar Shade Control Act (California)
Purpose: To exempt a local jurisdiction from the provisions of
the California Solar Shade Control Act.
Notes: The Solar Shade Control Act of 1979 (California Public
Resources Code Section 25980 et seq.) prohibits shading of solar collectors
that results from tree growth occurring after a solar collector is installed.
One problem with this law is that trees which are in place before a solar
collector is installed may come to be in violation through further growth.
Cities and counties may, by majority vote of the governing body, exempt
themselves from the provisions of the act.
| The city is exempt from the provisions of
Chapter 12 (commencing with Public Resources Code section 25980), Division
15 of the Public Resources Code which chapter is known as the Solar Shade
Control Act.
[Carmel-By-The-Sea, CA: City Code
12.28.050]
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21.
Responsibilities of property owners
Purpose: To set forth any responsibilities for maintenance of
trees, either public or private, assigned to property owners.
Key elements:
- Designation of responsible parties
- Assignment of responsibilities
- Performance standards for maintenance activities
Notes: In many communities, residents are responsible for some types
of tree maintenance, particularly for trees which extend over public rights-of-way.
In such cases, it is the responsibility of the municipal tree program to
provide information on the types of care to be provided and complete instructions
on proper methods. For example, if residents are responsible for tree trimming
to maintain clearance for pedestrian and vehicular traffic, standards for
clearances and information on proper pruning methods should be readily
available to residents. Even if standards are set and distributed, the
municipality may still have little control over the quality of maintenance
performed by residents. As an alternative, the municipality may simply
require residents to notify the tree program when problems occur, and have
work done by municipal crews or contractors. This allows for greater control
over the quality of tree maintenance.
| (a) It shall be the duty and responsibility
of all property owners to maintain the grounds of maintenance strips on
the owner's property, regardless of whether such property is developed.
This maintenance shall include watering as needed and keeping such strips
free from weeds or any obstructions contrary to public safety. Property
owners shall be responsible for watering mature city street trees whenever
landscaping of the property is changed in such a manner as to deprive the
tree of its normal source of moisture. Such watering shall be continued
during dry weather until the street tree becomes acclimated to the new
environment, but need not exceed three years. All watering requirements
shall be waived to the extent they are inconsistent with governmental restrictions
on water use.
(b) It shall be the duty and responsibility
of every person owning or occupying any real property within the City of
Sacramento, to keep all trees on that property trimmed in such a manner
that there is a clearance of at least fourteen feet above any street or
alley, and a clearance of at least seven feet over any sidewalk. It shall
also be the duty and responsibility of every person owning or occupying
any real property within the City of Sacramento to keep all trees on that
property trimmed in such a manner that they do not obstruct the view of
any traffic sign or device for vehicle traffic in the direction controlled
by that traffic sign or device.
[Sacramento, CA: City Code Section
45.5]
The owner or occupant of any corner lot or premises in the town shall
keep trees, hedges and growth at the corners of intersecting streets,
whether between the curb line and the private lot line, or within the
private lot or premises, so trimmed that the height of the same shall
not exceed three feet above the curb level for a distance of thirty feet
measured horizontally in any direction from the point of intersection
of the property lines at street corners; provided, that trees whose main
trunks are exposed to a height of seven and one-half feet above the curb
need not be so trimmed or cut.
[Los Gatos, CA: Town Code Section
31-15]
The duty is imposed upon a property owner to notify the parks and recreation
department when any tree, palm, shrub or plant in a public street adjacent
to his property is injuring or damaging any public sidewalk...
[Carlsbad, CA: City Code Section
11.12.120]
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22.
Help for citizens performing tree maintenance
Purpose: To assist citizens in meeting requirements mandated
by the local government.
Key elements:
- Types of assistance to be provided
- Method of applying and qualifying for assistance
- Authority charged with granting assistance
Notes: Some street tree ordinances contain a provision which allows
the city to assist citizens with street tree maintenance, if the citizen
reimburses the city for the work it performs. The following example is
typical of such provisions.
| ...On application of any person to whom there
has been issued a permit to trim, prune or remove a tree from a City right-of-way,
the City Engineer may trim, prune or remove such tree described in such
permit provided the cost thereof is paid by the permittee and provided
there shall first be deposited with the City Engineer a sum determined
to be the estimated cost of such work. All such deposits shall be placed
in a trust fund. Following completion of the work the City Engineer shall
determine the actual cost of the work and transfer that portion of the
deposit to the appropriate City fund and return the balance to the depositor.
