Colorado Wetland Information Center Logo Colorado Wetland Information Center Logo CWIC
  • About CWIC
    • What Are Wetlands?
    • Why Are Wetlands Important?
    • Colorado Wetland Plan
    • Wetland Partners
  • Wetland Types
    • Overview
    • Ecological Systems
    • Natural Plant Communities
    • Field Guides and App
    • Fen Mapping
  • Wetland Condition
    • Overview
    • Ecological Condition
    • Habitat Quality
    • Biodiversity Significance
    • Colorado Wetland Assessment Projects
    • National Wetland Condition Assessment
    • BLM Assessment Inventory and Monitoring
  • Working in Wetlands
    • Overview
    • Conservation
    • Restoration
    • Regulation
    • Best Management Practices
    • Funding and Technical Support
  • Data & Tools
    • Wetlands Mapper
    • Floristic Quality Calculator
    • Landscape Summaries
    • Watershed Toolbox
    • Wetland Plots Database
  • Library
    • Wetland Reports
    • Potential Conservation Areas
    • County Survey Reports
    • Field Guides and App
    • Field Manuals
    • Educational Resources
  • CNHP Home

Why Are Wetlands Important?

Wetlands perform many essential ecological functions in Colorado's watersheds, from water storage to wildlife habitat. One of the most important functions for Coloradans is the role of wetlands in providing clean water. Wetland vegetation acts as a filter or sponge for water and sediment that may contain heavy metals, pesticides or fertilizers. Many Colorado wetlands also provide water storage during floods, buffering Colorado’s working lands, cities and towns from flood damage.

Wetlands provide important wildlife habitat
Wetlands provide important wildlife habitat

By supporting clean water, and helping store water throughout the growing season, wetlands play a key role in providing water for agriculture and cities, as well as many of Colorado's best-known recreational activities like hunting, fishing, wildlife viewing, and rafting. Wetlands also provide critical wildlife habitat. In many areas of the Intermountain West, more than 80% of wildlife species depend on wetland and riparian areas at some point in their lives. In arid climates like Colorado, where evaporation often exceeds precipitation, wetlands are irreplaceable habitats for vast numbers of ducks, shorebirds, wading birds, cranes, and raptors that either breed or stopover in wetlands during migration.

Colorado Wetland Functions

Wetlands provide a large number of functions across the state. We've provided summaries for some of the most well-documented wetland functions below.

Click a link below for details.

  • Conservation of Biodiversity
  • Amphibian Habitat
  • Aquatic Invertebrate Habitat
  • Shorebird Habitat
  • Waterfowl Habitat
  • Bank and Shoreline Stabilization
  • Flood Attenuation
  • Groundwater Recharge
  • Sediment Capture and Retention
  • Stream Flow Maintenance
  • Carbon Sequestration and Storage
  • Metal Removal and Storage
  • Nitrogen Uptake and Transformation
  • Phosphorus Removal and Storage
  • Temperature Regulation
Rare wetlands orchid, Epipactis gigantea. Jill Handwerk, CNHP.
Rare wetlands orchid, Epipactis gigantea. Jill Handwerk, CNHP.

Conservation of Biodiversity

Back to top

Wetlands are located at the interface between terrestrial and aquatic environments, and are often hotspots for a diverse array of terrestrial and aquatic wildlife and plants, including rare species. Biodiversity, or the presence of the full suite of organisms capable of inhabiting a given environment, is a critical part of maintaining Colorado’s wetland and terrestrial ecosystems into the future.

In the web of living organisms, each species is tied to many other species, and removing one species—from a tiny aquatic invertebrate to a large carnivore—may have rippling direct and indirect effects on the rest of the ecosystem. Often, these effects include an ecosystem’s ability to sustain the clean water and natural resources that we depend on to meet our basic needs. Biodiversity also provides aesthetic values, and many of our essential Colorado landscapes are tied to specific communities of plants, animals, and other organisms.

Read more

Northern leopard frog. Keith Penner.
Northern leopard frog. Keith Penner.

Amphibian Habitat

Back to top

Wetlands provide breeding, foraging, and overwintering habitat for Colorado’s 17 species of native amphibians. All of Colorado’s amphibians require temporary or permanent standing water for breeding habitat, but many species spend the remainder of the year in adjacent terrestrial habitats.

