Turbidity Curtain DOT Requirements by State

Turbidity curtains, also known as silt curtains, are essential tools for construction projects near water bodies. They act as barriers, containing sediment and preventing it from clouding the water and harming aquatic life. While the overall goal of these curtains is the same across the US, the specific requirements set by each state’s Department of Transportation (DOT) can vary significantly.

Always consult your state’s DOT website or contact the relevant authorities for the latest and most accurate information. By staying informed, you can ensure your construction project minimizes its impact on the environment and complies with all regulations.

Additional Tips:

• Partner with an experienced turbidity curtain supplier or contractor familiar with your state’s specific requirements. Elastec’s representatives can provide the expertise you need regarding deployment, anchoring and turbidity curtain price.
• Choose curtains appropriate for the water conditions and project duration.
• Properly deploy and maintain the curtains according to regulations and best practices.
• Monitor turbidity levels and adjust the curtains as needed throughout the project.

By taking these steps, you can ensure your construction project runs smoothly while protecting the health of our waterways. Below are links to each state’s department of transportation website to help you gather more information. View our guide on how to install turbidity curtains and make sure to tell us about your project. Our team can give you the expert advice you need for a successful installation.

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Alabama

The Alabama Department of Transportation (ALDOT) requires that silt or turbidity curtains be installed in accordance with their Standard Specifications for Highway Construction (section 665) and the “Alabama Handbook for Erosion Control, Sediment Control, and Storm Water Management.” These temporary sediment barriers must be placed as shown on project plans or as directed by the engineer, oriented parallel to water flow in moving conditions, and be compatible with manufacturer’s recommendations. ALDOT specifies that turbidity curtains should use Type I DOT curtains—featuring 6″ or 8″ foam floats with at least 18 oz PVC fabric—and must be regularly inspected and maintained alongside other best management practices and NPDES permit requirements.

Alabama Department of Transportation (ALDOT)

Alaska

Alaska DOT’s Stormwater Pollution Prevention Plan (SWPPP) guidance (BMP 19.00) and its associated specifications (680 – Silt Curtain) require that silt or turbidity curtains—also known as floating silt curtains—be used to isolate in- or near‑water work areas by deploying geotextile fabric skirts suspended from floats and anchored at the bottom by weights (typically chain), ensuring the curtain remains vertical in calm or tidal waters; designers must specify curtain depth, fabric permeability, bottom gap clearance, float sizing, anchor-chain length, anchor point spacing, and high‑visibility floats, and should avoid curtain placement across active flow paths and minimize impacts to substrate and habitat. The DOT also mandates proper installation and maintenance throughout construction, with barriers placed within 10 ft of any fill toe or within 25 ft of open water, to effectively contain sediment and turbidity until project completion.

Alaska Department of Transportation

Arizona

Arizona DOT mandates the use of silt or turbidity curtains for all work in or adjacent to surface waters—including rivers, lakes, and wetlands—to satisfy Clean Water Act (CWA) §401/402 requirements under its Construction General Permit (AZG2008‑001). These curtains must meet the design, installation, anchoring, and maintenance standards specified in the ADOT Erosion & Pollution Control Manual, ensuring effective sediment containment during construction activities. ADOT projects that involve dredging or fill in U.S. waters must secure §404/401 permits and adhere to monitoring protocols to confirm turbidity remains within allowed limits; turbidity curtains must be properly deployed, inspected regularly, and adjusted or maintained as necessary throughout the project.

Arizona Department of Transportation (ADOT)

Arkansas

The Arkansas DOT mandates use of turbidity (silt) curtains to control sediment runoff during aquatic construction and maintenance activities—especially those disturbing ≥1 acre, which require NPDES Construction General Permit coverage. Designing and installing barriers in accordance with DOT and FHWA standards is essential: curtains must be selected by type (DOT Type 1, 2, or 3) based on water depth, currents, and conditions, and must include floating booms, ballast chains, anchorage (stakes, weighted anchors) at intervals (typically ≤100 ft), and secure shoreline tie‑ins. Type 3 DOT curtains include permeable polypropylene filter panels replacing ~20 % of the skirt to help manage pressure while retaining silt, and all installations must be engineered to local site conditions and approved by the ARDOT Engineer prior to deployment.

