FINAL_Weland_Functions_and_Values.pdf

FORT BELVOIR WETLAND FUNCTIONS AND VALUES

SPECIFIC CHARACTERISTICS

Considerations are based on best professional judgment and interdisciplinary team consensus.

GROUNDWATER RECHARGE/DISCHARGE — This function considers the potential for a wetland to serve as a groundwater recharge and/or discharge area. It refers to the fundamental interaction between wetlands and aquifers, regardless of the size or importance of either.

CONSIDERATIONS/QUALIFIERS

1. Gravel or sandy soils present in or adjacent to the wetland.

2. Wetland is associated with a perennial or intermittent watercourse.

3. Signs of groundwater recharge are present or piezometer data demonstrates recharge.

4. Wetland is associated with a watercourse but lacks a defined outlet or contains a constricted outlet.

5. Wetland contains only an outlet, no inlet.

6. Quality of water associated with the wetland is high.

7. Signs of groundwater discharge are present (e.g., springs).

FLOODFLOW ALTERATION (Storage & Desynchronization) — This function considers the effectiveness of the wetland in reducing flood damage by water retention for prolonged periods following precipitation events and the gradual release of floodwaters. It adds to the stability of the wetland ecological system or its buffering characteristics and provides social or economic value relative to erosion and/or flood prone areas.

CONSIDERATIONS/QUALIFIERS

1. Wetland watershed contains greater than 25 percent of impervious surfaces.

2. Wetland has an intermittent outlet, ponded water, or signs are present of variable water level.

3. During flood events, this wetland can retain higher volumes of water than under normal or average rainfall conditions.

4. Wetland receives and retains overland or sheet flow runoff from surrounding uplands.

5. In the event of a large storm, this wetland may receive and detain excessive flood water from a nearby watercourse.

6. Valuable properties, structures, or resources are located in or near the floodplain downstream from the wetland.

7. This wetland watercourse is sinuous or diffuse.

8. This wetland outlet is constricted.

9. Channel flow velocity is affected by this wetland.

FISH, SHELLFISH, AMPHIBIAN AND REPTILE HABITAT — This function considers the effectiveness of seasonal or permanent watercourses associated with the wetland in question for fish and shellfish habitat.

CONSIDERATIONS/QUALIFIERS

1. Size of this wetland is able to support large fish, shellfish, amphibian and reptile populations.

2. Stream width (bank to bank) is more than 50 feet.

3. Watercourse associated with this wetland is able to support healthy fish, shellfish, amphibian and reptile populations.

4. Streamside vegetation provides shade for the watercourse.

5. Spawning/bredding areas are present (submerged vegetation or gravel beds).

6. Food is available to fish, shellfish, amphibian and reptile populations within this wetland.

7. Barrier(s) to anadromous fish (such as dams, including beaver dams, waterfalls, road crossing) are absent from the stream reach associated with this wetland.

8. Water velocities are not too excessive for fish usage.

SEDIMENT/TOXICANT/PATHOGEN RETENTION — This function reduces or prevents degradation of water quality. It relates to the effectiveness of the wetland as a trap for sediments, toxicants, or pathogens in runoff water from surrounding uplands or upstream eroding wetland areas.

CONSIDERATIONS/QUALIFIERS

1. Potential sources of excess sediment are in the watershed above the wetland.

2. Potential or known sources of toxicants are in the watershed above the wetland.

3. Opportunity for sediment trapping by slow moving water or deepwater habitat are present in this wetland.

4. The wetland is known to have existed for more than 50 years.

5. Effective floodwater storage in wetland is occurring. Areas of impounded open water are present.

6. No indicators of erosive forces are present. No high water velocities are present.

7. Diffuse water flows are present in the wetland.

8. Wetland has a high degree of water and vegetation interspersion.

9. Dense vegetation provides opportunity for sediment trapping and/or signs of sediment accumulation by dense vegetation is present.

NUTRIENT REMOVAL/RETENTION/TRANSFORMATION — This function considers the effectiveness of the wetland as a trap for nutrients in runoff water from surrounding uplands or contiguous wetlands and the ability of the wetland to process these nutrients into other forms or trophic levels. One aspect of this function is to prevent ill effects of nutrients entering aquifers or surface waters such as ponds, lakes, streams, rivers, or estuaries.