Some species, or individuals of a species, retain juvenile characteristics (neotenic larvae) and spend multiple years in standing water. Colorado’s frogs, toads, and salamanders consume a variety of aquatic and terrestrial organisms for food, from aquatic insects, worms, crustaceans, mollusks, and other invertebrates to small vertebrates and sometimes algae and plants. Amphibians have highly absorbent skin, and are particularly sensitive to water quality, including the presence of excess nutrients (eutrophication), pesticides and other synthetic chemicals, along with land use/management adjacent to the full range of habitats that they utilize throughout the year. Boreal toads populations have also been greatly reduced by the chytrid fungus (Batrachochytrium dendrobatidis), which is widespread across the toad’s Colorado range.

Read more

Susan's purse-making caddisfly. Dave Ruiter, USFWS.
Susan's purse-making caddisfly. Dave Ruiter, USFWS.

Aquatic Invertebrate Habitat

Back to top

Aquatic invertebrates, including insect larvae, inhabit wetland habitats from mountain streams to vegetated ponds in the plains. Larval and adult invertebrates are a critical food source for fish (including trout and other recreationally important species), amphibians, reptiles, shorebirds, wading birds, ducks and other waterfowl, mammals, and other wetland-dependent species, and often help break down leaves, wood, algae, and other material in streams and other aquatic environments.

Depending on the duration of standing water, and other habitat characteristics like water chemistry and vegetation type, each wetland or waterbody may host an entirely different, yet diverse community of aquatic invertebrates. The types of invertebrates present in a wetland or waterbody are often used as an indicator of water quality (temperature, dissolved oxygen, etc.), and other habitat characteristics like the degree to which the natural hydrologic regime (including the magnitude, duration, frequency, rate of rise and recession, and variability in flows or water levels) has been altered by human water management.

Read more

Long-billed Curlew - Laguna Atoscosa NWR, Texas. Brian Tang.
Long-billed Curlew - Laguna Atoscosa NWR, Texas. Brian Tang.

Shorebird Habitat

Back to top

Shorebirds like sandpipers, plovers, and curlews use a variety of Colorado wetland habitats from lake shores to river sand bars and playas. Most Colorado shorebirds are migratory species, and rely on Colorado wetlands and adjacent grassland habitats to rest, forage, and sometimes nest between seasonal flights across state and international boundaries.

While shorebirds can often coexist with agricultural and ranching activities, they are sensitive to wetland and grassland conversion and loss (including woody species encroachment), impacts to insect prey from insecticides, human disturbance, and factors that increase their exposure to native and non-native predators. In addition to being an important part of Colorado’s wetland ecosystems, these avian travelers often benefit Colorado’s rural communities when birders flock to local wildlife areas to observe shorebirds during migration.

Read more

Blue-winged Teal. Tom Koerner, USFWS.
Blue-winged Teal. Tom Koerner, USFWS.

Waterfowl Habitat

Back to top

Colorado’s wetlands provide important stopover habitat during spring and fall migration, along with habitat for overwintering and breeding ducks and geese.

Seasonal and permanently inundated wetlands provide waterfowl habitat across Colorado’s diverse landscapes, from agricultural areas in intermountain valleys like North Park and the San Luis Valley to riverine wetlands along the South Platte as it flows through the eastern plains and montane beaver complexes. Key habitat elements include submerged and emergent aquatic vegetation (interspersed with open water), along with other food sources like invertebrates, seeds and grains. Waterfowl provide prey for raptors and other wildlife, as well as hunting and other recreational (birding) resources for humans.

Read more

Aerial view of the Tarryall Creek riparian and stream restoration site. Mark Beardsley, EcoMetrics.
Aerial view of the Tarryall Creek riparian and stream restoration site. Mark Beardsley, EcoMetrics.

Bank and Shoreline Stabilization

Back to top

Vegetated wetlands help to minimize lake shoreline and stream bank erosion from wave action and flowing water by stabilizing soil and sediment, and reducing the velocity of flowing water along lake or channel margins.

The ability of wetlands to stabilize banks and shorelines depends on many environmental factors, including vegetation density, rooting depth, strength and structural complexity of vegetation (e.g., multi-layered vegetation canopies with a mixture of woody and emergent herbaceous plants), soil and/or sediment composition and structure, amount and distribution of bare soil and sediment, degree of soil and plant disturbance (e.g., from livestock or wild ungulate grazing), and the degree of alteration of the natural flow regime (streams), surface water levels (lakes and ponds), or wave action.

Read more

Riparian vegetation holds back flood waters. CNHP Staff.
Riparian vegetation holds back flood waters. CNHP Staff.