Arkansas Department of Transportation (ARDOT) 

California

Caltrans specifies that silt/turbidity curtains—also known as turbidity barriers—must be used in calm or slow-moving water environments (ponds, lakes, lagoons, slow-flowing rivers) where sediment discharge is unavoidable. These curtains rely on a floating top boom and a weighted bottom hem (steel chain or ballast) to maintain vertical positioning in the water. They must be installed parallel to water flow (when present), with anchors spaced every ~30 m (100 ft), and extend to either the full depth or within one foot of the bottom (using permeable fabric if closer). Daily inspections are required; any damage, gaps, or dislocation must be repaired promptly. Sediment must be allowed to settle for at least 6–12 hours before removing either the sediment or the curtain itself. Removal must be done carefully—curtains are detached from anchors, furled, and towed out—only after visible turbidity has dissipated and sampled water meets quality standards.

California Department of Transportation (CALTRANS)

Colorado

The Colorado Department of Transportation (CDOT) requires the use of silt and turbidity curtains as part of its erosion‑control specifications outlined in Section 208 of the 2023 Standard Specifications for Road and Bridge Construction. These must be constructed and installed in English measurements, with geotextile materials meeting minimum performance standards for strength, permittivity, and UV stability. While “silt fence” and “silt berms” are specifically detailed—requiring wooden or metal posts, specified fabric properties, proper anchoring, and regular maintenance—CDOT mandates that any in- or near-water work be contained using appropriate sediment barriers. These curtains must be deployed per contract plans, positioned to block sediment runoff, extended to the bottom substrate, firmly anchored, and inspected consistently to ensure compliance with NPDES and watershed protection requirements.

Colorado Department of Transportation (CDOT)

Connecticut

Connecticut’s Department of Transportation (CT DOT), aligning with CT DEEP and the statewide Soil Erosion and Sediment Control Guidelines, mandates that turbidity or silt curtains—referred to as floating turbidity barriers—be utilized around in-water work sites to contain sediment and prevent its migration into surrounding waterbodies. These curtains must form a continuous vertical seal (with bottom resting on the substrate and at least a 3″ freeboard above water), be securely anchored, maintained in working condition throughout the project, and inspected regularly per manufacturer and engineer specifications. CT DOT restricts their deployment seasonally—installation and removal are allowed only between July 1 and March 31 — and prohibits using silt curtains alone to confine flowing water for unconfined in-stream work, which must instead be contained via cofferdams, sheet piles, or similar techniques.

Connecticut Department of Transportation

Delaware

Delaware’s Department of Transportation (DELDOT) mandates the use of floating turbidity (silt) curtains for any in‑ or near‑water construction—such as pile installation/removal, scour protection, soil borings, or bridge work—to control sediment and turbidity. The standard detail requires at least one curtain panel for depths up to 5 ft, two panels to reach the bottom in depths up to 10 ft, and special deep‑water panels where depths exceed 10 ft. Curtains must include flotation, bottom-load and top-load lines, be anchored or staked per engineer’s direction, and be deployed to fully enclose the work area without crossing active flow paths. Throughout the project, they must remain intact and properly maintained so that no project-related sediment escapes the enclosure.

Delaware Department of Transportation (DELDOT)

Florida

Florida DOT requires both floating and staked turbidity (silt) curtains to control sediment during in‑water or shoreline construction. Under Section 104‑6.4.119, contractors must install turbidity barriers—floating or anchored—before any work that could stir up turbidity, based on plans or engineer approval. These barriers must be maintained throughout the project to minimize water quality impacts, with prompt repair or adjustment as needed. FDOT allows using new or approved used geotextile, vinyl or PVC materials for silt fences and turbidity barriers, subject to engineer approval. Silt fences are restricted to upland areas and must not cross active flows; in or near flowing water, turbidity curtains must be used and sized appropriately by type (I, II, III) according to site conditions to effectively contain sediment and avoid degradation of water quality.

Florida Department of Transportation (FDOT)

Georgia

Georgia DOT outlines clear standards for the use of silt (turbidity) curtains—also known as floating booms or silt retention barriers—to control sediment in or adjacent to water bodies. They must be installed per Standard Specifications Sections 165/170 with details in Drawing D‑51 (4‑22‑2016): curtains are either floating or staked, using impermeable vinyl or permeable geotextile, kept vertical with floats on top and ballast or anchors at the bottom, with a maximum staked height of 5 ft unless directed. Installation requires placement roughly 25 ft outside the active work zone and within 5 ft of the bed bottom, with the top extending 2 ft above normal waterline, aligned parallel to current if present. The curtain design must be sized to contain sediment effectively, and contractors must follow manufacturer guidelines, perform regular maintenance, and adhere to quality acceptance and warranty provisions.

