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My Water Quality: Aquatic Ecosystem Health - Wetlands

How Do We Classify Wetlands in California?

wetland

The California Aquatic Resource Classification System or CARCS is used to classify wetlands in the California Aquatic Resource Inventory (CARI). Wetland managers and scientists from across the state developed CARCS to support effort to track changes in the diversity, distribution, abundance, and condition of wetlands throughout the state. CARCS is based on existing federal classification systems that have been tailored to fit the needs of California. CARCS recognizes 6 classes of wetlands among 2 major categories. CARCS allows wetlands to be further classified based on their landscape connection, naturalness, vegetation, hydrology, and substrate. CARCS can be translated into federal and regional classification systems. For more information on the development of CARCS and wetland definitions visit the CARI info page.

  • The first step in CARCS is to digitize a given feature using remotely sensed imagery (ex. aerial or satellite photos) and ancillary data (ex. slope, soil) and decide which major category and class it belongs to. Landscape connection (position in landscape relative to other areas) designation is highly recommended if discernible from the data sources.
REQUIRED CLASSIFICATION OBTAINED THROUGH REMOTE SENSING
HIERARCHICAL
HYDROGEOMORPHOLOGY LANDSCAPE CONNECTION
Major Class Type Sub-Type
Non-wetland Open Water LACUSTRINE Same as Associated Wetland
RIVERINE
ESTUARINE
MARINE Intertidal Cove, Embayment, Exposed Shoreline
Subtidal Cove, Embayment, Exposed Shoreline
Wetlands DEPRESSIONAL Floodplain Defined outlet, Undefined outlet
Non-floodplain Defined outlet, Undefined outlet
LACUSTRINE Structural Basin
Topographic Plain
 
SLOPE Hillslopes
Break in slope
Topographic Plain
RIVERINE High-gradient
Low-gradient Confined, Unconfined
ESTUARINE Canyon Mouth
River Valley Mouth
Delta
 
Structural Basin Embayment-Rocky Headland, Embayment-Bar Built,
Lagoon, Dune Strand/Dammed


  • The next step is to collect more specific information on land use and vegetation characteristics. These data are recommended, but not required as it may be difficult to discern from the imagery or other data.
REMOTE SENSING, RECOMMENDED
ANTHROPOGENIC INFLUENCE VEGETATION MODIFIER
WHOLE SYSTEM Non-vegetated
Forested
Scrub-shrub
Herbaceous
Emergent
Floating
Submerged
Algal
Modified
Remnant
WATER SOURCE / HYDROPERIOD
Agricultural Runoff
Constrained /
Impounded
Diked
Ditched / Drained
Diverted
Infiltration
Stormwater Control
Urban Runoff
SUBSTRATE AND BANK
Armored
Excavated
Filled / Graded
Realigned
Marine Control
Structures
 
AGRICULTURE OR OTHER USE
Aquaculture
Flooded  Agriculture
Flood Irrigation
Orchards
Ranchland
Rangeland
Harbors / Marinas / Ports
Recreation
Row or Sown Agriculture
Silviculture


  • The final step is to collect, if possible, hydrology and substrate data that help further characterize the wetland. These data are also difficult to interpret based on the imagery, though indicators can be used and can sometimes be found in other data sources. If these resources are not available, field methods are likely necessary.
FIELD-BASED, RECOMMENDED
HYDROLOGY MODIFIERS SUBSTRATE MODIFIER
TIDAL RIVERINE OR FLOW-THROUGH
Regularly tidal
Seasonally tidal
Irregularly tidal
Labile
Transitional
Consolidated
FLOWING LENTIC OR CLOSED-BASIN
Perennially flowing
Seasonally flowing
Ephemera
Unconsolidated
Rock Bottom
INUNDATION MARINE
Perennially flowing
Seasonally flowing
Temporarily flooded
Rock
Coarse Unconsolidated
Fine Unconsolidated
Faunal Reef
Coral Reef
SATURATION
Perennially saturated
Seasonally saturated
Temporarily saturated

( Updated 9/20/13 )