03 - Annexations / Detachments

Revised on 06-19-2020

Annexations and detachments (also called "boundary adjustments") are controlled by State Law, and the Los Angeles Administrative Code. They may be initiated by interested citizens acting independently or collectively, by landowners of affected land, by Councilpersons, or the City Department of Planning.


During its first century of existence, the City of Los Angeles changed its boundary only once, when the annexation of one square mile increased the City's area to twenty-eight square miles. When Los Angeles celebrated its Bicentennial, an additional two hundred sixty-six boundary changes had increased its area to four hundred sixty-five square miles. These boundary changes included ten consolidations with smaller adjacent cities, and forty-four detachments to unincorporated county area or adjacent cities. The remainder of the changes were for annexations or inclusions. 

Uniformity of boundary change policies and procedures were established in 1960 with the passage of Ordinance 116,817 (amended by Ordinance 143,333 in 1972). Those acts required that each proposal be submitted to the General Plan Advisory Board (GPAB), for a report and recommendation to the City Council (LAAC 19.15). The City Engineer is a member of the GPAB and is represented on its City Boundaries Committee.

The State's overall annexation and boundary change policies and procedures were established primarily by the Knox-Nisbet Act and MORGA (defined in the Purpose & Definition section of the Land Development Manual).


Chief Legislative Analyst

The City Council's Chief Legislative Analyst is the Council's representative on the GPAB, and acts as liaison to affected Councilpersons in boundary changes. They may request information, maps, or legal descriptions directly from the City Engineer, such as when annexation requests are submitted directly to a councilperson or to Council. 

BOE Procedures

The staff of LGD coordinates BOE's activities in boundary changes, prepares reports to the Boundaries Committee, and prepares briefing reports to the City Engineer prior to GPAB meetings. 

Review and Comments

In response to a request from the City Boundaries Committee regarding a proposed boundary change, LGD shall prepare and submit a timely report to the Committee Secretary. Key aspects of this report include:

  • Sewers
  • Drainage
  • Street improvements
  • Street lights
  • Sanitation
  • Street maintenance

Reports on services provided by other departments are provided by those agencies. These reports are combined for review by all members prior to the meeting.

Report to Boundaries Committee

  1. LGD will solicit recommendations and comments from BOE divisions only, including:
    1. Affected District Office 
      1. In the response, the District Office should include a Flood Hazard Report and estimated costs to complete street improvements, sewerage and drainage facilities when the area is fully developed. 
    2. Wastewater Conveyance Engineering Division
      1. Comment on present levels of service, the viability of assuming jurisdiction from the present operator, and cost estimates for present operating levels and future expansion
    3. Structural Engineering Division (where applicable)
    4. Other BOE Divisions as applicable
  2. Once all the comments are received from other Department/Bureau's, LGD will submit their comments to the City Boundaries Committee. 
  3. Possible attendance at the Boundaries Committee meeting if requested

City Engineer's GPAB Briefing Memorandum

When the GPAB is to consider a proposed boundary change, LGD shall prepare and forward a Briefing Memorandum to the City Engineer if requested.  The memorandum should advise the City Engineer of committee actions or omissions which are considered adverse to BOE operations or positions. New material may be added if considered relevant to the BOE's position.

Planning and Land Use Management Committee

After the GPAB considers boundary changes, the Planning Commission acts by making it recommendation to City Council. The Planning and Land Use Management Committee of the Council considers the boundary change prior to Council action. This meeting is the last opportunity for the City Engineer has to comment on the boundary change prior to Council action.

Council Considerations of Boundary Changes

When the Council places a boundary change on the agenda, BOE's Council Liaison may contact LGD for an informal briefing prior to the meeting.

House Numbering Maps (Jerry Del Rosario)

County House Numbering Maps are procured by LGD Mapping when requested by the Boundaries Committee chairman. When ordering maps, LGD staff should perform the following:

  1. Order three (3) copies
    1. Two (2) copies to the Boundaries Committee Chairman
    2. One (1) for Mapping Annexation File
  2. Outline the area to be annexed on a small-scale map copy
  3. Add an informal written request to the copy 
  4. Transmit the order and return the requested maps from the County Engineer

Legal Description Preparation

The Survey Division prepares the initial legal description for a boundary change, when requested by the Committee Secretary or the Chief Legislative Analyst (CLA).