Should the original deposit be insufficient to cover the actual cost of
the work the permittee shall be liable to the City for the unpaid balance
and shall promptly pay such amount to the City upon demand of the City
Engineer.
[San Carlos, CA: City Code Section
6504]
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The City of Visalia, California, tree ordinance authorizes the Director
to require that citizens hire a professional to trim their oak trees. To
offset this burden, the city provides financial assistance to help low
income residents hire professional tree trimmers. The ordinance creates
a special "Oak Maintenance Fund" to finance the assistance program. The
fund derives its income from fines and penalties assessed for violations
of the tree ordinance.
If the Director determines that a property
owner who has submitted a Notice of Intent to Prune an Oak Tree, cannot
properly prune his or her Oak Tree without the assistance of a professional
tree trimmer, and that said property owner cannot afford to hire a professional
tree trimmer because he or she does not have the financial resources to
pay for such services, the Director may provide financial assistance to
said property owner for the purpose of pruning the tree or trees, if the
following conditions are met:
(a) The property owner uses the property where
the tree(s) are located as his or her principal place of residence;
(b) The aggregate gross income of all persons
eighteen (18) years of age or older residing on the property does not exceed
the minimum amount as may be set from time to time, by resolution of the
City Council, pursuant to this subdivision; and
(c) The Director determines that it is necessary
to prune the tree to remove hazardous conditions, remove disease, rot,
pests, other harmful conditions, or promote healthy growth of the tree(s).
Such financial assistance shall include, but not
be limited to, low interest loans, work done by the City with the cost
borne in part or in whole by the property owner, work done by the City
with the cost borne by the City to be repaid by the property owner upon
such terms as the City and property owner shall agree, or any combination
thereof.
[Visalia, CA: Ordinance Code Section
2349]
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23. Topping prohibited
Purpose: To prohibit the practice of topping and/or other especially
destructive maintenance practices in public and private trees.
Key elements:
- Definition of topping and other prohibited practices, if not included in
provision 4 (Definitions)
- Classes of trees covered by the provision
Notes: A community's investment in its tree resources, which are accrued
over many years, can be rapidly squandered through poor tree maintenance practices
even if the trees are not actually removed. Poor pruning practices such as topping
(aka hat-racking, stubbing, dehorning), i.e., cutting back large diameter branches
of a mature tree to stubs, are particularly damaging. The excessive removal of
canopy associated with topping is often stressful to mature trees, and may result
in reduced vigor, decline, or even death of the tree. In addition, new branches
that form below the cuts are only weakly attached to the tree, and are in danger
of splitting out. Topped trees require constant maintenance to prevent this from
happening, and it is often impossible to restore the structure of the tree crown
after topping. Unfortunately, many people believe that topping is a proper way
to prune a tree, and this destructive practice is very prevalent in some communities.
In such cases, a vigorous program of public education should be pursued in combination
with the ordinance.
Ordinances that restrict topping may apply to public trees only, or
may extend to all trees, both public and private, within the community.
For example, the City of San Juan Capistrano, California, has detailed
regulations regarding topping. The regulations define topping (as "severe
trimming"), prohibit it in certain zoning districts, and describe the type
of pruning which is to occur.
Rather than including detailed specifications in the ordinance itself,
we recommend that the ordinance authorize the preparation, adoption, and
enforcement of tree pruning standards by the tree program manager (see
provisions 15 - Designate
administrative responsibilities and 18 - Develop
a comprehensive management plan). This allows for greater flexibility
and easier updating of the standards when necessary.
| ..."Severely trimmed" shall mean the cutting
of the branches and/or trunk of a tree in a manner which will substantially
reduce the overall size of the tree area so as to destroy the existing
symmetrical appearance or natural shape of the tree in a manner which results
in the removal of main lateral branches leaving the trunk of the tree in
a stub appearances as shown is Exhibits A and B... ...No property owner
or his agent in the Tourist Commercial, ... or any residential zoning district
located within 500 ft of a scenic highway or drive ... shall cause any
tree on his property to be severely trimmed ... ...The following standards
identify trimming methods which will give maximum benefits to both trees
and people:...
[San Juan Capistrano, CA: City
Code Section 9-3.625]
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The following example includes selections from a portion of an
ordinance that restricts topping ("hatracking") and several other
destructive practices under the general term "tree abuse". The code
includes specific definitions of what practices are and aren't prohibited, a
mechanism for waivers and appropriate penalties, which include remedial maintenance
or, if necessary, replacement (see also provision
11).
