Glossary

Backshore - The portion of the shoreline located landward of the berm crest, only wetted in very high tides or storms, technically between "ordinary high water" and the highest water line.

Bank - The rising ground bordering the sea, a river, or lake. Also see BLUFF and CLIFF.

Beach - The zone of unconsolidated material that extends landward from the low water line to the place where there is marked change in material or physiographic form, or to the line of permanent vegetation (usually the effective limit of storm waves). The seaward limit of a beach is the extreme low water line. A beach includes FORESHORE and BACKSHORE.

Bedrock - A general term for the rock, usually solid, that underlies soil or other unconsolidated, surficial material.

Bioengineering - In soil applications, refers to the use of live plants and plant parts to reinforce soil, serve as water drains, act as erosion prevention barriers, and promote dewatering of water laden soils.

Biotechnical - In slope stability engineering, refers to the use of both live plant material and inert structures to stabilize and reinforce slopes.

Bluff - An unvegetated high bank composed largely of unconsolidated deposits with a near-vertical face overlooking a body of water.

Bluff Crest - Upper edge or margin of a shoreline bluff.

Bluff Face - The sloping portion of a high bank.

Bluff Toe - The base of a bluff where it meets the beach.

Catch Basin - A structure usually buried, where surface water is captured and conveyed into pipes and/or where piping (often of different sizes) is connected.

Cliff - A high, very steep to perpendicular or overhanging face of rock rising above the shore.

Coastal Zone - The sea-land fringe area bordering the SHORELINE where to coastal waters and adjacent lands exert a measurable influence on each other.

Culvert - A pipe or concrete box structure that conveys flow from open channels, swales, or ditches under a roadway, driveway, fill soil, or surface structure.

Curtain Drain - Drainage trench that is excavated into an impermeable soil layer to collect groundwater that is perched on that layer. Trench is backfilled with drain rock (gravel) that is enclosed in a geotextile. A perforated pipe is placed within the drain rock backfill to collect and convey the groundwater to a suitable discharge point.

Detention Facility - A structure or ground surface feature that temporarily stores water and releases it at a controlled rate.

Drainage (soil) - The rapidity and extent of the removal of water from the soil by surface runoff and by down-draw flow through the soil. Also, the natural and artificial means for improving this removal by a system of surface and subsurface channels and piping systems.

Drain Rock - Rounded gravel ranging in diameter from 11/2 to 3" with no fine particles, used in drainage trenches.

Erosion - The wearing away of rock or soil and the movement of the resulting particles by wind, water, ice, or gravity, but usually excluding MASS MOVEMENTS.

Extreme High Water (EHW) - The average height of the highest tidal waters reached during the year over a 19-year period.

Foreshore - The lowest segment of a beach, between lowest tide and the berm crest, covered by most daily tides, technically between the "lowest low water" line and the "ordinary high water" line.

Formation - (geologic) - The ordinary unit of geologic mapping recognized by field criteria consisting of a larger, persistent, and mappable strata of predominantly one kind of rock or sediment type.

Geotechnical - Refers to the application of civil engineering technology to some aspect of the earth.

Geotechnical Structures - Along coastal slopes, refers to slope protection designs such as retaining wall, revetments, and designed slope recontouring.

Geotextile - Synthetic fabric used to return soil while allowing water to pass through the soil and fabric into drainage collection system.

Groundwater - Water collected or flowing under-ground usually in the interstices of soil or rock fractures. Typical soils containing groundwater are relatively permeable soils such as sand and gravel.

Gully - Large intermittent drainage channel developed from the erosion forces of drainages occurring from surface water runoff.

Hardpan - A hard, relatively impervious, layer of SOIL lying just below the surface. Sometimes synonymous for TILL.

Hummocky - Having an uneven, jumbled or erratic appearance characteristic of landslide movement.

Impermeable - Having a structural density that does not permit fluids to move through it freely.

Infiltration - The movement of water or solutions into or through a rock or soil through its INTERSTICES or fractures; the flow of rain water into soil material.

Interstices - Openings or spaces in rock or soil that are not occupied by solid matter.

Mass Movement - A unit movement of a portion of the land surface down a slope as a SLIDE, a flow, or SOIL CREEP in which gravity is the main driving force.

Natural Landscape Elements - The natural watercourses, topography, hydrology and vegetation which comprise a particular site.

Percent Slope - The direct ratio (multiplied by 100) between the vertical and the horizontal distance for a given slope; e.g., a 3-foot rise in a 10-foot horizontal distance would be a 30 percent slope.

Perforated "Perf" Pipe - A pipe with small slots or holes typically used to either capture and route groundwater to a tightline drainage system or release captured water from a drainage collection system to the local soils.

Poorly Sorted - Unconsolidated deposits that consist of particles of many sizes mixed together in an unsystematic manner so that no one size fraction predominates.

Relief Drains - Series of drainage trenches laid out in a pattern to lower water levels to a specific elevation. Construction is similar to an interceptor drain.

Rill - A tiny drainage channel cut in a slope by the flow of water. Can develop into a gully with continuing erosion.

Runoff - That part of the precipitation that appears in uncontrolled surface ground floor, drains, or sewers.

Saturated - A condition in which the INTERSTICES of a material are filled with a liquid, usually water.

Sheet Flow - A thin layer of water moving across a surface without the formation of concentrated streams of water.

Shoreline - The intersection of a specified plane of water with BEACH; it migrates with changes of the tide.

Slide - A MASS MOVEMENT resulting from failure of SOIL or rock along a rotational or planar surface.

Slope - The inclination of the land surface from the horizontal percentage of slope is the vertical distance divided by the horizontal distance, then multiplied by 100.

Slope Erosion - The wearing away of rock or soil from a slope crest, face, or toe due to water, wind, ice, or gravity. Typical slope erosion from water results in RILL or GULLY erosion features.

Slump - A SLIDE characterized by a rotary movement of a generally independent mass of rock or earth along a curved slip surface.

Soil - In engineering work a soil is any earthen material, excluding hard bedrock, composed of 1) loosely bound mineral and organic particles, 2) water, and 3) gases. In agriculture, a soil is the loose surface material capable of supporting plant growth, and having properties resulting from the integrated effect of climate and living matter on the decomposition of bedrock and surficial deposits.

Soil Creep - The gradual and steady downhill movement of soil and loose rock material on a slope.

Strata - A layer of soil.

Surface Water - Water standing, ponding, or flowing on the ground or other surface feature.

Swale - Shallow open earth channel used to intercept and route surface water flows to a discharge location.

Tightline (solid pipe) - Typically used to describe a solid wall, rigid or flexible pipe used to transport water from one location to another, either buried or positioned along the ground surface. A tightline does not have slots or holes like a perforated pipe.

Till - POORLY SORTED and generally unstratified sediments, deposited directly by and underneath a glacier. Usually very hard and compact, with good bearing capacity and low permeability.

Toe of Slope - See BLUFF TOE.

Trench - In drainage applications, temporary ditch excavated in the ground to install drainage system components.

Undercutting - The removal of material at the base of a steep slope or cliff or other exposed rock by the erosive action of waves, running water, or sand-laden wind.

Upland - A general term for elevated land above the beach which lies above the EXTREME HIGH WATER level.

Wetlands (Biological) - Lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surfaces or the land is covered by shallow water.

Wetlands (Jurisdictional) - Land forms which support under normal conditions a predominance of hydrophytic (wetland) vegetation, hydric (wetland) soil types, and wetland hydrology. Typically, they are jurisdictionally defined as: "Those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions (Federal Interagency Committee for Wetland Delineation, 1989)".

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