Wetland rating system

We recently developed an online application, the Washington Tool for Online Rating (WATOR), to support the Washington Wetland Rating System. The application is designed to assist users in completing the required figures and forms and to help generate more accurate and consistent ratings. It also helps with a more efficient review of project proposals and permitting.

Parallel to this effort, we've been working on Version 2 of the Washington Wetland Rating System for both eastern and western Washington. These are the annotated versions of the 2014 wetland rating system manuals. They incorporate comments and requests for clarification Ecology has received since the 2014 version was published.

The help text in WATOR is currently a draft form of the text in Version 2. It'll be updated with the final text after publication of the Version 2 manuals.

Requesting access to WATOR

Please carefully read and follow the instructions to sign up for WATOR through Secure Access Washington (SAW).

Important note about creating an account

When you sign up for WATOR, it requires you to select an organization. Access to an organization through WATOR can only be approved if the domain name of your email address matches the organization you are requesting to access (e.g., users requesting access to the Washington Department of Transportation organization should have a @wsdot.wa.gov domain name).

WATOR allows users within an organization to collaborate on projects, and organizations can have more control over their data when users are no longer affiliated with them. This effectively acts like a shared filing system.

If you're not affiliated with an organization, use your first and last name as your organization when you sign up.

If working for an agency (e.g., Washington Department of Transportation) that wants data created and stored under their own organization, you can create a separate username for that work. Contact us for more information before setting up a separate account.

Questions?
Amy Yahnke
Senior Ecologist
amy.yahnke@ecy.wa.gov
360-688-4263

Version 2 of the 2014 Wetland Rating System for western Washington is now available. Version 2 of the 2014 rating system for eastern Washington will be published later this year.

This new version includes annotations developed in response to questions and comments we've received since the publication of the 2014 update.

We made no changes to the underlying model of the rating system.

New text was added for clarification and is prefaced in the manual by the bolded “Annotation” header.

Additional improvements include:

Accessible formatting
Hyperlinked web addresses
A glossary
Instructions for identifying Wetlands of High Conservation Value using the Washington Natural Heritage Program’s new Data Explorer
Instructions for using Ecology’s Water Quality Atlas and Washington Department of Fish and Wildlife’s (WDFW) Priority Habitats and Species on the Web map
Additional resources for identifying land cover and land uses, flood damage, and habitat value
Updated Priority Habitats and Species list for consistency with guidance from WDFW

Rating systems are designed to help agencies make decisions about standards for protecting wetlands, including buffers. There are two wetland rating system manuals: one for the west side of the state and one for east of the Cascade range.

Washington's wetlands vary widely in their functions and values. Some types are common while others are rare. Some are heavily disturbed while others are still relatively undisturbed. All, however, provide some valuable wetland functions and resources that are ecological, economic, recreational, or aesthetic.

To protect individual wetlands effectively, managers, planners, and citizens need tools to understand the resource value each wetland provides. The rating system was designed to differentiate between wetlands based on:

Sensitivity to disturbance
Rarity
Our ability to replace them
Functions they provide

The rating system groups wetlands into four categories.

In 2014, we updated the Washington State Wetland Rating System for both eastern and western Washington. The 2014 publications marked the third update for the rating system for eastern Washington and the fourth update for western Washington since 1991.

The 2014 rating system took effect Jan. 1, 2015. This means you're required to use the 2014 updates for projects needing our authorization.

Applicants applying for a local permit need to consult with each specific city or county government regarding their critical areas ordinance (CAO). If a CAO contains the language “2004 rating system or as revised,” the applicant will likely need to use the 2014 updates to address local government requirements.

Some local jurisdictions may have language in their CAO that requires the use of the earlier 2004 rating systems. This means we'll keep the 2004 versions available electronically.

Version 2 of the 2014 rating system for western Washington was published in July 2023. If you have any questions about how Version 2 of the 2014 wetland rating system may affect CAO or SMP updates, email Rick Mraz, Ecology's wetland policy lead.

The rating system is primarily intended for use with vegetated, freshwater wetlands identified using the federal delineation manual and regional supplements. The rating system also categorizes estuarine wetlands but doesn't characterize their functions.

The “rating” categories are intended to be used as the basis for developing standards for protecting and managing wetlands to reduce further loss of their value.

Wetland rating can help you decide:

The width of buffers needed to protect the wetland from adjacent development.
The amount of mitigation needed to compensate for impacts to the wetland.
Permitted uses in the wetland.

We've developed recommendations for standards in volume two of our best available science report and wetland guidance for CAO updates.

Using the rating system for compensatory mitigation planning

The rating system doesn't replace a full assessment of wetland functions that may be necessary to plan and monitor a compensatory mitigation project.

The rating system shouldn't be used to estimate the changes in the functions of wetlands as a result of impacts or mitigation.

We've developed a separate tool to address this issue called the Credit/Debit Method.

