Accretion - May be either natural or artificial. Natural accretion is the buildup of land, solely by the action of the forces of nature, on a beach by deposition of water or airborne material.
Artificial accretion is a similar buildup of land by reason of an act of man, such as the accretion formed by a groin, breakwater, or beach fill deposited by mechanical means.
Aerobic - Growing or occurring only in the presence of molecular oxygen. Oxygenated.
Aesthetic improvement - Disposal site appearance improvement that makes it more pleasing and acceptable to the general public living and working around the site.
Agricultural use - The beneficial use of dredged material by the application of dewatered or slurry dredged material to farmland, for the purpose of improving the soil for farming.
Algae - Any of a group of nonvascular plants with chlorophyll, lacking true stems, leaves, and roots.
Anadromous - A life cycle in which maturity is attained in the ocean and adults ascend rivers and streams to spawn in fresh water (e.g., salmons, shad, etc.).
Anaerobic - Growing or occurring in the absence of molecular oxygen. Deoxygenated.
Aquaculture - Cultivation of aquatic plants and animals for human use or consumption.
Aquatic habitat - Typical submerged communities extending from near sea, river, or lake level down several feet, such as tidal flats, oyster beds, clam flats, seagrass beds, or reefs.
Arable - Land that is cultivated or fit for cultivation.
Atterberg Limits - Consistency limits, including the liquid limit, the plastic limit, and the shrinkage limit, which define the three stages of fine-grained material.
Avian habitat - Any area that meets all or part of the life requirements of birds, a very large and wide-ranging group of species with a variety of habitat requirements.
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Backshore - The zone of the shore or beach lying between the foreshore and the coastline and acted upon by waves only during severe storms, especially when combined with exceptionally high water.
Bar - A ridge or succession of ridges of sand or other substances, especially a formation
extending across the mouth of a river or harbor, which may obstruct navigation.
Basalt - A dark gray to black, dense to fine-grained igneous rock.
Baseline data - Data used as a temporal control, collected prior to the environmental disturbance of interest.
Basin - A naturally or artificially enclosed or nearly enclosed aquatic area.
Bathymetry - Physical configuration of the seabed; the measurement of depths of water in
oceans, seas, and lakes; also information derived from such measurements.
Bay - A recess in the shore or an inlet of a sea between two capes or headlands, not so large as a gulf but larger than a cove.
Beach - The zone of sedimentary material that extends landward from the low water line to the place where there is marked change in material or form, or to the line of permanent vegetation
(usually the effective limit of storm waves). The seaward limit of a beach - unless otherwise
specified - is the mean low water line. A beach includes foreshore and backshore.
Beach biota - All living organisms that occupy the intertidal and dune zones of beaches.
Beach nourishment - The practice of hydraulically pumping clean, sandy sediment onto an eroded beach.
Beneficial use - Utilizing dredged sediments as resource materials in productive ways.
Benthic - Pertaining to the subaquatic bottom or organisms that live on the bottom of water
Benthos - A collective term describing (1) bottom organisms attached or resting on or in the bottom sediments, and (2) community of animals living in or on the bottom.
Berm - Narrow shelf of ground left naturally occurring or purposefully constructed at the base of a levee or offshore along the coast.
Bioaccumulation - TThe process in which chemicals gradually accumulate in living tissue by respiration, ingestion, or other contact.
Biochemical oxygen demand (BOD) - The amount of oxygen required during the aerobic decomposition of organic matter in a body of water. High BOD usually indicates large amounts of organic material.
Biological calendar - The life cycle of any living organism, especially pertaining to any critical area requirements where a species is more vulnerable than at other times during the life cycle.
Biomass - The amount of living material in a unit area for a unit time.
Biota - The living part of a system (flora and fauna).
Bluff - A high, steep bank composed of erodible materials.
Borrow material - Soil or sediment taken from a site for use at another site, such as sandy sediment dredged and pumped onto an eroded beach, or clay taken from one site to build a levee or dike elsewhere.
Borrow pit - The term used to describe the site remaining after borrow material has been removed. In upland areas, the site frequently becomes a body of water. In marine areas, the site becomes a deep hole in a bay or near-shore area.
Brackish - Refers to water with a salt content between that of fresh water and seawater.
Breaker - A wave meeting a shore, reef, sandbar, or rock and collapsing.
Breakwater - A fixed or floating structure that protects a shore area, harbor, anchorage, or basin by intercepting waves.
Breeding season - The period of time used by a living organism for mating, nesting or denning, rearing of young, and other activities related to reproduction.
Bulk density - An indicator of size and arrangement of various soil particles, and the weight measurement by which the entire soil volume is considered.
Bulkhead - - A structure or partition placed on a bank or bluff to retain sediment or prevent sliding or erosion of the land to protect the inland area against damage from wave action.
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Capital dredging - Dredging carried out to create new channels, etc., as distinct from
maintenance dredging; also called new-work dredging.
Capping - Use of clean dredged material as a cover for contaminated dredged material disposed in open water or upland as a means of isolating the contaminated sediment from the surrounding environment. Also, the use of dredged sediments to cover a municipal landfill.
Carrying capacity - The maximum number of individuals or biomass that any particular area can support over an extended period of time.
Carrying capacity, recreational - The ability of a given recreational site to sustain planned levels of human recreational use without environmental damage.
Cation exchange capacity (CEC) - The capacity of soil or dredged material particulates to adsorb nutrients which then become available for plant growth.
Channel - (1) A natural or artificial waterway of perceptible extent which either periodically or continuously contains moving water, or which forms a connecting link between two bodies of
water. (2) The part of a body of water deep enough to be used for navigation through a body of
water otherwise too shallow for navigation.
Chemical oxygen demand (COD) - The amount of oxygen required to oxidize organic chemical compounds and oxidizable inorganic compounds in a body of water. These chemicals rapidly oxidize, requiring great quantities of oxygen.
Chlorinated hydrocarbons - Polychlorinated biphenyls (PCBs) and similar compounds which can be harmful to living organisms, and which can sometimes be found in certain dredged material substrates, especially in urban areas and especially in fin-grained material.
Clam flat - Any aquatic habitat, both natural and man-made, occupied by colonies of clams, including those occurring in shellfish farming operations.
Clay - Soil particle having a grain size of less than 2 micrometers.
Clean material - Dredged material that is not contaminated.