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(a)Declaration of intent. The city commission
(city) finds and declares that regulation of the cutting, trimming,
and pruning of trees within the city will help ensure that the health,
function and value of trees are protected, and will help to prevent
dangerous branching conditions that may result in danger or injury to
citizens or property...
(a.3) Tree abuse means:
a. To hatrack a tree; or ..,
c. Cutting upon a tree which destroys its natural habit of growth [as
defined herein]; or
d. Pruning that leaves stubs or
results in a flush cut; or splitting of limb ends; or ...
f. The use of climbing spikes, nails, or hooks, except for the purpose
of total tree removal or as specifically permitted by the American National
Standards Institute; or ...
(5) Violator means a person who abuses a tree
or otherwise violates this section. The owner of property upon which
the abused tree is located shall also be deemed a violator if the tree
abuse is undertaken by the owner's employee, agent or person under the
owner's control...
(b.1) No person shall abuse a tree unless
one (1) of the following exemptions applies:
a. The abuse is necessary to alleviate a dangerous condition posing
an imminent threat to the public or property,
b. Franchised utilities may obtain a permit form the city, renewable
on an annual basis, authorizing the pruning of trees in a manner that
may be defined herein as tree abuse provided such pruning is necessary
to prevent service interruptions.
(b2) Any person may apply to the planning
and development department for an administrative waiver from the terms
of this section, provided that:
a. The application is made before any actions for which a waiver is
sought have been undertaken;
b. Any alleged hardship is not self created by any person having any
interest in the property. A hardship shall not be considered self created
if the subject tree was installed prior to the effective date of this
section;
c. There are unique and special circumstances or conditions applying
to the subject tree or the property upon which it is located, that do
not apply generally to other trees or properties.
d. The waiver proposed is the minimum variance necessary to alleviate
the hardship.
e. That the granting of the waiver will be in harmony with the general
intent and purposes of this section and will not create a dangerous
condition that threatens the public or property.
[Sunrise, FL: City Code Section
16-173]
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While it is probably impossible to construct a concise list of all the ways
that trees may be damaged, restricting the most common damaging practices
may be of value if combined with an ongoing campaign of public education on
proper tree care practices. Another approach to improving tree care, targeted
at individuals and firms that perform tree work for hire, is discussed under
provision 28 - Licensing
of private tree care firms.
24.
Permit required for planting trees in the public right-of-way
Purpose: To ensure that street tree selection and placement conforms
with municipal standards.
Key elements:
- Permit process for planting in the public right-of-way
- Prohibition of planting in conflict with established standards
- Remedies to be applied in case of violation
Notes: In order to avoid future maintenance problems, conflicts
with overhead utilities, and potential sidewalk damage, local governments
usually reserve the right to control plantings in the public right-of-way.
The tree program manager should be given authority over such plantings
in provision 15 (Designate
administrative responsibilities ). Acceptable tree species and planting
specifications should be described in the comprehensive urban forest management
plan (see provision
18).
| No person shall plant any street tree except
according to policies, regulations and specifications established pursuant
to this chapter...
[San Luis Obispo, CA: City Code
Section 12.24.130 F.]
All trees planted in the public street or sidewalk area
and all tree planting required by this code shall be located and planted
under the supervision of the city forester, who shall supervise such planting
and locating. In the performance of such work, consideration shall be
given to the following factors; provided, that setbacks permit and considerations
of safety do not interfere. These factors are determined to be of primary
importance in maintaining the city forest.
A. Trees that must be removed shall be replaced
by new planting, except in unusual circumstances.
B. Wherever feasible, trees shall be planted
near old and dying ones in anticipation of their removal.
C. Unnatural regularity of spacing and arrangement
shall be avoided; staggered, or irregular locations or a simulated forest
arrangement being preferred.
D. Species selected may vary, depending on
location; however, the preference of native species is urged; the Monterey
pine is to be perpetuated as our dominant forest tree within the city.
E. The coordinating of tree planting on public
ways with landscaping on private property so as at achieve the above purposes
is deemed desirable.
[Carmel-By-The-Sea, CA: City Code
Section 12.28.230]
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Although some ordinances require removal of any tree planted without a
permit, it may be preferable to require removal of only those trees that
do not conform with standards. Some jurisdictions will allow nonconforming
trees to remain, but require the property owner to accept all financial
responsibility for tree maintenance and damage that may be caused by the
tree.
| Whenever any tree is planted or set out in
conflict with the provisions of the Article, it shall be lawful for the
Parks Superintendent to remove or cause removal of the same. The cost of
removal of such tree may be charged to the property owner responsible for
the planting thereof.
