SHORELINE GLOSSARY 

100 Year Flood - A flood stage that statistically has a 1% probability of occurring in any given year.

Abiotic – Are physical environmental factors (e.g. water, temperature, soil and light) that influence the composition and growth of an ecosystem.

Accretion – Is the deposition of sediment, sometimes indicated by the seaward advance of a shoreline indicator such as the water line, the berm crest or the vegetation line.

Aeolian – caused by the wind or wind-blown 

Algae - group of primitive, non-flowering plants which include certain seaweeds and microscopic phytoplankton

Anadromous fish - fish such as American shad that migrate from their primary habitat in the ocean to freshwater to spawn

Anaerobic - not containing oxygen of not requiring oxygen

Anchor Piling – Is a pile located on the land side of a bulkhead or pier and anchors it with devices such as rods, cables or chains. 

Anoxic - a condition where no oxygen is present. Much of the "anoxic zone" is anaerobic, with absolutely no oxygen, a condition in which toxic hydrogen sulfide gas is emitted in the decomposition process

Armoring – The deposition of sediment, sometimes indicated by the seaward advance of a shoreline indicator such as the water line, the berm crest, or the vegetation line. 

Bank height – Is the approximate height of the upland bank above mean low water. 

Bathymetry – Is the topography, or contours of a waterway correlated to water depths. 

Beach – Is the shoreline zone comprised of unconsolidated sandy material upon which there is mutual interaction of the forces of erosion, sediment transport and deposition extending from the low water line landward to the uplands. 

Beach Nourishment – The addition of sand (sand fill) to a shoreline to enhance or create a beach area, offering both shore protection and recreational opportunities. 

Benthic organisms - plants and animals living in or on the bottom in aquatic habitats

Berm – Is a geo-morphological feature usually located at mid-beach and characterized by a sharp break in slope, separating the flatter backshore from the seaward-sloping foreshore. 

Best Management Practice (BMP) – Measures that have the combined effect of ensuring project integrity for the design life of the project while minimizing the potential adverse impacts associated with construction and maintenance. 

Bluff – An elevated landform composed of partially consolidated and unconsolidated sediments, typically sands, gravel and/or clays. 

Brackish water - mixture of fresh and salt water

Breakwater – A single structure or a series of units placed offshore of the project site to reduce wave action on the shoreline.

 

Bulkhead – Is a vertical shoreline stabilization structure that primarily retains soil.

   

Buried toe – Is a trenched seaward toe of a revetment to help prevent scour and shifting of the structure. 

CAMA – Coastal Area Management Act 

Catadromous fish - fish such as the American eel that migrate from their primary habitat in freshwater to the ocean to spawn

CWA – Clean Water Act 

CZMA – Coastal Zone Management Act 

 Chesapeake Bay Foundation –

Mission

Pollution and other harmful activities degrade the Bay. The Chesapeake Bay Foundation (CBF) fights for strong and effective laws and regulations. CBF also works cooperatively with government, business, and citizens in partnerships to protect and restore the Bay. When necessary, we use legal means to force compliance with existing laws.

Since being created in 1967, we have achieved significant milestones to arrest the Bay system's decline and to begin to restore its health. From the landmark EPA study of the Chesapeake Bay in the 1970s to the first interstate Chesapeake Bay Agreement in 1983 to Maryland's historic sewage treatment bond bill in the 2004 and Virginia’s comparable legislative commitment in 2005, CBF has been saving the Bay. Learn more about CBF's programs.

Vision

Our vision is that the Chesapeake Bay and its tributary rivers will be highly productive and in good health as measured by water clarity, lack of toxic contaminants, and abundance of natural filters in the water and on the land. Read our strategy for getting there 

Continuous no-till - no-till agriculture practiced for multiple years (see no-till below)

Control – Is the part of the experiment that is used as a basis for comparison. 

Convergence – Zones where sediment deposition exceeds sediment loss and accretion of sediment occurs. 

Copepods - minute shrimp-like crustaceans; often they are the most common zooplankton in estuarine waters

Cumulative impacts – The impacts on the environment, which result from the incremental impact of the action when added to other past, present and reasonably forseeable future actions regardless of what agency (federal or nonfederal) or person undertakes such other actions.  

Core stone – Smaller stone used as the base of a revetment to provide a stable base for armor stone. 