Cliff - A high, steep face of rock; a precipice.
Coast - The strip of land, of indefinite width (up to several miles), that extends from the
shoreline inland to the first major change in terrain features.
Colonial-nesting - A term used to describe the habit of numerous bird species, especially waterbirds, of nesting in large groups, often with nests only 1 to 2 feet apart.
Colonies - Large groups of breeding birds that habitually nest together for protection and sociability, either in single species groups, such as least terns, or in mixed species groups, such as herons, egrets, and ibises.
Confined disposal facility (CDF) - (1) Upland (including along the shoreline) CDF- Area that has been diked or otherwise constructed to contain dredged material; (2) Aquatic CDF – Stable underwater depression into which dredged material could be contained.
Consolidation - A term used to describe the effect caused by dewatering and desiccation of dredged material substrates, usually resulting in significant lessening of volume of the material.
Consumptive use - A term usually used in reference to hunting and fishing on a site where a product (fish or wildlife) is obtained by the site user.
Contaminant - Chemical or biological substance in a form that can be incorporated into, onto, or be ingested by and is harmful to organisms, consumers of organisms, or users of the environment in which the substance exists.
Containment area - Any site used for the temporary or permanent confinement of dredged material, and which may or may not have a permanent retaining structure.
Contaminated sediment - Sediment that has been demonstrated to cause an unacceptable adverse effect on human health or the environment.
Continental shelf - The zone bordering a continent and extending from the low-water line to the depth (usually about 180 meters) where there is a marked or rather steep descent toward a greater
Contour benching - The soil conservation practice of building soil benches or terraces along natural or man-made contour lines on erodible slopes.
Contour farming - The agronomic practice of planting erodible slopes along natural or man-made contour benches in alternating and rotating strips of grass cover and row crops.
Coral - The hard stony skeleton secreted by certain marine polyps (class Anthozoa) and often deposited in extensive masses, forming reefs and atolls in tropical seas.
Coral reef - A fragile, living, marine structure made up of a number of species of coral organisms that occurs in tropical waters. In the United States, coral reefs only occur off the coasts of Florida, Hawaii, and Puerto Rico.
Creche - The term used for groups of chicks of some seabird species that form when the chicks leave their nests at a few days of age and congregate.
Critical habitat - Any habitat officially designated or generally accepted as essential to any or all life requirements of an endangered or threatened plant or animal.
Crop rotation - The agronomic practice of rotating grass cover and row crops from year to year to improve soil fertility and prevent erosion.
Crops, food - Agricultural and horticultural crops planted a food sources for humans, domestic livestock, and wildlife, and which can sometimes be grown on dredged material substrates.
Crops, nonfood - Horticultural and forestry crops planted for use by humans but not as food, such as timber, paper products, sod, and Christmas trees, and which can sometimes be grown on dredged material substrates.
Cross dike - A dike structure built within and across a CDF, usually for the purpose of compartmentalizing the CDF for incremental dredging.
Culch - Old shells, stones, etc., that form a spawning bed for oysters.
Current - A flow of water.
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Delta - An alluvial deposit, roughly triangular or digitate in shape, formed at a river mouth.
Demersal - Organisms (usually fish) that live on or slightly above the bottom.
Desiccation cracks - The phenomenon that occurs on fine-grained dredged material or deposited river sediment in which large cracks form as the material dewaters and consolidates.
Dewatering - Use of trenches or other engineering techniques to expedite removal of water from dredged material at confined disposal facility.
Dike - An engineering structure built for the purpose of retaining dredged material, separating sediments from adjacent waters or other sediments, or training sediments.
Disposal alternative - Any method of disposal and dredged material use that is proposed by the CE, one of which will be found to be acceptable to the CE, sponsors, resource agencies, and the public.
Disposal site - Any area, confined or unconfined, that is used for the diseposalition of dredged material.
Dissolved oxygen (DO) - The amount of oxygen dissolved in water.
Diversion channels - Ditches or channels used to divert rainwater and snowmelt on erodible slopes and soils.
Downdrift - The direction of predominant movement of littoral materials.
Dragline trenching - The practice of dewatering dredged material by making trenches inside disposal sites with dragline equipment.
Dredge - An apparatus used in the removal of substrate; usually to create or deepen water passages for safe navigation.
Dredged material - Material excavated from inland or ocean waters.
Dredging window - That period of time when it is environmentally safe to dredge and deposit dredged material in an area occupied by species of concern, such as in the nonbreeding season in areas with important waterbird colonies or the nonspawning season for locally important fish species.
Dune - A ridge or mound of loose, wind-blown material, usually sand.
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Ebb current - The tidal current away from shore or down a tidal stream; usually associated with the decrease in height of the tide.
Ebb tide - The period of tide between high water and the succeeding low water; a falling tide.
Ecological stage - A specific period of growth or development of an ecological community; i.e., grassland is an intermediate stage in the developmental process of a site that will ultimately become a forest. See ecological succession.
Ecological succession - The progression of a site from early growth stages to maturity; i.e., on a new, coastal dredged material island the stages of succession over time are: bare ground, sparse herbaceous cover, dense herbaceous cover, shrub/grasses, shrub/trees, and finally, maritime forest.
Ecosystem - A system made up of a community of animals, plants, and bacteria and its
interrelated physical and chemical environment.
Eddy - A circular movement of water formed on the side of a main current. Eddies may be
created at points where the main stream passes projecting obstructions or where two adjacent
currents flow counter to each other.
Effluent quality - The measure of quality of water coming over the weir in a confined dredged material disposal site during and after a disposal operation.
Endangered species - Plant or animal species of such limited and declining populations that they have been legally placed on a Federal or state Endangered Species List. Federally listed species and their needs are published in the Federal Register. Species that decline to the endangered status usually do so as a result of degradation or destruction of habitat.
Environmental legislation - Federal and state laws enacted to reestablish and maintain environmental quality in the United States. Many apply directly and indirectly to dredging activities.
Epibenthic - Organisms that attach themselves to structures (e.g. rocks) that lie on the aquatic bottom.
Equipment accessibility - On placement and disposal sites, this term refers to the ability of heavy equipment to economically and efficiently travel to and work in the sites and handle dredged materials.
Erodible slopes - Slopes of more than 3 feet per 100 feet that, when bare of vegetative cover are highly erosive, especially those primarily made of silt and silty clay soils.
