Erosion and Sediment Pollution Control Program Manual.pdf

Surface Retention -----The part of a storm that does not contribute to runoff. Retention is composed of
depression storage, interception, and evaporation.
Surface Roughening -----The practice of providing a rough soil surface with horizontal depressions for
the purpose of reducing runoff velocity, increasing infiltration, aiding the establishment of
vegetation, and reducing erosion.
Surface Runoff -----The portion of rainfall that moves over the ground surface toward a lower elevation
and does not infiltrate the soil.
Surface Waters -----Perennial and intermittent streams, rivers, lakes, reservoirs, ponds, wetlands,
springs, natural seeps and estuaries, excluding water at facilities approved for wastewater
treatment such as wastewater treatment impoundments, cooling water ponds and constructed
wetlands used as part of a wastewater treatment process.
Suspended Solids -----Solids that are not in true solution and can be removed by filtration.
Swale -----A watercourse without defined bed and banks.
Switchback -----A 180 degree — or nearly so — turn in a trail or road used to climb steep slopes.
SWMP -----Storm water management plan.
Synthetic Mat -----An erosion control blanket manufactured from synthetic materials.
T
T -----In channel calculations, it is the top width of the channel.
Tackifier -----A substance sprayed on straw or hay mulch or exposed soil to increase its resistance to
wind and reduce its potential for being washed away by runoff.
Tail Race -----An open waterway leading water out of a dam spillway and back to a natural channel.
Tailwater -----1. The water into which a spillway or outfall discharges. 2. The depth of water
downstream of a culvert measured from the outlet invert.
TC -----In the Rational Equation it is the symbol for time of concentration.
TDS -----Total dissolved solids.
Technical Review Checklist -----A checklist provided by the Department to aid plan preparers in doing
in-house checks of E&S control plans before submitting them and plan reviewers in doing
consistent plan reviews.
Temporary Bypass Channel -----A suitably sized and stabilized channel constructed for the purpose
of conveying base flow around a work area.
Temporary Riser -----That part of a barrel/riser type spillway which extends vertically from the bottom
of the impoundment to the top of the Settling Zone. See Standard Construction Detail #7-7.
Temporary Road Crossing -----A road installed for a period of time not to exceed one year across a
wetland or across or along a stream using a pipe culvert or a series of culverts, a bridge, a
causeway or a ford.
Temporary Slope Pipe -----A pipe installed on a long or steep slope for the purpose of conveying
runoff or a discharge down the slope to the desired discharge point.
Temporary Stabilization -----Provision of immediate protection from accelerated erosion pending
future disturbance, typically in the form of annual seed mixtures and/or mulch.
Temporary Stream Crossing -----A stabilized culverted crossing or bridge installed for the purpose of
providing access for construction equipment to an area on the other side of a stream channel.
Temporary Stub -----A short pipe connecting a temporary riser to a permanent riser in a sediment
basin, which will later be converted to a stormwater detention pond. See Standard Construction
Detail # 7-8.
Temporary Vegetation -----A vegetative cover — annual or perennial, but typically rapid growing
annual grasses, small grains, or legumes — used to provide erosion protection to a disturbed
area until active earthmoving resumes or permanent protection is provided.
10-year Storm -----1. A storm event of such intensity that it occurs on average once every 10 years;
2. A rainfall event having a ten-percent chance of being equaled or exceeded in any given year.
Tension Crack -----An opening parallel to the edge of a cut slope or fill slope. It may be a sign of
incipient movement.
363-2134-008 / March 31, 2012 / Page 552