[San Buenaventura, CA: City Code
Section 8421.2]
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If one of your goals is to encourage tree planting, the permit process
for planting should be as simple as possible, and no permit fee should
be charged. We highly recommend a program to educate the public on appropriate
tree selection and siting for local conditions to complement this provision.
It is more productive to spend time and effort encouraging proper tree
selection and planting than removing offending trees.
25. Planting
requirements
Purpose: To ensure appropriate tree planting in new developments, including
parking lots.
Key elements:
- Performance standards for tree planting and maintenance during establishment
- Designation of responsibility for planting and maintenance
- Protocol to ensure that planting complies with the comprehensive management
plan (see provision
18) or other standards
- a mechanism to provide for monitoring of tree establishment unless specifically
addressed elsewhere (e.g., provision
13)
Notes: Some communities include tree planting requirements in a separate
landscape ordinance, or in the zoning code under various development standards.
However, in many cases, tree planting requirements are appropriately placed
in the tree ordinance or at minimum should be cross-referenced in the tree ordinance.
It is very important that basic performance standards be set in this provision.
The provision can specify minimum tree densities (e.g., numbers of trees per
street mile) or canopy standards (e.g., amount of canopy cover or shading to
be provided within a set period of years). The tree program manager should then
be given the latitude to develop appropriate implementation standards and approve
specific plans.
Responsibility for planting and maintenance varies by community. If developers
do not perform the actual planting, they are normally required to pay in-lieu
fees and tree planting is handled by the local government.
The building permit approval process is frequently used to ensure compliance
with tree planting regulations. Communities may withhold occupancy permits
until trees have been satisfactorily installed, and require performance
bonds to ensure establishment. Performance bonding should be for at least
three years to guarantee good long-term survival. Furthermore, unacceptable
tree growth or condition, as well as actual tree death, should be grounds
for bond forfeiture. Trees that are of poor quality when planted or are
maintained poorly may not actually die within three years, but their future
survival and performance may still be unacceptable.
| No subdivision shall be approved unless it
is found to include planting of official, approved street trees within
the adjacent parkways in conformity with the Street Tree Management Plan
and under the Director's supervision...
In-lieu fees, which are established by resolution
of the City Council, may be deposited by the developer or applicant upon
the recommendation of the Director. In cases when a subdivision is being
approved, and the building process may be over a prolonged period of time,
in-lieu fees may be required...
In the event a subdivider desires to plant
trees within the parkway adjacent to a new subdivision, he may apply to
the Director for a permit. Such permit may be issued by the Director only
after the subdivider has posted a a bond pursuant to Chapter 2.17 of this
Code, guaranteeing the planting of all street trees, and paid the estimated
cost of all irrigation and maintenance for a three-year period. All such
planting shall be done in accordance with the Street Tree Master Plan,
as shall any necessary replanting which would be required should any of
the planted trees die within [or be deemed unacceptable by the Director
at the end of] the three- year period.
The costs of planting and the first three years
of maintenance, including irrigation, of all street trees in a new subdivision,
shall be borne by the subdivider. The Director shall determine the cost
involved for each subdivision, which shall be paid to the City prior to
City Council approval of the final map of the subdivision. The Director
shall plant, maintain, and irrigate such trees at such times and places
as the development of the subdivision, its occupants, and other conditions
make feasible.
[Carpinteria, CA: City Code Section
12.28.160]
B. Before planting, all street trees must be inspected
and approved by the city arborist or his designee...
F. So the city arborist can determine the tree
requirements for site development, any subdivider or developer shall submit
to the city a plot plan of the proposed subdivision which shall:
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Parking lot
shading provisions
Especially in warm climates, unshaded parking lots become extremely
hot, contributing to both the urban heat island effect and increased air pollution
through enhanced volatilization of reactive hydrocarbons from parked vehicles
(Scott et al 1999; Center
for Urban Forest Research 2001a). Hence, many communities require that
newly constructed or reconstructed parking lots be shaded by incorporating
tree plantings into the parking lot design. Requirements for tree planting
in parking lots are sometimes enacted though a specific parking lot shading
ordinance, but the code may be incorporated into the city code related to
trees, landscaping, parking lots, or elsewhere.
Key elements:
- basic performance standards related to the amount of shade or tree planting
required. The most common types of standards include:
- shading standards based on the amount of shade to be provided by trees
after a set period of time, such as 50% of pavement shaded in fifteen
years.
