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Los Angeles County Sub Watersheds

Abstract: Boundaries of sub watersheds or watershed sub areas. Original areas were drawn on U.S.G.S. 7 ½ minute, 1:24,000 scale topo quad sheets by Hydraulic Water Conservation Division. Digitized into ComputerVision CADDS4 by Environmental Programs Division (EPD). Converted to Atlas GIS Atlas Graphic Format (.agf) by EPD. Cleaned up, topology built, downstream connectivity developed […]

Santa Monica Bay Major Watersheds

Abstract: Major individual Watersheds within the Santa Monica Bay Watersheds. Purpose: To identify Major watersheds within the Santa Monica Bay Watersheds

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Spreading Grounds

Abstract: This layer was created to represent stormwater spreading grounds operated by the Los Angeles County Department of Public Works. These spreading grounds are selected and managed for capturing as much water as possible during storms. Locations were chosen with permeable soil formations to enable recharging of underground aquifers. An estimated 30 to 40 […]

Debris Basin – Right of Way

Abstract: The debris basin right of way depicts the limits of ownership or access rights in fee or ease within the facility. The debris basin itself consists of an earth dam or other barrier constructed across a drainageway or other suitable location for collecting sediment. The dam is provided with properly designed spillways to […]

Dams and Debris Basins – Point Locations


Debris Basins are key components of the Los Angeles County Flood Control District’s (LACFCD) flood control system. Typically located at the mouths of canyons, debris basins capture sediment, gravel, boulders, and vegetative debris that are washed out of the canyons during storms, protecting lower lying communities from possible flooding and property damage. Due […]

Catch Basins


Abstract: Location of DPW, LACFCD and some City catchbasins.


Purpose: To map Catch Basin locations for cleanout contracts. Also for general mapping purposes.

This data has been phased out of use. For current data, please visit the Storm Drain System page on this portal.


Building and Safety District Boundaries

Abstract: Polygon layer showing areas serviced by the different building and safety district offices within unincorporated county areas.

Purpose: Polygons used to show which Building and Safety office to obtain Permits.

Building and Safety is a Division of the Los Angeles County Department of Public Works.



Catch Basin Retrofits

Abstract: Catch basins retrofitted with manually retractable screen (MRS), automatic retractable screen (ARS) or fixed basket insert (FBI). Purpose: To identify and locate catch basins with retrofit for inspection purposes. This is to ensure that they are functioning properly during a storm event. Data can be downloaded here […]

Aerial Imagery (2001) – Pre-LARIAC

This aerial imagery was captured in 2001 in a cooperative project between the Los Angeles County Department of Public Works and Regional Planning.

It represents the initial imagery capture by the County of Los Angeles, which later become the Los Angeles Regional Imagery Acquisition Consortium (LAR-IAC).

Three imagery resolutions were captured:

1 […]

Public Works (Spatial Information Library)

Fairwell to an Old Friend

Effective July 1 2014, the old Spatial Library was shut down.

All regular GIS data that was on the Spatial Library is available on this GIS Data Portal, which is optimized for Internet search.

If you are looking for legacy data, we provide this spreadsheet.

If you have questions […]