Decomposers - organisms (chiefly bacteria and fungi) that break down dead organic matter

Delta – A nearly flat plain of alluvial deposit between diverging branches of the mouth of a river, often though not necessarily triangular.

 Deposition – Is the process of sediment settling back to the bed or particles settling out of the water column. 

Detritus - decomposed or partly decomposed plant and animal matter

Dissolved oxygen - microscopic bubbles of oxygen that are mixed in the water and occur between water molecules. Dissolved oxygen is necessary for healthy lakes, rivers, and estuaries. Most aquatic plants and animals need oxygen to survive. Fish will drown in water when the dissolved oxygen levels get too low. The absence of dissolved oxygen in water is a sign of possible pollution

Divergence – Zones where the amount of sediment mobilized and lost exceeds the amount deposited. 

Downdrift – The resulting direction material is carried as waves strike a shore and move “down” along a shoreline. 

Dune – A landform characterized by an accumulation of wind-blown sand, often vegetated. 

Ebb tide - falling or lowering tide

Ecology - the study of interrelationships of living things to one another and to their environment

Ecosystem - an interactive system of a biological community and its non-living environment

Edaphic – They are the organisms living on or in the soil.

EFH – Essential Fish Habitat 

EPA – Environmental Protection Agency 

ESA – Endangered Species Act  

Entrainment – The picking up and setting into motion of particles, either by wind or by water.  The main entrainment forces are provided by impact, life force and turbulence. 

Erosion – Is the loss of sediment, sometimes indicated by the landward retreat of a shoreline indicator such as the water line, the berm crest, or the vegetation line.  The loss occurs when sediment grains are entrained into the water column and transported away from the source. 

Erosion mitigation – Are efforts to reduce or lessen the severity of erosion. 

Estuary – Is a place where fresh and salt water mix (e.g. a bay, salt marsh); a place where a river enters an ocean.  Semi-enclosed, tidal, coastal body of water open to the sea in which fresh and salt water mix 

Ethnology – Is the branch of anthropology that compares and analyzes the origins, distribution, technology, religion, language, and social structure of the ethnic, racial, and/or national divisions of humanity.  

Eustatic sea-level rise – Results from changes in global sea level.  Eustatic changes represent global sea level.  The causes can be complex, such as ice-sheet melting, increasing temperature of the surface waters, and increasing the volume of the spreading ridge.

Eutrophication - the fertilization of surface waters by nutrients that were previously scarce. Eutrophication through nutrient and sediment inflow is a natural aging process by which warm shallow lakes evolve to dry land. Human activities are greatly accelerating the process. The most visible consequence is the proliferation of algae. The increased growth of algae and aquatic weeds can degrade water quality 

Fall Line – This is the boundary between an upland region and a coastal plain across which rivers from the upland region drop to the plain as falls or rapids. 

Fetch – Is the distance that a wave travels from the point of origin to the shore where it breaks.  In sheltered areas, the fetch corresponds to the distance across a span of water over which wind-generated waves may grow before breaking on the opposing shore. 

Filter Cloth – Is a synthetic textile placed between bulkhead sheeting and backfill or underneath a revetment to prevent soil loss yet provide permeability.

Flood Control – Wetlands trap and filter pollutants and sediments.

Flood tide - rising tide

Flume - A constructed channel lined with erosion-resistant materials used to convey water on the steep grades without erosion.

Food chain - the sequence in which energy as food is transferred from one group of organisms to another

Food web - complex interaction of food chains in a biological community

FWS – Fish and Wildlife Service 

Gabions – Is a basket or a cage filled with stone, brick or other material to give it a weight suitable for use in revetments or breakwaters.  In the marine environment it is usually made with galvanized steel wire mesh with a PVC coating. 

Geomorphic – of resembling, or pertaining to the form of the earth or of its surface features

Groins – Are a breakwater running seawards from the land, used on a variety of coasts including sheltered shores and open coasts, constructed to trap sand by interrupting long shore transport. A groin extends from the backshore into the littoral zone and is normally constructed perpendicular to the shore out of concrete, timbers, steel or rock.

 

Habitat - the place where a plant or animal lives

Hardening – see Armoring. 

Headland – Is a point of land jutting out into a body of water or a shoreline section less resistant to erosion process than adjacent shorelines. 

Head water -

Halophyte – A plant that naturally grows where it is affected by salinity in the root area or by salt spray.

Hydrophyte – These are plants that have adapted to living in or on aquatic environments. 

