Tree Program

street lined with trees

Unincorporated Alameda County has approximately 280,168 acres in which substantial portions were and are covered by native, indigenous and historical trees. The County recognizes that the preservation of these trees and our urban forest enhances the natural scenic beauty, sustains the long term potential increase in property values, which encourages quality development, maintains the ecology, moderates the effect of extreme temperatures, prevents the erosion of topsoil, helps create an identity and quality, which enhances the attractiveness of the County to visitors and increases the oxygen output of the area which is needed to combat air pollution. For these reasons the Alameda County Board of Supervisors finds that in order to promote the public health, safety and general welfare of the County while at the same time recognizing individual rights to develop and maintain private property in a manner which will not be prejudicial to the public interest it is necessary to enact regulations controlling the planting, pruning and removal in order to preserve trees within the County right-of-way.

Alameda County Permit Portal: Your one-stop-shop for permits.

(click here for Alameda County Tree Ordinance)

The Alameda County Board of Supervisors recognized the need for tree preservation and adopted the Alameda County Pilot Tree Policy in April of 2000. By May 2002 the need for a Tree Ordinance became apparent and the Alameda County Tree Ordinance was adopted. After a year of implementation, problems were identified and changes to the Ordinance were necessary. In September 2003 the Alameda County Board of Supervisors adopted the revisions to the Alameda County Tree Ordinance.

The Tree Ordinance is the County's primary regulatory tool to provide for orderly protection and preservation of all street trees located within the County right-of-way. Enforcement of the Tree Ordinance promotes health, safety, welfare, and quality of life for residents of the unincorporated areas of Alameda County. Additionally, educating citizens with the standards of tree care as well as the Tree Ordinance guidelines and regulations will assure the preservation and protection of trees.

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Program Goals and Objectives

  1. To manage tree resources in the County right-of-way; to protect and promote community values consistent with the safety of the motoring and pedestrian public and of public and private property.
  2. To protect and preserve urban trees which have high value for unincorporated communities and neighborhoods.
  3. To plan and implement innovative programs to enhance and expand urban and suburban tree resources, and supporting activities.
  4. To communicate the importance of urban and community forestry activities to a broad range of community participants through outreach and education and encourage and support grassroots and local efforts in building sustainable urban forest ecosystems.
  5. To integrate guidelines and services of the Urban Forestry Program with other County and agency programs to maximize effectiveness and provide technology sharing.


Per the Alameda County Sidewalk Repair Procedures, if a tree within the County right-of-way is found to be the cause of a tripping condition, the County will evaluate its condition to determine if the tree can be retained in conjunction with work to correct the sidewalk condition. If the tree is in good condition, the County will recommend retaining the tree whenever possible. Preserving healthy trees can be achieved through minor root pruning and sometimes by rerouting the sidewalk around the tree. Should the tree be recommended for removal, the property owner would be required to complete the removal, grind the stump and replace the tree, and will be responsible for all costs associated with the repairs of the sidewalk (see California Street and Highways Code, Section 5610). For more information regarding the Sidewalk Repair Program, please call (510) 670-5500.

Tree Trimming Program


The Urban Forestry Program provides Landscape Architectural design services for many of the County's capital improvement projects and reviews the design of landscaping for private developments. The County Forester and Arborist work with the Project Engineers to identify exceptional trees and begin early discussions with developers.


The Urban Parkways Program was established to preserve and promote public area landscape planting, including trees, along County-maintained, designated roadways, consistent with requirements for community identity and aesthetics, and for a roadway design that is safe for motorists, bicyclists and pedestrians. This program is solely funded through federal grants and partnerships.

In addition to street and parkway trees in the unincorporated communities of Ashland, Castro Valley, Cherryland, Fairview, San Lorenzo, and Sunol, the program addresses other unincorporated areas of environmental significance, including scenic corridors, recreational trails, creeks, and Flood Control District lands.

For more information regarding the Alameda County Urban Forestry Program, please call the Alameda County Public Works Agency's Maintenance and Operations Department at (510) 670-5500.

Click here for more Alameda County Tree Ordinance information