Los Angeles County Department of Regional Planning

Significant Ecological Areas

SEA Frequently Asked Questions

The update to the Los Angeles County General Plan includes major revisions to the Significant Ecological Area (SEA) Program. Changes include expansion of the SEA boundaries as well as modifications to the regulations covering activities within the SEAs. Detailed information about each proposed SEA is available on this website and a draft of the SEA Conditional Use Permit is also provided for public for review and comment.

General Plan Program

California state law requires every city and county adopt a general plan and emphasizes the need to review and update the plan on a regular basis. The Los Angeles County Board of Supervisors authorized the Department of Regional Planning to pursue a multi-year update of the 1980 Countywide General Plan to address this mandate. The draft General Plan is composed of state-mandated elements, which include a combined Conservation and Open Space Element. The State requires that the Conservation/Open Space Element address “open space for the preservation of natural resources, including, but not limited to: areas required for the preservation of plant and animal life including habitat for fish and wildlife; areas required for ecologic and other scientific study; and rivers, streams, coastal beaches, lake shores, banks of rivers and streams and watersheds.” The proposed General Plan meets the State’s resource preservation guidelines through its goals and policies and implements a majority of the biological resource-related policies through the implementation of the SEA Program.

Significant Ecological Area Program

The Significant Ecological Area (SEA) Program is a component of the Los Angeles County Conservation/Open Space Element. This program is a resource identification tool that indicates the existence of important biological resources. SEAs are not preserves, but are areas where the county deems it important to facilitate a balance between limited development and resource conservation. Limited development activities are reviewed closely in these areas where site design is a key element in conserving fragile resources such as streams, oak woodlands and threatened or endangered species and their habitat.

SEA Regulations

The intent of the proposed SEA regulations is not to preclude development, but to allow limited, controlled development that does not jeopardize the unique biotic diversity within the County. The SEA conditional use permit requires development activities be reviewed by the Significant Ecological Area Technical Advisory Committee (SEATAC). Additional information about regulatory requirements is available on this website.


SEATAC is an advisory body to the Regional Planning Commission and is composed of biologists who have specialized knowledge of the biotic resources of Los Angeles County. The General Plan authorizes SEATAC to review the biotic data submitted by the applicant for accuracy and to recommend site design and project conditions. This may include recommendations to avoid development in sensitive resources area on the site, including streams and associated riparian habitat, sensitive species habitat, and woodlands.

Los Angeles County Significant Ecological Area Update Study 2000

In 1999, the County contracted with an environmental consultant team to prepare a Significant Ecological Area Update Study. This Study recommended expanding the existing SEA boundaries in areas that met the SEA criteria. The consultant team recommended that the County’s existing SEAs be consolidated into fewer but larger SEAs. Taking the consultant team’s biological assessment of these areas into consideration, County staff has incorporated many of their recommendations into the proposed SEA Program.

Proposed SEA Boundaries

Most SEAs are depicted as a single connected geographic system, which encompass biological resources that cumulatively meet the SEA criteria. Each SEA is described in detail on this website and in the Technical Appendix of the draft General Plan. These descriptions include details about the vegetation communities, sensitive species data, and discussion of how these resources meet the SEA criteria.


The SEAs are depicted within cities to show the extent of biological resources within an ecological system. However, the County has no land use jurisdiction within cities, therefore the SEA designation does not apply within city boundaries, nor do the County’s SEA regulations. Cities have their own General Plans and environmental preservation programs unrelated to the County. It is up to each individual city to decide how they will conserve the natural resources within their boundaries.

Land Use and Zoning

The SEA does not change the land use designation or the zoning of a property; however a conditional use permit is required for development activities within a Significant Ecological Area, unless the activity is exempt from the ordinance.

Santa Monica Mountains Coastal Zone and Santa Catalina Island

The proposed SEA ordinance does not apply within the Santa Monica Mountains Coastal Zone boundary and Santa Catalina Island. The regulatory procedure for coastal development is generally more restrictive in these areas. For information on applicable plans and regulations within the Coastal Zone, applicants should refer to the Los Angeles County Malibu Land Use Plan and the Los Angeles County Santa Catalina Island Local Coastal Program.

DRP en Español

Online Appointment Now Available!

Metro Area Plan Outdoor Permit Covid-19 UAS Drone Housing Element Update SB 9 Oil Well Tree Pest Disease FFCP Homeless Buying Property SEATAC Historic Preservation DRP Video Library

Follow Us

Twitter Facebook Instagram YouTube

©2009 Los Angeles County Department of Regional Planning.

All Rights Reserved. Terms under which this service is provided to you. Privacy Statement.

Please send website questions and comments to webadmin@planning.lacounty.gov

Many of our documents are in PDF format. You can download Adobe Reader by clicking this link.

Department of Regional Planning
320 West Temple Street
Los Angeles, CA 90012
T: (213) 974-6411 . F: (213) 626-0434
TDD: (213) 617-2292
Twitter Facebook Instagram YouTube