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85th and 95th Percentile Rainfall

These layers represent the spatial distribution of the 85th and 95th percentile, 24-hour rainfall within the County of Los Angeles.

Rainfall gages throughout the County were selected based on spatial distribution and rainfall record length to determine the 85th and 95th  percentile, 24-hour rainfall.  The 85th and 95th percentile, 24-hour rainfall can be used to determine the stormwater quality design volume per DPW’s Low Impact Design Manual.

You can also check out this data on an interactive map located here: http://dpw.lacounty.gov/wrd/hydrologygis/ 

Data Downloads

Click here to download the LA County 95th_Percentile_Isohyet

Click here to download the LA County 85th_Percentile_Isohyet



Using GIS Data on this site

GIS Data downloaded from this site generally requires GIS software to view. Click here for a list of GIS Data Viewers

GIS data available on this website is provided AS IS - please read the GIS Data Portal Terms of Use

Data Field Descriptions

GIS Source Information
Database Name: eGIS_Hydro
Feature Class Name:
Feature Dataset Name (if applicable):
Reference Date:
Accuracy: Other
Update Frequency: As Needed
Access Constraints:None

Contact Information
Martin Araiza

Los Angeles County
Public Works


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