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Temporary Silt Fence (TSF) : 1605.01 |
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IS a silt fence which reduces water flow and retains sediment in order to prevent off-site sedimentation. |
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USE at the toe of a fill section where sediment runoff can be contained and stored within project limits. Do not install across a stream, ditch or waterway. |
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CONSTRUCT posts to be 5 ft. in height and space them 10 ft. apart with wire or 6 ft. apart without wire. Bury fabric a minimum of 8 in. deep The fence must be maintained regularly and monitored after rainfall. |
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Special Sediment Control Fence : 1606.01 |
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IS a hardware cloth device with sediment control stone at the base of the hardware cloth. It reduces water flow and retains sediment. |
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USE at the toe of fill sections or other areas where silt fence will not function adequately to control sediment. Use in environmentally sesitive areas and in areas of inadequate right-of-way in place of silt ditch. |
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CONSTRUCT using 1/4 in. wire mesh with a 2 ft. minimum height. Posts to be 5 ft. in height, spaced 3 ft. apart and use sediment control stone at the base of the wire. |
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Temporary Silt Ditch (TSD) : 1630.03 |
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IS a small ditch or channel that intercepts water flow from slopes and directs the runoff into a basin, sediment dam and/or rock silt check. |
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USE at the toe of a fill slope where vertical fill height exceeds 3 ft. or along a stream bank to divert water flow into a controlled outlet. |
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CONSTRUCT the ditch to be 1 ft. deep with a 2:1 side slope. |
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Temporary Diversion (TD) : 1630.05 |
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IS an excavated channel with a berm on its lower side that directs water runoff into a basin, through a sediment dam or through rock silt checks. |
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USE at the perimeter of a project site and below a slope during clearing and grubbing to temporarily control water flow patterns and to divert water runoff into a sediment control structure. Maintain structure in place until the installation of final drainageways. |
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CONSTRUCT to be a minimum 1 ft.-6in. deep with approximate 2:1side slopes. Earthen berm is optional. |
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Temporary Slope Drain with Earth Berm (TSDN) : 1622.01 |
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IS a berm with a flexible pipe that carries concentrated water runoff down a cut or fill slope without causing erosion. A T-section or elbow at the pipe inlet protects the slope drain from washouts, while the earthen berm channels runoff into the slope drain. |
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USE above cut or fill slopes where storm water runoff flowing over the slope would cause erosion if left unchecked.above cut or fill slopes where storm water runoff flowing over the slope would cause erosion if left unchecked. |
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CONSTRUCT with minimum 12 in. diameter flexible pipe, installing T-sections at inlets for multi-direction water flow and elbows at inlets for single-direction water flow. |
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Riser Basin : 1630.01 |
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IS an earthen embankment which captures water runoff leaving a drainage turnout that serves a large project site drainage area. A perforated riser pipe drains the basin, and an overflow spillway controls any runoff that might exceed riser capacity. |
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USE at a site with concentrated water flow where other erosion control devices are inadequate. Do not use in a perennial stream. |
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CONSTRUCT to a sediment storage volume of at least 1800 cubic ft. per acre of disturbed area (for drainage areas less than 100 acres). For corrugated metal pipe, barrel must be 24 in. maximum. Structure must have capacity to accommodate 25-year storm runoff. |
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Silt Basin Type-B (SB-B) : 1630.02 |
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IS a defined pit or basin which collects sediment flowing through a drainageway (often built in conjunction with temporary rock silt checks in order to slow water flow). |
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USE in a drainage ditch with temporary rock silt checks. Maintain until vegetation becomes established. |
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CONSTRUCT basin width variable to the size of the drainageway, so that the basin’s length equals twice its width, and its depth is a minimum of 2 feet. Storage capacity is 1800 cubic ft. per acre (capacity = length * width * height). Clean the basin regularly. |
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Temporary Rock Silt Check Type-A (TRSC-A) : 1633.01 |
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IS a small dam with a weir outlet that uses a naturally-formed storage area to trap sediment (rather than an excavated pit). |
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USE at the outlet of a temporary diversion, temporary slope drain, temporary silt ditch, drainage ditch or channel that outlets off the project site. |
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CONSTRUCT of Class-B stone lined with sediment-control stone. Install a weir at the center of the dam that is approximately 2/3 channel width. The weir should be at least 4 ft. long for a drainage area of 1 acre or less, and the apron length should be approximately 3 times the height of the dam. |
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Temporary Rock Silt Check Type B (TRSC-B) : 1633.02 |
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IS a small dam with a centered weir that limits erosion in a drainage ditch and helps to reduce the flow velocity of water. |
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USE during construction in a channel, roadside ditch outlet, temporary silt ditch or temporary diversion ditch where grade meets and/or exceeds 3 %. |
