3 Layer Guide
This guide serves to provide greater detail about each layer included in the Tribal Water Data Map.
When opening the map in Map Viewer, the default layers that will be displayed include all 7 (seven) of the Bureau of Indian Affairs layers and the California Regional Boards Boundaries. To see more details about these layers, read below or click on the layer in the Layer Dictionary (see instructions on Map Guide page)
3.1 Tribal Land Layers
3.1.1 Bureau of Indian Affairs (BIA)
Layer displaying areas of XXXX .
Source: Bureau of Indian Affairs, from the Pacific Regional Office (PRO)
Data Update Frequency: As needed
Last Updated: June 29th, 2021, added to Tribal Water Data Map in May 2025
Contact: BIA
BIA’s mission is to “enhance the quality of life, promote economic opportunities, and to carry out the federal responsibilities entrusted to us to protect and improve the trust assets of American Indians and Alaska Natives. We accomplish this by directly empowering Tribal governments through self-governance agreements.”
3.1.1.1 Bureau_of_Land_Management_Lots
This sublayers includes data about Bureau of Land Management (BLM) lands that are managed within the boundaries of BIA lands.
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3.1.1.2 Indian_Lands
“The term “Indian land” means: (A) Any land located within the boundaries of an Indian reservation, pueblo, or rancheria; (B) Any land not located within the boundaries of an Indian reservation, pueblo, or rancheria, the title to which is help: (i) In trust by the United States for the benefit of an Indian tribe or an individual Indian; (ii) By an Indian tribe or an individual Indian, subject to restriction against alienation under laws of the United States Definition: Indian land from 25 USC § 3501(2) | LII / Legal Information Institute”, BIA Tract Viewer - Catalog
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3.1.1.3 Land_Grants
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3.1.1.4 Public_Domain_Allotment_Tracts
These are parcels of Tribal lands, typically up to 160 acres, that were divided up and “allotted” to individual Tribal members, see: Allotment Act of 1887.
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3.1.1.5 Reservation_Boundary
This sublayer refers to the outer limits or perimeter of federal American Indian reservations. These boundaries are established by treaties, agreements, executive orders, or other federal actions and define the land reserved for a Tribe or Tribes.
3.1.1.6 Reservation_Tracts
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3.1.1.7 All_Tracts
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3.1.2 Indigenous Territories
Layer displaying historic Indigenous Territories within California.
Source: Water Boards ArcGIS Portal, data used in this layer was accessed and downloaded from native-land.ca
Data Update Frequency: As needed
Last Updated: May 2024
Contact: Native Land Digital
Native Land Digital “strives to create and foster conversations about the history of colonialism, Indigenous ways of knowing, and settler-Indigenous relations, through educational resources such as our map and Territory Acknowledgement Guide. We strive to go beyond old ways of talking about Indigenous people and to develop a platform where Indigenous communities can represent themselves and their histories on their own terms. In doing so, Native Land Digital creates spaces where non-Indigenous people can be invited and challenged to learn more about the lands they inhabit, the history of those lands, and how to actively be part of a better future going forward together.”
3.1.3 Other Sources of American Indian and Tribal Land
3.1.3.1 Tribal Census Tract 2021
Layer showing Tribal areas identified by the U.S. Census Bureau. You can zoom in further to see specific areas more closely.
Source: U.S. Census Bureau, TIGER/Line Shapefiles
Data Update Frequency: Every 10 years
Last updated: 2024
Contact: U.S Census Bureau
3.1.3.2 Tribal and Native Entities
Layer showing American Indians Reservations/Federally Recognized Tribal Entities.
Source: California Governor’s Office of Emergency Services (Cal OES)
Data Update Frequency: As needed
Last updated: 2019
Contact: Cal OES
The American Indians Reservations/Federally Recognized Tribal Entities data set depicts feature location, selected demographics and other associated data for the 561 Federally Recognized Tribal entities in the contiguous U.S. and Alaska. Categories included are: American Indian Reservations (AIR), Federally Recognized Tribal Entities (FRTE) and Alaska Native Villages (ANV).
3.2 Integrated Report and Beneficial Use Layers
3.2.1 2024 Integrated Report
What is the Integrated Report?
Waterbodies assessed in the Integrated Report (IR) include surface waterbodies, such as rivers, lakes, and beaches.
Assessed waterbodies are placed into one of five Integrated Report Condition Categories based on the waterbody’s ability to support beneficial use(s).
The 303(d) list consists of the waterbodies in Categories 4a, 4b, and 5. These waterbodies can be referred to as “listed” or “impaired”.
The 303(d) list is based off of Section 303(d) of the Clean Water Act, which requires each state to identify waters that do not meet water quality standards and to prioritize those waters for development of total maximum daily load (TMDL)
The Clean Water Act also requires each state to report on the overall condition of its surface waterbodies, which is Section 305(b).
California combines its 303(d) lists and 305(b) reports into a single “California Integrated Report”.