Writing Standard

When requested to prepare a legal description, it shall be prepared in accordance with current standards. When following existing boundaries, reference should be made to the ordinance establishing that line, and to the boundary change date. Label the description with the title furnished by the Boundaries Committee.

Future City-County Boundary

When a proposed annexation's new city-county boundary follows a street, the street centerline is preferred over either street easement line as the future boundary. Backlines of lots may also be used, but cutting existing lots or parcels with future boundary lines is to be avoided. 

Description Approval

The corrected description is to be stamped and signed by a BOE staff member authorized to sign for the City Engineer. 

Distribution of Legal Description

  1. One (1) original and one (1) copy of the signed legal description - Committee Secretary
  2. One (1) copy to CLA
  3. One (1) copy to the appropriate District
  4. One (1) copy to each affected Divisions
  5. One (1) copy shall be kept in the Survey files

If during the process a revision is required of the legal description, Survey will revise it as necessary. The County Engineer will either copy or rewrite the description for inclusion in final documents.

Map Preparation (Brian Yodder or Jerry del Rosario)

Mapping prepares the official map for the proposed boundary changes, and revises it as necessary. If the boundary change becomes official, Mapping will correct and process it and distribute to City and outside agencies.

Map Format

Examples of large-area and small-area annexations are shown in Figure D423.1A and D423.1B, respectively. These examples are "half-size" maps (see Section D423.2).  Mapping shall show:

  1. Points called for in the legal description and enough surrounding area to identify location, such as major street intersections
  2. Street widths
  3. Tract and lot information, space permitting

Map Size

Prepare the original map on 17-inch by 22-inch or 17-inch by 28-inch sheets (these reduce to letter or legal size half-size sheets). The base material may be on a stable plastic film, or a high quality vellum material. Proposed boundaries and other details which may change during proceedings should be placed on a suitable transparent overlay sheet, carefully keyed for accurate registration.

Title Block

Use the updated title block and note format shown in Figure D423.3. Preparer and checker should sign the title block on the original. 

Preliminary Map Reproduction

The necessary number of transparencies should be produced from the corrected preliminary original. The original should be preserved for eventual updating when the project is completed. One transparency shall be used as a master for full-size prints. See Section D423.5 for the number and disposition of the prints and disposition of the remaining preliminary transparencies. The master transparency shall be kept with the Mapping boundary change file.

One half-size reduction shall be produced, on an opaque paper or plastic base. This will become the master for photocopy prints to distribute as noted in D423.5. See Figure D423.4 for sample order for half-size master and copies.  File the master in the LGD boundary change file.

Preliminary Map Distribution

Office Full-Size Office Transparency Half-Size Master Prints-Full Half Prints-Size Size
City Clerk 1
Room 360, City Hall, MS 160
Attention: Planning and Land Use Management Secretary
1     10
Office of the Chief Legislative
Analyst, City Council
Room 255, City Hall, MS 136
Attention Federal and State Coordination Section
    1 2

City Boundaries Committee
Department of City Planning
5th Floor City Hall, MS 395
Attention:  Secretary

1     2

LGD Boundary Change File

1 1   2

Preliminary Map Updating

As changes are made in the boundary and other map details by the GPAB, Planning Commission, City Council, or LAFCO during the boundary change procedure, the base map shall be revised and new masters and copies produced and distributed as in Sections D423.4 and D423.5. Note in transmittal memos that earlier versions are superseded and are to be discarded. 

Final Map Disposition

When the boundary change is completed, the boundary change map must be updated and distributed immediately by the City Engineer.

Notice of Proceedings Completion

Mapping will receive notification of proceedings completion from either the Secretary of LAFCO or the City Clerk, giving the date of filing and the Secretary of State's Instrument Number. If the information is received by phone, request that copies be sent promptly.

Map Completion

Mapping will complete the notes and title block with the information received in Section D424.1. If corrections are needed, the original drawing and overlay shall be corrected using CAD. 

Copies of filing documents must be used by the final checker to verify document and filing numbers.


The responsible supervisor shall sign the new (or corrected) transparency, and forward to Mapping Division Manager and the City Engineer for signature. In the transmittal, specify that the map be returned after signing for indexing and distribution. Make a security print for the Mapping file before proceeding to the next step.


