Wetlands 101: Introduction to Wetlands


[music playing] Hi, I’m Rick Mraz wetland specialist with Washington Department of Ecology. And I’m here at the Mclane Creek Nature Trail to introduce our Wetlands 101 Education Series. The goals of the presentation are to give planners the tools to be able to recognize a wetland or at least to make them suspicious that a site could be a wetland. Also to enable planners to recognize flaws or faults in a wetland delineation report and to increase their comfort level in discussing wetlands with applicants and their consultants. We intend to do this through our presentation of four modules which introduce wetlands in an ecological and regulatory context and then explore the three parameters necessary for a positive finding of wetland presence. Following this introductory session subsequent modules will examine a specific wetland parameter using the federal wetland delineation manual and appropriate regional supplement to frame the discussion. The topical material for this webinar will be Eastern Washington focused. The first of the four modules will be an introductory presentation that will explore some of the most basic concepts about wetlands; the second module will introduce and explore the concept of wetland hydrology; third module will examine hydric soils; the fourth and final module will discuss hydrophytic vegetation. This introductory discussion will provide an overview of wetlands from a qualitative perspective. It should answer questions like What are wetlands? Where would I find wetlands? And it will include a brief look at some tools that are helpful in determining wetland presence. And we’ll also discuss why wetlands are important. We will also briefly discuss one wetland assessment tool that helps quantify certain benefits of wetlands. The first question: “what are wetlands” is answered by using the legal definition, which is present in a number of Washington state laws, including the Growth Management Act and the Shoreline Management Act. Wetlands are identified through three unique but inter-related parameters. Water which is a fundamental component is often described as wetland hydrology. Please forgive this misnomer “hydrology” actually means the study of water. But in the context of wetlands, hydrology has a very specific meaning that will be discussed in the next module. These next two slides display the regulatory definition of wetlands with key terms underlined. The parentheses contain a distilled version of the concept. Inundation is showed on this image. A prevalence of vegetation implies that there is a dominance of hydrophytes in a potential wetland area. Saturation will be discussed in more detail in the hydrology and hydric soils modules. Here’s the state definition of wetlands for Washington state and the state has added language in its definition and these additions include a mention of synonyms for the term “wetland”. Words like swamps, marshes, bogs, a clarification of what is and what is not considered a wetland for regulatory purposes, so Washington excludes irrigation and drainage ditches for example. And an important side note on this definition these additions are not present in the federal definition of wetlands as used by the Army Corps of Engineers and the EPA so these changes or these additions are not recognized by federal regulatory agencies. So, let’s take a closer look at the three parameters: water, soil, vegetation. As previously noted these individual parameters will be explored in much greater detail in the coming modules of this webinar. Water, it’s not a wetland without water. As I said, wetlands are regulated as critical areas, waters of the state and waters of the United States. In each context the key requirement is water. As we saw in the wetland definition, important wetland hydrology concepts are frequency and duration, but other factors, like timing can also be very important. For example, parts of eastern Washington receive enough rainfall during the winter to become inundated. However, this winter inundation alone does not make an area a wetland. It’s not a wetland if it’s all water. Lake Chelan is not a wetland. While open water bodies may be regulated in other ways, they are not considered wetlands. One needs the other two parameters to be present as well. Hydric soils. It takes special conditions to form a hydric soil and these soils exhibit unique features. Persistent wetland hydrology during the right times of the year will create distinctive characteristics in the soil. Some of these characteristics are mineral depletion, which is the pale appearance in these soils, and redoximorphic features, which are the rusty appearances in the left side image. These will be discussed in greater detail in future webinars. Hydrophytic vegetation. Plants need water to live, but too much water will kill most plants. Certain species have special adaptations to live in very wet conditions. Such plants are called hydrophytes. Many hydrophytes can also grow in uplands. We’ll discuss how to determine if there’s a dominance of hydrophytes in a future webinar. And these three aspects: hydrology, soils, and vegetation are the parameters necessary to call an area a wetland. Wetlands can be found all over eastern Washington. This is a National Wetlands Inventory map of a small part of Eastern Adams County. The different colored polygons are different types of wetlands and the coloration is based on vegetation type. National Wetlands Inventory mapping can be found at the US Fish and Wildlife Service website. There is an older projection of the NWI that is also available on Ecology’s Coastal Atlas. And while generally consistent with the most recent NWI mapping, the older coverages on Ecology’s Atlas are not entirely identical. So, we recommend you use the US Fish and Wildlife Service website for the most current data. Here’s another area in Chelan County as depicted by the Wetland Change Analysis project. This mapping is another source of information that can give evidence of wetland presence. These maps were produced by Ecology and will be used as a wetland status