Erosion and Sediment Control Glossary

CB - Catch Basin

A structure designed to collect and temporarily hold stormwater runoff, allowing sediment and debris to settle before water enters the storm drain system.

DCB - Double Catch Basin

A drainage structure with two connected catch basins used to increase stormwater collection capacity and improve sediment and debris removal before discharge.

SSMH - Sanitary Sewer Manhole

An access point in a sanitary sewer system that allows inspection, maintenance, and cleaning of underground sewer lines.

SMH - Storm Manhole

An access structure in a stormwater drainage system that provides entry for inspection, maintenance, and cleaning of storm drain pipes or culverts.

BMP - Best Management Practice

Products, structures, or activities designed to reduce erosion and control sediment or pollutants during construction.

HP - High-Performance Pipe (High-Performance Polypropylene Pipe) (Grey Plastic)

A type of durable, corrugated plastic storm pipe designed for strength, flexibility, and resistance to corrosion — commonly used in drainage systems within the right-of-way (R.O.W.).

HDPE - High-Density Polyethylene (Black Plastic)

A strong, flexible plastic material used for storm and sanitary pipes; resistant to corrosion, chemicals, and abrasion, making it ideal for long-term underground drainage systems.

R.O.W. - Right of Way

A designated area of land reserved for public infrastructure such as roads, utilities, and drainage systems, where construction and maintenance activities are permitted.

RCP - Reinforced Concrete Pipe

A durable, rigid pipe made from reinforced concrete, commonly used for stormwater and sanitary sewer systems due to its strength and long service life.

SCM - Stormwater Control Measure

A structural or non-structural practice designed to manage the quantity and quality of stormwater runoff by reducing flow rates, filtering pollutants, and promoting infiltration.

MTA - Main Treatment Area

The primary section of a stormwater pond or treatment system where water from the forebay is filtered, detained, and discharged through the riser and outlet structure.

NOV - Notice of Violation

A formal enforcement document issued by a regulatory agency to notify a contractor or permit holder of noncompliance with environmental, stormwater, or erosion control regulations.

TB - Top of Bank

The highest point of a stream, ditch, or channel where the bank slope meets level ground; used as a reference point for buffer zones and erosion control placement.

SWPPP - Stormwater Pollution Prevention Plan

A site-specific plan that outlines erosion, sediment, and pollution control measures to prevent contaminated runoff from leaving a construction site.

CGP - Construction General Permit

A federal permit issued under the NPDES program that regulates stormwater discharges from construction activities, requiring implementation of erosion, sediment, and pollution control measures.

EOD - End of Day

A standard deadline in inspection and maintenance requirements, often referring to the timeframe by which sediment removal or corrective actions must be completed.

Spring Line

The horizontal midpoint of a pipe's diameter — used as a reference for proper bedding and backfill placement during pipe installation.

Screening

A layer of fine, granular material (often stone or gravel) used for bedding and backfilling around pipes to provide uniform support, aid drainage, and prevent damage to the pipe structure.

Anchor / Fastener

Device used to secure erosion control materials (staples, pins, stakes, anchors).

Anchor Trench

Small trench used to bury and secure the edge of mats, blankets, or silt fences.

Acre Disturbance

The total area of soil disturbed during construction; NPDES applies to sites 1 acre or larger.

Baffles

Vertical barriers in basins that slow flow and promote sediment settling.

Bare Spots

Areas lacking vegetation or cover, indicating poor stabilization.

Bioengineering

Erosion control using living plants and natural materials (e.g., brush layering, live staking).

Biodegradable Netting

Netting that naturally decomposes; used to hold seeds or soil in place.

Bonded Fiber Matrix (BFM)

Engineered mulch with high tackifiers for strong erosion protection on steep slopes.

Buffer (Natural)

Undisturbed vegetated area between disturbed soil and waterways; reduces sediment runoff.

Check Dam

Small barrier (stone, fiber rolls, etc.) placed in ditches or channels to slow flow and trap sediment.

Chemical Stabilization

Temporary method using soil binders or polymers to reduce erosion.

Corrective Action

Significant maintenance or repair required when routine fixes fail (after 3+ occurrences).

Dewatering

Removing sediment-laden water from excavations or low areas before discharge or infiltration.

Diversion / Swale / Dike

Channel or berm designed to redirect surface water flow.

