Wetlands 101
What is a Wetland?
A special recipe of soil, plants, and water. Specifically, only certain soils make wetlands, only certain plants can handle wetland conditions, and water must be present for some amount of time, all depending on the wetland. If a place has all three– special soils, plants, and hydrology (or how water moves through an area)- then it’s a wetland!
Wetland soils are often water-logged, dark in color, and often sticky, because they’re made of tiny microscopic soil particles, unlike the sand at the beach where you can identify individual grains of sand. Although wetland soils are different depending on the wetland and where it is, one thing remains the same among them all: very little oxygen. With almost no space between the soil particles and all the water in between what space there is, very little air and oxygen makes its way into the soil. Oxygen is needed to break down or degrade materials. This means that organic material (think plants, wood, even dead animals) takes a very long time to decompose and break down in wetlands. This can make wetland soils have a distinct odor, and why some of the oldest preserved remains and artifacts come out of peat bog, a type of wetland in Europe!
The formal process of identifying a wetland for the purposes of development is called a wetland delineation. Often done by a professional wetland scientist or other environmental professional, this process identifies the plants, assesses the soils, and evaluates the hydrology over a designated area to determine if there’s a wetland present, the extent of the wetland, and what type of wetland it is.
Using the Munsell Soil Color Chart to determine soil type.
Photo Credit: © J. Kelley, http://soilScience.info
Wetland Types
There are so many different types of wetlands across the world and dozens in Oregon.
These include alkaline wetlands, aquatic beds, fens, forested wetlands, freshwater marshes, freshwater tidal wetlands, salt & brackish marshes, serpentine fens, shrub swamps, vernal pools, wet meadows, and wet prairies. We know. It's a lot! They each have unique characteristics that distinguish each from one another. The most common wetland types in Oregon can be grouped in: Lacustrine (freshwater and lakeside), Palustrine (freshwater and forested), or Estuarine (tidally influenced where freshwater and seawater meet). The rarest are Serpentine fens mostly located in Josephine county in southwestern Oregon. They form on slopes or in basins where seepage and springs discharge in soils derived from peridotite and serpentinite bedrock.
Ducks swimming at Minthorn Springs Wetland, a freshwater scrub shrub wetland, in the heart of Milwaukie, OR.
Photo Credit: Steven Mortinson
Functions
Wetlands play a crucial role in supporting both humans and wildlife. They act as natural filters, purifying water by trapping pollutants and sediment. This helps maintain water quality and ensures a healthy environment for all life. Wetlands also provide important habitat for a wide variety of plant and animal species, serving as breeding grounds, nurseries, and stopover points for migratory birds. According to the Environmental Protection Agency (EPA), more than one-third of the United States’ threatened and endangered species live only in wetlands, and nearly half use wetlands at some point in their lives. In addition, wetlands help regulate water flow by absorbing excess rainfall and reducing the risk of floods.
Wetlands offer several functions that contribute to their ecological value. They serve as carbon sinks, capturing and storing large amounts of carbon dioxide from the atmosphere, which helps mitigate climate change. Wetlands also act as buffers against coastal erosion, protecting shorelines from the damaging effects of waves and storms. Moreover, wetlands provide recreational opportunities such as birdwatching, hiking, and fishing, offering a place for people to connect with nature.
A volunteer inspecting wetland soil.
Photo Credit: Steven Mortinson
History
The history of wetlands in Oregon since European colonization has been marked by significant changes. Native people thrived for generations because of their stewardship of forests, wetlands, oak prairies, and more ecosystems, and still do, despite efforts to stop them. Many wetlands were drained or filled after the removal of indigenous people to make way for agriculture, urban development, and infrastructure. These activities greatly reduced the extent and quality of wetlands in the state. While it is challenging to provide an exact figure for the total wetland loss, it is estimated freshwater and tidally-influenced wetlands once covered as much as 2.3 million acres in the late 1700s (Dahl 1990). Now, it is estimated to be 1.4 million. While land use changes have provided significant socioeconomic benefits for several generations of Oregonians, it has been at the expense of generations prior and eliminated and degraded many streams and wetlands needed by future generations. However, there is now a growing recognition of both the importance of wetlands and the injustice to indigenous people and their removal from their homelands. Now, efforts are being made to protect and restore wetlands with indigenous people, understanding that as the original stewards of these lands, wetland protection and indigenous justice go hand in hand.
Regulatory measures, conservation programs, and restoration initiatives have been implemented to mitigate wetland loss and promote the conservation and rehabilitation of these critical ecosystems. Restoration projects aim to enhance wetland habitats and reestablish their ecological functions. By conserving and rehabilitating wetlands, we can ensure their continued benefits for future generations and promote the well-being of both humans and wildlife.
Cattails surround an urban wetland, providing wildlife watching and water treatment.
Photo Credit: Steven Mortinson
Wetland Regulation in Oregon
In Oregon, wetlands are primarily regulated by a combination of federal, state, and local agencies. The main regulatory bodies involved in wetland management and protection in Oregon include:
Oregon Department of State Lands (DSL): DSL manages, protects, and regulates state wetlands and waterways. They regulate activities such as dredging, filling, and other uses that may impact wetlands in these areas.
U.S. Army Corps of Engineers (USACE): The USACE administers and enforces the federal Clean Water Act, which includes the regulation of activities that may impact wetlands. They are responsible for issuing permits, such as Section 404 permits, for activities that involve the discharge of dredged or fill material into wetlands and other waters of the United States.
Oregon Department of Environmental Quality (DEQ): DEQ oversees water quality protection in Oregon. They regulate activities that may affect water quality in wetlands, such as discharges of pollutants or stormwater runoff.
Local Land Use Planning Departments: County or city land use planning departments are responsible for implementing land use regulations and comprehensive plans that may include provisions for wetland protection and management at the local level.
It's important to note that regulations and permit requirements may vary depending on the specific location, size, and type of wetland, as well as the nature of the proposed activity. It is always recommended to consult with the relevant regulatory agencies early in the planning process to determine if any permits or approvals are required and to ensure compliance with wetland regulations in Oregon.
A volunteer walks through the shrubs of a tidal forested wetland.
Photo Credit: Steven Mortinson