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Wetland Planning and Conservation

 Waterway and Wetland Conservation

Oregon currently has approximately 1.4 million acres of wetlands, over 100,000 miles of rivers and streams, 1,400 named lakes, 360 miles of coastline, and an additional 3,800 ponds and reservoirs. However, extensive historical agricultural and urban development greatly affected the extent and quality of Oregon’s waters and wetlands. Oregon’s tidal and non-tidal wetlands once covered as much as 2.3 million acres in the late 1700s (Dahl 1990). While landscape-scale changes have provided significant socioeconomic benefits for several generations of Oregonians, they have eliminated and degraded vast areas of streams and wetlands needed by future generations. 

Despite this historical loss of natural resources, Oregon has a more recent history of protecting its waters and wetlands. Though there has been a decrease in the rate of loss, ongoing development and land use activities continue to threaten and degrade these resources. Cumulative effects of continuing small losses are compounded by the fact that functions and biological quality are often impaired and significantly degraded on remaining resources.  Therefore, continued protection, conservation and best use of the water and wetland resources of the state are vital to the economy and well-being of the state and its people.

​Managing water and wetland resources is an integral part of the state’s removal-fill permit program. The Oregon's Removal-Fill Law (ORS 196.795-990) is the primary state law, enacted in 1967, that authorizes the regulation of activities within waters and wetlands. In general, the law covers activities such as removal, fill and other ground-altering activities within “waters of the state” and requires people who plan such activities to obtain a permit from DSL. The state’s goal is to maintain a stable resource base through avoidance and minimization of adverse impacts and by compensating for unavoidable impacts. Unavoidable impacts are required to be compensated for through compensatory mitigation.

In addition to the removal-fill law, wetland conservation oversight was established by statute in 1989 through a comprehensive bill (ORS 196.668 and 196.672) that stressed the importance of wetlands. Professional wetlands staff – including jurisdictional coordinators and resource specialists - are responsible for:

  • Developing and maintaining the Statewide Wetland Inventory
  • Providing wetland planning assistance
  • Developing standards and tools for identifying and assessing wetlands and streams
  • Providing public information and training 
  • Reviewing and approving wetland delineations for planning and regulatory permitting

The following are some planning tools for improving the state’s ability to better protect and manage waters and wetlands:

The Oregon Wetland Program Plan (WPP) is designed to focus wetland protection and restoration work in a strategic way, communicate long- and short-term objectives to the Environmental Protection Agency, and help partner organizations stay informed and connected to wetland planning.

The Oregon Wetland Monitoring and Assessment Strategy’s goal is to guide and coordinate an integrated approach to statewide monitoring and assessment efforts in order to improve the States’ ability to sustainably regulate, manage and conserve Oregon’s wetlands. ​

What is a wetland?
Wetlands are called by many different names and occur in an array of landscapes. Oregon has many wetland types that range from tidal salt marshes along the coast to fresh water marshes along streams and ponds, seasonal prairie and meadow wetlands in the valleys to mossy mountain fens. Wetlands may form at the edges of lakes, rivers and streams, in low isolated spots on the landscape, and where groundwater comes to the surface via seeps or during winter rains. Despite the wide variety of wetland types, three features area common to all:

  • The presence of water at or just below the surface of the land for at least a portion of the year, 
  • Soils that developed under saturated (wet) conditions, and 
  • Distinctive plants that are uniquely adapted to seasonal or year-round saturated (wet) soils

Prolonged saturation creates a wetland, no matter the water source. A high seasonal or permanent water table, rainwater “perched” over impenetrable layers in the soil, and frequent flooding are common examples. Wetland – or hydric – soils usually have distinctive, visible characteristics, such as brownish-red veining and rusty-colored splotches. Saturated conditions support plants that have adapted to life in permanently or seasonally wet soils. 

Wetlands in Oregon provides an overview of how to identify wetlands.

Are there wetlands on my property? 
Identifying wetlands is often difficult, as many wetlands do not appear obviously wet or they are only seasonally wet. In addition, many wetland landscapes have been altered over time by activities such as farming, and no longer “look like” wetlands.