and trends inventory to help determine if the state goal of No Net Loss of wetlands is being achieved in Washington. The Wetland Change Analysis project provided a wetland inventory for portions of eastern Washington. It provides approximate locations for most wetlands larger than 1 acre. It also includes potentially disturbed wetlands and shows areas that have high potential to be a wetland but have an observed land cover of pasture, hay, or cultivated. It is more accurate than NWI for wetlands larger than 1 acre especially in agricultural, forest, and stream corridor settings. They can be used for planning purposes and for initial permit review but like other wetland maps, it cannot be used to determine regulatory boundaries. That requires fieldwork. Wetlands can be found in a variety of landscape settings. Those locations have important influences on certain wetland characteristics which we will discuss in more detail in just a few slides. The term that is used to describe landscape position is hydrogeomorphic setting or class. This image is of a lake fringe wetland which is one HGM class. Wetlands can be classified in other ways too. Sources of water, vegetation types, or their functions and values are different class types. The following slides will show a variety of wetland types found in eastern Washington. This slide shows a forested wetland, which can be difficult to identify in certain seasons. In late summer, the soils of this wetland may become dry in evidence of early season vegetation (skunk cabbage in this instance) may have disappeared. The timing of a wetland delineation is very important and will be discussed in more detail in future modules. Vernal pool ecosystems are formed when small depressions in scab rock or shallow soils fill with snow melt or spring rains. They retain water until late spring when reduced precipitation and increased evapotranspiration lead to a complete drying out. The wetlands hold water long enough throughout the year to allow some strictly aquatic organisms to flourish but not long enough for the development of a typical wetland environment. Alkali wetlands are wetlands with high concentrations of salt. They form where groundwater comes to the surface and evaporates. The evaporation over many years has concentrated the salts that were present in the groundwater. To our knowledge these wetlands cannot be replicated through any compensatory mitigation and they’re rare on the landscape. Depressional wetlands. This image is of a depressional wetland that drains to Toppenish Creek. Seasonal fluctuation in the influence of ponding are common. Riverine wetlands are those found in a valley or stream channel where they can be inundated by overbank flooding from the river or stream. They lie in the active floodplain of a river and have important links to the water dynamics of that river or stream. The distinguishing characteristic of riverine wetlands in Washington is that they are frequently flooded by over bank flow. The flood waters are a major environmental factor that structures the ecosystem in these wetlands and controls its functions. Wetlands in agricultural settings may be highly modified and are among the most challenging to identify. Vegetation is often managed for specific crops so native plants are usually absent. These wetlands are not typically subject to regulations unless a change of use is proposed. The process of determining where a wetland is and what its boundary is called a “delineation”. We’ll briefly touch on some aspects of delineation in the next few slides. Much more is coming in the next modules. Delineations are typically done by trained professionals, although there is no legal requirement to do this in Washington State. And this may be a very good reason for reviewing a delineation. The delineation is not officially valid until it’s confirmed by the Army Corps of Engineers and Ecology as a part of the permitting process. And in general a delineation is valid for five years. The procedures for conducting a delineation are standardized and described in the Federal Manual and appropriate regional supplement. The Washington State Wetlands Identification and Delineation Manual published in 1997 is no longer in use. It has been superseded by the Federal Manual and supplements. The subsequent modules will discuss the 1987 manual and the Arid West and Western Mountains, Valleys and Coast Region supplements. Regional differences in climate, geology, soils, hydrology, plant and animal communities, and other factors are important to the identification and functioning of wetlands. These differences cannot be adequately considered in a single national manual. Thus the regional supplements were developed as an approach to recognize geographic differences. In eastern Washington, we have two regional supplements that apply. The Arid West applies essentially to the Columbia Basin, Yakima, Walla Walla, and Tri-Cities. While the Western Mountains, Valleys, and Coast supplement applies to the higher elevation, mountainous areas. There are many tools used in conducting a delineation. And while this course is not intended to teach you how to conduct a delineation, it’s important to note whether the proper tools and methods have been used when reviewing a wetland report. The subsequent modules will use the Arid West and Western Mountains, Valleys and Coast Region field data sheets as teaching tools. They will also help you review field methods and information presented in a delineation report to ensure that the proper techniques were used. Data sheets are vital. And here’s a screenshot of the first part of a wetland delineation data sheet. This upper portion should be completed in its entirety. The project site should be given or named. The sampling date is critical for reasons that will be discussed in upcoming modules. The sampling point is a unique identifier that should correspond to a map provided in the report. It lets the reviewer know where a test pit was located and there should be a data sheet for every spot that was sampled during the delineation. Landforms, local relief and slope all