Georgia Department of Transportation (GDOT) 

Hawaii

Hawaii Department of Transportation requires the use of silt or turbidity curtains as a key best management practice (BMP) for any in‑water or near‑shore construction where sediment discharge cannot be avoided. According to its BMP Manual, these floating barriers must be deployed in calm or slow-moving waters—lakes, ponds, or slow streams—extending close to the bottom yet topped with flotation buoys, anchored (typically every 100 ft), and oriented parallel to water flow to effectively confine suspended sediment. The fabric curtain must be bright, impervious (or pervious in bottom foot for wave conditions), and weighted with a bottom ballast line. Active inspection and repair of any tears or gaps are required, and sediment should be allowed to settle for 6–12 hours before either removal of sediment or the curtain itself. In a site-specific example for Hilo Harbor (Pier 4), both a perimeter curtain around the work area and a separate curtain around barges are mandated, with daily inspections and work stoppage if barriers become ineffective until fully repaired.

Hawaii Department of Transportation (HDOT)

Idaho

The Idaho Transportation Department’s Standard Specifications for Highway Construction (2023) include Section 647, which governs the use of temporary turbidity (silt) curtains for in‑water work. These pre-assembled barriers must fully enclose the construction area using geotextile or geomembrane skirts, flotation devices, ballast chain, and securing hardware. They must be installed before work begins, maintained properly (aligned, inspected, free of gaps), and removed only once in‑water turbidity returns to pre‑construction levels. The Department measures these installations as a lump sum, and maintenance tasks (such as realignment and accessory removal) are included in that payment.

Idaho Department of Transportation

Illinois

Illinois DOT requires that any land-disturbing work near or in waterways include proper silt or turbidity curtains as part of the project’s Erosion and Sediment Control Plan (per Illinois Urban Manual Practice 930). Such floating curtains must be anchored on both banks (shoreward and streamside) to prevent downstream or lateral drift. They’re mandated whenever an acre or more is disturbed during roadway projects adjacent to rivers, streams, or wetlands, and must be installed prior to major land-disturbing activities. Materials must meet IDOT pay items (e.g., turbidity curtain – item XX005972, silt curtain – XX007107) and adhere to fabric, float, and anchoring specifications outlined in IDOT’s standard plans and the Erosion Control Field Guide. Maintenance and inspection during use are also required to ensure continued sediment containment and compliance with NPDES permit conditions.

Illinois Department of Transportation (IDOT)

Indiana

Indiana DOT’s Specification 205‑C‑231, adopted February 21, 2013, outlines rigorous standards for temporary turbidity (silt) curtains used in water‑adjacent construction. The curtains must use impermeable vinyl‑nylon laminate with 18 oz/sq yd fabric, have 6″ marine‑grade expanded polystyrene flotation with at least 13 lb/ft buoyancy, and include a 0.25″ galvanized ballast chain weighing a minimum of 0.7 lb/ft. Materials are required to meet ASTM D 4632 tensile strength standards (≥300 lb) and come in bright colors for visibility. Installation must precede any in‑water disturbance; curtains are inspected for sediment seepage, with tears promptly repaired, and removed only after 48 hours of site stabilization, minimizing re‑suspension. All seams must meet full product strength per manufacturer specs, and deviations require engineer approval. Curtain costs—including materials, installation, maintenance, and removal—are included in the linear‑foot pay item.

Indiana Department of Transportation (INDOT)

Iowa

Iowa DOT requires floating silt (turbidity) curtains—referred to under Standard Road Plan EC‑202—to be used during any in‑water or stream‑bank construction (e.g., temporary crossings, work pads) to isolate the work area and allow sediment to settle. These curtains consist of fabric skirts weighted along the bottom edge and supported by floats at the top, anchored laterally (anchors spaced per EC‑202: e.g., no more than 0.6 × stream width) to ensure a vertical barrier across varying flow conditions. They must extend nearly to the bed, with appropriate floatation and tensioning, and be located as close as practical to the disturbed area . Installation and maintenance—including inspections after storms—are required throughout construction. Silt curtain deployment is listed as a bid item under Iowa DOT Construction Manual CM 7.70 whenever bridge or stream‑bank work in water bodies is involved.