Our Department staff provides assistance by conducting wetland determinations for the public (e.g. property owners, real estate agents, appraisers). This free service is usually conducted offsite (i.e., at their desk using GIS and other available information). Occasionally staff are able to visit the site as part of the wetland determination process.

Request a determination by filling out the Wetlands and Waters Determination Request Form.

Many wetlands in the state have been mapped for planning purposes, some by the U.S. Fish & Wildlife Service (USFWS) and others by local governments. The two types of inventories can be accessed through the wetland inventories section on this page.

The fact sheet Wetlands in Oregon provides an overview of how to identify wetlands and what to consider when hiring a wetland consultant.

What if I have wetlands on my property?
If you know there are wetlands on the property or a determination reveals that wetlands are likely, and there are development plans for the site, you may need to hire a consultant to do a wetland delineation. A delineation is a detailed mapping of the wetland boundaries and boundaries of other waters, such a streams or ponds.

A wetland delineation report that includes your site’s characteristics, field data, and detailed mapping must be submitted to the Department of State Lands for review and concurrence. Department concurrences will indicate which areas on a property are subject to regulation and may need a removal-fill permit prior to any activities. 

You may wish to hire a private consultant who specializes in wetlands and waterways regulation to assist you with conducting a wetland delineation and/or removal-fill permit application and mitigation plan. Information to help you hire a qualified wetland consultant may be found in the Wetlands in Oregon fact sheet. The Wetland Delineation Consultants Summary​ is a listing of wetland consulting firms with the number of delineation reports submitted to the Department of State Lands (DSL) and subsequently approved, approved with revisions, and rejected for the previous five-year period. 

Many wetland professionals working in Oregon are certified as a Professional Wetland Scientist (PWS) or Wetland Professional in Training (WPIT) by the Society of Wetland Scientists’ Professional Certification Program. To be certified as a PWS or WPIT, a person must meet education and experience requirements, and adhere to a code of ethics and professional practice. The SWS Pacific Northwest Consultant list​ is provided as a service to its members and the general public.

A well-planned project will result in an easier and faster-permitting process. The Removal-Fill Guide: Chapter 4 – Planning Ahead provides guidance about early identification of waters on a project site, hiring a consultant, evaluating alternatives to avoid and minimize impacts, planning to mitigate for unavoidable impacts, and pre-application meetings.

Technical resources
The Department’s Technical Resources webpage has tools and guidance for conducting delineations, assessments, and mitigation.​

​Although Oregon’s wetlands comprise only about 2 percent of the state’s land base, these wetland ecosystems have many functions that provide numerous benefits to the environment and to people. Although all wetlands share many basic features, their ecological functions—and thus the services they provide (ecosystem services)—differ markedly between regions and between landscapes. Oregon’s wetlands and their ecosystems are a highly diverse resource that reflects the extreme physical and biological variability of the state. For example, Willamette River floodplain sloughs temporarily store flood waters, reducing peak flows downstream. The vast Klamath Basin marshes—dubbed the “Everglades of the West”—support millions of migratory waterfowl. Streamside wetlands in the Coast Range provide food and shelter to threatened juvenile salmon and trout. Additional examples of wetland functions and the services they provide:

Flood storage and water supply
Many wetlands absorb and temporarily store stormwater flows, which reduces flood velocities and streambank erosion. Preserving these wetlands reduces flood damage and the need for expensive flood-control devices such as levees. When the storms are over, these wetlands slowly release the stored water back to the stream system, augmenting summer stream flows when the water is needed. Seasonal wetlands—the most common in Oregon and the most easily overlooked because they are dry in the summer—have great capacity to absorb storm water as they “recharge” in the winter and spring.

Water quality improvement
Wetlands are highly effective at removing nitrogen and phosphorous (two main ingredients of fertilizers), some chemicals, heavy metals, and other pollutants from water. For this reason, artificial wetlands are often constructed for cleaning stormwater runoff and for tertiary treatment (polishing) of wastewater. Wetlands bordering streams and rivers and those that intercept runoff from fields and roads provide this valuable service free of charge.