Flood Attenuation

Back to top

Many types of wetlands store and delay water during rain storms or spring snowmelt, which can reduce and delay flood peaks and extend the overall duration of elevated stream flow.

These wetlands can help save human lives and property downstream, buffer aquatic ecosystems from extreme peak flows, and store water during drier periods following floods. Wetlands with the greatest potential to attenuate flood flows include floodplain wetlands, and basins and ponds with available water storage capacity during peak runoff or flooding. Some headwater wetlands, including slope wetlands that are saturated during runoff or flooding events, may increase flood peaks during larger storm events, but delay surface runoff with vegetation during smaller storms.

Read more

Kettle pond near Hayden, CO. Sarah Marshall, CNHP.
Kettle pond near Hayden, CO. Sarah Marshall, CNHP.

Groundwater Recharge

Back to top

Groundwater recharge, or downward flow of water through the soil to replenish groundwater aquifers, is a commonly cited wetland function that varies over space and time due to factors like underlying geology, soil type, surface water depth, depth to impermeable soil or rock layers, regional and local groundwater flow paths, and wetland water sources, outflows, and evapotranspiration rates (surface water evaporation + transpiration by plants).

Many of Colorado’s wetlands are groundwater discharge systems, as opposed to recharge-dominated systems, during all or part of the year. Select Colorado wetlands recharge local alluvial aquifers during all or part of the year (e.g., floodplain wetlands, many beaver complexes, and some irrigated wetlands), or other local and regional aquifers during spring snowmelt (e.g., kettle ponds) or summer monsoons (e.g., playas).

Read more

Bear track in sediment along a stream near Kremmling, CO. Sarah Marshall, CNHP.
Bear track in sediment along a stream near Kremmling, CO. Sarah Marshall, CNHP.

Sediment Capture and Retention

Back to top

Soil erosion and sediment transport are natural processes that are often altered or accelerated by land and water management (e.g., stream bank and channel erosion due to reduced sediment loads in streams and rivers downstream of dams, or soil erosion from tilled soil). Vegetated wetlands can stabilize soil and sediment to limit erosion, or intercept and physically filter sediment particles entrained in surface runoff or stream flow.

Excess sediment in streams can be detrimental to aquatic organisms that depend on gravel and cobble beds that are free of fine sediment (including spawning trout and many aquatic invertebrates), and costly for water providers to remove from in-stream reservoirs used to store drinking and irrigation water. The ability of wetlands to capture and retain sediment has both positive and negative consequences for wetland ecosystems. Most riverine wetland plant communities, including willow thickets in beaver complexes, have evolved to survive and thrive in dynamic environments, including periodic sediment scouring and deposition associated with floods. Playas and other natural wetland basins may have some natural sediment deposition, but can be filled by excess sediment in surface runoff from surrounding areas with tilling and other soil disturbance. Montane and subalpine fens and mires are relatively stable environments, and may be lost if large volumes of sediment are deposited by soil erosion or landslides (e.g., from a catastrophic wildfire).

Read more

Headwater stream in the Holy Cross Wilderness, CO. Sarah Marshall, CNHP.
Headwater stream in the Holy Cross Wilderness, CO. Sarah Marshall, CNHP.

Stream Flow Maintenance

Back to top

Headwater wetlands collect and store water from precipitation, snowmelt, surface runoff, and groundwater seeps and springs that is then discharged to streams and rivers during the growing season, or throughout the year.

Often, wetlands help maintain stream base flows and cool water temperatures into the late summer and fall. These base flows sustain fish and other aquatic organisms, along with human water uses from fishing and whitewater boating to drinking water and irrigation.

Read more

Wetlands soil core. Joanna Lemly, CNHP.
Wetlands soil core. Joanna Lemly, CNHP.

Carbon Sequestration and Storage

Back to top

Carbon storage in wetlands is a complex phenomenon that varies across geographic areas, climates, and time (seasonal or longer time periods). Wetlands often store a disproportionately large volume of carbon for their relatively small area on the landscape, but can also be sources of methane and other greenhouse gases.

The ability of wetlands to sequester carbon in the form of soil organic matter, sediment, and biomass (roots, woody plants, etc.) depends on growing season length (influenced by elevation and climate), the balance between production and decomposition of organic matter, degree of soil and vegetation disturbance, the duration (and depth) of soil or sediment saturation and inundation, soil temperature, and other environmental factors. In general, least-altered wetlands have the greatest potential to store carbon. Fens and beaver complexes are two types of Colorado wetlands that provide abundant carbon storage relative to forests and other adjacent terrestrial ecosystems. Wetlands with altered groundwater levels, such as drained fens, often become carbon sources rather than sinks when stored carbon is oxidized.