For more information see:
CEDEN - California Environmental Data Exchange Network
2024 Integrated Report | California State Water Resources Control Board
3.2.1.1 State Water Bodies (rivers, streams, and beaches)
This layer shows linear waterbodies in California, such as rivers, streams, and beaches, which were assessed for 305(b) in the 2022-2024 California Integrated Report. Blue waterbodies are listed in Category 1, 2, or 3. Orange waterbodies represent those placed on the 303(d) list of impaired waters.
Note, these are not the final assessments.
Source:
Data Update Frequency: Every two years
3.2.1.2 State Water Bodies (bays, lakes and reservoirs)
This layer shows non-linear (polygon) waterbodies in California, such as bays, lakes, and reservoirs, which were assessed for 305(b) in the 2020-2022 California Integrated Report. Blue waterbodies are listed in Category 1, 2, or 3. Orange waterbodies represent those placed on the 303(d) list of impaired waters.
Note, these are not the final assessments.
Source:
Data Update Frequency: Every 2 years
3.2.2 Waterbodies that haven’t been assessed
3.2.2.1 State Water Bodies (rivers, streams, and beaches)
3.2.2.2 State Water Bodies (bays, lakes and reservoirs)
3.2.3 Basin Plan Beneficial Uses
What are Beneficial Uses?
3.2.3.1 State Water Bodies (rivers, streams, and beaches)
3.2.3.2 State Water Bodies (bays, lakes and reservoirs)
3.3 CalEnviroScreen
3.3.1 CalEnviroScreen 4.0
This layer shows the CalEnviroScreen (CES) 4.0 based on the CES Score percentile.
CalEnviroScreen is a screening methodology that can be used to help identify California communities that are disproportionately burdened by multiple sources of pollution. CI score ranges from 10 to 100. For more information on CalEnviroScreen scoring, see Practice Examples page.
Source: California Office of Environmental Health Hazard Assessment (OEHHA)
Data Update Frequency: As needed
Contact: CalEnviroScreen
3.3.2 Disadvantaged Communities
This map shows the disadvantaged communities designated by CalEPA for the purpose of SB 535. These areas represent the 25% highest scoring census tracts in CalEnviroScreen 4.0, census tracts previously identified in the top 25% in CalEnviroScreen 3.0, census tracts with high amounts of pollution and low populations, and federally recognized tribal areasas identified by the Census in the 2021 American Indian Areas Related National Geodatabase.
Source: California Office of Environmental Health Hazard Assessment (OEHHA)
Data Update Frequency: As needed
Contact: CalEnviroScreen
3.4 Pollution Indicators
3.4.1 Agricultural Pesticides
This indicator represents the reported use of 132 hazardous and volatile pesticides in 2017-2019. Only pesticides used on agricultural commodities are included in the indicator. The data is averaged over the census tract area, and some application may be adjacent to (instead of within) the census tract.
Source: California Office of Environmental Health Hazard Assessment (OEHHA)
Data Update Frequency: As needed
Contact: CalEnviroScreen
3.4.2 Superfund Sites
This layer shows Superfund Site locations and data on the inventory of active and archived hazardous waste sites evaluated by the EPA’s Superfund program.
This data provides location and attribute information on Facilities regulated under the Superfund Enterprise Management System (SEMS). It contains sites that are either proposed to be, or are on, the National Priorities List (NPL) as well as sites that are in the screening and assessment phase for possible inclusion on the NPL.
Source: U.S. Environmental Protection Agency (EPA)
Data Update Frequency: As needed
3.4.3 NPL Superfund Site Boundaries
This layer shows entire Superfund Site boundaries.
U.S. EPA Superfund Site boundaries are polygons representing the footprint of a whole site, defined for purposes of this effort as the sum of all of the Operable Units and the current understanding of the full extent of contamination.
Source: U.S. Environmental Protection Agency (EPA)
Data Update Frequency: Monthly
Last updated: May 25th, 2025
3.4.4 Oil and Gas Wells
This layer shows oil and gas well locations (and their associated records) across California.
Source: WellFinder, published by the California Department of Conservation and Geologic Energy Management Division
Data Update Frequency: As needed
3.4.5 Mines
This layer shows all mines in California.
This data is published with the intent to aid mine reclamation and is gathered via annual reports under Public Resources Code section 2207.
Source: California Department of Conservation Division of Mine Reclamation
Data Update Frequency: As needed
3.4.6 Aquifer Water Quality Risk
3.4.6.1 State Small Water Systems
3.4.6.2 Source Data (All Contaminants)
3.4.6.3 Water Quality Risk by Section (All Contaminants)
This layer shows estimated water quality risk for domestic wells and state small water systems for a variety of contaminants.
This layer was developed for use by the State Water Boards SAFER Program to help prioritize areas where domestic wells and state small water systems may be accessing groundwater that does not meet primary drinking water standards.