Erosion - The wearing away of upland or submerged land by the action of natural forces.
Escarpment - A more or less continuous line of cliffs or steep slopes facing in one general
direction, which are caused by erosion or faulting (also scarp).
Estuary - (1) The part of a river that is affected by tides. (2) The region near a river mouth in which the fresh water of the river mixes with the salt water of the sea.
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Fauna - The entire group of animals in an area.
Feral animal - Any domestic animal such as a dog or cat that has gone wild or that was born to wild parents, survives by its own resources, and is no longer or has never been a pet or domesticated.
Fetch - The unobstructed distance over water in which waves are generated by wind of relatively constant direction and speed.
Fill material (construction) - In this case, soil or dewatered dredged material used as foundation material for the construction of any structure such as roads and buildings or to reclaim land lost to erosion such as gullies and recreational areas.
Fill material (Section 404) - Any material used to replace an aquatic area with upland, or for changing the bottom elevation of a water body.
Fish farm - The commercial production of several species of fish or shellfish (catfish, trout, red fish, shrimp, crayfish, and others) in carefully maintained, man-made ponds or in protected, maintained natural coastal bays.
Fishing reef - Any underwater structure, natural or man-made, which changes the bottom topography and offers cover, food, and protection to fish and other aquatic organisms.
Fish nursery areas - Natural or man-made shallow water and marshy areas where small fish and fry can feed and find cover from predators.
Floating pipeline - A dredged material discharge pipeline that is supported in water and in marsh by floats which prevent its sinking into the substrate during a dredging operation.
Floating tire breakwater - A temporary, floating structure made of foam-filled vehicle rubber tires. These form modules that are erected and anchored in moderate wave energy areas to protect the shoreline and marsh plants establishing behind the breakwater.
Floodplain islands - Natural or man-made islands occurring within the floodplain of a river or lake, including those within the body of water and those which only become islands at high water stages.
Flora - The entire group of plants found in an area.
Flowlane Dispersal - Placement of dredged sediment in a natural inlet thalweg such that it is transported out of the area without harm elsewhere. Flowlane dispersal is beneficial in returning sediment that was trapped in a harbor or navigation channel to the littoral system and, therefore, can be part of a regional sediment management plan.
Fluvial - Pertaining to rivers and river action.
Food chain - A sequence of organisms in a community in which each member of the chain feeds
on the member below it.
Forage - Food for animals, especially when taken by browsing or grazing.
Foreshore - The part of the shore lying between the crest of the seaward berm (or upper limit of wave wash) and the water's edge at low water. The foreshore is ordinarily traversed by the runup
and return of the waves.
Forestry use - The beneficial use of dredged material sites for the production of timber and timber products such as cottonwood or eucalyptus tree plantations.
Foundation qualities - The physical, chemical, and biological condition of the dredged material substrate which makes it suitable or unsuitable for beneficial uses, whether for building structures or for nonstructural use.
Freshwater marsh - Periodically inundated herbaceous vegetation community occurring in streams, lakes, and perched wetlands (salinity is near 0 ppt).
Functional life - The period of time during which a structure performs as intended. Performance can be expressed in terms of benefits obtained versus the cost of installation and maintenance.
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Gabions - Wire baskets filled with coarse rock material often used with filter cloths as temporary retention or breakwater structures.
Game mammal - Any mammal species hunted by gun, archery, or trapping, and that has a legal harvest season designated for the species.
Gas vents - Vents purposely placed in solid waste landfills to release and direct the flow of accumulated gas from decaying garbage to the atmosphere where it can dissipate.
Geomorphology - The branch of both physiography and geology which deals with the form of
the earth, the general configuration of its surface, and the changes that take place in the evolution
Granite - A very hard, crystalline, plutonic rock, gray to pink in color, consisting of feldspar, quartz, and smaller amounts of other minerals.
Grassed waterways - The practice of conserving soil on runoff ditches on slopes to trap sediment and stop erosion by gently sloping the ditch sides and perpetually maintaining them in mowed grass.
Gravel - A loose mixture of pebbles and rock fragments coarser than sand, often mixed with
Grazing area - Any land used for domestic livestock pasture. In this case, dredged material disposal areas that have been developed into pastureland.
Green manure - Legume or grass crops which are grown solely for fertilizer and while still in active growth are turned into the topsoil layer with a plow or disk to provide texture and nutrients to the top soil.
Groin (groyne) - A shore protection structure, usually built perpendicular to a coast to retard littoral transport.
Groundwater - Water within the earth that supplies wells and comes to the surface by seepage or in springs.
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Habitat - Area or environment in which a particular plant or animal lives or visits to meet all or part of its life requirements.
Habitat development - The construction and maintenance of a habitat for flora and/or fauna. In the Corps, often refers to the utilization of dredged sediments as a resource material for habitat development or the incidental/subsequent creation of fish and wildlife habitat on currently/formerly used dredged material disposal sites.
Habitat diversity - The occurrence within one ecosystem of several types of floral or faunal habitat. For example, on large dredged material islands, maritime forest, shrub communities, grass/herbaceous areas, bare ground, and marsh may all occur on different parts of the island simultaneously.
Habitat management - Deliberate, and often iterative, actions taken on upland and aquatic dredged material placement or disposal sites for the purpose of managing for target plant or animal populations or communities.
Habitat manipulation - Deliberate use of dredged material deposition to maintain a particular stage of ecological succession. Generally, such manipulation is used to maintain bare ground or very early stages.
Habitat patterning - The natural or deliberate positioning of different habitats in an ecosystem to provide diversity for the target wildlife or fish species.
Habitat protection - Deliberate and prudent posting, patrolling, fencing, or guarding of dredged material placement and disposal sites to protect a fish or wildlife population and its habitat from predators and potentially adverse human interactions.
Harbor - Any protected water area affording a place of safety for vessels.
Heavy metals - Metals known to be hazardous to living organisms ingesting them in sufficient quantities; generally, cadmium, nickel, lead, zinc, copper, mercury, chromium, and others.
Herbaceous vegetation - Plants without woody stems such as grasses, most legumes, forbs, and wildflowers (annuals or perennials).
Herbicides - Chemical compounds developed and used for the control or destruction of undesirable vegetation. They are often highly selective and specifically developed for target plant species.