Read more

Influx of metal-rich groundwater from natural springs (foreground) to Cement Creek, Colorado (background). Briant Kimball, USGS.
Influx of metal-rich groundwater from natural springs (foreground) to Cement Creek, Colorado (background). Briant Kimball, USGS.

Metal Removal and Storage

Back to top

Metals are naturally present in soils and rock formations, but often a concern for water quality in Colorado streams, rivers, lakes, and wetlands due to historic and current mining and industrial activities, as well as runoff from urban land use. Many of our state’s streams and rivers are on the 303(d) list of impaired waterways for metals like lead, arsenic, zinc, iron, uranium, and cadmium. Wetlands near mining areas and other sources often intercept and store metals in their soil, which can improve downstream water quality.

These metals are detrimental to fish and other aquatic life, as well as recreational and water supply uses. The ability of wetlands to remove and store metals is highly dependent on factors like pH, temperature, and substrate (e.g., soil vs. sediment and organic vs. mineral soil). Wetland soils with a high organic matter content, including peat-forming fens and mires, and certain types of clay particles, generally have the highest capacity for adsorbing metals (referred to as cation exchange capacity). Overall, wetlands are most effective in removing total metals (solids) than removing dissolved metals, and may often be sources of dissolved metals depending on their hydroperiod, hydrologic regime, water inflows and outflows (including dissolved metals and metals adsorbed to suspended sediment and soil particles), pH, temperature, and history of metal loading.

Read more

Marsh wetland habitat. CNHP Staff.
Marsh wetland habitat. CNHP Staff.

Nitrogen Uptake and Transformation

Back to top

Some Colorado wetlands are local and regional hotspots for denitrification (nitrate removal) and processing other forms of nitrogen. This wetland function has become even more important as humans have increased the amount of available nitrogen in the environment through fertilizer application, atmospheric deposition, animal waste, and septic systems.

As one of several limiting nutrients in most ecosystems, excess nitrogen can lead to eutrophication of waterbodies (and associated algal blooms), altered plant community composition, and drinking water contamination (especially with nitrate-nitrogen). Terrene and riparian wetlands that excel at removing nitrate have sufficient soil carbon (for denitrifying bacteria), are intercepting flow (and have higher soil water residence time for that flow), and have reducing conditions in the soil when water passes through the system.

Read more

Cattails growing within an emergent marsh. CNHP Staff.
Cattails growing within an emergent marsh. CNHP Staff.

Phosphorus Removal and Storage

Back to top

Phosphorus is a key limiting nutrient in many aquatic and terrestrial systems, and in excess, can cause eutrophication and associated algal blooms in surface water. Many Colorado wetlands capture and store (temporary or long-term) phosphorus (P) from sources like fertilizer, animal waste, septic systems, and bank erosion (P bound to soil and sediment particles).

The ability of wetlands to remove and store P depends on a complex array of biogeochemical, hydrologic, and biological processes. Phosphorus is often bound to soil and sediment particles, so this function is correlated with sediment retention and capture. In general, wetlands are better at capturing particulate P than removing and storing dissolved forms of P.

Read more

Cottonwood gallery forest along the South Platte River. CNHP Staff.
Cottonwood gallery forest along the South Platte River. CNHP Staff.

Temperature Regulation

Back to top

Many of Colorado’s fish and other aquatic organisms occupy narrow thermal niches within streams and waterbodies. Water temperatures that are too high in the summer and fall can often lead to trout and other cold water fish mortality and increased susceptibility to disease, as well as allowing competition from non-native fish species.

Wetlands help maintain low surface water temperatures during the growing season in several key ways. First, many headwater wetlands are subsurface flow-through systems (including wetlands that intercept seeps and springs) that augment summer and fall base flows with cool groundwater. Second, wetlands collect and store surface water (including snowmelt), often in the subsurface, which can then be slowly released to streams and other waterbodies throughout the growing season. Finally, trees, shrubs, and other dense wetland vegetation can physically shade surface water—especially on smaller streams. Riparian forested wetlands and shrublands (including willow carrs and lowland willow thickets) often provide dense shade over surface water.