Food-web support
Because of their high productivity, wetlands provide essential food-web support. Ample water and sun combine to produce that green scum that coats cattail stems and ankles, providing food for an abundance of tiny organisms that, in turn, feed fish, wildlife and humans.

Wildlife and fish habitat
Wetlands provide essential water, food, cover and reproductive areas for many wildlife species. For example, nearly two-thirds of the commercially important fish and shellfish species are dependent upon estuarine wetland habitats for food, spawning, or nursery areas. Similarly, millions of waterfowl, shorebirds and other birds depend on wetlands. In semi-arid eastern Oregon, riparian (stream-associated) wetlands and springs are crucial to the survival of many birds, amphibians and mammals.

Rare and endangered species
As the old wetlands definition suggests, wetlands are full of “strange and different” animals and plants. Take the carnivorous pitcher plant, for instance, a bog plant with a cobra-like hood that traps insects. Nationally, nearly 35 percent of all rare and endangered animal species depend on wetlands, even though wetlands comprise only about 5 percent of the land area. In Oregon, 29 percent of native wetland plant communities are “imperiled.”

Aesthetics, recreation, and education
Depending on their type and location, wetlands provide opportunities for fishing, hunting, plant identification and wildlife observation. They are also visually pleasing, interesting elements in the landscape, often increasing property values in urbanized areas. Wetlands are also wonderful outdoor classrooms and laboratories. ​

​The great diversity of wetland types and the variety of functions they perform make it difficult to generalize about wetland resource health. No one indicator provides a suitable or sufficient measure of health for all wetlands. However, wetland area is a basic indicator that can be used to track wetland extent and trends. How much of the state’s original wetlands remain? What are current loss rates? Are there disproportionate losses in some regions? These area measures are important because, to a great extent, the health of wetlands in Oregon is dependent on maintaining the remaining wetlands, a goal embodied in Oregon’s and federal “no-net-loss of wetlands” policies. 

Data suggest wetland losses in various regions of the state vary from 57 percent in the Willamette Valley to 75 percent in the Klamath Basin, while losses for individual coastal estuaries range from 2 to 94 percent (Oregon State of the Environment Report 2000). Losses for particular rare wetland types have high losses, such as 99.5 percent of wet prairie and 98 percent of peatland in the Willamette Valley, 88 percent of tidal spruce swamps along the coast and lower Columbia River, and 40 percent of Agate Desert vernal pools in southwestern Oregon (Christy 2010).

Wetland and Land Use Change in the Willamette Valley, Oregon: 1994 to 2005​ is a study by the Department of State Lands and the U.S. Fish and Wildlife Service that indicates that, although wetland loss in the Willamette Valley has slowed in recent decades, it continues to occur. During the first 12-year period (1982 to 1992) change study, there was an estimated net loss of 6,877 acres of wetland to upland land uses, an average of 573 acres per year. Between 1994 and 2005, there was an estimated net loss of 3,932 acres of wetland to upland, an average of 357 acres per year. The only type of wetland that showed an increase between 1994 and 2005 was open water ponds, which are primarily constructed farm ponds or aesthetic ponds. 
The main cause of wetland loss shifted significantly between the two time periods: 
  • Between 1982 and 1994, 67 percent of the loss was to upland agricultural land uses.
  • Between 1994 and 2005, a period of rapid population and economic growth, 68 percent of the loss was to urban and rural development.

  • Freshwater wetland health varies by ecoregion, with urbanized and agricultural regions exhibiting the most wetland losses and degradation of wetland condition. Although data on freshwater wetland health are very limited, most indicators point toward declining health.
  • Statewide, 29 percent of native wetland plant communities identified to date are ranked as “imperiled.” Only a few have been studied in detail, like the Willamette Valley wet prairie (99 percent lost) and the Agate Desert vernal pools (more than 40 percent gone and what’s left highly degraded). 
  • Twenty-four percent of wetland-dependent amphibians are ranked as imperiled.
  • Extensive modification of rivers and streams has reduced wetland area and complexity and altered wetland types and functions.
  • Water quality standards for wetlands have not been established, but wetland water quality condition and trends may roughly parallel stream condition.
  • Existing regulatory programs have slowed wetland loss substantially but are not sufficient in themselves to halt the loss of wetland acreage and functions.
  • New wetland restoration incentive programs are helping to reverse wetland loss trends and improve wetland ecosystem health, particularly in agricultural regions.
  • Principal threats to wetland ecosystem health today include continued pressure to convert wetlands to other economic uses, and the cumulative impacts from human activities—such as pollution, sedimentation, and invasion of nuisance species—on wetland condition.