Impervious – Impervious surfaces are mainly artificial structures, such as pavements, rooftops, sidewalks, roads, and parking lots - covered by impenetrable materials such as asphalt, concrete, brick, and stone. Soils compacted by urban development are also highly impervious. They are an environmental concern because, with their construction, a chain of events is initiated that modifies urban air and water resources:

                   Impervious surfaces seal the soil surface, eliminating rainwater infiltration and natural groundwater recharge.

                 Stream-flow in dry summers declines, leaving some cities with local water shortages. Storm water runs directly across the impervious surfaces, raising flood peaks into destructive bursts. Stream channels erode; sediment loads are high. The shifting substrate eliminates aquatic habitats. Oil and heavy metals, that leak and corrode from automobiles, flush into streams without modification. In some cities, the flood waters get into combined sewers, causing them to overflow, flushing their raw sewage into streams.

                 Impervious construction materials collect solar heat in their dense mass. When the heat is released, it raises air temperatures, producing urban "heat islands", and increasing energy consumption in buildings. The warm runoff from impervious surfaces reduces dissolved oxygen in stream water, making aquatic life still harder.

       Impervious pavements deprive tree roots of aeration, eliminating the "urban forest" and the canopy shade that would otherwise moderate urban climate. Because impervious surfaces displace living vegetation, they reduce ecological productivity, and interrupt atmospheric carbon cycling.

The total coverage by impervious surfaces in an area, such as a municipality or a watershed is usually expressed as a percentage of the total land area. The coverage increases with rising urbanization. In rural areas, impervious cover may only be one or two percent. In residential areas, coverage increases from about 10% in low-density subdivisions to over 50% in multi-family communities. In industrial and commercial areas, coverage rises over 70%. In regional shopping centers and dense downtown areas, it is over 90%. In the contiguous 48 states of the USA, urban impervious cover adds up to 43,000 square miles (110,000 km²) — an area nearly the size of the State of Ohio. Continuing development adds another quarter of a million acres (1,000 km²) each year. Typically two-thirds of the cover is pavements (streets, sidewalks, parking lots, driveways, etc.), and one-third is building roofs.

Incidental effects – Indirect impacts of an activity or structure, such as those resulting from redirected wave energy, trapped sand or sedimentation.

Infauna – Are animals that live in sediment.

Infiltration - A passage or movement of water into the soil.

Inundation – The temporary submergence of typically dry lands when there is an exceptional rise of the sea surface, and floodwaters cover the adjacent low-lying land. 

Incidental effects – Indirect impacts of an activity or structure, such as those resulting from redirected wave energy, trapped sand or sedimentation. 

Jetty – A jetty is any of a variety of structures used in river, dock, and maritime works which are generally carried out in pairs from river banks, or in continuation of river channels at their outlets into deep water; or out into docks, and outside their entrances; or for forming basins along the sea-coast for ports in tideless seas. The forms and construction of these jetties are as varied as their uses; for though they invariably extend out into water, and serve either for directing a current or for accommodating vessels, they are sometimes formed of high open timber-work, sometimes of low solid projections, and occasionally only differ from breakwaters in their object. The term derived from the French word jetée, "to throw", and signifies something thrown out. Thus a jetty is a structure similar to a groin, but typically designed to prevent shoaling of a navigation channel.

 

Joint Permit Application or JPA – The standard Joint Permit Application for shoreline stabilization structures and other activities conducted in wetlands and the marine environment.  The applicant completes one form and submits to either local agency or VMRC, which is responsible for distributing to local, state and federal permitting and advisory agencies (e.g. VIMS, Game & Inland Fisheries, Dept. of Conservation & Recreation, Department of Environmental Quality, and The U.S. Army Corps of Engineers). 

LCL – Low-crested structures 

Littoral cell – Are sections of coast for which sediment transport processes can be isolated from the adjacent coast.  Within each littoral cell, a sediment budget can be defined that describes sinks, sources, and internal fluxes (sediment transport). It is the movement of sand and other materials along the shoreline in the littoral zone, or the area between high and low watermarks during non-storm periods. 

Littoral transport – The movement of sand and other materials along the shoreline in the littoral zone, or the area between high and low watermarks during non-storm periods. 

Long-shore transport – Is sediment transport down the beach (parallel to the shore-line) caused by long-shore currents and/or waves approaching obliquely to the shoreline.  