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CONSTRUCT of Class-B stone, with spacing equal to: (3 % ditch grade) * (100 ft.). |
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Temporary Rock Sediment Dam Type-A (TRSD-A) : 1634.01 |
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IS a large dam structure with a weir outlet that traps sediment at drainage turnouts just prior to the point where water flow leaves the project site. |
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USE along the perimeter of a construction site, at drainage turnouts serving large areas or at natural drainage turnouts forming small valleys. |
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CONSTRUCT of rip-rap lined with sediment-control stone on the upstream side (minimum 2:1 side slope upstream, minimum 3:1 side slope downstream). The dam must not be higher than 8 ft., and apron length (below the weir) should be approximately equal to the height of the dam. |
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Temporary Rock Sediment Dam Type-B (TRSD-B) : 1634.02 |
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IS a small dam with a weir outlet and built-in sediment basin. |
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USE at the outlet of a temporary diversion, temporary slope drain, temporary silt ditch, drainage ditch or channel to trap sediment before water runoff leaves the project site. Do not use in a live stream |
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CONSTRUCT of Class-B stone lined with sediment-control stone. Basin should be 1800 cubic ft. per acre, and dam weir length variable to the drainage area (minimum 4 ft. for 1 acre or less). Apron length should be approximately equal to the height of the dam, with minimum 2:1 side slope. |
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Pipe Inlet Sediment Trap Type-A (PIST-A) : 1635.01 |
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IS a horseshoe-shaped device which prevents sediment from entering a pipe structure. |
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USE at a pipe inlet that receives water flow from one or more directions. Do not use with pipe having diameter larger than 36 inches. |
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CONSTRUCT of Class-B stone lined with sediment-control stone. Surround the structure with a sediment storage area built to 1800 cubic ft. per acre. The dam must be a minimum 3 ft. high. |
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Rock Silt Screen (RSS) : 1636.01 |
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IS a low-level dam structure that settles large sediment particles to the bottom of a stream by inducing a rippling effect in flowing water. |
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USE in a live stream below a culvert or project site where construction occurs at or near the stream. |
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CONSTRUCT of Class-B stone lined with sediment-control stone. The dam should be between 1 ft.-6in. and 3 ft. high, but must not be higher than 1 ft. above the normal flow of the stream. Clean the structure before removing it from the stream. |
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Stilling Basin : 1630.04 |
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IS an earthen basin that settles sediment in water being pumped from a culvert site. |
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USE at a culvert construction site where there is a diverted stream or whenever sediment-laden water must be filtered before being returned to a natural stream. Never pump sediment-laden water directly into a stream. |
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CONSTRUCT basin to ½ the volume of the site to be pumped. Earthen dikes must not exceed a maximum height of 4 ft., and the overflow pipe must have a minimum diameter of 8 inches. |
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| Special Stilling Basin : |
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IS a water permeable fabric bag that traps sand, silt and fines as sediment laden water is pumped from a culvert or bridge site. |
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USE as a portable stilling basin where there are drilled piers and/or diverted streams. Use at sites with limited right-of-way or where topography restricts the installation of a conventional stilling basin. |
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CONSTRUCT using a minimum size of 10 ft. x 15 ft. with a maximum 8 in. spout for receiving pump discharge. Place on stone or fabric on level ground. |
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Rock Inlet Sediment Trap Type-A (RIST-A): 1632.01 |
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IS a doughnut-shaped dam at a drop inlet which serves a large drainage area or receives high-velocity water flow. |
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USE at a drop inlet that receives heavy water flow and is at least 30 ft. from a vehicular travel lane. The structure can be modified to accommodate a drop inlet receiving water from only one direction. |
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CONSTRUCT of Class-B stone lined with sediment-control stone. The dam must be a minimum 2 ft. high. Install a sediment storage area around the structure’s perimeter. |
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Rock Inlet Sediment Trap Type-C (RIST-C) : 1632.03 |
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IS a wire-mesh hardware cloth, drop inlet protective structure with a small doughnut-shaped stone installation at the base of the wire. |
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USE to surround a catch basin in a curb and gutter section or at a drop inlet receiving light to moderate water flow where the flow velocity is too high for silt fencing. |
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CONSTRUCT of sediment-control stone and ¼ in. wire mesh hardware cloth. Install posts a minimum of 5 ft. in length, the wire mesh a minimum of 2 ft. high and the stone a minimum 1 ft. high. |
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| Temporary Stream Crossing |
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IS a temporary structure that allows construction equipment to cross a stream without harming or eroding the bank. |
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USE at a stream where construction equipment must cross. |
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CONSTRUCT of Class-A or rip-rap structural stone. The crossing device can be a ford or a temporary pipe. Include Type-II filter fabric underneath the device if its future removal might be necessary. |
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