Local wetland planning and inventories

Local governments inventory and include protections for resources listed in Oregon's land use planning goals 5 (Natural Resources), 16 (Estuaries) and 17 (Coastal Shorelands). The Department of State Lands' aquatic resource planner works with local governments and the Department of Land Conservation and Development (DLCD) to provide both technical and planning assistance to local governments that are completing inventories and other related tasks. Goal 5 wetland compliance includes using inventory information about the locations, type and functional capacity of wetlands within the city or county to make development planning decisions.

City and county planners use wetlands inventories to determine when to send a wetland land use notice to DSL. The response to this notice provides planners and applicants with information about the likelihood that wetlands and waters are in the project area, and if a removal-fill permit may be required for the proposed project.

DSL is responsible for developing and maintaining the Statewide Wetland Inventory (SWI). For more information see the “Wetlands inventories" tab below and the Statewide Wetlands Inventory

Please use the online form to submit a Wetland Land Use Notification to DSL.

NOTE: This form is to be used only by local governments, not by landowners or agents.

Cities and counties are required by statute to check the “Statewide Wetlands Inventory" (SWI) and notify DSL of local applications received for activities that might impact a mapped wetland or water. When wetlands, waters or certain soils are mapped within or partially within the project area, local planners must submit a Wetland Land Use Notification (WLUN) to DSL. For more information see the “Wetlands inventories" tab below and the Statewide Wetlands Inventory​

DSL staff review the WLUN information and maps submitted, and within 30 days respond to the local government, the applicant and the landowner providing clarification of removal-fill permit requirements for the project area. The DSL response alerts landowners and developers to the possible need for a wetland delineation or state permit and provides the DSL contact information. This local/state coordination helps prevent inadvertent violations.​

Wetland notification statutes (pdf)​
​Wetland Land Use Notification Guidance (pdf)​

Wetlands perform many important functions in urban areas and are valued for the ecological services they provide serving as natural water purifiers, reducing flood damage by absorbing and storing floodwater, providing food and habitat for fish and other species, and offering recreational opportunities.

To assist local efforts, DSL and DLCD coordinate the statewide land use planning program, and state and federal wetland regulatory programs. Local protection mechanisms for natural resources are based on location and assessment information from wetland and riparian inventories. Incorporating the local protection and inventory components into local comprehensive land use plans provides reliable information and certainty for landowners interested in developing their property. In general, DLCD establishes the procedural requirements and DSL provides technical methods and standards for resource inventories and assessments.

To complete the Goal 5 planning process for wetlands and waters, most cities must develop and adopt a Local Wetlands Inventory (LWI). The LWI includes mapping that identifies the location of wetlands and waters, an assessment of the functions of mapped wetlands using the Oregon Freshwater Wetland Assessment Methodology (OFWAM), and a determination of "locally significant wetlands." DSL's aquatic resource planner completes the technical review and the department approval of the LWI.

After adopting the LWI, the city develops a local protection program for “locally significant wetlands" and riparian corridors and incorporates the program into their comprehensive plan.

A very similar process is followed for Goal 17. Coastal shorelands are lands contiguous with the ocean, estuaries & coastal lakes. The inventory and functional assessment steps are the same as for Goal 5. Significant wetlands whose quality is derived from coastal waters are “major marshes." Major marshes must be protected; their potential “uses" must be consistent with their natural values.

The Goal 16 process for estuaries includes mapping and classification of Oregon estuaries into four categories: deep draft development (3 estuaries), shallow draft development (7 estuaries), conservation (5 estuaries) and natural (2 estuaries). Each estuary is subdivided into development, conservation and natural management units. State law prescribes uses permitted in different management units. Estuary plans include implementing ordinances and criteria for when removal or fill would be permitted. DSL and the Corps of Engineers will not issue a permit if the proposed project is not consistent with the estuary plan.