Low Profile – The recommended design for groins with a channelward elevation no greater than mean low water to allow sand bypass to continue once the groin cell is filled, reducing the potential for adverse downdrift effects. 

MCL – Means momentary coastline. 

MHW – Mean high water 

MLLW – Mean lower low water 

MLWL – Mean low-tide water line 

Marsh – Is a mudflat with vegetation.  Low, wet grassland without trees, periodically covered by water

 

Marsh fringe – A band of marsh plants which runs parallel to a shoreline. 

Marsh sill – A low revetment placed near the mean low water elevation then backfilled with sand to create a tidal marsh where it does not occur naturally. 

Marsh toe revetment – A low revetment placed along the edge of an eroding marsh shoreline. 

Mean high water – The average height of high tides over a nineteen year period. 

Mean low water – The average height of low tides over a nineteen year period.  Virginia is a low water state, meaning private property extends to the mean low water line. 

Mean tide range – The vertical distance between mean high water and mean low water. 

Mudflat – Is an intertidal area with relatively fine sediment that may have vegetation  by plant communities (marshes and mangroves) or colonized by microscopic plant communities (microalgae) and bacteria. 

NEPA – National Environmental Policy Act 

NHPA – National Historic Preservation Act 

NOAA – National Oceanic and Atmospheric Administration 

Nearshore – A term referring to the area close to the shore but still partly submerged.  This area is where sand bars and shoals often form. 

Nekton - free swimming aquatic organisms such as fish

Nitrogen - an inorganic nutrient essential for plant growth and reproduction when in oxidized forms (nitrate, nitrite, ammonia); excess can cause eutrophication; problems are usually associated with agricultural runoff and sewage

No-till - an agricultural practice that does not disturb the soil through tillage, leaving organic matter between crop rows, reducing erosion and runoff, preventing soil compaction, improving soil health, increasing water infiltration, and helping sequester carbon

Non – Point Source Pollution/Storm Water Runoff – the part of the precipitation, snow melt or irrigation water that appears in uncontrolled surface streams, rivers, drains, or sewers.  Runoff may be classified according to speed of appearance after rainfall or melting snow (direct or base runoff) or according to source (surface runoff or ground water runoff). 

Nutrient – Is a substance such as nitrogen, phosphorous and potassium that is needed for the survival, growth and development of an organism. 

Offshore – Is the portion of the littoral system that is always submerged. 

Ontogeny – the development or developmental history of an individual organism

Open coast - Are tidal shores that have little or no protection from wave action.

pH – Is a scale from 0 to 14 used to measure relative acidity or alkalinity.  A pH measurement less than 7 is acidic, 7 is neutral and greater than 7 is basic or alkaline.  pH is a measure of the acidity or alkalinity of a material, liquid or solid; estuarine water is naturally, slightly base.

strong acid - 0.0
neutral - 7.0
strong base - 14.0


battery acid - 0.2
orange juice - 4.2
blood - 7.5
Clorox bleach - 12.6

Percolation - The movement of water through soil.

Percolation Rate - The rate, usually expressed as inches per hour or inches per day, at which water moves through soil.

Phosphorous - an inorganic nutrient essential for plant growth and reproduction; excess can cause eutrophication; problems are usually associated with farmland runoff, sewage, and detergents

Phytoplankton - the plant form of plankton, most are microscopic; they are important as primary producers in an estuarine ecosystem

Photosynthesis - the process by which plants convert sunlight into living tissue using carbon dioxide, water, and nutrients; primary production

Planform – Is the outline or shape of a body of water as determined by the still-water line. 

Plankton - passively drifting or weakly swimming organisms living suspended in the water column, often microscopic but sometimes visible to the naked eye

Point source pollution - pollution from a definable source, such as an outfall pipe

Pollution - the addition of a substance(s) to an environment in greater than natural concentrations as a result of human activity producing a net detrimental effect on the environment

Pore water – Is water filling the spaces between grains of sediment.

Pressure treated – The process of preserving wood by impregnating it with chemicals to reduce or retard invasion by wood destroying organisms. 

RPA – Resource Protection Area is land at or near the shoreline which has important value to water quality.  These lands may help to protect water quality or be easily damaged by the impacts of development.  Local governments must include tidal wetlands, certain non-tidal wetlands, tidal shores and other lands that are especially important to water quality in these Areas.  An RPA must also include a buffer area, which is 100 feet wide measured from the landward side of these natural features.