- minimum distances from any parking stall to a tree,
- tree to parking stall ratios
- minimum landscaped area as a percent of paved area in conjunction with
tree density standards in the landscaped area.
- methods used to calculate tree shading and determine the amount of shaded
and nonshaded area to be counted in calculations or assess tree planting ratios
provided on parking lot plans
- person or body responsible for determining that a plan complies with the
standards
- a mechanism to provide for periodic monitoring of parking lots to assure
that tree maintenance is adequate and that standards are met
Based on their analysis the Center
for Urban Forest Research (2001b) notes several additional factors that
should be considered when developing parking lot tree shade ordinances. These
include:
-
provisions to deal with the common conflicts between
parking lot trees and business signage and parking area lighting
-
refining calculations for tree shade provided in the
plan to include only partial credit for trees that are located on the
periphery of the lot because only a portion of the canopies of these "edge"
trees actually shades pavement
-
requirement that removed trees be replaced according
to a replacement schedule based on equivalent size or value
-
funding compliance monitoring through fees paid at the
time of construction.
As discussed under the special topic Evaluating
parking lot shading, the success of parking lot tree shade provisions
depends on good implementing regulations or guidelines. The Center
of Urban Forest Research (2001b) suggests guidelines for tree planter
size, irrigation, and planting methods to ensure good tree growth. Local empirical
data on tree growth in parking lots is needed to develop realistic estimates
of tree canopy cover after various time intervals. Technical information and
specifications, such as lists of tree species and their respective canopy
spread after a set number of years, examples of shade calculations, and construction
details, are needed to implement this and other planting provisions. However,
these technical details are better placed in accompanying guidelines and regulations.
Inserting such technical details into the ordinance code not only clutters
it unduly, but can interfere with routine updating needed to keep specifications
up to date.
Finally, even with monitoring, the ordinance must provide for
enforcement of the provision, either as part of the provision or under a synoptic
enforcement provision (provision 12).
Enforcement is somewhat problematic because the party that submits the original
planting plan is typically not the eventual owner of the parking lot, and
ownership of the lot may change periodically. Hence, one enforcement method
(e.g., withholding of occupancy permits) may be appropriate for the planning
stage whereas another enforcement method (e.g., fines, abatement orders) may
be appropriate for the long-term maintenance of required plantings.
At least 50% of the paved area surface [of
parking areas] shall be shaded by tree canopies within 15 years of acquisition
of building permits. Trees to be planted to develop such a canopy shall
be in accordance with the City's Master Street Tree Plan and the requirements
of the Director of Parks and Trees. Plans submitted to the Development
Review Board shall show the estimated tree canopies after 15 years of
growth, the specific names, sizes and locations of trees to be planted,
and the total area in square feet of the area shaded by tree canopies.
In determining the area shaded, the following methodology shall be used:
- i. Measure the shaded area on the pavement
assuming that the shaded area is only that area directly under the
tree canopy or dripline.
- ii. Landscape planters under the canopy
may be counted as shaded area.
- iii. Paved areas shaded by structures
(such as second stories of buildings, carports) may be deducted
from the total paved area.
[Oroville, CA: City Code Section 26-49.k.10)
Tree Shading. Trees shall
be planted and maintained throughout the surface parking lot to
ensure that, within fifteen (15) years after establishment of the
parking lot, at least fifty (50) percent of the parking area will
be shaded.
1. Surface Parking Lot. Except
as provided below, all surfacing on which a vehicle can drive is
subject to shade calculation, including all parking stalls; all
drives within the property, regardless of length, and including
drive-through lanes; and all maneuvering area, regardless of depth.
The following surfaced areas are exempt from this shade requirement:
(i) truck loading area in front of overhead doors; (ii) truck maneuvering
and parking areas unconnected to and exclusive of any vehicle parking;
(iii) surfaced areas not to be used for vehicle parking, driving
or maneuvering, provided they are made inaccessible to vehicles
by a barrier such as bollards or fencing; (iv) automobile dealerships,
display/sales/service/vehicle storage areas (required parking for
auto dealerships is still subject to shading); and (v) existing
surfaced areas.
2. Shading. Shading should
be calculated by using the diameter of the tree crown at fifteen
(15) years. Each planting area shall be of adequate size for the
landscaping approved and shall have adequate irrigation for that
landscaping. All landscaping (trees, shrubs, and turf) in these
planting areas shall be properly maintained. The city landscape
architect shall establish a list of species appropriate for providing
shade in parking lots, and shall review site plans of each parking
lot to determine whether or not the lot complies with this chapter.