CONSIDERATIONS/QUALIFIERS

1. Wetland is large relative to the size of its watershed.

2. Deep water or open water habitat exists.

3. Overall potential for sediment trapping exists in the wetland.

4. Potential sources of excess nutrients are present in the watershed above the wetland.

5. Wetland saturated for most of the season. Ponded water is present in the wetland.

6. Deep organic/sediment deposits are present.

7. Vegetation cover is greater than 50 percent.

8. Emergent vegetation and/or dense woody stems are dominant.

9. Water retention/detention time in this wetland is increased by constricted outlet or thick vegetation.

PRODUCTION EXPORT (Nutrient) — This function evaluates the effectiveness of the wetland to produce food or usable products for humans or other living organisms.

CONSIDERATIONS/QUALIFIERS

1. Wildlife food sources grow within this wetland.

2. Detritus development is present within this wetland

3. Higher trophic level consumers are utilizing this wetland.

4. Fish, shellfish, amphibians or reptiles develop or occur in this wetland.

5. Wetland exhibits high degree of plant community structure/species diversity.

6. “Flushing” of relatively large amounts of organic plant material occurs from this wetland.

7. Wetland contains flowering plants that are used by nectar-gathering insects.

8. Indications of export are present.

9. High production levels occurring, however, no visible signs of export (assumes export is attenuated).

SEDIMENT/SHORELINE STABILIZATION — This function considers the effectiveness of a wetland to stabilize streambanks and shorelines against erosion.

CONSIDERATIONS/QUALIFIERS

1. Indications of erosion or siltation are present.

2. Potential sediment sources are present upstream

3. No distinct shoreline or bank is evident between the waterbody and the wetland or upland.

4. A distinct step between the open waterbody or stream and the adjacent land exists (i.e., sharp bank) with dense roots throughout.

5. Wide wetland (>10’) borders watercourse, lake, or pond.

6. High flow velocities in the wetland.

7. Boating activity is present.

8. High percentage of energy-absorbing emergents and/or shrubs border a watercourse, lake, or pond.

9. Vegetation is comprised of large trees and shrubs that withstand major flood events or erosive incidents and stabilize the shoreline on a large scale (feet).

10. Vegetation is comprised of a dense resilient herbaceous layer that stabilizes sediments and the shoreline on a small scale (inches) during minor flood events or potentially erosive events.

WILDLIFE HABITAT — This function considers the effectiveness of the wetland to provide habitat for various types and populations of animals typically associated with wetlands and the wetland edge.

Both resident and/or migrating species must be considered. 1

CONSIDERATIONS/QUALIFIERS

1. Wetland is not degraded by human activity.

2. Wetland is not fragmented by development.

3. Upland surrounding this wetland is less than 10 percent developed.

4. More than 40 percent of this wetland edge is bordered by upland wildlife habitat (e.g., brushland, woodland, active farmland, or idle land) at least 500 feet in width.

5. Wetland is contiguous with other wetland systems connected by a watercourse or lake. .

6. Wildlife food sources are within this wetland or are nearby.

7. More than three acres of shallow permanent open water (less than 6.6 feet deep), including streams in or adjacent to wetland, are present.

8. Wetland exhibits a high degree of plant species diversity.

9. Wetland exhibits a high degree of diversity in plant community structure (e.g., tree/ shrub/vine/grasses/mosses)

10. Plant/animal indicator species are present. (List species for project)

11. Animal signs observed (tracks, scats, nesting areas, etc.)

12. Seasonal uses vary for wildlife and wetland appears to support varied population diversity/abundance during different seasons.

13. Wetland contains or has potential to contain a high population of insects.

14. Wetland contains or has potential to contain large amphibian populations.

15. Wetland has a high avian utilization or its potential.

16. Indications of less disturbance-tolerant species are present.

17. Signs of wildlife habitat enhancement are present (birdhouses, nesting boxes, food sources, etc.).

ENDANGERED SPECIES HABITAT — This value considers the suitability of the wetland to support threatened or endangered species.