Rain Garden - A rain garden is a planted depression that is designed to absorb rainwater runoff from impervious urban areas like roofs, driveways, walkways, and compacted lawn areas.  This reduces rain runoff by allowing stormwater to soak into the ground (as opposed to flowing into storm drains and surface waters which causes erosion, water pollution, flooding and diminished groundwater.  Rain gardens can cut down on the amount of pollution reaching creeks and streams by up to 30%. Native plants are recommended for rain gardens because they generally don't require fertilizer and are more tolerant of one's local climate, soil, and water conditions.  The plants - a selection of wetland edge vegetation, such as wildflowers, sedges, rushes, ferns, shrubs and small trees - take up excess water flowing into the rain garden.  Water filters through soil layers before entering the groundwater system.  Root systems enhance infiltration, moisture redistribution, and diverse microbial populations involved in biofiltration. Also, through the process of transpiration rain garden plants return water vapor into the atmosphere.  A more wide - ranging definition covers all the possible elements that can be used to capture, channel, divert, and make the most of the natural rain and snow that falls on a property.  The whole garden can become a rain garden, and all of the individual elements that we deal with in detail are either components of it, or are small - scale rain gardens in themselves.  The concept of a rain garden began in the 1990s in the state of Maryland.  They are now one of the fastest growing areas of interest for home landscapes.

Plant Selection

Plants selected for use in a rain garden should tolerate both saturated and dry soil.  Using native plants is generally encouraged.  This way the rain garden may contribute to urban habitats for native butterflies, birds, and beneficial insects.

Well planned plantings require minimal maintenance to survive, and are compatible with adjacent land use.  Trees under power lines, or that up heave sidewalks when soils become moist, or whose roots seek out and clog drainage tiles can cause expensive damage.

Trees generally contribute most when located close enough to tap moisture in the rain garden depression, yet do not excessively shade the garden.  That said, shading open surface waters can reduce excessive heating of habitat.  Plants tolerate inundation by warm water for less time because heat drives out dissolved oxygen, thus a plant tolerant of early spring flooding may not survive summer inundation.

Bioretention

This is the process of biological removal of contaminants or nutrients as fluid passes through media or a biological system.  This can result in bioaccumulation within an organism and compounded at higher trophic levels of a food web.  Alternatively, metabolism and catabolism transform the substance into other substances.

In water treatment and stormwater management, bioretention by microbes growing within soil or filter media enhance retention and degradation of contaminants from the water.  Root surfaces also provide surfaces for biofilm growth from which plants extract nutrients, thus removing them from the filter media.  Bioretention cells often refer to chambers where plants grow in the filter media that water flows through.  Bioretention areas refer to vegetated areas where soil serves as the filter media.  The word retention implies that the substance of concern does not flow out of the soil plant system, regardless of whether surface water flows among plant shoots in a treatment wetland or infiltrated water is itself detained in rain garden soil from which evapotranspiration may greatly reduce groundwater outflow rates - hence extending contaminant retention times.

Retention of water within the filtration systems need not be absolute in order to achieve treatment.  The capacity to detain contaminants can buffer sudden concentration spikes from occurring in the outflow.

Rain Garden Design

Rain Garden Solutions

Rain Garden How to Manual for Homeowners (pdf)

Reach – A straight section of waterway that is uniform with respect to discharge, slope and cross-section.  It is a discrete portion of a shoreline somewhat homogenous in its physical characteristics and upon which there are mutual interaction of the forces of erosion, sediment transport and accretion. 

Recreation – Hampton Roads, along with our surrounding bay cities and states, boasts beautiful locations for fishing, hunting, painting, photography, bird watching, hiking, canoeing, crabbing and wildlife study. 

Relative sea-level rise – Is the sea level relative to the land, which relates changes in local water levels to local land elevations.  The rate of sea-level rise relative to a particular coast has a practical importance because some coastal land areas are subsiding, resulting in a relative rise in sea-level, while other land areas are rising, resulting in a slower or falling sea level. 

Return walls – Bulkhead end sections perpendicular to the shoreline to tie the bulkhead into the upland and prevent the bulkhead from being flanked as the shoreline continues to retreat on either side of the structure. 