Trees planted in order to comply with the regulations of the chapter
shall be selected from the list prepared by the landscape architect.
The city landscape architect shall have the discretion to modify
tree shading requirements under power lines and other obstructions
which prohibit strict compliance with shading requirements, and
to give shading credit for photovoltaic arrays, off-site trees and
structures, sidewalk canopies, and other structures, where appropriate.
[Sacramento, CA: City Code
Section 17.64.030.H.]
(d) Interior parking areas
shall be landscaped in addition to the required landscaped strip.
Trees must be provided in each parking lot at a minimum average
density of one (1) shade tree (three inch caliper minimum) for each
fifteen (15) parking spaces provided, or any fraction thereof. In
the case of mini warehouses, such parking spaces shall be determined
by the number of parallel parking spaces contained in the required
loading and unloading lanes. Additionally, interior parking lot
landscaping shall be provided in accordance with the following table...
|
Total Parking
Area
|
Interior Landscape
Area
|
|
0 - 24,999 square
feet
|
5%
|
|
25,000 - 49,999
square feet
|
8%
|
|
50,000 square feet
and larger
|
10%
|
(e) Except for customer and
employee parking, parking lot landscape requirements do not apply
to storage or standing parking spaces incidental to uses, such as
sales and rental of motor vehicles, mobile homes, boats, trailers
or other similar uses.
(f) To calculate the total
parking area and the subsequent percentage of required interior
lot landscaping, total the square footage of parking spaces, planting
islands, curbed areas and all interior driveways and aisles except
those with no parking spaces located on either side. Landscaped
areas located outside the parking lot may not be used to meet the
interior landscaping requirement.
(g) The required landscaping
for parking lots shall be more or less evenly distributed throughout
the parking lot, although adjustments may be approved by the Community
Development Department where the shape or size of the parking lot,
the location of existing trees or other natural constraints reasonably
prevent such distribution.
(h) All landscaped areas,
including the permeable areas and drip lines around trees and planting
beds used for visual screening which abut any parking lot or vehicular
travel area, shall be protected with curbs, parking blocks or similar
barriers sufficient to protect them from vehicular intrusion.
(i) An automatic irrigation
system is required for all landscaping. Water conservation is encouraged.
[Lewisville, TX General Development
Ordinance Sec 6-103]
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What levels of parking lot shading are realistic to include
in a parking lot shading provision? The answer depends not only on the eventual
size that trees will attain under parking lot growing conditions but on
the amount of space set aside as growing space for trees. We used Peper
et al's empirical crown projection data numbers to calculate how much
of the interior paved area of a parking lot would need to be set aside for
trees in order to reach a 50% pavement shading goal after 15 years. We made
the following assumptions in these calculations;
-
Landscaping consists of shade trees individually planted
in 6 foot by 8 foot planter islands located within the parking lot (i.e.,
all of the trees' canopy is over the parking lot).
-
The shade trees used reached an average crown diameter
of 21 ft after 15 years (according to Peper
et al, this is the average size of London plane trees in Sacramento,
CA, parking lots after 15 years).
-
Planting islands are configured so that there is no
overlapping shade from adjacent trees
-
All planted trees survive and trees are not topped
or otherwise pruned to reduce tree canopy development
-
Canopy over the planters counts toward the 50% shading
requirement even though planters are not actually paved areas.
|
Percent of interior paved area occupied
by 6 ft by 8 ft planters (1 tree/planter)
|
Projected parking lot shading after 15
years (average crown diameter= 21 ft)
|
|
5% of paved area
|
35%
|
|
7% of paved area
|
49%
|
|
10% of paved area
|
70%
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If we assume that trees are also planted at the edge of the
parking lot to provide at least partial shading, less than 7% of the parking
lot are would need to be devoted to tree planters to reach 50% shading in 15
years, again assuming that fast-growing trees with relatively large crowns are
used. If tree crown diameter is only a bit smaller after 15 years (17.5 ft),
a full 10% of the paved area will be required for tree planters to attain 50%
canopy. Good data on actual sizes trees attained in parking lots under local
growing conditions are essential for developing planting specifications that
will result in desired levels of canopy cover. Further information and technical
considerations related to parking lots and shade trees can be found at Center
for Urban Forest Research website at http://wcufre.ucdavis.edu/parkordinances.htm.
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