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What is a Wetland?

Some may be asking--what defines a wetland? According to the U.S. Fish and Wildlife Service, wetlands are generally “lands where saturation with water is the dominant factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface.” These natural gems provide countless benefits, and are worth understanding a little bit better.

There are actually many different types of wetlands than just the swampy, marshy place covered with cattails and ducks. Some wetlands lack visible water for most of the year, and might even be covered with dense trees and shrubs. There are eight major (and all very unique) types to consider.

Types of Wetlands


Seasonally Flooded Basin or Flat

This type has "seasonal" wetness, which references the typically well-drained nature of the wetland during a majority of the growing season. The vegetation here can vary greatly based on the season and duration of flooding, but can range from bottomland hardwoods to herbaceous plants. These types are commonly found in upland depressions and floodplain forests.


Seasonally Flooded Basin or Flat wetland


Wet Medows

Wet meadows are saturated during the majority of the growing season, and have very little visual water, but waterlogged soils can be found within a few inches of the surface. Vegetation is typically grasses, sedges, rushes, and an assortment of broad-leaved plants. These wetlands are sneaky, filling in shallow basins or farmland sags, and can also border shallow marshes or include low prairies, sedge meadows, and calcareous fens.

Wet Meadows


Shallow Marshes

These are typically waterlogged during the early stages of the growing season, and covered with 6 or more inches of water. The vegetation includes grasses, bulrush, spikerush, and other marsh plants (such as cattail, arrowhead, pickerelweed, and smartweed). Shallow marshes may form by filling in basins or sloughs, or may border deep marshes on the landward side.


Shallow marsh wetland


Deep Marshes

Deep hedges often form along the edges of lakes and streams and are characterized by grasses, sedges, rushes, and other vegetation, such as cattail, reed, and wild rice. Open areas may also have pondweed, naiad, coontail, or waterlily. These marsh plants can act to slow down water, sometimes allowing for nutrient enriched sediment to be deposited, or by acting as a filter for excess nutrients. They have evident standing water of 6 in - 3 ft or more during the growing season.

deep marsh wetland


Shallow Open Water Wetlands

These are usually covered with “less than 10-ft-deep water,” and can include shallow ponds and reservoirs. The vegetation here is similar to that of open water areas in deep marshes, with examples such as pondweed, naiad, coontail, watermilfoil, waterweed, duckweed, waterlily, and spatterdock.

Shallow open water wetland


Shrub Swamps

Shrub swamps are characterized by peaty soils, but dominated by grasses, grass like plants, sedges, and reeds. Unlike bogs, shrub swamps receive water from both surface and groundwater sources. Vegetation in a shrub swamp includes alder, willow, buttonbrush, dogwood, and it commonly occurs along slow-moving streams, drainage depressions, and the occasional floodplain.

shrub swamp


Wooded Swamps

This type is characterized by soils that drain poorly and the vegetation is tree-dominant (hardwood and coniferous swamps, with tamarack, northern white cedar, and red maple to name a few). They are found worldwide, but prefer to be in low-lying regions next to rivers where there is poor drainage, and sometimes swamps develop from filled-in marshes.

Wooded swamp



 Bogs are different from other types of wetlands because it exclusively receives water from rainfall. It is easily distinguished by “wet, spongy, poorly drained peaty soil which is dominated by the growth of bog mosses and heaths.” The vegetation here is woody, herbaceous, or both, easily identifiable by a squishy covering of moss.

bog wetland


Now that we understand the types, and know that wetlands are transitional areas between upland and aquatic environments, the science behind determining wetlands is a little less mysterious. As we now know, there are many types of wetlands, and they do not need to have standing water or cattails to qualify as a wetland. In more technical terms and for use in the court of law, wetlands are delineated according to the 1987 US Army Corps of Engineers Wetland Delineation Manual. Three conditions, or parameters are considered when determining whether an area is, or isn’t a wetland.

3 Parameters



The presence of water at or near the soil surface for a specific amount of time.

Hydric Soil

Hydric Soil

Low oxygen conditions in wetland soils will result in unique soil characteristics. 

hydrophytic vegetation

Hydrophytic Vegetation

Plants that are specifically adapted to wet conditions. 


Wetlands are both integral and historical aspects of Minnesota ecosystems.

A 2006-2008 survey found that there were 10.62 million acres of wetlands remaining in Minnesota (Minnesota Pollution Control Agency, 2016), which is approximately 19% of the total area of the state. These 10.62 million acres are constantly multi-tasking; they assist in erosion control, contribute to groundwater recharge and discharge, act as a natural filter for excess nutrients and pollutants, provide an opportunity for education and recreation, and they serve as habitat for fish, wildlife, and rare species, all important to the year-round health and prosperity of Minnesota.

In 1991, the Wetland Conservation Act (WCA) (pronounced “wack-uh”) was signed into law. This legislation was largely initiated by concern that increasing drainage and filling activity was resulting in the steady disappearance of wetlands. The resulting WCA legislation set a standard of rigorous protection for wetlands in the United States, with the goal of the act being to achieve “no net loss” of future wetlands.

wildlife in wetland

To accomplish this, the Wetland Conservation Act requires that anyone who proposes to fill, drain or excavate a wetland must first try to avoid wetland impacts at all cost.

If avoidance is impossible, the second step is to minimize those impacts and, finally, replacement is required for any unavoidable wetland excavations, fills, or drainage. There are exemptions within the law that may apply to specific situations, however the general attitude is that wetlands should remain untouched.

meadow wetland

This attitude is largely due to the countless benefits that wetlands provide, including:

  • Increase water quality by filtering pollutants out of surface and groundwater

  • Provide flood control during spring run-off and large storm events

  • Provide base flows to stream systems and recharge groundwater

  • Provide precise habitat conditions favorable to specific, and sometimes rare, plants and wildlife

  • Opportunities for public recreation and education


Wright County in total is 456,960 acres. Of those, approximately 63,371 or 13.9% are wetlands. That means that of the 10.62 million acres of wetlands in the state, approximately 0.5% are in Wright County (MN DNR, 2016).

Contact Senior Resource Wetland Conservationist - Andrew Grean

763-614-2918 for more information on wetlands

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