Transmit the signed transparency to the Bureau of Engineering's Index to Records for indexing and microfilming. See Figures D424.4A and D424.4B. This map becomes the vault "tracing". Retain one microfilm aperture card for the Mapping file.

Final Map Production

Make the necessary number of full-size prints for final distribution (see Section 424.6). Order a half-size plate and 100 paper prints (as in Section D423.4 - extra copies are to be retained in the LGD file until the file is stored). Return the tracing to the vault immediately after the prints and production of the "half-size" plate. 

Final Map Distribution

Maps are distributed by Mapping. 

Distribution to Outside Agencies

Transmit two half-size prints to each of the following agencies or firms, by first-class mail (transmittal letter, Figure D424.61): 

  • Bureau of Census
    Data Preparations Division
    15400 Sherman Way, Suite 295
    Van Nuys, CA 91406
    Attention Boundary and Annexation Survey 
  • Federal Emergency Management Agency
    Administrator, Federal Insurance Administration
    Washington, DC 20472
    Attention Chief, Risk Management Division
  • Postmaster, U. S. Postal Service
    Los Angeles GMC
    7001 Central Avenue, 3rd Floor
    Los Angeles, CA 90052
    Attention: Manager Delivery and Retail 
  • District Director
    California Department of Transportation,  District 7
    PO Box 2304
    Los Angeles, CA 90051
  • Los Angeles County Assessor
    Hall of Administration
    500 West Temple Street, Room 325
    Los Angeles, CA 90012
    Attention: Chief Cadastral Engineer
  • Los Angeles County Sanitation District
    PO Box 4998
    Whittier, CA 90607
    Attention: Right of Way Engineer
  • Los Angeles County Department of Health Services
    313 No. Figueroa Street
    Los Angeles, CA 90012
    Attention Records and Statistics, Room 127
  • Los Angeles County Department of Public Works
    900 S.. Fremont Avenue, 10th Floor
    Alhambra, CA 90020
    Attention: Mapping & Property Management, Mapping Services Section
  • Los Angeles County, Department of Regional Planning
    320 W. Temple Street,13th Floor
     Los Angeles, CA 90012
    Attention: Supervising Regional Planner II
  • Metropolitan Water District
    P. O. Box 54153
    Los Angeles, CA 90054
    Attention Right of Way and Land Division
  • Thomas Bros. Maps
    17731 Cowan
    Irvine, CA 92614
    Attention: Geographic Research Department
  • Automobile Club of Southern California
    P.O. Box 25001
    Santa Ana, CA 92799- 5001
    Attention: Cartography/Travel Research A375

Distribution to City Offices

Transmit two (2) half-size prints (except as noted) to each of the following City Offices by city messenger using the transmittal memo.  LGD staff should confirm the address/location of each prior to distribution:

  • Bureau of Engineering
  • City Administrative Officer
    Room 1500, City Hall East - Stop 130
    Attention: Disaster Preparedness Coordinator
  • City Clerk
    Planning and Land Use Management Committee Secretary
    Room 360, City Hall - Stop 160
    (Note: Twelve half-size copies, and one full-size copy on plastic base material)
  • Los Angeles World Airports (LAWA)
    Engineering - Stop 101
    (Note: Only maps for boundary changes within a five-mile radius of a LAWA controlled airport)
  • Animal Services Department
    221 N. Figueroa St.,5th Floor - Stop 105
    Attention: Administrative Services
    201 N. Figueroa St., 10th Floor, Stop 115
    Attention: Zoning Engineer
  • Office of the Chief Legislative Analyst Room 255,
    City Hall - Stop 136
    Attention: Intergovernmental Relations
  • Department of Water and Power
    111 No. Hope Street, Room 1367 - Stop 800
     Attention: Water Engr. Design Division Maps & Records Group
  • Department of Water and Power
    111 No. Hope Street, Room 836 - Stop 800
    Attention: Distribution Drafting
  • Los Angeles Fire Department
    Room 1800, City Hall East - Stop 250
    Attention: GIS Mapping & Graphics Section
  • Los Angeles Fire Department
    Room 1800, City Hall East - Stop 250
    Attention: Planning Section
  • Information Technology Agency
    13th Floor, City Hall East – Stop 232
    Attention: Data Network Engineering Section
  •  Library Department
    630 West 5th Street - Stop 300
    Attention Branch Library Services
  • Department of City Planning
    7th Floor, City Hall - Stop 395
    Attention: Chief Zoning Administrator
  • Department of City Planning
    7th Floor, City Hall - Stop 395
    Attention: Citywide Planning Division
  • Los Angeles Police Department
    221 N. Figueroa St., Suite 650 – Stop 1013
    Attention: Planning & Research Division, Cartography Unit
  • Los Angeles Police Department
    Information Technology Division
    1149 S. Broadway, Basement Level - Stop 447
    Attention: Statistics Section
  • Department of Recreation and Parks
    7th Floor, 1200 West 7th Street - Stop 682
    Attention: Planning & Development Division
  • Bureau of Sanitation
    1149 S. Broadway, Suite 900 - Stop 521
    Attention: Solid Resources Support Division
  • Bureau of Street Lighting
    2nd Floor, 1149 So. Broadway - Stop 545
    Attention: Information Technology Group
  • Bureau of Street Services
    1149 S. Broadway - Stop 550
    Attention: Pavement Management Section
  • Department of Transportation
    10th Floor, 100 So. Main Street - Stop 725
    Attention: Bureau of Planning and Land Use Development 