Revetment – A type of shoreline armoring that hardens the slope face and is often constructed from large boulders.  A revetment tends to have a rougher (less reflective) surface than a seawall, and often is constructed with one or more layers of graded riprap but can also be constructed with precast concrete mats, timber, gabions (stone filled, wire mesh baskets) and other materials.  Another definition is a sloped structure constructed with large, heavy stone, often in two layers, used to anchor the base of the upland bank.  The size of a revetment is dictated by the energy of the shoreline environment where it is proposed.

 

Riparian – Relating to or living or located on the bank of a natural watercourse, such as a river, stream, creek, lake or tidal waterway.

Riparian Rights - A principle of common law requiring that any user of waters adjoining or flowing through his lands must use and protect them in a manner that will enable his neighbor to utilize the same waters undiminished in quantity and undefiled in quality.

Riprap – Is rock or other material used to armor shorelines and streambeds against water and sometimes ice erosion.  The stone is hard and angular and will not disintegrate from exposure to water or weathering. 

Rivers – Are a large natural stream of water emptying into an ocean, lake or other body of water and usually fed along its course by converging tributaries. 

SAV – Means submerged aquatic vegetation.  Rooted plants found in shoal areas of Chesapeake Bay which provide important ecological roles, such as providing food, shelter and oxygen as well as trap sediment and dissipate wave energy.

 

Salinity – Is the amount of dissolved salt in water.  The measurement of the amount of dissolved salts in water, usually measured in parts per thousand; 35 ppt is average for seawater, 0 ppt for freshwater

Saturation - In soils, the point at which a soil or aquifer will not longer absorb any amount of water without losing an equal amount.

Scarp – Is a steep slope, usually along the foreshore and/or at the vegetation line, formed by wave attack and erosion. 

Seawall – Is a vertical or near vertical type of shoreline armoring characterized by a smooth surface.  It retains soil and reflects wave energy. It is usually taller and larger than a bulkhead.

Sediment - Solid material (both mineral and organic) that is in suspension, is being transported, or has moved from its site of origin by air, water, gravity or ice and has come to rest on the earth's surface.

Sedimentation - The process that deposits soils, debris and other materials either on the ground surfaces or in bodies of water or watercourses.  Silt. (1) Soil fraction consisting of particles between 0.002 and 0.05 in diameter. (2) A soil textural class indicating more than 80% silt.

Sediment barrier or Silt screens – Structures placed at the toe of a slope or in a drainageway to intercept and detain sediment and decrease flow velocities.  Barriers may be constructed of posts and filter fabric properly anchored at the base or hay bales staked in place end to end. 

Sewage treatment -
primary = screening or settling large solids out of sewage (only removes visible material)
secondary = removal of organic material in sewage by aeration and bacterial action
tertiary = removal of nutrients and traces of toxic organic material from sewage by additional treatment processes

Sheet pile – A wooden plank or steel sheet used in the construction of bulkheads and groins. 

Sheltered coast – A coastal area sheltered by headlands, coves, natural or harbor breakwaters, tidal inlets, and river mouths and estuaries which have a limited distance between banks (fetch) and hence limited exposure to wind-driven waves.  This area is usually characterized by low wave energies and stresses.  These lower energy conditions foster habitats and ecological communities, such as marshes and mudflats, not typically found on open coasts.

Shoal – A shallow area in a waterway often created by nearby sandbars or sandbanks. 

Shore orientation – The compass direction the shoreline faces.  Some directions are more prone that others to the erosive forces of storm events. 

Shore zone – Is the active volume of sediment affected by wave action. 

Sill – Generally a semi-continuous structure and an erosion protection measure that combines elements of both revetments and offshore breakwaters (e.g. a barrier of rock) built to reduce wave action and preserve, enhance or create a marsh grass fringe for shore erosion control. Sills are usually built of stone, low in profile and built close to shore. 

Slope – Degree of deviation of a surface from the horizontal; measured as a numeric ration, percent or in degrees.  When expressed as ratio, the first number is the horizontal distance and the second is the vertical distance. 

Splash apron – A structural component, often of rock, used to prevent forceful waves from scouring out material from the top of a revetment or bulkhead. 