Historic preservation - The protection from destruction and the maintenance of historic sites, such as Indian mounds in the Mississippi River floodplain and colonial archaeological sites on coastal islands.
Horticulture use - The beneficial use of dredged material placement sites or formerly used dredged material disposal sites as nursery or orchard sites; also, using dewatered dredged material as an ingredient in potting or plant bed soil mixtures.
Hydraulic pipeline - A dredged material discharge pipeline that carries slurry material from the dredging site to the beneficial use or disposal site. It may be floating or positioned on land, and may be movable or stationary.
Hydrolysis - A chemical process of decomposition involving the splitting of a bond and the addition of the elements of water.
Hypothesis - A tentative conclusion made in order to draw out and test its logical or empirical consequences.
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Incremental dredging - The deposition of dredged material in a beneficial use placement or disposal site in small lifts over an extended period of time.
Industrial/commercial use - The beneficial use of dredged material for port, harbor, airport, building, or other industrial and commercial enterprise construction.
Inflow - Water entering an estuary from rivers or bayous.
Inlet - (1) A short, narrow waterway connecting a bay, lagoon, or similar body of water with a large parent body of water. (2) An arm of the sea (or other body of water) that is long compared
to its width and may extend a considerable distance inland.
Innoculated seeds or rootstock - Seeds or roots exposed to beneficial fungi or other soil organisms that enhance the growth and survival of the plants. These mycorrhizal organisms aid in nutrient uptake and in root protection from toxic and saline soils.
Inshore - The zone of variable width extending from the low-water line through the breaker
Intermittent dredging - The shutting on and off of a dredging operation on a scheduled basis (i.e., 1 hour on/1 hour off) to allow settling to occur and effluent water to move at a slower rate.
Intertidal zone - That land area between mean low water and mean high water that is inundated periodically by tides.
Inundation - Flooding of an area, as when tides come into marshes.
Invertebrates - Animal without internal skeletons, such as insects, crabs and shrimp.
Island - An upland habitat distinguished by its isolation and completely surrounded by water or wetlands. Often, islands are fringed with or include interior wetland habitats.
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Jetty - A structure extending into a body of water, which is designed (1) to prevent shoaling of a channel by littoral materials, and/or (2)to direct and confine the current or tidal flow. Jetties are often built at the mouths of rivers or tidal inlets to help deepen and stabilize a channel.
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Land enhancement - The improvement in use, quality, and/or value of land through habitat management, manipulation, and/or protection.
Land use - The use, beneficial or otherwise, of a specific land parcel. In this case, the current or planned land use of dredged material disposal sites.
Land use control - The legal jurisdiction and ownership or lessee rights to control the use of a specific land parcel. For example, the Corps’ rights of control of disposal sites.
Leachate drain - Layers of pervious material such as sand or gravel placed to intercept leachate on a disposal site or solid waste landfill and drain it to an area for treatment or recirculation.
Leaching - The percolation of nutrients and other compounds such as salt within the top layers of soil into subsoil layers and ground-water zones.
Lee - Shelter, or the part or side sheltered or turned away from the wind or waves.
Legume - Any member of the Legumacae family, typically having the important ability to fix and use atmospheric nitrogen to enhance plant growth and survival. Clovers, lespedezas, and acacias are excellent examples.
Levee - Earthen structures (e.g., dike or embankment) built to contain periodic floodwater from river systems to within a specific area of the floodplain.
Lifts - A term describing deposits of dredged material into containment facilities. Each lift generally is allowed to dewater before another lift is deposited.
Limiting factor - Any physical, chemical, or biological factor that is the critical limitation on growth and survival of an organism; e.g., smooth cordgrass is limited in its growth by the boundaries of the intertidal zone.
Liners and barriers (leacheate control) - Physical structures or cloths used to partially enclose or seal off disposal areas to prevent translocation of contaminants into adjacent soils and ground and surface waters.
Liner shrubs - Small, potted and rooted shrub cuttings generally not more than 2 years of age that are developed for commercial and landscaping sales. (Larger, older shrubs are usually called ‘container stock’.) In this case, liner shrubs that can be grown in a soil/dredged material mix, or that can be planted on disposal sites for the purpose of habitat development or providing recreational opportunities.
Littoral - Of, on, along, or near to a shore.
Littoral drift - The sedimentary material transported along the shoreline by waves and currents.
Littoral transport - The movement of sedimentary material in the littoral zone by waves and
Littoral zone - The zone from high-tide level to the edge of the continental shelf.
Long-range project goals - Project goals that extend over a period of not less than 10 and up to 50 years, especially as they pertain to ultimate land use of disposal sites.
Longshore - Parallel to and near the shoreline.
Long-term management plans - Engineering and environmental management plans developed for beneficial use and disposal sites or dredging reaches that have at least a 10-year and not more than a 50-year life.
Low maintenance habitat - Habitat that requires almost no labor-intensive management activities such as mowing or protection and that, once developed, is generally allowed to progress naturally through ecological stages.
Low wave energy - Wave action with tidal ranges averaging not more than 1 to 2 feet, in areas naturally or artificially protected from wind fetches and ship traffic.
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Macrofauna - Those animals equal to or larger than 0.5 millimeter in size.
Maintenance dredging - The cyclic dredging of the same area over a period of time to remove accumulating sediments and to maintain ship, barge and boat traffic.
Man-made habitat - Any habitat that was created by humans, i.e., a salt marsh built of dredged material.
Man-made island - Any island that was created, often deliberately, by humans generally only referring to those built by the Corps using hydraulically pumped dredged material.
Marginal soil - Any soil not suitable for crop development or other beneficial uses by virtue of its physical and chemical characteristics. However, these soils are sometimes developed by landowners anyway, and are often further degraded, depleted, and eroded.
Mariculture - The practice of growing in commercial enterprises marine crops of shrimp, oysters, squid, clams, red fish, and other sea animals, that are highly-consumed species (by humans). Mariculture is practiced more in Japan and other Asian countries than in the United States.
Maritime forest - A coastal forest generally consisting of species tolerant of near-constant sea breezes and occasional salt spray including wax myrtle, groundsel tree, live oak, and other species.
Marl - A mixture of clay, sand, and limestone in varying proportions that is soft and crumbly and usually contains shell fragments.
Marsh - An area of soft, wet, or periodically submerged land, generally treeless and usually characterized by grasses and other low vegetation.
