Wetlands Portal Habitats

Wetlands Portal Habitats are used to record habitats and habitat changes at wetland project sites. Applying a standard set of habitat definitions across the entire state will make statewide habitat gain and loss summaries possible. Project proponents should use the Portal Habitats when submitting information about their projects.

The development of this set of habitats was influenced by the federal Cowardin and HGM (hydrogeomorphic) classifications, and California wetland habitat vernacular.

All wetland and riparian areas of California fall into the 14 Wetlands Portal Habitats:

Note that the Modern and Historical habitats layers in the Portal interactive map currently have their own habitat naming scheme that is distinct from the Portal Habitats. These habitats will be converted to the Portal Habitats in the future.

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Wetlands Portal Habitat Definitions

• Estuarine—marsh*
• Estuarine—mudflat
• Estuarine—open water
• Estuarine—submerged aquatic vegetation

Estuarine wetlands consist of three main parts: the vegetated marsh plain that is above the average high tide (Estuarine—marsh), the area of open water that is apparent during an average low tide (Estuarine—open water), and the area lacking vegetation that exists below the marsh plain that is exposed during the average low tide (Estuarine—mudflat). The open water area includes the pannes and ponds on the vegetated marsh plain. Open water and non-vegetated areas have less than 5% absolute cover of vegetation. In addition to these three main parts, some estuarine wetlands have submerged aquatic vegetation, such as eel grass, that is partially exposed during the average low tide. The minimum size of open water areas, non-vegetated areas, vegetated marsh plain, and submerged vegetation is 0.1 acre.

• Vernal pools & swales (always seasonal)*

Vernal Pools are ephemeral, depressional wetlands that typically support at least 30% relative cover of indicative plant species. The shallow depressions are underlain by bedrock or impervious soil. They fill with rainwater and runoff during the winter and may remain inundated until spring or early summer, sometimes filling and emptying repeatedly during the wet season. Vernal pools often occur together with vernal swales as vernal pool systems that have many pools of various sizes and shapes, varying floral and faunal composition, and various hydroperiods. Water can move between adjacent pools and swales through the thin soils above the underlying impervious substrate.

• Depressional wetlands except vernal pools & swales—marsh and unvegetated flats*
• Depressional wetlands except vernal pools & swales—open water*

Depressional Wetlands are places where runoff accumulates in a topographic depression. Water either does not flow through the wetland or the flow is essentially imperceptible. Depressional wetlands are smaller than lakes, lack the indicative plant community of vernal pools, and are neither saline nor alkaline like playas. Stock ponds, irrigation ponds, and treatment ponds that are smaller than lakes are examples of unnatural depressional wetlands. Ponds on fault traces, valley bottoms, and on broad saddles along ridge are examples of natural depressional wetlands. A depressional wetland can have three main parts: an area of open water (Depressional wetlands—open water), a non-vegetated area that is exposed when the wetland is not full, and an area of marsh vegetation that borders either the open water area or the non-vegetated area. The open water areas and non-vegetated areas have less than 5% absolute cover of vegetation; count these both as “Depressional wetlands—marsh and unvegetated flats.” Some depressional wetlands lack the open water area and/or the non-vegetated area. Depressional wetlands can be perennial or seasonal. Perennial depressional wetlands have some amount of standing water for at least 9 months during most years. Seasonal depressional wetlands have no standing water or it lasts for less than 9 months during most years.

• Seeps and springs wetlands*

Seeps and springs wetlands are also known as Slope Wetlands. They are formed by groundwater emerging onto the ground surface or into the root zone of wetland vegetation. They naturally occur on hillsides or at the bases of dunes, hills, alluvial fans, etc. In some cases, the emerging groundwater flows downhill through very small channels called rivulets or runnels that lack the banks, beds, and floodplains of larger streams. Many seeps and springs adjoin rivers, streams, lakes, and other kinds of wetlands.

• Playas—marsh*
• Playas—open water*

Playas consist of the three main parts: the area of open water that is apparent when the playa is full, the non-vegetated area that is exposed when the playa is not full, and the area of marsh vegetation that borders either the open water or the non-vegetated area (Playas—marsh vegetation). Open water and non-vegetated areas have less than 5% absolute cover of vegetation; count these both as “Playas—open water.” The central feature of a playa is a seasonal or perennial body of very sodic (i.e., strongly alkaline) or saline water with an average depth less than 6 ft during the dry season. The benthic sediments of a playa are mostly very fine-grain clays and silts. The fringing wetlands are characterized by grasses and herbaceous plants tolerant of the soluble salts that accumulate along the shoreline. The shallowness of the open water areas of playas distinguishes them from lakes. Playas differ from vernal pools by having little or no vascular vegetation within the area that is seasonally saturated or inundated.

• Lakes—marsh
• Lakes—open water

Lakes are at least 20 acres large and have an average depth of at least six feet during the dry season. A lake consists of the three main parts: the area of open water that is apparent when the lake is full, the non-vegetated area that is exposed when the lake is not full, and the area of marsh vegetation that borders either the open water or the non-vegetated area (Lakes—marsh). Open water and non-vegetated areas have less than 5% absolute cover of vegetation; count these both as “Lakes—open water.” The minimum size of open water areas, non-vegetated areas and vegetated areas is 0.1 acre.

• Streams and rivers—channel*
• Streams and rivers—riparian area*

Streams and rivers can consist of two main parts: the channel (Streams and rivers—channel) and its ripairian area (or active floodplain); count this as “Streams and rivers—riparian area.” The active floodplain is defined as the relatively level area that tends to be flooded every 1.5 to 2.0 years. It can be represented by a contour line on a steep bank, a very narrow flat area, or by broad areas of vegetated and non-vegetated bars, flats, and low benches. The channel consists of its banks and bed below the active floodplain. Channels can be perennial, intermittent, or ephemeral. Perennial channels have surface water flowing through them all year during most years. Ephemeral channels have flowing water only during the wet season. Intermittent channels have flowing water only during rains, or when water is released from upstream reservoirs, treatment ponds, etc. Braided channels have multiple sub-channels that diverge and converge.

* this habitat type can contain seasonal (ephemeral) wetlands