Read more

About CWIC

What Are Wetlands?
Why Are Wetlands Important?
Colorado Wetland Plan
Wetland Partners

Related Topics

Wetland Reports
PCA Reports
County Survey Reports
Field Guides and App
Field Manuals
Educational Resources
Watershed Toolbox

Web Projects

  • CODEX - Colorado’s Conservation Data Explorer
  • Rare Plant Guide Online
  • Colorado Wetland Info Center
  • COMaP - Colorado Protected Lands
  • Colorado Bat Working Group
  • STReaMS - Endangered Fishes Database
  • Colorado Native Plant Database Data Portal

About Us

  • About Us
  • Conserving Biodiversity
  • Contact Us
  • Staff Directory
  • Careers
  • Site Map
Warner College of Natural Resources Logo
  • Apply to CSU
  • Equal Opportunity
  • Disclaimer
  • Privacy Statement
  • Search CSU
  • CSU Land Acknowledgement
  • CSU Principles of Community
© 2025 Colorado Natural Heritage Program
Colorado State University Logo
  • About CWIC
    ▼
    • What Are Wetlands?
    • Why Are Wetlands Important?
    • Colorado Wetland Plan
    • Wetland Partners
  • Wetland Types
    ▼
    • Overview
    • Ecological Systems
    • Natural Plant Communities
    • Field Guides and App
    • Fen Mapping
  • Wetland Condition
    ▼
    • Overview
    • Ecological Condition
    • Habitat Quality
    • Biodiversity Significance
    • Colorado Wetland Assessment Projects
    • National Wetland Condition Assessment
    • BLM Assessment Inventory and Monitoring
  • Working in Wetlands
    ▼
    • Overview
    • Conservation
    • Restoration
    • Regulation
    • Best Management Practices
    • Funding and Technical Support
  • Data & Tools
    ▼
    • Wetlands Mapper
    • Floristic Quality Calculator
    • Landscape Summaries
    • Watershed Toolbox
    • Wetland Plots Database
  • Library
    ▼
    • Wetland Reports
    • Potential Conservation Areas
    • County Survey Reports
    • Field Guides and App
    • Field Manuals
    • Educational Resources
  • CNHP Home
  • About CWIC
    ▼
    • What Are Wetlands?
    • Why Are Wetlands Important?
    • Colorado Wetland Plan
    • Wetland Partners
  • Wetland Types
    ▼
    • Overview
    • Ecological Systems
    • Natural Plant Communities
    • Field Guides and App
    • Fen Mapping
  • Wetland Condition
    ▼
    • Overview
    • Ecological Condition
    • Habitat Quality
    • Biodiversity Significance
    • Colorado Wetland Assessment Projects
    • National Wetland Condition Assessment
    • BLM Assessment Inventory and Monitoring
  • Working in Wetlands
    ▼
    • Overview
    • Conservation
    • Restoration
    • Regulation
    • Best Management Practices
    • Funding and Technical Support
  • Data & Tools
    ▼
    • Wetlands Mapper
    • Floristic Quality Calculator
    • Landscape Summaries
    • Watershed Toolbox
    • Wetland Plots Database
  • Library
    ▼
    • Wetland Reports
    • Potential Conservation Areas
    • County Survey Reports
    • Field Guides and App
    • Field Manuals
    • Educational Resources
  • CNHP Home
  • About CWIC
    ▼
    • What Are Wetlands?
    • Why Are Wetlands Important?
    • Colorado Wetland Plan
    • Wetland Partners
  • Wetland Types
    ▼
    • Overview
    • Ecological Systems
    • Natural Plant Communities
    • Field Guides and App
    • Fen Mapping
  • Wetland Condition
    ▼
    • Overview
    • Ecological Condition
    • Habitat Quality
    • Biodiversity Significance
    • Colorado Wetland Assessment Projects
    • National Wetland Condition Assessment
    • BLM Assessment Inventory and Monitoring
  • Working in Wetlands
    ▼
    • Overview
    • Conservation
    • Restoration
    • Regulation
    • Best Management Practices
    • Funding and Technical Support
  • Data & Tools
    ▼
    • Wetlands Mapper
    • Floristic Quality Calculator
    • Landscape Summaries
    • Watershed Toolbox
    • Wetland Plots Database
  • Library
    ▼
    • Wetland Reports
    • Potential Conservation Areas
    • County Survey Reports
    • Field Guides and App
    • Field Manuals
    • Educational Resources
  • CNHP Home