Material rehandling - The requirement of handling dredged material more than one time, such as with booster pumps, hopper barges, or as dewatered and stockpiled material.
Mean high water (MHW) - The average height of the high waters over a 19-year period. For
shorter periods of observation, corrections are applied to eliminate known variations and reduce
the results to the equivalent of a mean 19-year value. All high-water heights are included in the
average where the type of tide is either semidiurnal or mixed. Only the higher high-water
heights are included in the average where the type of tide is diurnal. So determined, mean high
water in the latter case is the same as mean higher high water.
Mean low water (MLW) - The average height of the low waters over a 19-year period. For
shorter periods of observation, corrections are applied to eliminate known variations and reduce
the results to the equivalent of a mean 19-year value. All low-water heights are included in the
average where the type of tide is either semidiurnal or mixed. Only lower low-water heights are
included in the average where the type of tide is diurnal. So determined, mean low water in the
latter case is the same as mean lower low water.
Meiofauna - Generally those interstitial animals below 0.5 millimeter.
Midden - Large piles of debris, such as piles of shells, created by early inhabitants of an area.
Migratory species - All bird species that make semi-annual migrations and who are protected by the U.S. Migratory Bird Treaty Act and its amendments. Also, all fish and mammal species which migrate for spawning, foraging, or other life purposes.
Mine spoils - The material removed and/or processed in the mining of a site that is left behind as the mining operation moves forward to unmined areas.
Mitigation - Avoiding the impact of a certain action or part of an action; minimizing impacts by limiting the degree of magnitude of an action; rectifying an impact by repairing, rehabilitating, or restoring the affected environment; reducing an impact over time by preserving and maintaining
operations during the life of the action; compensating the impact by replacing or providing substitute resources or environments.
Moderate wave energy - Wave action with tidal ranges of 2 or more feet in unprotected areas, but with waves that are not normally severe or extremely forceful upon impact.
Monitoring - The process of collecting (before, during, and after disposal) physical, chemical, and environmental data to determine the potential impacts of a particular dredging and dredged material placement or disposal operation.
Monoplanting - Plantings of only one species on a site, i.e., cottonwood tree plantations, smooth cordgrass saltmarshes, or agronomic crops in large fields.
Multiple-head discharge pipe - A discharge pipe with more than one head or more than one opening on the same head to allow better spreading and distribution of dredged material. This type of pipe is not used except in low-flow discharges.
Multipurpose use - More than one beneficial use of the same dredged material placement project.
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Natural colonization - The habitation by natural invasion of any site by generally highly adaptable and opportunistic species, i.e., smartweeds colonizing a newly exposed mudflat in a lake, river, or reservoir.
Navigation Dredging Project - Projects consisting of the creation and/or maintenance of features conducive to safe aquatic navigation such as channels, turning basins, and anchorages.
Nearshore - An indefinite zone extending seaward from the shoreline well beyond the breaker
Nekton - Those aquatic animals able to swim efficiently, and not mainly at the mercy of currents.
Nesting beaches - Sand beaches which are used by certain bird and sea turtle species for digging nests and laying eggs. Encroaching development and increasing recreational use of nesting beaches by humans makes these endangered species increasingly vulnerable to loss of eggs and young.
Nesting island - Any island, natural or manmade, which is used for nesting; commonly used by colonial sea- and shore-birds.
Nesting substrate - Any foundation used for supporting nests, i.e., trees for wading birds; bare sand for terns and skimmers; sparse grass for gulls; wet marshy mounds for rails, loons, grebes, and others; and grassy meadows for ducks, geese, and swans.
New work dredging - Dredging in an area that has not previously been dredged; often includes clay bottom or bedrock material.
Nonconsumptive use - Use activities on dredged material placement sites that do not harvest or destroy animals or plants on the site, e.g., bird watching, hiking, jogging, or bike riding.
Nongame species - Any animal species that is not legally hunted or trapped.
Nonmotile benthos - Benthic organisms occurring both in the intertidal zone and in deeper water that lack locomotive capabilities; these species cannot move out of the way of dredging operations and may be severely or fatally impacted by dredging.
Non-navigation Dredging Project - Projects where dredging is conducted solely to acquire sediment for an objective (other than the allowance of navigation) such as obtaining fill for port or airport expansion, habitat restoration, and shore protection. This term is synonymous with “dedicated dredging”.
Nourishment - The process of replenishing a beach or wetland. It may be brought about naturally, by accretion due to longshore or downstream transport, or artificially, by the deposition of dredged materials.
Nutrient load - The level of nutrients, primarily nitrogen, phosphorus, and potassium, in soil or dredged material usually caused by agricultural runoff from fertilized fields. Excess nutrient loads can occasionally cause detrimental effects in disposal sites, especially in ponded areas.
Nylon fabric sandbags - Large-capacity (4 by 8 feet) bags made of woven nylon, that are hydraulically filled in place with sand, and which are used as temporary breakwaters in moderate wave energy environments.
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Ocean dumping - The practice of dredged material disposal via oceangoing barge into a designated disposal site in deep, open water, often miles from shore.
Offshore - The direction away from the shore, toward a large body of water.
One-time dredging - The placement of dredged material into a disposal site only once; then the site is converted to other use.
Onshore - The landward direction, away from the water.
Open-water disposal - The practice of dredged material disposal anywhere into open water; e.g., in the Lower Mississippi River above Head of Passes almost all dredged material is sidecast into open water to allow it to remain in suspension and move downriver.
Overtopping - The passing of water over the top of a natural or man-made structure as a result of wave runup or surge.
Overwash - That portion of the uprush that carries over the crest of a berm or structure.
Oyster bed - Any foundation used by oysters as a place of attachment to grow and complete their life cycles, i.e., rocks, submerged boats, or old oyster shells in shallow water.
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Pelagic - All ocean waters covering (above) the lower benthic region.
Perched beach - A beach retained above the otherwise normal profile level by a submerged sill.
Periphyton - Organism (such as algae, cyanobacteria, and others) attached or clinging to stems, leaves, or other surfaces of plants under the water.
Permeability - The ease with which water can move or pass through a soil, dredged material, or other material.