Spur – A vertical structure normally used perpendicular to groins to redirect incoming waves to allow a sheltered area in the lee and promote the accumulation of sand 

Stone size – classes of riprap stone based on weight per VDOT specifications

        Class A 1 25-75 lbs, ≤ 10% weighing more than 75 lbs “man-sized”

            Class 1     50-150 lbs, 60% weighing more than 100 lbs

            Class 2     150-500 lbs, 50% weighing more than 300 lbs

            Class 3     500-1,500 lbs, 50% weighing more than 900 lbs

            Type 1      1,500-4,000, average weight 2,000 lbs

            Type 2      6,000-20,000 lbs, average weight 8,000 lbs. 

Storm Buffers – Wetlands along the coast protect areas immediately inland from storms coming ashore, breaking the force of wind and water.  

Storm surge – Is a temporary rise in sea level associated with a storm’s low barometric pressure and onshore wind.  

Stream – Is a small body of water flowing in a natural channel and containing water at least part of the year. 

Subaqueous or Submerged lands – The ungranted lands beneath the tidal waters of the Commonwealth extending seaward from the mean low water mark to the 3 mile limit.

Submerged Aquatic Vegetation (SAV) - rooted vegetation which grows beneath the water surface

Swale - an elongated depression in the land surface that is at least seasonally wet, is usually heavily vegetated, and it normally without flowing water.  Swales conduct stormwater into primary drainage channels and may provide some groundwater recharge.

Tidal – Are waters that experience daily changes in elevation or height due to the influence of the tide are referred to as tidal.  Tidal shorelines are the shorelines of tidal waters and generally include the area between Mean High Water and Mean Low Water.  Tidal wetlands are wetlands located along tidal waters. 

Tides - periodic movement (raising and lowering) of a body of water by the gravitational attraction of the moon and sun with the rotation of the earth

Time of year restrictions – Restrictions that limit construction projects during periods of heightened sensitivity for species of concern, such as anadromous fish, nesting shorebirds, shellfish, submerged aquatic vegetation (SAV), and threatened and endangered species, such as the bald eagle and northeastern beach tiger beetle.

Tributaries - streams and rivers that supply a larger body of water 

Tombolo – The area of accumulated beach material in the levee of a breakwater structure.

Turbidity - the measurement of water cloudiness; it may be affected by sediment and plankton concentrations 

USACE – U.S. Army Corps of Engineers 

USGS – U.S. Geological Survey 

VDOT - Virginia Department of Transportation 

VIMS - The College of William & Mary Virginia Institute of Marine Science, a graduate school for the study of oceanography at The College of William & Mary in Williamsburg, Virginia, USA. 

VMRC – The Virginia Marine Resources Commission serves as stewards of Virginia's marine and aquatic resources, and protectors of its tidal waters and homelands.

Water Table - (1) The free surface of the groundwater. (2) That surface subject to atmospheric pressure under the ground, generally rising and falling with the season or from other conditions such as water withdrawal. 

Watershed – Is a land area that drains water to a particular stream, river or lake. Its boundary can be identified by locating the highest points of land around the waterway. 

Water Quality – Wetlands trap and filter pollutants and sediments. 

Wave attenuation - Is the power loss (the reduction in power density of a wave with distance) when a wave disperses over a larger area. 

Wave climate – The average wave conditions as they impact a shoreline, including fetch, waves, dominant seasonal winds and bathymetry. 

Wave energy –The force a wave is likely to have on a shoreline depending on environmental factors, such as shore orientation, wind, channel width and bathymetry. 

Wave height – The vertical measurement of a single wave from its base or trough to its top or crest. 

Wetlands – Are areas of wet soil where water is normally found on or slightly below the surface of the land.   Tidal wetlands, under Virginia law, are those lands “lying between and contiguous to mean low water and an elevation above mean low water equal to the factor 1.5 s-times the mean tide range.”  They can be either vegetated or non-vegetated.  Non-tidal wetlands are areas containing wet soils, plants adapted to growing in such areas and evidence of water on the land surface during the growing season. 

Wetlands Board – Is a local government advisory board that consists of 5 or 7 residents of that locality appointed by the local governing body.  The Wetlands Board holds public hearings and issues permits for activities that require impacts to tidal wetlands for various purposes, such as erosion protection, riparian access and to improve navigation. 

Wildlife Habitat – Roughly 2/3rds of our commercially valuable fish and shellfish use tidal wetlands as spawning or nursery areas.  Wetlands, also, provide habitats for approximately 35 % of the United States’ listed or threatened species of plants and animals.  This means that 1/3 of our nation’s rare species are inseparable linked to wetlands. 

Wind fetch – is the distance the wind blows over water with similar speed and direction.