Erosion

The wearing away of soil by wind, water, or human activity.

Erosion Control

Measures preventing soil displacement (e.g., blankets, vegetation, mulch).

Fiber Roll / Wattle / SRFR

Cylindrical barrier of straw, wood, or coconut fiber used to intercept runoff and trap sediment.

Flow Rate

The volume or speed of stormwater; must be controlled to prevent erosion.

Forebay

The first cell of a retention pond; captures sediment before water moves to the main treatment area.

Geotextile Fabric

Permeable textile used under riprap or erosion mats to prevent soil loss and scouring.

Hard Armor

Rigid erosion protection like riprap, concrete, or articulated concrete blocks.

HBSA (Hydraulic Biotic Soil Amendment)

A spray-applied soil additive that promotes topsoil and vegetation growth.

HECP (Hydraulic Erosion Control Product)

Spray-applied mulch or seed mix used for erosion control and vegetation establishment.

High Performance Turf Reinforcement Mat (HP-TRM)

Non-degradable, long-term mat for high-stress slopes or channels.

Hydro-Mulching

HECP application without seed for temporary erosion control.

Hydro-Seeding

HECP with seed for vegetation establishment.

Impoundment Depth

The vertical water depth (12-18", max 24") used in sediment barrier design.

Inlet Protection

Barriers (silt sacks, fiber rolls, filters) that trap sediment before it enters a storm drain.

Level Spreader

Device that distributes concentrated flow evenly across a slope.

Low Impact Development (LID)

Smaller Developments

RECP - Rolled Erosion Control Products

Biodegradable or synthetic cover used to stabilize soil and retain seeds.

Mulching

Covering bare soil with straw, wood chips, or gravel to reduce erosion and retain moisture.

NPDES (National Pollutant Discharge Elimination System)

Federal program that regulates stormwater discharge from construction sites.

Perimeter Control

Barriers (silt fence, wattles, brush barriers) that trap sediment along site boundaries.

pH Adjustment

Soil treatment to optimize conditions for vegetation growth.

Revegetation

The process of reestablishing plant cover to stabilize soil.

Riprap

Large stones placed to protect against erosion in high-velocity or concentrated flow areas.

Routine Maintenance

Minor, regular upkeep of erosion controls.

Runoff

Water that flows over the ground surface, potentially carrying sediment and pollutants.

Sediment

Displaced soil particles transported by water or wind.

Sediment Basin

Temporary pond that captures runoff and allows sediment to settle before discharge.

Sediment Control

Measures to capture and contain displaced sediment (e.g., basins, silt fence).

Silt Fence

Fabric barrier with metal stakes used to capture sediment along site perimeters.

Slope Interruption Device

Structure (fiber rolls, small berms) used to shorten slope length and reduce runoff velocity.

Soft Armor

Erosion protection that reinforces vegetation (blankets, mats, mulch, etc.).

Soil Compaction

Compression of soil that reduces infiltration and increases runoff.

Soil Roughening

Scarifying or tracking soil to reduce erosion and promote seed retention.

SRFR (Sediment Retention Fiber Roll)

See Fiber Roll / Wattle.

Stabilization

Process of covering or protecting disturbed soil to prevent erosion.

Stabilized Construction Entrance

Gravel or rock pad at exits to reduce sediment track-out onto roads.

Storm Drain Inlet Protection

Barriers or filters preventing sediment from entering storm systems.

Temporary Sediment Basin

Basin used to trap sediment during construction; includes baffles and a skimmer.

Topsoil

The nutrient-rich upper soil layer essential for vegetation growth.

Transition Mat

Flexible mat installed where flow transitions from concentrated to sheet flow (e.g., pipe outlets).

TRM (Turf Reinforcement Mat)

Long-term synthetic mat used to stabilize steep slopes and high-flow areas.

Turbidity

Cloudiness or muddiness in water caused by suspended sediment.

Vegetation (Temporary/Permanent)

Plants used to stabilize soil; temporary species germinate fast, permanent are perennial.

Velocity Control

Techniques that reduce water speed to prevent erosion (check dams, slope breaks, etc.).

Weir

Barrier that controls discharge rate or dewatering from basins.

Woven / Open Weave Mats

Erosion mats made from woven textiles designed for moderate to long-term protection.