Permit - A document issued that expresses the assent of a government agency, so far as concerns the public rights and the general public interest, for the accomplishment of certain works.
pH - The standard measure of 0.0 to 14.0 of acidity and alkalinity of soil, water, and other liquids. A pH of 7.0 is neutral, and uncontaminated rainfall is generally 6.0 to 7.0. A pH of 5.5 to 7.5 is the range generally found best for plant and animal growth.
Pile - A long, heavy timber or section of concrete or metal that is driven or jetted into the earth or bottom of a water body to serve as a structural support or protection.
Placement Site – Any area, aquatic or upland, at which dredged material is utilized, or disposed.
Plankton - Those organisms passively drifting or weakly swimming in marine or fresh water.
Planktonic larva - Floating or weakly swimming and often microscopic aquatic juvenile forms of organisms such as coral or shellfish.
Plant material - Any plant growing on a site or intended for growth on a site can be referred to as plant material.
Plant nursery - A commercial or public enterprise where plants are propagated and grown for sale or for public use sites. Public plant nurseries are generally those of the U.S. Forest Service and the U.S. Natural Resources Conservation Service.
Plant propagation - The human act of obtaining, maintaining, and growing propagules; includes cultivating the site, or preparing the growing medium; planting, fertilizing and making soil amendments; and other acts as needed.
Plasticity - A measure, obtained by calculating the Atterburg liquid limit and the plasticity limit, which determines the use and load-bearing ability of a fine-grained soil or dredged material.
Ponding - The collection of water by gravity flow on any site. In this case, a disposal site that may hold ponded water due to consolidation or improper weir placement, or a beneficial use site may be designed to encourage ponding for aquaculture purposes.
ppt - parts per thousand
Prairie pothole - Isolated, shallow depressions that support freshwater marsh species.
Primary production - The rate at which energy is stored by photosynthesizing organism (chiefly green plants) in the form of organic substances.
Problem soil - Any soil (or dredged material) not suitable for beneficial use purposes due to its physical or chemical conditions or engineering properties.
Progressive trenching - The progressive deepening of surface drainage ditches lower than the base of crust desiccation cracks on fine-grained dredged material as the water table falls.
Propagules - Any piece of plant material that will form a new plant, i.e., seeds, tubers, transplant sprigs, rhizomes, corms, bulbs, and cuttings.
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Rare or threatened species - Plant or animal species of declining populations that have not reached the threshold of being considered endangered to the point of extinction.
Reclamation - The process of restoring and revegetating a disturbed site to or near its previous habitat quality, or, generally, to a state of usefulness.
Recreational use - The beneficial use of a dredged material disposal site for recreation, including camping, boating, swimming, picnicking, hiking, and other recreation activities.
Remote sensing - In this case, the use of high-intensity, infrared aerial photography for habitat mapping, plant community identification, and broad-scale planning.
Retaining structure - A temporary or permanent structure used for holding dredged material on a limited basis, not to be confused with a long-term use CDF structure.
Revegetation - The process of reestablishing vegetation cover on any disturbed or newly formed site through a variety of methods.
Revetment - A facing of stone placed on a bank or bluff to protect a slope, embankment, or shore structure against erosion by wave action or currents.
Riparian - Of, on, or pertaining to, the banks of a river or other body of water.
Riparian rights - The rights of a person owning land containing or bordering on a water course or other body of water in or to its banks, bed, or waters.
Riprap - A foundation or wall made of broken stones placed together irregularly or loosely, in water or on a soft bottom.
Riverine environment - The river, island, on-bank, and near-bank plant and animal community within a floodplain.
Riverine Utility Craft (RUC) - A specially developed craft for use in water and soft mud whose flotation is provided by twin Styrofoam-filled rotors which make trenches that are useful in dewatering fine-grained dredged material. The RUC does not work well in coarse-grained material.
Rocks - Mineral matter variously composed, formed in masses or large quantities in the earth's crust by the action of heat, pressure, etc.
Rotating disposal pipe - A disposal pipe that has a swinging discharge head to allow dredged material to be placed over a wider area. This pipe is only for low-flow discharge and can be used to help maintain an intertidal elevation for marsh creation.
Rubble - Rough, irregular fragments of rock or concrete.
Rubble-mound structure - A mound of random-shaped and random-placed stones protected with
a cover layer of selected stones or specially shaped concrete armor units. (Armor units in a
primary cover layer may be placed in an orderly manner or dumped at random).
Runup - The rush of water up a beach or structure, associated with the breaking of a wave. Runup equals the vertical height above still-water level that the rush
of water reaches.
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Saline - Containing salts, in reference to habitats, it usually refers to waters having 30-40 parts per thousand dissolved salts.
Salinity - The measure of soluble salts in soil or water (or dredged material) that make it suitable or unsuitable for particular beneficial uses. The measure of salt content, usually expressed in grams of salt per kilogram of water.
Salt marsh - A marsh periodically flooded by salt water. Herbaceous vegetation growing at a saline intertidal elevation. Primary U.S. saltmarsh species at mean low water are smooth cordgrass on the east and gulf coasts and Pacific cordgrass on the west coast.
Sanctuary - Any area totally and legally protecting designated plant or animal species, for example, dredged material islands which have been designated waterbird sanctuaries.
Sand - That fraction of soil or dredged material whose grain size distribution is 2.00 to 0.05 mm, generally referred to as coarse-grained.
Sandbar - A natural or man-made bare sand area within the channel of a river, either attached to the bank or in midstream.
Sand dike - A temporary dike structure made chiefly of sand and often emplaced via hydraulic dredging of sandy underwater deposits.
Sandstone - A common bedded sedimentary rock much used for building, composed largely of
sand grains, mainly quartz, held together by silica, lime, etc.
Scour - Removal of underwater material by waves and currents, especially at the base or toe of a shoreline structure.
Seabirds - A group of birds that live around and over large bodies of water. In the United States, they live primarily in coastal bays, oceans, estuaries, large rivers, the Great Lakes, and the Great Salt Lake, and include gull, tern, and skimmer species.
Seagrass - Members of marine seed plants that grow chiefly on sand or sand-mud bottom. They are most abundant in water less than 9 meters deep.
Seagrass bed - A fragile, shallow, underwater marine ecosystem colonized by eel grass, turtle grass, shoal grass, and other marine plant species. These species are very specific in their requirements for nonturbid, clean, open water and can be greatly impacted by dredging.
Sea turtles - Extremely vulnerable, endangered or threatened, motile vertebrate marine animals whose nesting seasons and movements can conflict with dredging operations.