CONSIDERATIONS/QUALIFIERS

1. Wetland contains or is known to contain threatened or endangered species.

2. Wetland contains critical habitat for a state or federally listed threatened or endangered species.

RECREATION (Consumptive and Non-Consumptive) — This value considers the suitability of the wetland and associated watercourses to provide recreational opportunities such as hiking, canoeing, boating, fishing, hunting, and other active or passive recreational activities. Consumptive opportunities consume or diminish the plants, animals, or other resources that are intrinsic to the wetland. Non-consumptive opportunities do not consume or diminish these resources of the wetland.

CONSIDERATIONS/QUALIFIERS

1. Wetland is part of a recreation area, park, forest, or refuge.

2. Fishing is available within or from the wetland.

3. Hunting is permitted in the wetland.

4. Hiking occurs or has potential to occur within the wetland.

5. Wetland is a valuable wildlife habitat.

6. The watercourse, pond, or lake associated with the wetland is unpolluted.

7. High visual/aesthetic quality of this potential recreation site.

8. Access to water is available at this potential recreation site for boating, canoeing, or fishing.

9. The watercourse associated with this wetland is wide and deep enough to accommodate canoeing and/or non-powered boating.

10. Off-road public parking available at the potential recreation site.

11. Accessibility and travel ease is present at this site.

12. The wetland is within a short drive or safe walk from highly populated public and private areas.

EDUCATIONAL/SCIENTIFIC VALUE — This value considers the suitability of the wetland as a site for an “outdoor classroom” or as a location for scientific study or research.

CONSIDERATIONS/QUALIFIERS

1. Wetland contains or is known to contain threatened, rare, or endangered species.

2. Little or no disturbance is occurring in this wetland.

3. Potential educational site contains a diversity of wetland classes which are accessible or potentially accessible.

4. Potential educational site is undisturbed and natural.

6. Wetland is located within a nature preserve or wildlife management area.

7. Signs of wildlife habitat enhancement present (bird houses, nesting boxes, food sources, etc.). .

8. Site is currently used for educational or scientific purposes.

UNIQUENESS/HERITAGE — This value considers the effectiveness of the wetland or its associated waterbodies to provide certain special values. These may include archaeological sites, critical habitat for endangered species, its overall health and appearance, its role in the ecological system of the area, its relative importance as a typical wetland class for this geographic location. These functions are clearly valuable wetland attributes relative to aspects of public health, recreation, and habitat diversity.

CONSIDERATIONS/QUALIFIERS

1. Upland surrounding wetland is primarily urban.

2. Upland surrounding wetland is developing rapidly.

3. Large area of wetland is dominated by flowering plants or plants that turn vibrant colors in different seasons.

4. General appearance of the wetland visible from primary viewing locations is unpolluted and/or undisturbed.

5. Historical buildings are found within the wetland.

6. Visible stone or earthen foundations, berms, dams, standing structures, or associated features occur within the wetland.

7. Wetland contains critical habitat for a state- or federally-listed threatened or endangered species.

8. Wetland is a natural landmark or recognized by the state natural heritage inventory authority as an exemplary natural community.

9. Wetland is known to contain an important archaeological site.

10. Wetland is hydrologically connected to a state or federally designated scenic river.

VISUAL QUALITY/AESTHETICS — This value considers the visual and aesthetic quality or usefulness of the wetland.

CONSIDERATIONS/QUALIFIERS

1. Multiple wetland classes are visible from primary viewing locations.

2. Emergent marsh and/or open water are visible from primary viewing locations.

3. A diversity of vegetative species is visible from primary viewing locations.

4. Land use surrounding the wetland is undeveloped as seen from primary viewing locations.

5. Visible surrounding land use form contrasts with wetland.

6. Wetland views absent of trash, debris, and signs of disturbance.

7. Wetland is considered to be a valuable wildlife habitat.

8. Wetland is easily accessed.

9. Low noise level at primary viewing locations.

10. Relatively unobstructed sight line exists through wetland.

Source: The Highway Methodology Workbook Supplement: Wetland Functions and Values, US Army Corps of Engineers, New England District.