Distribution to BOE Offices

Distribute as to other City offices:

  • Central Engineering District
    201 N. Figueroa St., 3rd Floor- Stop 503
    Los Angeles
    Attention: Street Address Numbers/Highway Dedications
    (Note: Include two (2) copies of County House Numbering Map)
  •  Geotechnical Engineering Group
    1149 S. Broadway, Suite 100- Stop 495
    Attention Geology and Soils Division
  • District Engineering Offices - affected district(s) only
    • Central District Office
      201 N. Figueroa St., 3rd Floor- Stop 494
      Los Angeles, CA
    • Harbor District Office
      636 S. Beacon St., Suite 402 - Stop 497
      Los Angeles, CA
    • Valley District Office
      6262 Van Nuys Blvd., Rm.351 - Stop 496
      Los Angeles, CA
    • West Los Angeles District Office
      1828 Sawtelle Blvd., 3rd Floor - Stop 499
      Los Angeles, CA
  • Land Development and GIS Division
    201 N. Figueroa St., Suite 290 – Stop 901
    Los Angeles, CA
  • Real Estate Group
    1149 S. Broadway, Suite 610 - Stop 515
    Los Angeles, CA
  • Structural Engineering Division
    1149 S. Broadway, Suite 740 – Stop 491
    Los Angeles, CA
  • Survey Division
    201 N. Figueroa St., Suite 1100 - Stop 904
    Los Angeles, CA
  • Wastewater Conveyance Engineering Division
    1149 S. Broadway, Suite 620 –Stop 538
    Los Angeles, CA


Each agency and department shall be responsible for plotting boundary changes on the maps it maintains.


Early in each calendar year, the Bureau of the Census of the U. S. Department of Commerce will forward maps and forms to the City requesting information on all boundary changes during the preceding year. Mapping staff will supply the information in accordance with instructions accompanying the request.

In general, the US Bureau of the Census will contact the City to verify the City's boundaries prior to actual census that occurs once every 10 years.

Annexation Files

Boundary Change Files:  The City Engineer's primary boundary change files shall be maintained by LGD GIS Section.  Please click here to see an example of a Boundary Change (also under Checklists and Sample Documents in the Land Development section).

File Classification:  Boundary change files are classified as Historical Records (Division 12 of the City Administrative Code).

File Maintenance:  When a new boundary change is proposed, a new file shall be created and designated by the Local Agency Formation Commission (LAFCO) title.  LAFCO is the county-wide regulatory agency that is responsible for coordinating logical and timely changes in local governmental boundaries, including: annexations and detachments of territory; incorporations of cities; formations of special districts; and, consolidations, mergers, and dissolutions of districts.  

Record Material:  Notices, publications, correspondence or copies, maps, and other data having permanent significance shall be kept therein.   Calculations and sketches which explain details not otherwise apparent should be retained. Such material should be labeled so that it may be easily identified by future file users.