Eastern Washington

Eastern Washington, Version 1, October 2014, Publication #14-06-030
- Updated web page links (as of 6/13/2023)
- 2014 Eastern Washington Rating Form, Version 1 (PDF)

Western Washington

Western Washington, Version 2, July 2023, Publication #23-06-009
- 2014 Western Washington Rating Form, Version 2 (PDF)
Western Washington, Version 1, October 2014, Publication #14-06-029
- Updated web page links (as of 6/13/2023)
- 2014 Western Washington Rating Form, Version 1 (PDF)

WDFW Priority Habitats

WDFW Priority Habitats: The current definitions of WDFW priority habitats should be consulted to answer the habitat questions (the descriptions on the rating forms do not describe the priority habitats adequately).

Eastern Washington

Eastern Washington (Publication #0406015): We added annotations to address frequently asked questions to this version in March 2007.
Eastern Washington Rating Form (Version 2)

Western Washington

Western Washington (Publication #0406025): We added annotations to address frequently asked questions to this version in August 2006.
Western Washington Rating Form (Version 2)

WDFW Priority Habitats

WDFW Priority Habitats: The current definitions of WDFW priority habitats should be consulted to answer question H2.3 correctly (the descriptions on the rating forms don't describe the priority habitats adequately).

We highly recommend that those who use this tool take the training we provide through the Coastal Training Program. We offer one-day and two-day classes on the 2014 wetland rating system updates.

Note: If you have taken the two-day training on the 2004 rating system and the one-day training on the Credit/Debit Method, we'll consider you to be trained in the updated rating systems.The new questions in the updates are the same as in the Credit/Debit Method.

Our recommendations for buffers are based, in part, on the category of wetland and scores for functions. The 2014 version of the rating system keeps the same four wetland categories as the 2004 version, but the scale of scores has been adjusted.

This means the buffer guidance for critical areas ordinances (CAOs) or shoreline master programs (SMPs) based on scores for functions will need to be adjusted to reflect the new range.

For example, in the 2004 version of the rating system, the high score range for habitat was 29-36. However, under the 2014 version, it is now 8-9. See the score translation tables below.

Tables for translating category scores

Category	2004 Score Range	Western WA 2014 Score Range	Eastern WA 2014 Score Range
I	> 70	23-27	22-27
II	51-69	20-22	19-21
III	30-50	16-19	16-18
IV	< 30	9-15	9-15

Tables for translating function scores

Function scores	2004 Score Range	2014 Score Range
Habitat — High	29-36	8-9
Habitat — Medium	20-28	5-7 (July 2018 modified to 6-7)*
Habitat — Low	< 19	3-4 (July 2018 modified to 3-5)*
Water quality — High	24-32	8-9

*Based on a review of the rating system reference wetland data, Ecology adjusted the ranges for the habitat scores.

We use the term "Wetland of High Conservation Value" (WHCV) to describe a wetland that supports rare species or a rare or high-quality ecosystem type. These are known and historical locations of:

Any plant, nonvascular species, or ecosystem considered endangered, threatened, or sensitive; or
Ecosystems prioritized by the Washington Department of Natural Resources' Natural Heritage Program (WNHP) based on a combination of the plant community type’s rarity or risk of extinction and its ecological integrity.

All wetlands that have overlap occurrences of rare species or rare ecosystem types, regardless of their condition, are considered to be WHCV, while occurrences of wetlands with common ecosystem types are WHCV only if they're in good-to-excellent condition, as determined by the WNHP (e.g., high-quality ecosystems).

The WNHP Data Explorer shows known and historical locations of rare plants, as well as rare and high-quality ecosystems.

Historical data are records where species haven't been observed in over 40 years, but the area may not have been surveyed during that time. Historical data indicate the potential for rare plants to occur in the area, and they're considered when applying a wetland rating.

If a "known or historical rare plants and rare and high-quality ecosystems" polygon overlaps the wetland that you're rating, you'll need to look at the Element Occurrence Precision field in the pop-up box for the polygon to determine if its precision level is General, Minute, or Second.

If any part of a wetland overlaps data from any known or historical polygon with Second-level accuracy, regardless of the plants’ wetland indicator status rating, the wetland meets the criteria for WHCV in the Washington Wetland Rating System, and that wetland is a Category I.

When assessing for the presence of rare plants or plant communities, consider known and historical data with Minute-level accuracy. These larger polygons do give uncertainty in location and will require follow up to determine the presence of these elements.

Treat known and historical data with General-level accuracy, like mapped Priority Habitats, where the mapped location is an indicator to look for presence in the field.

If the data are for a polygon of a lichen or other nonvascular species at the General or Minute-level accuracy, we currently don't have the resources or availability of skilled lichenologists to support determinations of the species presence, and we don't expect these to be considered when scoring wetland ratings at this time.

By categorizing these wetlands as Category I, we're trying to provide an important and high level of protection to these vital and rare wetlands. These natural systems and species will survive in Washington only if we give them special attention and protection.

Contact information

Amy Yahnke
Senior Ecologist
amy.yahnke@ecy.wa.gov
360-688-4263

Wetland rating system

Using the rating system for compensatory mitigation planning

Related links

Contact information