help the reviewer consider whether the area might be more likely to contain wetlands. The questions about whether the site is significantly disturbed or naturally problematic are also very important. The manual provides detailed guidance on how to approach a delineation in disturbed areas and the regional supplements list several types of problem areas common to our region. Normal circumstances is what it sounds like: the term refers to situations in which the vegetation has not been substantially altered by human activities. Whether conducting a delineation or reviewing one, certain tools and perspectives are necessary. National Wetlands Inventory maps can provide evidence of wetland presence. Aerial photos can provide evidence of seasonal ponding. Soil maps can identify mapped hydric soils. Knowing those plants that commonly occur in wetlands is a valuable skill. The upcoming modules will help address using this information to your advantage. When reviewing a delineation consider the larger contexts of climate, season, and other weather events. Is it the dry season or the rainy season? Has it been raining more or less than normal? Consider land modifications that have happened. Has the site been altered by ditching, draining, fill, or other land disturbance? Are circumstances normal? These aspects should all be considered when conducting or reviewing a delineation. Why do we care? Well, wetlands are protected by federal, state, and local laws. These protections exist because science has shown us that wetlands provide significant benefits to humans, directly and indirectly. Wetland functions are the physical, biological, chemical, and geologic interactions among different components of the environment that occur within a wetland. While wetland values are the benefits that we (humans) receive when wetlands perform certain functions. Wetlands can store water during high flow or recharge during low flow. This is often described as the hydrologic function. Because of their low topographic position relative to uplands, wetlands store and release surface water more slowly. Trees and other wetland vegetation also impede the movement of flood waters and distribute them more slowly over floodplains. This combined water storage and slowing action lowers flood heights, reduces erosion, and improves downstream lands. Wetlands within and downstream of urban areas are particularly valuable in this regard, counteracting the greatly increased rate and volume of surface water runoff from pavement and buildings. Wetlands can remove pollutants. Wetlands greatly influence the quality of water in a watershed by removing many different types of contaminants. They help improve water quality including that of drinking water by intercepting surface runoff and removing or retaining inorganic nutrients, processing organic wastes, removing pathogens, and reducing suspended sediments before they reach open water. And wetlands can provide habitat to a wide range of animals. Some live in wetlands for their entire lives; others require wetland habitat for at least a part of their life cycle. Although wetlands only represent about two percent of the area of Washington state over two-thirds of all the terrestrial vertebrate species in Washington can be considered wetland users. The more functions that a wetland has, the greater value is to us and the natural world. Wetland functions depend on a number of factors and one way to assess the functions and values a wetland provides is to use the Washington State Wetlands Rating System. This method is in wide application in Washington state. Local regulations often coordinate functional ratings with protection strategies like buffers and mitigation requirements. The Department of Ecology published its first version of the Washington State Wetlands Rating System in 1991, subsequent updates to reflect current science were published in ’93, 2004, and most recently 2014. As was noted in a prior webinar, we have updated the Rating System again and the new version is now required for state and federal permitting. There is a version for eastern Washington and western Washington. The Rating System assesses wetland functions for water quality, hydrology, and habitat. We will now spend just a few minutes discussing the Washington State Wetland Rating System. For more in-depth training on the use of the Rating System or for classes on how to review wetland ratings, please check with the Coastal Training Program. Wetlands are grouped by category in the Washington State Wetland Rating System. And Category 1 wetlands are deemed the highest value wetlands. We cannot afford the risk of any degradation to these wetlands because their functions and values are too difficult to replace. Generally, these wetlands are not common and make up a small percentage of wetlands in the region. Bogs are considered Category 1 wetlands. Category 2 wetlands are difficult though not impossible to replace and provide high levels of some functions. These wetlands occur more commonly than Category 1 but still need a relatively high level of protection. Category 2 wetlands in eastern Washington include forested wetlands in floodplains. Category 3 wetlands are those with low to moderate functions. They may have high functions in one area, but low in others. This forested slope wetland provides moderate levels of habitat function with relatively low levels of water quality and hydrologic function. Category IV wetlands have the lowest level of functions and are often heavily disturbed. These are wetlands that we should be able to replace and in some cases improve. However, experience has shown that replacement cannot be guaranteed in any specific case. These wetlands may also provide some important functions and also need protection. Thanks for taking time out of your day to watch this video. We hope that the information in it will be useful for your work. If you have more questions or want to learn more about wetlands, please watch some of the additional videos in our Wetlands 101 Education series. [music playing]

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