Seawall - A structure separating land and water areas, primarily designed to prevent erosion and other damage due to wave action.
Sediment - Material such as sand, silt, or clay suspended in or settled on the bottom of a water body.
Sedimentation - The process of deposition of sediment in water through settling out of heavier coarse-grained particles. This term also refers to the deposition of alluvial sediment in a floodplain at river flood stage.
Seedbed preparation - The clearing, plowing, disking, and cultivation of a soil or dredged material to prepare it for seeding.
Seed farm - A farm used for the commercial production of seeds, generally associated with agronomic crops such as food grains and soybeans, but also including flower and vegetable seed production.
Seed mixture - A general mixture of locally acclimated seeds of several grass and legume species (usually at least three but not more than eight to ten) for planting in sites to become natural areas and grazing meadows.
Self-weight consolidation - Consolidation caused by the actual weight of the dredged material placed inside the disposal site, which forces water out of the material and to the surface or into underdrainage systems.
Sessile - Any organism that usually is fixed but may move infrequently or may be permanently attached.
Shear strength - That point and beyond at which a dredged material substrate begins to consolidate and develop strength as a soil material after leaving the slurry state.
Sheet pile - A pile with a generally slender flat cross section to be driven into the ground or seabed and meshed or interlocked with like members to form a diaphragm, wall, or bulkhead.
Shellfish - Any aquatic invertebrate with a hard external covering; more commonly mollusks and crustaceans.
Ship-generated waves - Waves that are a direct result of ship traffic rather than wind or tidally influenced, and that are often severe on shorelines for a short period after ship or barge passage.
Shore - The narrow strip of land in immediate contact with the water, including the zone
between high- and low-water lines.
Shoreline - The intersection of a specified plane of water with the shore or beach (e.g., the high-water shoreline would be the intersection of the plane of mean high water with the shore or
beach). The line delineating the shoreline on National Ocean Survey nautical charts and surveys
approximates the mean high-water line.
Shoreline stabilization - The erosion protection of shorelines by engineering structures such as riprap or by biological features such as salt marshes or willow banks.
Sidecasting – Activity during which a dredge pumps dredged material through an elevated discharge boom and discharges the material away from and beyond the channel prism.
Sill - A structure built with the objective of 1) reducing erosive wave action on the shoreline by forcing waves to break over the sill, or 2) retaining sediment between the sill and shoreline. Sills are most often built parallel to the shore.
Silt - The fraction of soil or dredged material whose grain size distribution is 0.05 to 0.002 mm, generally referred to as fine grained.
Silt curtain - A floating fabric curtain device suspended around a dredging operation or disposal site to prevent rapid movement of suspended sediment out of the area.
Site maintenance - the care and management of placement and disposal sites to accomplish the planned project and site goals.
Site specific - Rigid environmental and physical conditions which pertain to development and management of a particular site.
Site suitability, biological - The biological conditions of soil, substrate, and surrounding area that limit or enhance a site’s appropriateness for beneficial uses of material disposal. Such factors include water depth, vegetation stage, existing biological resources and others.
Site suitability, chemical - The chemical conditions of the substrate and soil that limit or enhance a site’s appropriateness for beneficial uses or material disposal. This includes nutrient levels, sulfur, heavy metals, pesticide compounds, salinity, oil and grease, and others.
Site suitability, physical - The physical conditions of soil, substrate, slope, wave action, climate, water stages, distance to point of disturbance, presence or absence of a dike, etc, that limit or enhance a site’s appropriateness for beneficial uses or material disposal.
Site suitability, socioeconomic - The social and economic conditions that limit or enhance a site’s appropriateness for beneficial uses or material disposal.
Site topography - On disposal sites, the various elevations, hills and mounds, and ponded areas achieved by the position of the disposal pipe. Topography can be altered by mechanical means for beneficial uses.
Slurry - A term describing the mixture of soil or sediment and water hydraulically dredged and pumped to a placement or disposal site.
Socioeconomic benefits - The positive benefits to a community where a beneficial use project or dredged material disposal site is located in terms of dollars returned to the community in jobs, recreational use, and general improvement of public perception and well-being.
Socioeconomic considerations - Social and economic conditions and opinions that must be evaluated for any project to determine project feasibility and cost:benefit ratios, as well as the potential project benefits and detriments to the community.
Sod farm - The commercial production and sale of sod blocks, usually of lawn and golf course grasses such as Tifgreen and Zoysia. In this case, sod growing on dredged material as a commercial beneficial use.
Soil amendment - Fertilizers, lime, mulches, and any material added to the soil or dredged material to improve its quality for beneficial uses.
Solid waste landfill - Any area, usually associated with urban communities, where disposal of human refuse and garbage takes place. The waste is capped daily with at least 6 inches of soil (or dewatered dredged material).
Soluble salts - The fraction of salts in a moist soil (or dredged material) that becomes available to plants for aborption.
Sorption - The process of being taken up and held by either absorption or adsorption.
Sound - A relatively long arm of the sea or ocean forming a channel between an island and a
mainland or connecting two larger bodies, as a sea and the ocean, or two parts of the same body;
usually wider and more extensive than a strait.
Spat - Young oysters during early growth and attached to a hard substrate.
Spawning season - The particular biological time in which mating and egg-laying occurs in fish species.
Species - A taxonomic designation assigned to a distinct group of plants or animals which can only breed with another like organism, and which is usually characterized by individual differences from any other species.
Species specific - Rigid environmental and physical conditions that pertain to development and maintenance of habitat for a particular species.
Sport fishery - A term which applies to fishing areas with sustainable populations of certain species of game fish.
Spur dike - A partial dike built within a CDF for purposes of directing and slowing flow of the slurry within the site to allow more sedimentation to occur before the slurry reaches the weir outlet.
Stockpiling - The practice of placing dewatered dredged material in a holding area, where it is slated for future beneficial uses.
Striking off - The method used in strip mine reclamation or dewatered dredged material spreading in which the disposal ridges are knocked into the valleys between those ridges, thereby leveling the site.
Strip-cropping - The agronomic practice of alternating a row crop with a grass or legume cover crop or a fallow strip to conserve soil and improve soil properties.
Strip mine reclamation - The grading, shaping, and revegetating of strip-mined soil to regain lost habitat and to prevent erosion and downstream toxicity problems.