Iowa Department of Transportation

Kansas

Kansas DOT requires that silt or turbidity curtains—also known as floating silt curtains—be used during in‑water or near‑water construction to control erosion and sedimentation, per its standard specifications for road and bridge work. These barriers must consist of buoyant floats and an attached geotextile skirt, anchored securely (such as with chains or stakes) to maintain a vertical barrier from surface to near‑bottom, and keep sediment contained. Depending on site conditions (wave, current, tidal forces), curtains must meet DOT‑defined types (Type I–III) which specify float size, fabric weight (typically heavy PVC), top cable strength, and bottom ballast. Installation must be complete before construction begins, and curtains must be positioned as approved—ideally parallel to flow in moving water—with consistent spacing of anchors and maintaining minimal gap at the skirt’s bottom. Regular inspections, maintenance, sediment clean‑up, and adjustment throughout the project are required to ensure compliance with water quality and erosion control permits (e.g. NPDES).

Kansas Department of Transportation (KDOT)

Kentucky

The Kentucky Transportation Cabinet (KYTC) requires the use of silt or turbidity curtains—along with a full suite of erosion- and sediment-control measures—on all in‑ or near‑water construction sites to prevent sediment from leaving project boundaries. These barriers, typically specified in KYTC’s Specifications for Road and Bridge Construction (Sections 212–214) and detailed in the BMP Field Guide, must be installed downhill of bare soil areas, anchored securely, and maintained to intercept sheet flow and allow sediment to settle before discharge. KYTC enforces a standard that no sediment may leave the site and mandates inspections weekly and after rainfall (>0.5″), with accumulated sediment removed at one-third the barrier’s height. All disturbed areas must be stabilized—by seeding, mulching, sodding, or blankets—within 14 days of inactivity, or 21 days if temporary, ensuring full containment of turbidity and compliance with KPDES permit requirements.

Kentucky Department of Transportation

Louisiana

Louisiana DOT requires the use of silt or turbidity curtains (also known as floating sediment barriers) on any in‑ or near‑water construction activities in accordance with its Standard Specifications for Roads and Bridges (notably Section 204 and related erosion‑control subsections). These barriers must consist of a buoyant flotation boom supporting a geotextile skirt that extends close to the channel bottom, sufficiently weighted or anchored to maintain a vertical position in calm or flowing water. Curtain type (typically DOT Type I, II, or III) is selected based on water conditions—Type I for calm protected waters, up through Type III for moderate currents and wave action. Installation must occur before work begins, with end‑to‑end connections sealed, anchoring specified per site conditions, and routine inspection and maintenance required throughout the project in compliance with NPDES permit obligations.

Louisiana Department of Transportation

Maine

Main Department of Transportation

Maryland

Maryland Department of Transportation (MDOT)

Massachusetts

Massachusetts Department of Transportation (MASSDOT)

Michigan

Michigan Department of Transportation (MDOT)

Minnesota

Minnesota Department of Transportation

Mississippi

Mississippi Department of Transportation

Missouri

Missouri Department of Transportation (MODOT)

Montanna

Montanna Department of Transportation 

Nebraska

Nebraska Department of Transportation

Nevada

Nevada Department of Transportation

New Hampshire

New Hampshire Department of Transportation

New Jersey

New Jersey Department of Transportation

New Mexico

New Mexico Department of Transportation

New York

New York Department of Transportation

North Carolina

North Carolina Dpartment of Transportation (NCDOT)

North Dakota

North Dakota Department of Transportation

Ohio

Ohio Department of Transportation (ODOT)

Oklahoma

Oklahoma Department of Transportation (ODOT)

Oregon

Oregon Department of Transportation

Pennsylvania

Pennsylvania Department of Transportation (PENNDOT)

Rhode Island

Rhode Island Department of Transportation (RIDOT)

South Carolina

South Carolina Department of Transportation (SCDOT)

South Dakota

South Dakota Department of Transportation

Tennessee

Tennessee Department of Transportation (TDOT)

Texas

Texas Department of Transportation (TXDOT)

Utah

Utah Department of Transportation (UDOT)

Vermont

Vermont Department of Transportation

Virginia

Virginia Department of Transportation (VDOT)

Washington

Washington State Department of Transportation

West Virginia

West Virginia Department of Transportation

Wisconsin

Wisconsin Department of Transportation

Wyoming

Wyoming Department of Transportation (WYDOT)

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TURBIDITY CURTAIN QUESTIONNAIRE

In order that we may recommend the best Turbidity Curtain for your project, please provide the following information. We have included some questions that will help us better understand your needs. Please answer as many as possible. If the flow rate is high, Elastec can provide modeling data to determine anchor spacing and feasibility of systems.