Wetlands of High Conservation Value Map Viewer

This map viewer depicts the location of Wetlands of High Conservation Value and Reference Standard Wetlands. These data are a subset of the Washington Natural Heritage Program’s (WNHP) database of locations of rare species and ecosystems.

A Wetland of High Conservation Value (WHCV) is a term used in the Washington Wetland Rating System that refers to a wetland that supports an element occurrence recognized by WNHP [Note: WHCV were previously called “Natural Heritage Wetlands” in older versions of the Washington Wetland Rating System.]

An element occurrence refers to a specific location of a rare species or a rare or high-quality ecosystem type. The element occurrence is considered the most fundamental unit of conservation interest and is at the heart of Natural Heritage Methodology. Because one of the primary objectives of the WNHP is to prioritize conservation actions, only those element occurrences thought to be the most important for conservation are entered into the Program’s database. Known locations of any plant species considered to be Endangered, Threatened, or Sensitive are entered in WNHP's database as an element occurrence. Wetland ecosystem element occurrences are prioritized for inclusion in the database based on a combination of the wetland type’s conservation status rank (e.g., how rare or threatened is the wetland type) and the ‘element occurrence rank’ (current ecological integrity or condition) of a specific location of that wetland type. Basically, all occurrences of rare wetland types, regardless of their condition, are considered element occurrences, while only good to excellent condition examples of common wetlands types are considered element occurrences (see Conservation Priorities decision matrix). If an element occurrence currently documented in WNHP's database is located within the bounds of a wetland being assessed by the Wetland Rating System, that wetland is considered a WHCV.

In summary, a WHCV could be designated based on the presence of a rare plant, rare (or high-quality common) plant community, or both. A single WHCV could have more than one element occurrence. The number of element occurrences does not change the WHCV status within the context of the Wetland Rating System. However, a high number of element occurrences would suggest that particular wetland is significant in terms of the concentration of rare elements it supports.

Reference Standard Wetlands are a subset of WHCV that are considered to be among the best examples of specific wetland types and generally are located in areas with long-term protection status. Reference standard wetlands need to be anchored to a specific classification scheme and specific ecological condition criteria. Here, wetland Subgroups were used as the classification standard and ecological integrity (as measured by the EIA method) as benchmark conditions. Reference standard wetlands shown in the map viewer reflect ecological conditions representative of wetlands with minimal human-induced disturbance and/or the best quality wetlands for a given type remaining on the landscape. These reference standard wetlands can be used to identify restoration potential and benchmarks, mitigation performance standards, conservation priorities, or to provide benchmark data to help understand how wetland’s respond to human-induced disturbance.

For more information about Wetlands of High Conservation Value and Reference Standard Wetlands please see this report.

Disclaimers: The map viewer depicts over 1,100 WHCV which have been identified by WNHP over a 30-year time frame. However, not every wetland in Washington has been visited, so additional sites that meet WHCV criteria may occur on the landscape. If you believe you've discovered a new location for a vascular plant or nonvascular species considered to be Endangered, Threatened, or Sensitive by our program, or discovered a rare wetland ecosystem type, then see the 'Submitting Data to the Natural Heritage Program' section on our Data Products and Requests web page. WNHP scientists will review submitted data and determine whether sites meet the standard for a new element occurrence. If so, these wetlands will be considered new Wetlands of High Conservation Value.

The accuracy of the boundaries of each WHCV varies depending on the quality of underlying data. Within the Data Dictionary, see 'Precision Code' for clarification.


WA Wetlands of High Conservation Value Map Viewer