Caution: Wetlands that are not determined to be “significant" for Goal 5 or Goal 17 purposes are still regulated by DSL through the Removal-Fill Law and may also be regulated by the Corps of Engineers under section 404 of the federal Clean Water Act.

The Aquatic Resource Planner collaborates with local governments and DLCD to provide both technical and planning assistance with Goal 5 and 17 wetland and waters resource tasks. Assistance may include:

  • Working with a wetland consultant.
  • Participating in public involvement meetings.
  • Providing comments on the proposed local protection program and adoption.
  • Giving educational presentations to public groups and planning staff on wetland inventories and DSL's regulatory program and services.

    The following are some resources to assist planners to complete tasks for related statewide planning goals:

The Department of State Lands is responsible for developing and maintaining the Statewide Wetlands Inventory (SWI). The SWI includes two types of wetlands inventories, the National Wetlands Inventory (NWI) and Local Wetlands Inventories (LWIs). Also included is the National Hydrography Dataset, a nationwide waters inventory and mapping of certain soils associated with wetland conditions.

It's important to recognize that the SWI is for planning and general information uses only. Each map dataset has limitations and provide estimated boundary locations. Within LWI study areas, the LWI mapping replaces the NWI mapping. Often on-site investigation is the only way to verify if wetlands and waters exist on a given property. The more accurate DSL-approved wetland delineation mapping supersedes inventory mapping within the delineation study area, but it is not available in digital format to display on the SWI.

The SWI web page includes information on how to use the SWI and LWIs for project screening and planning.

For more information see the Statewide Wetlands Inventory​ and the web map.

National Wetlands Inventory (NWI)

The NWI was developed by the U.S. Fish and Wildlife Service and is available statewide. NWI mapping is based on wetlands and other waters that were visible on high-altitude aerial photography with little field verification. There are limitations with the NWI because most of the mapping dates to the mid-1980s. In addition, many wetlands between one and five acres may not have been detected and mapped, and the NWI generally does not map some types of “farmed wetlands," although many farmed areas in Oregon meet wetland criteria.

Information and mapper

Local Wetlands Inventory (LWI)

An LWI provides information needed to incorporate wetlands and streams into comprehensive plans. LWIs are developed by cities and some counties according to standards set by DSL.

LWIs include a report describing the study methods, study area and wetlands identified; a functional assessment of each wetland greater than 0.5 acre in size; and maps showing the locations and extent of each wetland. The LWI mapping is based on field investigations to the extent possible. The “Oregon Freshwater Wetland Assessment Method" is used to assess the functional capacity of each wetland. These findings are used as some of the criteria that determine if a wetland is “locally significant." The LWI and wetland significance determinations form the basis for many important local planning decisions.

Characteristics of LWI mapping include:

  • Wetland boundaries are mapped onsite where access permission is granted. Where access is not granted, resource boundaries are estimated using offsite methods. LWIs developed after 2009 have a boundary accuracy of approximately 5 meters (16.4 feet). Prior to 2009 boundary accuracy was approximately +/- 25 feet.
  • Wetlands greater than 0.5 acre are mapped and assessed.
  • LWIs developed after 2001 represent wetlands smaller than 0.5 acre as “probable wetlands," noted as “PW." Earlier LWIs did not map these small wetlands and waters.

​An Advance Aquatic Resource Plan (AARP) is a planning tool that cities, counties and community groups may pursue when large areas of potentially developable lands are constrained by the presence of wetlands.  To apply for the approval of an AARP, a community must sponsor the project and work with agencies, jurisdictions, land owners and other interested parties to agree on the objectives and content of the plan application.


A person stands in a wetland making scientific observations


Fees & payment

Wetland delineation report fee is $540.

Resubmittal of a previously rejected report (if initial fee was paid) is $100.

Send checks to:
775 Summer St. NE Suite 100 
Salem, OR 97301-1279