Erosion and Sedimentation Practice Flashcards

Vocabulary terms and definitions related to erosion, sedimentation, soil characteristics, best management practices (BMPs), vegetation, and regulatory requirements based on the lecture transcript.

Erosion

The process by which the land surface is worn away by the action of wind, water, and gravity.

Sedimentation

The settling out of soil particles transported by water and wind.

Overland Erosion Types

Splash or rain drop erosion, sheet erosion, rill erosion, and gully erosion.

Principle Factors Influencing Soil Erosion

Soil characteristics, vegetative cover, topography, and climate.

Clay and Muck

Soil particles smaller than $0.002\,mm$ that cause the most erosion and turbidity problems in Florida and the world.

Type A Hydrologic Group

Soils with high infiltration rates and low runoff potential even when thoroughly wetted.

Type D Hydrologic Group

Soils with very low infiltration rates and high runoff potential when thoroughly wetted.

RUSLE

The Revised Universal Soil Loss Equation used on construction sites to predict soil loss.

Soil Forming Factors

Climate, topography, organisms, parent material, and time.

Temporary Gravel Construction Entrance

An entrance extending the full width of the access point, at least $50\,feet$ long and $6\,inches$ thick, using $2\,in.$ stone or FDOT No. 1 stone.

Silt Fence Utility Limits

An average usable life of $6\,months$ with a maximum drainage area of $\frac{1}{4}\,acre$ per $100\,feet$ of barrier length.

Silt Fence Installation

Requires a trench $4\,inches$ deep and $4\,inches$ wide to allow $8\,inches$ of fabric to extend into the ground.

Inlet Protection Device

A device with a maximum drainage area of $1\,acre$ used for sediment control.

Temporary Sediment Trap

A device designed to detain turbid water with a maximum drainage area of $5\,acres$, an initial storage capacity of $134\,cu.\,yd.$ per acre, and a maximum life of $18\,months$.

Sediment Basin

A pond designed to detain turbid runoff from disturbed areas, required for drainage areas of more than $10\,acres$.

Baffles

Structures used in a sediment basin to increase flow length.

Temporary Slope Drain

A pipe used with a diversion or earthen dike to direct stormwater, limited to a maximum drainage area of $5\,acres$.

Check Dam Spacing

Arrangement where the bottom of the upstream dam is at the same elevation as the top of the downstream dam.

Floating Turbidity Curtain

A floating barrier designed to contain sediment laden water to allow enough time for sediments to settle out of suspension.

Type III Floating Turbidity Curtain

A curtain used in flow conditions less than $5\,feet\,per\,second$ or $3\,knots$.

Soil Roughening

The process of aid in establishment of vegetative cover, reducing runoff velocity, increasing infiltration, and providing for sediment trapping.

Topsoiling

Providing a suitable growth medium for final site stabilization with vegetation.

Soil Amendments

Materials usually required prior to permanent seeding, specifically fertilizer and lime.

Sodding Strips

Strips of sod laid perpendicular to the contour with staggered joints, starting from the bottom and working toward the top.

Mulch

Material that protects soil from raindrop erosion, moderates soil temperature and moisture, reduces velocity of overland flow, and controls weeds.

Tree Protection Zone

Area installed no closer than $8\,feet$ from the trunk or the dripline of the tree; storage and parking are prohibited inside.

Well-point and Sock/Horizontal Pumps

Dewatering systems that generally produce clear, non-turbid groundwater but require sandy soils to function.

Rim Ditch System

A dewatering system that produces the poorest water quality with the highest turbidity NTU levels.

FDEP General Permit for Dewatering Distance

Requires the discharge point to be $500\,feet$ or greater from a known contamination source.

Flocculant Chemicals

Most common approved chemicals used are Anionic Polyacrylamide (PAM) and Aluminum Sulfate (Alum).

Operator

The person, firm, contractor, public organization, or other legal entity responsible for the site and for developing the SWPPP.

Qualified Inspector

Someone who has taken a stormwater class or higher training on erosion and sediment control.

Notice of Termination (NOT)

A document submitted within $14$ calendar days after a site has achieved final stabilization of $70\%$ or greater.

Retention Basin

A basin designed to retain stormwater on site and allow time for percolation into the ground, with storage volume recovered within $72\,hours$.

Detention Basin

A basin designed to temporarily store runoff and release it at a controlled rate.

Underdrain

A system used to filter stormwater/runoff contained in detention facilities prior to discharge to receiving waters.

Swale

A designed waterway with side slopes no steeper than $3:1$.

Stormwater Conveyance Channel

A permanent, designed waterway shaped and lined with erosion-resistant material to safely conduct runoff away from a developing area.

Check Dam Height

The maximum height is $2\,feet$, with the center at least $6\,inches$ lower than the outer edges.

Outlet Protection Device

A device designed to prevent scour at outlets and minimize erosion downstream by reducing the velocity of concentrated flows.

Riprap

Stone used to protect soil surface from erosion, slow flow velocity, and stabilize slopes.