Source: Groundwater Ambient Monitoring and Assessment (GAMA) Program
Data Update Frequency: As needed
Contact: SAFER Program
3.4.6.4 Arsenic
3.4.6.5 Hexavalent Chromium
3.4.6.6 Nitrate
3.4.6.7 Tricholoropropane
3.4.6.8 Uranium
3.4.7 Cleanup Program Sites
The Cleanup Program Sites have 36 different classifications. For ease of viewing on this map, we have combined similar classifications into groups. You can find the specific classification if you click on the individual point of interest, or you can refer here for the full list.
Source: GeoTracker
Data Update Frequency: Daily
Last Updated: downloaded 2025/05/21
3.4.8 Regulated Wastewater Treatment & Discharge Facilities
Layer showing National Pollutant Discharge Elimination System (NPDES) and Waste Discharge Requirements (WDR) facilities regulated by State Water Board programs, as reflected in the California Integrated Water Quality System (CIWQS) project.
These facilities are mandated to hold active permits to discharge into or alter the surface or ground water. More information about these permits can be found in the CIWQS database.
Source: California Integrated Water Quality System (CIWQS)
Data Update Frequency: Nightly
3.4.9 Sanitary Sewer System Spills
Layer showing locations with XXXXXXXX
Source:
Data Update Frequency:
3.5 Water Quality
New layers coming soon
3.6 Climate Change Indicators
3.6.1 Drought Intensity
Drought Outlook: This layer shows regions in California impacted by drought.
Drought severity is determined by precipitation deviation, stream flow, soil moisture content, subjective observation, and reported impact.
Source: U.S. Drought Monitor
Data Update Frequency: Weekly, on Thursdays
3.7 Hydrology
3.7.1 Groundwater Basins
This layer shows the boundaries of 515 groundwater basins and subbasins as defined by the California Department of Water Resources.
Source: California Department of Water Resources
Data Update Frequency: As needed
3.7.2 Hydrography, Water Boundaries
The California Interagency Watershed Map is the State of California’s working definition of watershed boundaries. Previous Calwater versions described California watersheds, beginning with the division of the State’s 101 million acres into ten Hydrologic Regions (HR). Each HR is progressively subdivided into six smaller, nested levels: the Hydrologic Unit (HU, major rivers), Hydrologic Area (HA, major tributaries), Hydrologic Sub-Area (HSA), Super Planning Watershed (SPW), and Planning Watershed (PW), with the Planning Watershed as the most detailed level. See metadata for more information.
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Source: CalWater Watersheds - Overview
Data Update Frequency: As needed
Last Updated: September 7th, 2023
3.8 Geopolitical Boundaries
3.8.1 Regional Water Board Boundaries
Layer showing the boundaries of the nine Regional Water Quality Control Boards in California.
Source: California State Water Resources Control Board (SWRCB)
Data Update Frequency: As needed
3.8.2 Census Tracts
3.8.3 County Boundaries
This layer shows County boundaries within California.
In this dataset, all bays (plus bay islands and constructed features) are merged into the mainland, and coastal features (such as islands and constructed features) are not included, with the exception of the Channel Islands which ARE included.
Source: California Dept. of Forestry and Fire Protection (CalFIRE)
Data Update Frequency: As needed
3.8.4 Non-private Land Holders
This layer shows boundaries for non-private land holders in California.
Source: California Land Ownership | California State Geoportal
Data Update Frequency: As needed
3.8.5 California National Parks
3.8.6 State Park Boundaries
This layer shows the State Parks in California.
Source: California Dept. of Pesticides Regulation (DPR)
Data Update Frequency: As needed
3.8.7 Groundwater Sustainability Agencies
This layer shows the boundaries of California’s Groundwater Sustainability Agencies as defined on the DWR SGMA Data Viewer.
Source: California Department of Water Resources, for use by Groundwater Ambient Monitoring and Assessment (GAMA) Program
Data Update Frequency: As needed
3.8.8 Marine Protected Areas
California’s MPA Network includes different types of MPAs as well as other designations. Each designation is unique in its purpose and allowed uses - CDFW
State Marine Reserve (SMP): An MPA where no take, damage, injury, or possession of any living, geologic, or cultural marine resource is allowed.
No-Take State Marine Conservation Area (NoTake SMCA): An MPA where no take of any living, geologic, or cultural resource is allowed, EXCEPT for take incidental to specified activities permitted by other agencies (e.g. infrastructure maintenance, sand renourishment).
State Marine Park (SMP): An MPA that allows some recreational take but does not allow commerical take.
State Marine Conservation Area (SMCA): An MPA where some recreational and/or commercial take of marine resources may be allowed (restrictions vary)
State Marine Recreational Management Area (SMRMA): A marine managed area where some take of marine resources may be allowed and legal waterfowl hunting is allowed (restrictions vary)
Special Closure: Prohibits or restricts access in waters adjacent to seabird rookeries or marine mammal haul-out sites.
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Source: California Marine Protected Areas [ds582] GIS Dataset
Data Update Frequency: As needed
Last Updated: 2019