Caltrans Water Quality Planning Tool

The Water Quality Planning Tool was created to help planners and designers comply with environmental permits. It uses a map interface to find information based on a project’s location. This application is being updated for digital accessibility and will continue to function while updates are in progress.


303(d) List and TMDLs 2014-2016 (Legend)

Areas of Special Biological Significance

Arid and Semi-Arid Regions

Caltrans Districts

Caltrans Facilities

Caltrans Tier 1 Monitoring Sites

Calwater Watersheds

Coastal Zone


Geologic Map (Legend)

High Risk Receiving Watersheds

Monthly Precipitation

MS4 Areas

Post Miles

Rainfall Distribution

RWQCB Boundaries

USGS Topo Maps

Watershed Boundary Dataset

Risk Level Determination

Erosivity Index

K Factor

R Factor (calculations)

LS Factor

Soil Details

Compliance Storm Events

5-yr 24-hr North

10-yr 24-hr North

5-yr 24-hr South

10-yr 24-hr South

Distance and Area

Feet:  0
Acres:  0

Postmile Lookup


Hover over a layer name for a description.
Additional information, tables, coordinates, and links are below the map.

Postmile Lookup

PM Click PM Point PM Line -