Subsidence - An elevational change caused by the inability of foundation material to hold up the load placed on it by natural or deposition or human activities such as dredged material placement For example, the Louisiana coastal marshes where subsidence is occurring at a very rapid rate.
Substrate - The foundation upon which all things exist; for example, the soil in a substrate supporting plants, animals, buildings, and other structures; trees are the substrate in which birds build nests; the bay bottom is the substrate supporting benthic communities.
Subtidal - The region extending below the intertidal to the edge of the continental shelf.
Superfund site - A site contaminated by hazardous waste or toxic substances which has been listed on the National Priorities List by the federal government (through the Comprehensive Environmental Response, Compensation and Liability Act of 1980, as amended) forremediation.
Supratidal - The zone immediately adjacent to the mean high-water level; commonly called the splash zone.
Surf zone - The area between the outermost breaker and the limit of wave uprush.
Suspended solids - Soil particles and organic matter which remain suspended in the water column after agitation from dredging, or during movement downstream in river systems.
Swamp - A periodically inundated wooded area occurring predominantly in the southern United States, generally dominated by forest trees such as bald cypress and/or tupelo gum.
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Target species - A desired species or group of species toward which habitat development and management are directed.
Temporary breakwater - A structure with a design life of 1 to 5 years erected for the purposes of slowing down or preventing wave action and for protection of the area behind the breakwater.
Terraces - A low earth structure created on farms and erodible land where steep slopes exist to conserve soil and aid in rainfall absorption.
Thalweg Dispersal - In the river setting: The placement of dredged material in a deepwater portion of the channel thalweg where it will become a natural element of the sediment transport system and will be assimilated into the system with minimal impacts to either the sediment transport system or the environment
Tidal flat - An intertidal area exposed at low tide on which no marsh grows, usually called a mudflat. Tidal flats are often colonized by high numbers of small benthic organisms which are fed upon by a variety of other species such as shorebirds.
Tidal range - The ebb and flow over land between low water and mean high water where tide water is periodically present.
Tide - The periodic rising and falling of water that results from the gravitational attraction of the moon and sun acting on the rotating earth.
Tolerance level - That point at which a living organism can no longer survive a chronic or short-term environmental, physical, or chemical condition, such as a toxicity of heavy metals or pesticide compounds or extreme turbidity.
Tombolo - A bar or spit that connects or "ties" an island to the mainland or to another island.
Topsoil - The upper layer of soil, usually darker and richer than the subsoil; surface soil.
Toxicant - A poisonous agent.
Toxicity - A term describing the limit of intolerance of organisms to survive lethal chronic or short-term subjection to certain chemical and contaminating substances, or physical and environmental conditions.
Transplant - The most common type of propagule used in wetland habitat development and in landscaping work; this term applies to a well-rooted, vegetative propagule of several stems or a single strong stem.
Transport - Any method used for the transportation of dredged material, usually by hydraulic pipeline or barge, or if dewatered, by barge, truck, or railroad.
Turbidity - Turbidity - A condition in bodies of water where high sediment loads cause clouding of the water to varying extents. It is an optical phenomenon and does not necessarily have a direct linear relationship to particulate concentration. In the case of feeding animals, turbidity limits visual feeding. It also will shade out or smother aquatic vegetation.
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Unconfined disposal site - Any dredged material disposal site where the material is not placed behind a retaining structure but is allowed to flow freely out of the disposal site.
Underdrainage dewatering - A method of dewatering dredged material disposal areas, where drainage materials such as sand or gravel layers or tiles are permanently emplaced before any dredged material is deposited.
Updrift - The direction opposite that of the predominant movement of littoral materials.
Uplands - Lands elevated above the effect of tides, water tables, etc. Any terrestrial community characterized by vegetation not usually tolerant of inundation, ranging from bare ground to mature forest.
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Value methodology - Determination of potential socioeconomic benefits of dredged material sites by use of a matrix that categorizes and describes the effects and impacts.
Vascular - Having small vessels for transporting fluids, e.g., the small vessels in plants which transport sap.
Vegetation - Plants of all species and families, tooted, attached, or floating, deciduous or evergreen, woody or herbaceous, commercial or noncommercial. In this case, referring to any plant growing on dredged material or affected by dredging and dredged material placement.
Vegetation control - The practice of managing vegetation to maintain certain stages of growth through mechanical, biological, or chemical methods.
Volatile - The tendency of a substance to erupt violently or evaporate.
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Waterbirds - A diverse group of birds recognized by scientists according to their colonial-nesting habits and their feeding in water; the group can be further refined into wading birds, diving birds, and seabirds.
Waterfowl - A group of birds that includes ducks, geese, and swans. (No swan can be legally hunted in North America)
Water retention - The moisture-storing capacity of a soil or dredged material that is strongly influenced by the arrangement and quantity of fine particles and organic matter.
Watershed - An area of land drained by a single stream, river, bay, or lake.
Wave - A ridge, deformation, or undulation of the surface of a liquid.
Wave height - The vertical distance between a wave crest and the preceding trough.
Wave length - The horizontal distance between similar points on two successive waves (for
example, crest to crest or trough to trough), measured in the direction of wave travel.
Wave period - The time in which a wave crest travels a distance equal to one wave length. Can be measured as the time for two successive wave crests to pass a fixed point.
Weir - One type of outfall structure built into the dike of a CDF at the farthest point from the discharge pipe.
Weir placement - The location of the weir in a CDF for the best possible drainage of ponded water and for the longest distance for slurry travel from the discharge pipe to allow more dropout of sediment.
Wetland - Periodically inundated communities characterized hydric soils and by vegetation that survives in wet soils,; ranging from coastal intertidal marshes to freshwater swamps and bottomland hardwoods. These areas usually have quite distinctive vegetation communities.
Wildlife - Any animal species or group of animals that range free and are not normally commercially produced for human food or use; includes both game and nongame species.
Wind fetch - A term used to describe the open area and distance across a bay or body of water in which wind can exert energy on waves to cause them to be higher and more forceful upon impact with shorelines.
Wind waves - Waves caused by wind action, especially across shallow bays with long wind fetches.
Winnow - Natural removal of sediments through suspension and erosion of fine particles by
Wooded wetland - A wetland that is dominated by trees and shrubs, and includes swamps, bottomland hardwoods, and wooded bogs.